1
|
Karmakar A, Bernard GM, Pominov A, Tabassum T, Chaklashiya R, Han S, Jain SK, Michaelis VK. Triangulating Dopant-Level Mn(II) Insertion in a Cs 2NaBiCl 6 Double Perovskite Using Magnetic Resonance Spectroscopy. J Am Chem Soc 2023; 145:4485-4499. [PMID: 36787417 DOI: 10.1021/jacs.2c10915] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Lead-free metal halide double perovskites are gaining increasing attention for optoelectronic applications. Specifically, doping metal halide double perovskites using transition metals enables broadband tailorability of the optical bandgap for these emerging semiconducting materials. One candidate material is Mn(II)-doped Cs2NaBiCl6, but the nature of Mn(II) insertion on chemical structure is poorly understood due to low Mn loading. It is critical to determine the atomic-level structure at the site of Mn(II) incorporation in doped perovskites to better understand the structure-property relationships in these materials and thus to advance their applicability to optoelectronic applications. Magnetic resonance spectroscopy is uniquely qualified to address this, and thus a comprehensive three-pronged strategy, involving solid-state nuclear magnetic resonance (NMR), high-field dynamic nuclear polarization (DNP), and electron paramagnetic resonance (EPR) spectroscopies, is used to identify the location of Mn(II) insertion in Cs2NaBiCl6. Multinuclear (23Na, 35Cl, 133Cs, and 209Bi) one-dimensional (1D) magnetic resonance spectra reveal a low level of Mn(II) incorporation, with select spins affected by paramagnetic relaxation enhancement (PRE) induced by Mn(II) neighbors. EPR measurements confirm the oxidation state, octahedral symmetry, and low doping levels of the Mn(II) centers. Complementary EPR and NMR measurements confirm that the cubic structure is maintained with Mn(II) incorporation at room temperature, but the structure deviates slightly from cubic symmetry at low temperatures (<30 K). HYperfine Sublevel CORrelation (HYSCORE) EPR spectroscopy explores the electron-nuclear correlations of Mn(II) with 23Na, 133Cs, and 35Cl. The absence of 209Bi correlations suggests that Bi centers are replaced by Mn(II). Endogenous DNP NMR measurements from Mn(II) → 133Cs (<30 K) reveal that the solid effect is the dominant mechanism for DNP transfer and supports that Mn(II) is homogeneously distributed within the double-perovskite structure.
Collapse
Affiliation(s)
- Abhoy Karmakar
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Arkadii Pominov
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Tarnuma Tabassum
- Department of Chemistry and Biochemistry, University of California─Santa Barbara, Santa Barbara, California 93106, United States
| | - Raj Chaklashiya
- Materials Department, University of California─Santa Barbara, Santa Barbara, California 93106, United States
| | - Songi Han
- Department of Chemistry and Biochemistry, University of California─Santa Barbara, Santa Barbara, California 93106, United States
| | - Sheetal K Jain
- Department of Chemistry and Biochemistry, University of California─Santa Barbara, Santa Barbara, California 93106, United States.,Solid-State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Vladimir K Michaelis
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
2
|
Bobrov G, Kedzior SA, Pervez SA, Govedarica A, Kloker G, Fichtner M, Michaelis VK, Bernard GM, Veelken PM, Hausen F, Trifkovic M. Coupling Particle Ordering and Spherulitic Growth for Long-Term Performance of Nanocellulose/Poly(ethylene oxide) Electrolytes. ACS Appl Mater Interfaces 2023; 15:1996-2008. [PMID: 36592370 DOI: 10.1021/acsami.2c16402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Development of lithium-ion batteries with composite solid polymer electrolytes (CPSEs) has attracted attention due to their higher energy density and improved safety compared to systems utilizing liquid electrolytes. While it is well known that the microstructure of CPSEs affects the ionic conductivity, thermal stability, and mechanical integrity/long-term stability, the bridge between the microscopic and macroscopic scales is still unclear. Herein, we present a systematic investigation of the distribution of TEMPO-oxidized cellulose nanofibrils (t-CNFs) in two different molecular weights of poly(ethylene oxide) (PEO) and its effect on Li+ ion mobility, bulk conductivity, and long-term stability. For the first time, we link local Li-ion mobility at the nanoscale level to the morphology of CPSEs defined by PEO spherulitic growth in the presence of t-CNF. In a low-MW PEO system, spherulites occupy a whole volume of the derived CPSE with t-CNF being incorporated in between lamellas, while their nuclei remain particle-free. In a high-MW PEO system, spherulites are scarce and their growth is arrested in a non-equilibrium cubic shape due to the strong t-CNF network surrounding them. Electrochemical strain microscopy and solid-state 7Li nuclear magnetic resonance spectroscopy confirm that t-CNF does not partake in Li+ ion transport regardless of its distribution within the polymer matrix. Free-standing CSPE films with low-MW PEO have higher conductivity but lack long-term stability due to the existence of uniformly distributed, particle-free, spherulite nuclei, which have very little resistance to Li dendrite growth. On the other hand, high-MW PEO has lower conductivity but demonstrates a highly stable Li cycling response for more than 1000 h at 0.2 mA/cm2 and 65 °C and more than 100 h at 85 °C. The study provides a direct link between the microscopic dynamic, Li-ion transport, bulk mechanical properties and long-term stability of the derived CPSE and, and as such, offers a pathway towards design of robust all-solid-state Li-metal batteries.
Collapse
Affiliation(s)
- Gleb Bobrov
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary, ABT2N 1N4, Canada
| | - Stephanie A Kedzior
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary, ABT2N 1N4, Canada
| | | | - Aleksandra Govedarica
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary, ABT2N 1N4, Canada
| | - Gabriele Kloker
- Helmholtz Institute Ulm, Helmholtzstraße 11, Ulm89081, Germany
| | | | - Vladimir K Michaelis
- Faculty of Science - Chemistry, University of Alberta, 11227 Saskatchewan Drive NW, Edmonton, ABT6G 2G2, Canada
| | - Guy M Bernard
- Faculty of Science - Chemistry, University of Alberta, 11227 Saskatchewan Drive NW, Edmonton, ABT6G 2G2, Canada
| | - Philipp M Veelken
- Institute of Energy and Climate Research, IEK9, Forschungszentrum Juelich, Juelich52425, Germany
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen52074, Germany
| | - Florian Hausen
- Institute of Energy and Climate Research, IEK9, Forschungszentrum Juelich, Juelich52425, Germany
- Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, Aachen52074, Germany
| | - Milana Trifkovic
- Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Dr NW, Calgary, ABT2N 1N4, Canada
| |
Collapse
|
3
|
Alam KM, Jensen CE, Kumar P, Hooper RW, Bernard GM, Patidar A, Manuel AP, Amer N, Palmgren A, Purschke DN, Chaulagain N, Garcia J, Kirwin PS, Shoute LCT, Cui K, Gusarov S, Kobryn AE, Michaelis VK, Hegmann FA, Shankar K. Photocatalytic Mechanism Control and Study of Carrier Dynamics in CdS@C 3N 5 Core-Shell Nanowires. ACS Appl Mater Interfaces 2021; 13:47418-47439. [PMID: 34608803 DOI: 10.1021/acsami.1c08550] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We present a potential solution to the problem of extraction of photogenerated holes from CdS nanocrystals and nanowires. The nanosheet form of C3N5 is a low-band-gap (Eg = 2.03 eV), azo-linked graphenic carbon nitride framework formed by the polymerization of melem hydrazine (MHP). C3N5 nanosheets were either wrapped around CdS nanorods (NRs) following the synthesis of pristine chalcogenide or intercalated among them by an in situ synthesis protocol to form two kinds of heterostructures, CdS-MHP and CdS-MHPINS, respectively. CdS-MHP improved the photocatalytic degradation rate of 4-nitrophenol by nearly an order of magnitude in comparison to bare CdS NRs. CdS-MHP also enhanced the sunlight-driven photocatalytic activity of bare CdS NWs for the decolorization of rhodamine B (RhB) by a remarkable 300% through the improved extraction and utilization of photogenerated holes due to surface passivation. More interestingly, CdS-MHP provided reaction pathway control over RhB degradation. In the absence of scavengers, CdS-MHP degraded RhB through the N-deethylation pathway. When either hole scavenger or electron scavenger was added to the RhB solution, the photocatalytic activity of CdS-MHP remained mostly unchanged, while the degradation mechanism shifted to the chromophore cleavage (cycloreversion) pathway. We investigated the optoelectronic properties of CdS-C3N5 heterojunctions using density functional theory (DFT) simulations, finite difference time domain (FDTD) simulations, time-resolved terahertz spectroscopy (TRTS), and photoconductivity measurements. TRTS indicated high carrier mobilities >450 cm2 V-1 s-1 and carrier relaxation times >60 ps for CdS-MHP, while CdS-MHPINS exhibited much lower mobilities <150 cm2 V-1 s-1 and short carrier relaxation times <20 ps. Hysteresis in the photoconductive J-V characteristics of CdS NWs disappeared in CdS-MHP, confirming surface passivation. Dispersion-corrected DFT simulations indicated a delocalized HOMO and a LUMO localized on C3N5 in CdS-MHP. C3N5, with its extended π-conjugation and low band gap, can function as a shuttle to extract carriers and excitons in nanostructured heterojunctions, and enhance performance in optoelectronic devices. Our results demonstrate how carrier dynamics in core-shell heterostructures can be manipulated to achieve control over the reaction mechanism in photocatalysis.
Collapse
Affiliation(s)
- Kazi M Alam
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Charles E Jensen
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Pawan Kumar
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Riley W Hooper
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Aakash Patidar
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Ajay P Manuel
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Naaman Amer
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Anders Palmgren
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - David N Purschke
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Narendra Chaulagain
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - John Garcia
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Phillip S Kirwin
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Lian C T Shoute
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Kai Cui
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Sergey Gusarov
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Alexander E Kobryn
- Nanotechnology Research Centre, National Research Council Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Vladimir K Michaelis
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Frank A Hegmann
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Karthik Shankar
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| |
Collapse
|
4
|
Puerta Lombardi BM, Gendy C, Gelfand BS, Bernard GM, Wasylishen RE, Tuononen HM, Roesler R. Side‐on Coordination in Isostructural Nitrous Oxide and Carbon Dioxide Complexes of Nickel. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202011301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Chris Gendy
- Department of Chemistry University of Calgary 2500 University Drive NW Calgary AB T2N 1N4 Canada
- Department of Chemistry, Nanoscience Centre University of Jyväskylä, P.O. Box 35 FI-40014 Jyväskylä Finland
| | - Benjamin S. Gelfand
- Department of Chemistry University of Calgary 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Guy M. Bernard
- Gunning-Lemieux Chemistry Centre University of Alberta 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Roderick E. Wasylishen
- Gunning-Lemieux Chemistry Centre University of Alberta 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Heikki M. Tuononen
- Department of Chemistry, Nanoscience Centre University of Jyväskylä, P.O. Box 35 FI-40014 Jyväskylä Finland
| | - Roland Roesler
- Department of Chemistry University of Calgary 2500 University Drive NW Calgary AB T2N 1N4 Canada
| |
Collapse
|
5
|
Mutschke A, Bernard GM, Bertmer M, Karttunen AJ, Ritter C, Michaelis VK, Kunkel N. Na
3
SO
4
H – ein erster Vertreter der Materialklasse der Sulfathydride. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Alexander Mutschke
- Institut für Anorganische Chemie Georg-August-University, Goettingen Tammannstraße 4 37077 Goettingen Deutschland
- Chair for Inorganic Chemistry with Focus on Novel Materials Technical University of Munich Lichtenbergstraße 4 85748 Garching Deutschland
| | - Guy M. Bernard
- Department of Chemistry University of Alberta Edmonton Alberta T6G 2G2 Kanada
| | - Marko Bertmer
- Felix Bloch Institute for Solid State Physics Leipzig University Linnéstraße 5 04103 Leipzig Deutschland
| | - Antti J. Karttunen
- Department of Chemistry and Materials Science Aalto University P.O. Box 16100 FI-00076 Aalto Finnland
| | - Clemens Ritter
- Institut Laue-Langevin 71 avenue des Martyrs 38042 Grenoble Cedex 9 Frankreich
| | | | - Nathalie Kunkel
- Institut für Anorganische Chemie Georg-August-University, Goettingen Tammannstraße 4 37077 Goettingen Deutschland
- Chair for Inorganic Chemistry with Focus on Novel Materials Technical University of Munich Lichtenbergstraße 4 85748 Garching Deutschland
- Woehler Research Institute for Sustainable Chemistry (WISCh) Georg-August-University, Göttingen Deutschland
| |
Collapse
|
6
|
Mutschke A, Bernard GM, Bertmer M, Karttunen AJ, Ritter C, Michaelis VK, Kunkel N. Na 3 SO 4 H-The First Representative of the Material Class of Sulfate Hydrides. Angew Chem Int Ed Engl 2021; 60:5683-5687. [PMID: 33438295 PMCID: PMC7986708 DOI: 10.1002/anie.202016582] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Indexed: 01/22/2023]
Abstract
The first representative of a novel class of mixed-anionic compounds, the sulfate hydride Na3 SO4 H, and the corresponding deuteride Na3 SO4 D were obtained from the solid-state reaction of NaH or NaD with dry Na2 SO4 . Precise reaction control is required, because too harsh conditions lead to the reduction of sulfate to sulfide. A combined X-ray and neutron diffraction study revealed that the compound crystallizes in the tetragonal space group P4/nmm with the lattice parameters a=7.0034(2) Å and c=4.8569(2) Å. The sole presence of hydride and absence of hydroxide ions is proven by vibrational spectroscopy and comparison with spectra predicted from quantum chemical calculations. 1 H and 23 Na MAS NMR spectra are consistent with the structure of Na3 SO4 H: a single 1 H peak at 2.9 ppm is observed, while two peaks at 15.0 and 6.2 ppm for the inequivalent 23 Na sites are observed. Elemental analysis and quantum chemical calculations further support these results.
Collapse
Affiliation(s)
- Alexander Mutschke
- Institut für Anorganische ChemieGeorg-August-University GoettingenTammannstrasse 437077GoettingenGermany
- Chair for Inorganic Chemistry with Focus on Novel MaterialsTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
| | - Guy M. Bernard
- Department of ChemistryUniversity of AlbertaEdmontonAlbertaT6G 2G2Canada
| | - Marko Bertmer
- Felix Bloch Institute for Solid State PhysicsLeipzig UniversityLinnéstrasse 504103LeipzigGermany
| | - Antti J. Karttunen
- Department of Chemistry and Materials ScienceAalto UniversityP.O. Box 16100FI-00076AaltoFinland
| | - Clemens Ritter
- Institut Laue-Langevin71 avenue des Martyrs38042Grenoble Cedex 9France
| | | | - Nathalie Kunkel
- Institut für Anorganische ChemieGeorg-August-University GoettingenTammannstrasse 437077GoettingenGermany
- Chair for Inorganic Chemistry with Focus on Novel MaterialsTechnical University of MunichLichtenbergstrasse 485748GarchingGermany
- Woehler Research Institute for Sustainable Chemistry (WISCh)Georg-August-University, GoettingenGermany
| |
Collapse
|
7
|
Puerta Lombardi BM, Gendy C, Gelfand BS, Bernard GM, Wasylishen RE, Tuononen HM, Roesler R. Side-on Coordination in Isostructural Nitrous Oxide and Carbon Dioxide Complexes of Nickel. Angew Chem Int Ed Engl 2021; 60:7077-7081. [PMID: 33111387 PMCID: PMC8048599 DOI: 10.1002/anie.202011301] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/05/2020] [Indexed: 11/09/2022]
Abstract
A nickel complex incorporating an N2 O ligand with a rare η2 -N,N'-coordination mode was isolated and characterized by X-ray crystallography, as well as by IR and solid-state NMR spectroscopy augmented by 15 N-labeling experiments. The isoelectronic nickel CO2 complex reported for comparison features a very similar solid-state structure. Computational studies revealed that η2 -N2 O binds to nickel slightly stronger than η2 -CO2 in this case, and comparably to or slightly stronger than η2 -CO2 to transition metals in general. Comparable transition-state energies for the formation of isomeric η2 -N,N'- and η2 -N,O-complexes, and a negligible activation barrier for the decomposition of the latter likely account for the limited stability of the N2 O complex.
Collapse
Affiliation(s)
- Braulio M Puerta Lombardi
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Chris Gendy
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.,Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland
| | - Benjamin S Gelfand
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Guy M Bernard
- Gunning-Lemieux Chemistry Centre, University of Alberta, 11227 Saskatchewan Drive NW, Edmonton, AB, T6G 2G2, Canada
| | - Roderick E Wasylishen
- Gunning-Lemieux Chemistry Centre, University of Alberta, 11227 Saskatchewan Drive NW, Edmonton, AB, T6G 2G2, Canada
| | - Heikki M Tuononen
- Department of Chemistry, Nanoscience Centre, University of Jyväskylä, P.O. Box 35, FI-40014, Jyväskylä, Finland
| | - Roland Roesler
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| |
Collapse
|
8
|
Banda H, Dou JH, Chen T, Libretto NJ, Chaudhary M, Bernard GM, Miller JT, Michaelis VK, Dincă M. High-Capacitance Pseudocapacitors from Li+ Ion Intercalation in Nonporous, Electrically Conductive 2D Coordination Polymers. J Am Chem Soc 2021; 143:2285-2292. [DOI: 10.1021/jacs.0c10849] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Harish Banda
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138, United States
| | - Jin-Hu Dou
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138, United States
| | - Tianyang Chen
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138, United States
| | - Nicole J. Libretto
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Madhusudan Chaudhary
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Jeffrey T. Miller
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | | | - Mircea Dincă
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138, United States
| |
Collapse
|
9
|
Karmakar A, Bhattacharya A, Sarkar D, Bernard GM, Mar A, Michaelis VK. Influence of hidden halogen mobility on local structure of CsSn(Cl 1-x Br x ) 3 mixed-halide perovskites by solid-state NMR. Chem Sci 2020; 12:3253-3263. [PMID: 34164094 PMCID: PMC8179406 DOI: 10.1039/d0sc05614f] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Tin halide perovskites are promising candidates for lead-free photovoltaic and optoelectronic materials, but not all of them have been well characterized. It is essential to determine how the bulk photophysical properties are correlated with their structures at both short and long ranges. Although CsSnCl3 is normally stable in the cubic perovskite structure only above 379 K, it was prepared as a metastable phase at room temperature. The transition from the cubic to the monoclinic phase, which is the stable form at room temperature, was tracked by solid-state 133Cs NMR spectroscopy and shown to take place through a first-order kinetics process. The complete solid solution CsSn(Cl1−xBrx)3 (0 ≤ x ≤ 1) was successfully prepared, exhibiting cubic perovskite structures extending between the metastable CsSnCl3 and stable CsSnBr3 end-members. The NMR spectra of CsSnBr3 samples obtained by three routes (high-temperature, mechanochemical, and solvent-assisted reactions) show distinct chemical shift ranges, spin-lattice relaxation parameters and peak widths, indicative of differences in local structure, defects and degree of crystallinity within these samples. Variable-temperature 119Sn spin-lattice relaxation measurements reveal spontaneous mobility of Br atoms in CsSnBr3. The degradation of CsSnBr3, exposed to an ambient atmosphere for nearly a year, was monitored by NMR spectroscopy and powder X-ray diffraction, as well as by optical absorption spectroscopy. Unravelling the atomic-level chemical structure, slow phase conversion or degradation pathways and rapid halogen hopping of cesium tin(ii) halide perovskites using solid-state 119Sn and 133Cs NMR spectroscopy.![]()
Collapse
Affiliation(s)
- Abhoy Karmakar
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Amit Bhattacharya
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Diganta Sarkar
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Guy M Bernard
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | - Arthur Mar
- Department of Chemistry, University of Alberta Edmonton Alberta T6G 2G2 Canada
| | | |
Collapse
|
10
|
Bernard GM, Michaelis VK. Lead-207 NMR spectroscopy at 1.4 T: Application of benchtop instrumentation to a challenging I = ½ nucleus. Magn Reson Chem 2020; 58:1203-1212. [PMID: 32364623 DOI: 10.1002/mrc.5036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 06/11/2023]
Abstract
The practicality of obtaining liquid- and solid-state 207 Pb nuclear magnetic resonance (NMR) spectra with a low permanent-field magnet is investigated. Obtaining 207 Pb NMR spectra of salts in solution is shown to be viable for samples as dilute as 0.05 M. The concentration dependence of the 207 Pb chemical shifts for lead nitrate was investigated; the results are comparable with those obtained with high-field instruments. Likewise, the isotope effect of substituting D2 O for H2 O as the solvent was investigated and found to be comparable with those reported previously. Obtaining solid-state 207 Pb NMR spectra is challenging, but we demonstrate the ability to obtain such spectra for three unique solid samples. An axially symmetric 207 Pb powder pattern for lead nitrate and the powder pattern expected for lead chloride reveal linewidths dominated by shielding anisotropy, while 207 Pb-35/37 Cl J-coupling dominates in the methylammonium lead chloride perovskite material. Finally, recent innovations and the future potential of the instruments are considered.
Collapse
Affiliation(s)
- Guy M Bernard
- Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada
| | - Vladimir K Michaelis
- Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
11
|
Mishra V, Iyer AK, Mumbaraddi D, Oliynyk AO, Zuber G, Boucheron A, Dmytriv G, Bernard GM, Michaelis VK, Mar A. Coloured intermetallic compounds LiCu2Al and LiCu2Ga. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2020.121703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Bhattacharya A, Qiu Y, Bernard GM, Butler S, Mar A, Michaelis VK. Annealing induced structural evolution in feldspar dental glass-ceramics investigated by solid-state NMR spectroscopy. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2020.121501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
13
|
Böttger S, Gruber M, Münzer JE, Bernard GM, Kneusels NJH, Poggel C, Klein M, Hampel F, Neumüller B, Sundermeyer J, Michaelis VK, Tonner R, Tykwinski RR, Kuzu I. Solvent-Induced Bond-Bending Isomerism in Hexaphenyl Carbodiphosphorane: Decisive Dispersion Interactions in the Solid State. Inorg Chem 2020; 59:12054-12064. [DOI: 10.1021/acs.inorgchem.0c00994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Silas Böttger
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Marco Gruber
- Interdisciplinary Center of Molecular Materials (ICMM), Department of Chemistry and Pharmacy, Friedrich-Alexander-University of Erlangen-Nuremberg (FAU), Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Jörn Eike Münzer
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Nis-Julian H. Kneusels
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Christina Poggel
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Marius Klein
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Frank Hampel
- Interdisciplinary Center of Molecular Materials (ICMM), Department of Chemistry and Pharmacy, Friedrich-Alexander-University of Erlangen-Nuremberg (FAU), Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany
| | - Bernhard Neumüller
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Jörg Sundermeyer
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | | | - Ralf Tonner
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Rik R. Tykwinski
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Istemi Kuzu
- Department of Chemistry, Philipps-University of Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| |
Collapse
|
14
|
Karmakar A, Bernard GM, Meldrum A, Oliynyk AO, Michaelis VK. Tailorable Indirect to Direct Band-Gap Double Perovskites with Bright White-Light Emission: Decoding Chemical Structure Using Solid-State NMR. J Am Chem Soc 2020; 142:10780-10793. [PMID: 32426971 DOI: 10.1021/jacs.0c02198] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Efficient white-light-emitting single-material sources are ideal for sustainable lighting applications. Though layered hybrid lead-halide perovskite materials have demonstrated attractive broad-band white-light emission properties, they pose a serious long-term environmental and health risk as they contain lead (Pb2+) and are readily soluble in water. Recently, lead-free halide double perovskite (HDP) materials with a generic formula A(I)2B'(III)B″(I)X6 (where A and B are cations and X is a halide ion) have demonstrated white-light emission with improved photoluminescence quantum yields (PLQYs). Here, we present a series of Bi3+/In3+ mixed-cationic Cs2Bi1-xInxAgCl6 HDP solid solutions that span the indirect to direct band-gap modification which exhibit tailorable optical properties. Density functional theory (DFT) calculations indicate an indirect-direct band-gap crossover composition when x > 0.50. These HDP materials emit over the entire visible light spectrum, centered at 600 ± 30 nm with full-width at half maxima of ca. 200 nm upon ultraviolet light excitation and a maximum PLQY of 34 ± 4% for Cs2Bi0.085In0.915AgCl6. Short-range structural insight for these materials is crucial to unravel the unique atomic-level structural properties which are difficult to distinguish by diffraction-based techniques. Hence, we demonstrate the advantage of using solid-state nuclear magnetic resonance (NMR) spectroscopy to deconvolute the local structural environments of these mixed-cationic HDPs. Using ultrahigh-field (21.14 T) NMR spectroscopy of quadrupolar nuclei (115In, 133Cs, and 209Bi), we show that there is a high degree of atomic-level B'(III)/B″(I) site ordering (i.e., no evidence of antisite defects). Furthermore, a combination of XRD, NMR, and DFT calculations was used to unravel the complete atomic-level random Bi3+/In3+ cationic mixing in Cs2Bi1-xInxAgCl6 HDPs. Briefly, this work provides an advance in understanding the photophysical properties that correlate long- to short-range structural elucidation of these newly developed solid-state white-light emitting HDP materials.
Collapse
Affiliation(s)
- Abhoy Karmakar
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Alkiviathes Meldrum
- Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Anton O Oliynyk
- Chemistry and Biochemistry Department, Manhattan College, Riverdale, New York 10471, United States
| | - Vladimir K Michaelis
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
15
|
Matlinska MA, Ha M, Hughton B, Oliynyk AO, Iyer AK, Bernard GM, Lambkin G, Lawrence MC, Katz MJ, Mar A, Michaelis VK. Alkaline Earth Metal-Organic Frameworks with Tailorable Ion Release: A Path for Supporting Biomineralization. ACS Appl Mater Interfaces 2019; 11:32739-32745. [PMID: 31414791 DOI: 10.1021/acsami.9b11004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An innovative application of metal-organic frameworks (MOFs) is in biomedical materials. To treat bone demineralization, which is a hallmark of osteoporosis, biocompatible MOFs (bioMOFs) have been proposed in which various components, such as alkaline-earth cations and bisphosphonate molecules, can be delivered to maintain normal bone density. Multicomponent bioMOFs that release several components simultaneously at a controlled rate thus offer an attractive solution. We report two new bioMOFs, comprising strontium and calcium ions linked by p-xylylenebisphosphonate molecules that release these three components and display no cytotoxic effects on human osteosarcoma cells. Varying the Sr2+/Ca2+ ratio in these bioMOFs causes the rate of ions dissolving into simulated body fluid to be unique; along with the ability to adsorb proteins, this property is crucial for future efforts in drug-release control and promotion of mineral formation. The one-pot synthesis of these bioMOFs demonstrates the utility of MOF design strategies.
Collapse
Affiliation(s)
- Maria A Matlinska
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Michelle Ha
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Bryden Hughton
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Anton O Oliynyk
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Abishek K Iyer
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Guy M Bernard
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Gareth Lambkin
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Mason C Lawrence
- Department of Chemistry , Memorial University of Newfoundland , St. John's , Newfoundland A1C 5S7 , Canada
| | - Michael J Katz
- Department of Chemistry , Memorial University of Newfoundland , St. John's , Newfoundland A1C 5S7 , Canada
| | - Arthur Mar
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Vladimir K Michaelis
- Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| |
Collapse
|
16
|
Wasylishen RE, Matlinska MA, Bernard GM, Terskikh VV, Brinkmann A. Hydrogen-bonding in the enol tautomer of 1,3-diketones: insights from 2/1H isotope effects on NMR parameters in the solid state as well as computational chemistry. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s0108767319097149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
17
|
Kumar P, Vahidzadeh E, Thakur UK, Kar P, Alam KM, Goswami A, Mahdi N, Cui K, Bernard GM, Michaelis VK, Shankar K. C3N5: A Low Bandgap Semiconductor Containing an Azo-Linked Carbon Nitride Framework for Photocatalytic, Photovoltaic and Adsorbent Applications. J Am Chem Soc 2019; 141:5415-5436. [DOI: 10.1021/jacs.9b00144] [Citation(s) in RCA: 253] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Pawan Kumar
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Ehsan Vahidzadeh
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Ujwal K. Thakur
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Piyush Kar
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Kazi M. Alam
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Ankur Goswami
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Najia Mahdi
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| | - Kai Cui
- Nanotechnology
Research Centre, National Research Council of Canada, Edmonton, Alberta T6G 2M9, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | | | - Karthik Shankar
- Department of Electrical and Computer Engineering, University of Alberta, 9211 116 Street, Edmonton, Alberta T6G 1H9, Canada
| |
Collapse
|
18
|
He P, Wang A, Meng S, Bernard GM, Liu L, Michaelis VK, Song H. Impact of Al sites on the methane co-aromatization with alkanes over Zn/HZSM-5. Catal Today 2019. [DOI: 10.1016/j.cattod.2018.05.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
19
|
Gendy C, Mansikkamäki A, Valjus J, Heidebrecht J, Hui PCY, Bernard GM, Tuononen HM, Wasylishen RE, Michaelis VK, Roesler R. Nickel as a Lewis Base in a T-Shaped Nickel(0) Germylene Complex Incorporating a Flexible Bis(NHC) Ligand. Angew Chem Int Ed Engl 2018; 58:154-158. [DOI: 10.1002/anie.201809889] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 10/25/2018] [Indexed: 01/12/2023]
Affiliation(s)
- Chris Gendy
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Akseli Mansikkamäki
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Juuso Valjus
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Joshua Heidebrecht
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Paul Chuk-Yan Hui
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Guy M. Bernard
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Heikki M. Tuononen
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Roderick E. Wasylishen
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Vladimir K. Michaelis
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Roland Roesler
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| |
Collapse
|
20
|
Gendy C, Mansikkamäki A, Valjus J, Heidebrecht J, Hui PCY, Bernard GM, Tuononen HM, Wasylishen RE, Michaelis VK, Roesler R. Nickel as a Lewis Base in a T-Shaped Nickel(0) Germylene Complex Incorporating a Flexible Bis(NHC) Ligand. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201809889] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Chris Gendy
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Akseli Mansikkamäki
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Juuso Valjus
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Joshua Heidebrecht
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Paul Chuk-Yan Hui
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| | - Guy M. Bernard
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Heikki M. Tuononen
- Department of Chemistry; Nanoscience Centre; University of Jyväskylä; 40014 University of Jyväskylä Finland
| | - Roderick E. Wasylishen
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Vladimir K. Michaelis
- Gunning-Lemieux Chemistry Centre; University of Alberta; 11227 Saskatchewan Drive NW Edmonton AB T6G 2G2 Canada
| | - Roland Roesler
- Department of Chemistry; University of Calgary; 2500 University Drive NW Calgary AB T2N 1N4 Canada
| |
Collapse
|
21
|
Askar AM, Karmakar A, Bernard GM, Ha M, Terskikh VV, Wiltshire BD, Patel S, Fleet J, Shankar K, Michaelis VK. Composition-Tunable Formamidinium Lead Mixed Halide Perovskites via Solvent-Free Mechanochemical Synthesis: Decoding the Pb Environments Using Solid-State NMR Spectroscopy. J Phys Chem Lett 2018; 9:2671-2677. [PMID: 29715040 DOI: 10.1021/acs.jpclett.8b01084] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Mixed-halide lead perovskites are becoming of paramount interest in the optoelectronic and photovoltaic research fields, offering band gap tunability, improved efficiency, and enhanced stability compared to their single halide counterparts. Formamidinium-based mixed halide perovskites (FA-MHPs) are critical to obtaining optimum solar cell performance. Here, we report a solvent-free mechanochemical synthesis (MCS) method to prepare FA-MHPs, starting with their parent compounds (FAPbX3; X = Cl, Br, I), achieving compositions not previously accessible through the solvent synthesis (SS) technique. By probing local Pb environments in MCS FA-MHPs using solid-state nuclear magnetic resonance spectroscopy, along with powder X-ray diffraction for long-range crystallinity and reflectance measurements to determine the optical band gap, we show that MCS FA-MHPs form atomic-level solid solutions between Cl/Br and Br/I MHPs. Our results pave the way for advanced methods in atomic-level structural understanding while offering a one-pot synthetic approach to prepare MHPs with superior control of stoichiometry.
Collapse
Affiliation(s)
- Abdelrahman M Askar
- Department of Electrical and Computer Engineering , University of Alberta , Edmonton , Alberta , Canada T6G 1H9
| | - Abhoy Karmakar
- Department of Chemistry , University of Alberta , Edmonton , Alberta , Canada T6G 2G2
| | - Guy M Bernard
- Department of Chemistry , University of Alberta , Edmonton , Alberta , Canada T6G 2G2
| | - Michelle Ha
- Department of Chemistry , University of Alberta , Edmonton , Alberta , Canada T6G 2G2
| | - Victor V Terskikh
- Department of Chemistry , University of Ottawa , Ottawa , Ontario , Canada K1N 6N5
| | - Benjamin D Wiltshire
- Department of Electrical and Computer Engineering , University of Alberta , Edmonton , Alberta , Canada T6G 1H9
| | - Sahil Patel
- Department of Electrical and Computer Engineering , University of Alberta , Edmonton , Alberta , Canada T6G 1H9
| | - Jonathan Fleet
- Department of Electrical and Computer Engineering , University of Alberta , Edmonton , Alberta , Canada T6G 1H9
| | - Karthik Shankar
- Department of Electrical and Computer Engineering , University of Alberta , Edmonton , Alberta , Canada T6G 1H9
| | - Vladimir K Michaelis
- Department of Chemistry , University of Alberta , Edmonton , Alberta , Canada T6G 2G2
| |
Collapse
|
22
|
Li X, Charaya H, Bernard GM, Elliott JAW, Michaelis VK, Lee B, Chung HJ. Low-Temperature Ionic Conductivity Enhanced by Disrupted Ice Formation in Polyampholyte Hydrogels. Macromolecules 2018. [DOI: 10.1021/acs.macromol.7b02498] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Xinda Li
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Hemant Charaya
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Janet A. W. Elliott
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| | | | - Byeongdu Lee
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Hyun-Joong Chung
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada
| |
Collapse
|
23
|
Bernard GM, Wasylishen RE, Ratcliffe CI, Terskikh V, Wu Q, Buriak JM, Hauger T. Methylammonium Cation Dynamics in Methylammonium Lead Halide Perovskites: A Solid-State NMR Perspective. J Phys Chem A 2018; 122:1560-1573. [PMID: 29337561 DOI: 10.1021/acs.jpca.7b11558] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In light of the intense recent interest in the methylammonium lead halides, CH3NH3PbX3 (X = Cl, Br, and I) as sensitizers for photovoltaic cells, the dynamics of the methylammonium (MA) cation in these perovskite salts has been reinvestigated as a function of temperature via 2H, 14N, and 207Pb NMR spectroscopy. In the cubic phase of all three salts, the MA cation undergoes pseudoisotropic tumbling (picosecond time scale). For example, the correlation time, τ2, for the C-N axis of the iodide salt is 0.85 ± 0.30 ps at 330 K. The dynamics of the MA cation are essentially continuous across the cubic ↔ tetragonal phase transition; however, 2H and 14N NMR line shapes indicate that subtle ordering of the MA cation occurs in the tetragonal phase. The temperature dependence of the cation ordering is rationalized using a six-site model, with two equivalent sites along the c-axis and four equivalent sites either perpendicular or approximately perpendicular to this axis. As the cubic ↔ tetragonal phase transition temperature is approached, the six sites are nearly equally populated. Below the tetragonal ↔ orthorhombic phase transition, 2H NMR line shapes indicate that the C-N axis is essentially frozen.
Collapse
Affiliation(s)
- Guy M Bernard
- Gunning-Lemieux Chemistry Centre, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, Alberta, Canada T6G 2G2
| | - Roderick E Wasylishen
- Gunning-Lemieux Chemistry Centre, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, Alberta, Canada T6G 2G2
| | | | - Victor Terskikh
- Department of Chemistry, University of Ottawa , 10 Marie Curie Private, Ottawa, Ontario, Canada K1N 6N5
| | - Qichao Wu
- Gunning-Lemieux Chemistry Centre, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, Alberta, Canada T6G 2G2
| | - Jillian M Buriak
- Gunning-Lemieux Chemistry Centre, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, Alberta, Canada T6G 2G2
| | - Tate Hauger
- Gunning-Lemieux Chemistry Centre, University of Alberta , 11227 Saskatchewan Drive NW, Edmonton, Alberta, Canada T6G 2G2
| |
Collapse
|
24
|
Bernard GM, Goyal A, Miskolzie M, McKay R, Wu Q, Wasylishen RE, Michaelis VK. Methylammonium lead chloride: A sensitive sample for an accurate NMR thermometer. J Magn Reson 2017; 283:14-21. [PMID: 28843057 DOI: 10.1016/j.jmr.2017.08.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/28/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
A new solid-state nuclear magnetic resonance (NMR) thermometry sample is proposed. The 207Pb NMR chemical shift of a lead halide perovskite, methylammonium lead chloride (MAPbCl3) is very sensitive to temperature, 0.905±0.010ppmK-1. The response to temperature is linear over a wide temperature range, from its tetragonal to cubic phase transition at 178K to >410K, making it an ideal standard for temperature calibrations in this range. Because the 207Pb NMR lineshape for MAPbCl3 appears symmetric, the sample is ideal for calibration of variable temperature NMR data acquired for spinning or non-spinning samples. A frequency-ratio method is proposed for referencing 207Pb chemical shifts, based on the 1H and 13C frequencies of the methylammonium cation, which are used asan internal standard. Finally, this new NMR thermometer has been used to measure the degree of frictional heating asa function of spinning frequency for a series of MAS rotors ranging in outer diameter from 1.3 to 7.0mm. As expected, the largest diameter rotors are more susceptible to frictional heating, but lower diameter rotors are subjected to higher frictional heating temperatures as they are typically spun at much higher spinning frequencies.
Collapse
Affiliation(s)
- Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Atul Goyal
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Mark Miskolzie
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Ryan McKay
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Qichao Wu
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | | | | |
Collapse
|
25
|
Affiliation(s)
- Abishek K. Iyer
- Department of Chemistry; University of Alberta; T6G 2G2 Edmonton AB Canada
| | - Wenlong Yin
- Department of Chemistry; University of Alberta; T6G 2G2 Edmonton AB Canada
- Institute of Chemical Materials; China Academy of Engineering Physics; 621900 Mianyang P. R. China
| | - Emma J. Lee
- Department of Chemistry; University of Alberta; T6G 2G2 Edmonton AB Canada
| | - Guy M. Bernard
- Department of Chemistry; University of Alberta; T6G 2G2 Edmonton AB Canada
| | | | - Arthur Mar
- Department of Chemistry; University of Alberta; T6G 2G2 Edmonton AB Canada
| |
Collapse
|
26
|
Wang A, Austin D, Karmakar A, Bernard GM, Michaelis VK, Yung MM, Zeng H, Song H. Methane Upgrading of Acetic Acid as a Model Compound for a Biomass-Derived Liquid over a Modified Zeolite Catalyst. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00296] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aiguo Wang
- Department
of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| | - Danielle Austin
- Department
of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| | - Abhoy Karmakar
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M. Bernard
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Vladimir K. Michaelis
- Department
of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Matthew M. Yung
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Hongbo Zeng
- Department
of Chemical and Materials Engineering, University of Alberta, 9211-116
Street NW, Edmonton, Alberta T6G 1H9, Canada
| | - Hua Song
- Department
of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive, NW, Calgary, Alberta T2N 1N4, Canada
| |
Collapse
|
27
|
Kong X, Brinkmann A, Terskikh V, Wasylishen RE, Bernard GM, Duan Z, Wu Q, Wu G. Proton Probability Distribution in the O···H···O Low-Barrier Hydrogen Bond: A Combined Solid-State NMR and Quantum Chemical Computational Study of Dibenzoylmethane and Curcumin. J Phys Chem B 2016; 120:11692-11704. [PMID: 27782387 DOI: 10.1021/acs.jpcb.6b08091] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a combined solid-state (1H, 2H, 13C, 17O) NMR and plane-wave density functional theory (DFT) computational study of the O···H···O low-barrier hydrogen bonds (LBHBs) in two 1,3-diketone compounds: dibenzoylmethane (1) and curcumin (2). In the solid state, both 1 and 2 exist in the cis-keto-enol tautomeric form, each exhibiting an intramolecular LBHB with a short O···O distance (2.435 Å in 1 and 2.455 Å in 2). Whereas numerous experimental (structural and spectroscopic) and computational studies have been reported for the enol isomers of 1,3-diketones, a unified picture about the proton location within an LBHB is still lacking. This work reports for the first time the solid-state 17O NMR data for the O···H···O LBHBs in 1,3-diketones. The central conclusion of this work is that detailed information about the probability density distribution of the proton (nuclear zero-point motion) across an LBHB can be obtained from a combination of solid-state NMR and plane-wave DFT computations (both NMR parameter calculations and ab initio molecular dynamics simulations). We propose that the precise proton probability distribution across an LBHB should provide a common basis on which different and sometimes seemingly contradicting experimental results obtained from complementary techniques, such as X-ray diffraction, neutron diffraction, and solid-state NMR, can be reconciled.
Collapse
Affiliation(s)
- Xianqi Kong
- Department of Chemistry, Queen's University , 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
| | - Andreas Brinkmann
- Measurement Science and Standards, National Research Council Canada , 1200 Montreal Road, M-40, Ottawa, Ontario, Canada K1A 0R6
| | - Victor Terskikh
- Department of Chemistry, Queen's University , 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6.,Department of Chemistry, University of Ottawa , 10 Marie Curie Private, Ottawa, Ontario, Canada K1N 6N5
| | | | - Guy M Bernard
- Department of Chemistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G2
| | - Zhuang Duan
- Department of Chemistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G2
| | - Qichao Wu
- Department of Chemistry, University of Alberta , Edmonton, Alberta, Canada T6G 2G2
| | - Gang Wu
- Department of Chemistry, Queen's University , 90 Bader Lane, Kingston, Ontario, Canada K7L 3N6
| |
Collapse
|
28
|
Faucher A, Terskikh VV, Ye E, Bernard GM, Wasylishen RE. Solid-State 87Sr NMR Spectroscopy at Natural Abundance and High Magnetic Field Strength. J Phys Chem A 2015; 119:11847-61. [DOI: 10.1021/acs.jpca.5b09392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexandra Faucher
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Victor V. Terskikh
- Department
of Chemistry, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Eric Ye
- Department
of Chemistry, University of Ottawa, Ottawa, ON, Canada K1N 6N5
| | - Guy M. Bernard
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Roderick E. Wasylishen
- Department
of Chemistry, Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2
| |
Collapse
|
29
|
Yu H, Tan X, Bernard GM, Terskikh VV, Chen J, Wasylishen RE. Solid-State (63)Cu, (65)Cu, and (31)P NMR Spectroscopy of Photoluminescent Copper(I) Triazole Phosphine Complexes. J Phys Chem A 2015; 119:8279-93. [PMID: 26101890 DOI: 10.1021/acs.jpca.5b04270] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The results of a solid-state (63/65)Cu and (31)P NMR investigation of several copper(I) complexes with functionalized 3-(2'-pyridyl)-1,2,4-triazole and phosphine ligands that have shown potential in the preparation of photoluminescent devices are reported. For each complex studied, distinct NMR parameters, with moderate (63)Cu nuclear quadrupolar coupling constant (CQ) values ranging from -17.2 to -23.7 MHz, are attributed to subtle variations in the distorted four-coordinate environments about the copper nuclei. The spans of the copper chemical shift (CS) tensors, δ11-δ33, for the mono- and bisphosphine complexes are also similar, ranging from 1000 to 1150 ppm, but that for a complex with a strained bidentate phosphine ligand is only 650 ppm. The effects of residual dipolar and indirect spin-spin coupling arising from the (63/65)Cu- (31)P spin pairs, observed in the solid-state (31)P NMR spectra of these complexes, yield information about the orientations of the copper electric field gradient (EFG) tensors relative to the Cu-P bond. Variable-temperature (31)P NMR measurements for [Cu(bptzH)(dppe)]ClO4 (bptzH = 5-tert-butyl-3-(2'-pyridyl)-1,2,4-triazole; dppe = 1,2-bis(diphenylphosphino)ethane), undertaken to investigate the cause of the broad unresolved spectra observed at room temperature, demonstrate that the broadening arises from partial self-decoupling of the (63/65)Cu nuclei, a consequence of rapid quadrupolar relaxation. Ab initio calculations of copper EFG and CS tensors were performed to probe relationships between NMR parameters and molecular structure. The analysis demonstrated that CQ((63/65)Cu) is negative for all complexes studied here and that the largest components of the EFG tensors are generally coincident with δ11.
Collapse
Affiliation(s)
- Huaguang Yu
- †Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.,§College of Physics Science and Technology, Yangzhou University, Yangzhou 225002, P. R. China
| | - Xiuzhen Tan
- ‡School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China
| | - Guy M Bernard
- †Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Victor V Terskikh
- ∥Department of Chemistry, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Jinglin Chen
- ‡School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China
| | - Roderick E Wasylishen
- †Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
30
|
Garbacz P, Terskikh VV, Ferguson MJ, Bernard GM, Kędziorek M, Wasylishen RE. Experimental characterization of the hydride 1H shielding tensors for HIrX2(PR3)2 and HRhCl2(PR3)2: extremely shielded hydride protons with unusually large magnetic shielding anisotropies. J Phys Chem A 2014; 118:1203-12. [PMID: 24460126 DOI: 10.1021/jp411378j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hydride proton magnetic shielding tensors for a series of iridium(III) and rhodium(III) complexes are determined. Although it has long been known that hydridic protons for transition-metal hydrides are often extremely shielded, this is the first experimental determination of the shielding tensors for such complexes. Isolating the (1)H NMR signal for a hydride proton requires careful experimental strategies because the spectra are generally dominated by ligand (1)H signals. We show that this can be accomplished for complexes containing as many as 66 ligand protons by substituting the latter with deuterium and by using hyperbolic secant pulses to selectively irradiate the hydride proton signal. We also demonstrate that the quality of the results is improved by performing experiments at the highest practical magnetic field (21.14 T for the work presented here). The hydride protons for iridium hydride complexes HIrX2(PR3)2 (X = Cl, Br, or I; R = isopropyl, cyclohexyl) are highly shielded with isotropic chemical shifts of approximately -50 ppm and are also highly anisotropic, with spans (=δ11 - δ33) ranging from 85.1 to 110.7 ppm. The hydridic protons for related rhodium complexes HRhCl2(PR3)2 also have unusual magnetic shielding properties with chemical shifts and spans of approximately -32 and 85 ppm, respectively. Relativistic density functional theory computations were performed to determine the orientation of the principal components of the hydride proton shielding tensors and to provide insights into the origin of these highly anisotropic shielding tensors. The results of our computations agree well with experiment, and our conclusions concerning the importance of relativistic effects support those recently reported by Kaupp and co-workers.
Collapse
Affiliation(s)
- Piotr Garbacz
- Gunning/Lemieux Chemistry Centre, University of Alberta , Edmonton, Alberta T6G 2G2, Canada
| | | | | | | | | | | |
Collapse
|
31
|
Chen F, Ma G, Bernard GM, Wasylishen RE, Cavell RG, McDonald R, Ferguson MJ. An Investigation of 1:1 Adducts of Gallium Trihalides with Triarylphosphines by Solid-State69/71Ga and31P NMR Spectroscopy. Chemistry 2013; 19:2826-38. [DOI: 10.1002/chem.201202954] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Indexed: 11/09/2022]
|
32
|
Zhao Y, Luu T, Bernard GM, Taerum T, McDonald R, Wasylishen RE, Tykwinski RR. Synthesis, characterization, and solid-state polymerization of cross-conjugated octatetraynes. CAN J CHEM 2012. [DOI: 10.1139/v2012-075] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two series of cross-conjugated 1,3,5,7-octatetraynes (1a–1l and 6a–6d) have been synthesized. UV–vis spectroscopic analysis shows that pendent groups connected to the cross-conjugated skeleton have little effect on the λmax energies, irrespective of whether the groups are electron withdrawing or donating. A number of the isolated products readily give crystals suitable for X-ray crystallography, and the solid-state structural properties of five derivatives (1k, 1l, 6a, 6c, and 6d) have been examined by X-ray crystallographic analysis. Parallel packing of the polyynes in the solid state indicates that four of the five samples are potentially suitable for topochemical polymerization, based on solid-state packing parameters θ, R, and d. Attempts to effect a solid-state reaction have been explored through UV–vis and γ-ray irradiation as well as thermal heating. The course of these reactions was monitored by differential scanning calorimetry (DSC) analysis, as well as UV–vis and solid-state 13C NMR spectroscopy (for 1d, 1j, 1k, and 6d), which offered evidence of polymer formation from these reactions. Structural determination of the product(s), however, remains elusive.
Collapse
Affiliation(s)
- Yuming Zhao
- Department of Chemistry Memorial University of Newfoundland, St. John’s, NL A1B 3X7, Canada
| | - Thanh Luu
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Tyler Taerum
- Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | - Robert McDonald
- X-ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
| | | | - Rik R. Tykwinski
- Department of Chemistry and Pharmacy & Interdisciplinary Center of Molecular Materials (ICMM), University of Erlangen-Nuremberg, Henkestrasse 42, 91054 Erlangen, Germany
| |
Collapse
|
33
|
Norris CE, Quideau SA, Landhäusser SM, Bernard GM, Wasylishen RE. Tracking stable isotope enrichment in tree seedlings with solid-state NMR spectroscopy. Sci Rep 2012; 2:719. [PMID: 23056911 PMCID: PMC3466447 DOI: 10.1038/srep00719] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/13/2012] [Indexed: 11/14/2022] Open
Abstract
Enriching plant tissues with 13C and 15N isotopes has provided long-lasting, non-reactive tracers to quantify rates of terrestrial elemental fluxes (e.g., soil organic matter decomposition). However, the molecular location and level of isotope enrichment may differ among plant tissues. This factor is central to the integrity and interpretation of tracer data, but is seldom considered in experiments. We propose a rapid, non-destructive method to quantify molecular isotope allocation using solid-state 13C and 15N nuclear magnetic resonance spectroscopy. With this method, we tracked and quantified the fate of multiple pulses of 13CO2(g) and K 15NO3(l) in boreal tree seedling roots and leaves as a function of time. Results show that initial preferential 13C carbohydrate enrichment in the leaves was followed by redistribution to more complex compounds after seven days. While 13C allocation within the roots was uniform across molecules, 15N results indicate an initial enrichment of amine molecules after two hours.
Collapse
Affiliation(s)
- Charlotte E Norris
- Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada.
| | | | | | | | | |
Collapse
|
34
|
Abstract
Presented here is a solid-state NMR investigation of the so-called “colossal expansion” material, Ag3Co(CN)6, a compound that exhibits some of the largest positive and negative thermal expansion properties reported. This study explores the 13C, 15N, and 59Co NMR properties of this material at room temperature and at variable temperatures with the goal of probing the effects of this colossal expansion behaviour on these properties. We found that the flexible nature of the crystal framework leads to a distribution of electric field gradients, and that, oddly enough, no strong correlation is observed between the NMR parameters of Ag3Co(CN)6 and its colossal expansion nature. The 59Co isotropic chemical shift increased and the 59Co nuclear quadrupolar coupling constant decreased with increasing temperature, but neither of these relationships were extraordinary when compared to other octahedral Co(III) complexes. The link between the colossal expansion and the NMR properties of Ag3Co(CN)6 may be the distribution of lattice parameters and hence unusually broad features in the 59Co NMR spectra. The high order of symmetry at the cobalt site resulted in a small quadrupolar coupling constant less than 1 MHz in magnitude. We also observed a |1J(107/109Ag,15N)| value of 96 Hz, the largest 107/109Ag–15N coupling constant reported to date.
Collapse
Affiliation(s)
- Brett C. Feland
- Department of Chemistry, University of Alberta, 11227 SK Drive N.W., Edmonton, AB T6G 2G2, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, 11227 SK Drive N.W., Edmonton, AB T6G 2G2, Canada
| | - Roderick E. Wasylishen
- Department of Chemistry, University of Alberta, 11227 SK Drive N.W., Edmonton, AB T6G 2G2, Canada
| |
Collapse
|
35
|
Chen F, Ma G, Bernard GM, Cavell RG, McDonald R, Ferguson MJ, Wasylishen RE. Solid-State 115In and 31P NMR Studies of Triarylphosphine Indium Trihalide Adducts. J Am Chem Soc 2010; 132:5479-93. [DOI: 10.1021/ja100625p] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Fu Chen
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Guibin Ma
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Guy M. Bernard
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Ronald G. Cavell
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Robert McDonald
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Michael J. Ferguson
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| | - Roderick E. Wasylishen
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
| |
Collapse
|
36
|
Lane EM, Chapp TW, Hughes RP, Glueck DS, Feland BC, Bernard GM, Wasylishen RE, Rheingold AL. Synthesis of Gold Phosphido Complexes Derived from Bis(secondary) Phosphines. Structure of Tetrameric [Au(MesP(CH2)3PMes)Au]4. Inorg Chem 2010; 49:3950-7. [DOI: 10.1021/ic100219j] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elizabeth M. Lane
- 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Timothy W. Chapp
- 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Russell P. Hughes
- 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - David S. Glueck
- 6128 Burke Laboratory, Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Brett C. Feland
- Department of Chemistry, University of Alberta, E3-24 Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Guy M. Bernard
- Department of Chemistry, University of Alberta, E3-24 Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Roderick E. Wasylishen
- Department of Chemistry, University of Alberta, E3-24 Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Arnold L. Rheingold
- Department of Chemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093
| |
Collapse
|
37
|
Jalilehvand F, Mah V, Leung BO, Mink J, Bernard GM, Hajba L. Cadmium(II) cysteine complexes in the solid state: a multispectroscopic study. Inorg Chem 2009; 48:4219-30. [PMID: 19351134 DOI: 10.1021/ic900145n] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cadmium(II) cysteinate compounds have recently been recognized to provide an environmentally friendly route for the production of CdS nanoparticles, used in semiconductors. In this article, we have studied the coordination for two cadmium(II) cysteinates, Cd(HCys)(2) x H(2)O (1) and {Cd(HCys)(2) x H(2)O}(2) x H(3)O(+)ClO(4)(-) (2), by means of vibrational (Raman and IR absorption), solid-state NMR ((113)Cd and (13)C), and Cd K- and L(3)-edge X-ray absorption spectroscopy. Indistinguishable Cd K-edge extended X-ray absorption fine structure (EXAFS) and Cd L(3)-edge X-ray absorption near edge structure (XANES) spectra were obtained for the two compounds, showing similar local structure around the cadmium(II) ions. The vibrational spectra show that the cysteine amine group is protonated (NH(3)(+)) and not involved in bonding. The (113)Cd solid-state cross-polarization magic angle spinning NMR spectra showed a broad signal in the approximately 500-700 ppm range, with the peak maximum at about 650 ppm, indicating three to four coordinated thiolate groups. Careful analyses of low-frequency Raman and far-IR spectra revealed bridging and terminal Cd-S vibrational bands. The average Cd-S distance of 2.52 +/- 0.02 A that constantly emerged from least-squares curve-fitting of the EXAFS spectra is consistent with CdS(4) and CdS(3)O coordination. Both structural models yielded reasonable values for the refined parameters, with a slightly better fit for the CdS(3)O configuration, for which the Cd-O distance of 2.27 +/- 0.04 A was obtained. The Cd L(3)-edge XANES spectra of 1 and 2 resembled that of the CdS(3)O model compound and showed that the coordination around Cd(II) ions in 1 and 2 cannot be exclusively CdS(4). The small separation of 176 cm(-1) between the infrared symmetric and antisymmetric COO(-) stretching modes indicates monodentate or strongly asymmetrical bidentate coordination of a cysteine carboxylate group in the CdS(3)O units. The combined results are consistent with a "cyclic/cage" type of structure for both the amorphous solids 1 and 2, composed of CdS(4) and CdS(3)O units with single thiolate (Cd-S-Cd) bridges, although a minor amount of cadmium(II) sites with CdS(3)O(2-3) and CdS(4)O coordination geometries cannot be ruled out.
Collapse
Affiliation(s)
- Farideh Jalilehvand
- Department of Chemistry, University of Calgary, Calgary, AB, Canada T2N 1N4.
| | | | | | | | | | | |
Collapse
|
38
|
Ooms KJ, Bernard GM, Kadziola A, Kofod P, Wasylishen RE. Solid-state 13C and 59Co NMR spectroscopy of 13C-methylcobalt(iii) complexes with amine ligands. Phys Chem Chem Phys 2009; 11:2690-9. [PMID: 19421527 DOI: 10.1039/b820753d] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Five octahedral Co(iii) cations, [trans-Co(en)(2)(X)((13)CH(3))](n+) where en = ethylenediamine, X = CN(-), N(3)(-), NH(3), NO(2)(-) or H(2)O and n = 1 or 2, as well as [Co(NH(3))(5)(13)CH(3)](2+), have been investigated by solid-state (13)C and (59)Co NMR spectroscopy. We show that the determination of the (59)Co nuclear quadrupolar parameters both directly via(59)Co NMR and indirectly via(13)C NMR provide complementary information that is unavailable if one investigates only one nucleus. Specifically, (1)J((59)Co,(13)C) and the orientation of the largest component of the EFG were determined via(13)C NMR spectroscopy, which also established the negative sign of C(Q)((59)Co). Cobalt-59 NMR spectroscopy was used to characterize the cobalt magnetic shielding tensor, to verify the magnitudes of C(Q)((59)Co) and to establish the value of eta(Q), which is difficult to determine indirectly. The measurements show that the EFG tensors are either axially symmetric or close to being so, but there is a wide range of C(Q) values, from -40 MHz for the complex with X = H(2)O to -105 MHz with X = CN(-). The Co chemical shift tensors are approximately axially symmetric with the spans, delta(11)-delta(33), ranging from 3700 to 5600 ppm for X = H(2)O and CN(-), respectively. The latter measurements also established the relative orientations of the Co EFG and chemical shift tensors. Density functional theory calculations of the (59)Co EFG and magnetic shielding tensors as well as of (1)J((59)Co,(13)C) for the NO(2)(-) and N(3)(-) complexes were undertaken. These calculations confirm the experimental observation that the sign of C(Q) is negative and that the largest component of the EFG is along the Co-methyl-carbon bond.
Collapse
Affiliation(s)
- Kristopher J Ooms
- Gunning-Lemieux Chemistry Centre, Department of Chemistry, University of Alberta, Edmonton, Alberta, CanadaT6G 2G2
| | | | | | | | | |
Collapse
|
39
|
Bernard GM, Feindel KW, Wasylishen RE, Cameron TS. Solid-state phosphorus-31 NMR spectroscopy of a multiple-spin system: an investigation of a rhodium-triphosphine complex. Phys Chem Chem Phys 2008; 10:5552-63. [PMID: 18956090 DOI: 10.1039/b803596b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Phosphorus-31 NMR spectra of solid [tris(dimethylphenylphosphine)](2,5-norbornadiene) rhodium(I) hexafluorophosphate have been acquired at several applied magnetic field strengths. The phosphorus nuclei of the three phosphine ligands are spin-spin coupled to each other and to 103Rh, resulting in complex NMR spectra; however, the three phosphorus chemical shift (CS) tensors were determined through the analysis of NMR spectra of slow magic angle spinning and stationary samples. Spectra of spinning samples in rotational resonance and two-dimensional 31P NMR spectra were particularly useful for determining the magnitudes of the indirect spin-spin couplings, and to probe their signs. Despite being in similar environments, the three phosphorus nuclei of the phosphine ligands have distinct CS tensors. In particular, the spans of these tensors, delta11-delta33, range from 80 to 176 ppm. The phosphorus CS tensors have been assigned to specific sites determined by X-ray crystallography, based on a combination of the experimental results and the results of quantum chemical calculations of the phosphorus shielding and 2J(31P,31P) values. The effect of coordination of dimethylphenylphosphine with rhodium has been investigated by comparing calculated phosphorus CS tensors for the uncoordinated ligand with those obtained for the ligands in the complex.
Collapse
Affiliation(s)
- Guy M Bernard
- Gunning-Lemieux Chemistry Centre, University of Alberta, Edmonton AB, Canada T6G 2G2
| | | | | | | |
Collapse
|
40
|
Wang M, Bernard GM, Wasylishen RE, Choi P. A Solid-State 13C NMR Investigation of the Morphology of Single-Site and Ziegler−Natta Linear Low-Density Polyethylenes with Varying Branch Contents. Macromolecules 2007. [DOI: 10.1021/ma071119w] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mingtao Wang
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, CANADA T6G 2G6, and Department of Chemistry, University of Alberta, Edmonton, Alberta, CANADA T6G 2G2
| | - Guy M. Bernard
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, CANADA T6G 2G6, and Department of Chemistry, University of Alberta, Edmonton, Alberta, CANADA T6G 2G2
| | - Roderick E. Wasylishen
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, CANADA T6G 2G6, and Department of Chemistry, University of Alberta, Edmonton, Alberta, CANADA T6G 2G2
| | - Phillip Choi
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, CANADA T6G 2G6, and Department of Chemistry, University of Alberta, Edmonton, Alberta, CANADA T6G 2G2
| |
Collapse
|
41
|
Dickie DA, Lee PTK, Labeodan OA, Schatte G, Weinberg N, Lewis AR, Bernard GM, Wasylishen RE, Clyburne JAC. Flexible coordination of the carboxylate ligand in tin(ii) amides and a 1,3-diaza-2,4-distannacyclobutanediyl. Dalton Trans 2007:2862-9. [PMID: 17607400 DOI: 10.1039/b704588c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of tin(II) amido complexes possessing m-terphenyl carboxylate ligands have been prepared. These complexes, namely [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(2)Ph(3))](2), [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(3)Mes(2))](2), and [(Me(3)Si)(2)NSn(mu-O(2)CC(6)H(2)Mes(2)Me)](2) [Mes = 2,4,6-trimethylphenyl], are the first structurally characterized examples of tin(II) carboxylate complexes exhibiting discrete Sn(2)O(4)C(2) heterocyclic cores. Initial reactivity studies led to the isolation of a 1,3-diaza-2,4-distannacyclobutanediyl, [(Mes(2)C(6)H(3)CO(2))Sn(mu-NSiMe(3))](2). This molecule possesses a Sn(2)N(2) heterocyclic core and it was crystallised as both the CH(2)Cl(2) and Et(2)O solvates. Although the tin atoms in this molecule have a formal oxidation state of 3+, preliminary computational studies on this molecule suggest that it is best described as a ground state singlet. Finally, the X-ray crystal structure of (CH(2)Cl)(Cl)Sn[N(SiMe(3))(2)](2), the product of oxidative addition of CH(2)Cl(2) to Sn[N(SiMe(3))(2)](2), is also presented herein.
Collapse
Affiliation(s)
- Diane A Dickie
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Harris KJ, Bernard GM, McDonald C, McDonald R, Ferguson MJ, Wasylishen RE. Acetylenic Carbon-13 Chemical Shift Tensors for Diphenylacetylene and (η2-Diphenylacetylene)Pt(PPh3)2: A Solid-State NMR and Theoretical Study. Inorg Chem 2006; 45:2461-73. [PMID: 16529466 DOI: 10.1021/ic051548f] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structure of (eta2-diphenylacetylene)Pt(PPh3) (2), as well as those of its dichloromethane and benzene solvates, is determined via X-ray crystallography. An investigation of the chemical shift (CS) tensors of the 13C-labeled carbons in Ph13C13CPh and (eta2-Ph13C13CPh)Pt(PPh3)2.(C6H6) is carried out via analysis of 13C NMR spectra from stationary solid samples. The principal components of the CS tensors as well as their orientations with respect to the 13C,13C internuclear vector are determined. DFT calculations of these CS tensors are in close agreement with the experimental values. For diphenylacetylene (tolane), the orientations and principal-component magnitudes of the alkynyl carbon CS tensors are comparable to those for other alkynyl carbons, although the CS tensor is not axially symmetric in this case. Coordination to platinum causes a change in the CS tensor orientation and a net increase in the isotropic chemical shift, resulting from a significant increase in two principal components (delta11 and delta33) while the third (delta22) decreases only slightly. The measured carbon CS tensors in the platinum complex bear a striking similarity to those of the alkenyl carbons in trans-Ph(H)C=C(H)Ph, and a short theoretical discussion of these observations is presented.
Collapse
Affiliation(s)
- Kristopher J Harris
- Department of Chemistry and X-ray Crystallography Laboratory, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | | | | | | | | | | |
Collapse
|
43
|
Oh SW, Bernard GM, Wasylishen RE, McDonald R, Ferguson MJ. A multinuclear solid-state magnetic resonance study of silver nitrate triphenylphosphine. CAN J CHEM 2005. [DOI: 10.1139/v05-174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Variable-temperature solid-state31P,15N, and2H NMR spectroscopy, X-ray diffraction, and differential scanning calorimetry studies of the 1:1 adduct of silver nitrate and triphenylphosphine (AgNO3·PPh3) reveal a solidsolid phase transition at 300 K. The principal components of the phosphorus and nitrogen chemical shift tensors for both phases are determined from NMR spectra of MAS and stationary samples. In addition, the indirect spin-spin coupling between phosphorus and the naturally occurring isotopes of silver (107Ag and109Ag) are resolved. Experimental2H NMR line shapes for silver nitrate perdeuterated triphenylphosphine are those characteristic of rigid phenyl groups at temperatures above and below the phase-transition temperature. Powder and single-crystal X-ray diffraction data for AgNO3·PPh3obtained at 193, 295, and 313 K are reported; data obtained at 193 and 295 K are almost identical, but are significantly different from those obtained at 313 K and from an earlier single-crystal X-ray diffraction investigation performed at 298 K. All X-ray studies found that AgNO3·PPh3crystallizes in the monoclinic form, space group P21/c.Key words: 1:1 silver nitrate triphenylphosphine adduct, solid-state NMR, X-ray diffraction, phase transition.
Collapse
|
44
|
Abstract
Some key aspects of the secondary structure of solid orexin-B, a 28 amino-acid peptide, have been investigated by solid-state NMR spectroscopy. The 13C15N dipolar coupling between the carbonyl carbon of Leu11 and the nitrogen of Leu15, as determined by rotational echo double resonance (REDOR) experiments, is 35 Hz, indicating that these nuclei are separated by approximately 4.5 Å. This distance is consistent with the α-helical structure determined for this segment of orexin-B by solution NMR measurements. REDOR measurements of the dipolar coupling between the carbonyl carbon of Ala17 and the nitrogen of Ala22 support the contention in an earlier solution NMR study that a bend exists between the two α helices of orexin-B. However, in the solid state the internuclear distance (6.4 Å) is significantly greater than that observed for orexin-B in aqueous solution. In addition to the distance measurements, the principal components of the amide carbonyl carbon chemical shift (CS) tensors for Leu11 and Ala17 and of the amide nitrogen CS tensors for Leu15 and Ala22 are reported. There are only minor differences between the amide carbonyl carbon CS tensors for Leu11 and Ala17 and between the nitrogen CS tensors for Leu15 and Ala22.Key words: orexin-B, solid-state NMR, REDOR, chemical shift tensors.
Collapse
|
45
|
Ueda T, Bernard GM, McDonald R, Wasylishen RE. Cobalt-59 NMR and X-ray diffraction studies of hydrated and dehydrated (+/-)-tris(ethylenediamine) cobalt(III) chloride. Solid State Nucl Magn Reson 2003; 24:163-183. [PMID: 12943912 DOI: 10.1016/s0926-2040(03)00049-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cobalt-59 NMR experiments have been carried out on single-crystal and polycrystalline (powder) samples of (+/-)-tris(ethylenediamine)cobalt(III) chloride trihydrate, (+/-)-[Co(en)(3)]Cl(3) x 3H(2)O, and of its dehydrate. In addition, the X-ray crystal structure of the dehydrated sample has been determined. X-ray diffraction measurements confirm a long-held assumption that dehydration has only minor effects on the structure of the [Co(en)(3)](3+) cation. Nevertheless, these small differences have a detectable effect on the 59Co nuclear magnetic resonance properties of these compounds; in particular, the nuclear quadrupole coupling constant, C(Q). Straightforward identification of the c-axis for large single crystals of (+/-)-[Co(en)(3)]Cl(3).3H(2)O and of its dehydrate allowed us to obtain single-crystal 59 Co NMR data by orienting the crystals in an MAS rotor. Data collected on single crystals and polycrystalline samples indicate that C(Q)=-3.05+/-0.05 and -2.80+/-0.05 MHz for the hydrated and dehydrated samples, respectively; the signs have been assigned on the basis of a point charge model. The chemical shift tensor principal components were also determined: for the hydrated sample, delta(perpendicular)=7281+/-2 ppm, delta(parallel)=7004+/-4 ppm and delta(iso)=7189 ppm; for the dehydrated sample, delta(perpendicular)=7288+/-2 ppm, delta(parallel)=7008+/-4 ppm and delta(iso)=7195 ppm. The electric field gradient and chemical shift tensors are axially symmetric, as required by crystal symmetry.
Collapse
Affiliation(s)
- Takahiro Ueda
- Department of Chemistry, University of Alberta, Edmonton, Alta, Canada T6G 2G2
| | | | | | | |
Collapse
|
46
|
Abstract
Insight into the unexpectedly small range of isotropic nitrogen chemical shifts in nitrobenzene derivatives is gained through measurements of the chemical shift (CS) tensor by solid-state NMR experiments and ab initio molecular orbital (MO) and density functional theory (DFT) calculations. The principal components, delta(ii), of the (15)N CS tensors have been measured for nitrobenzene, 4-nitroaniline, 4-nitrotoluene, 4-nitroanisole, 4-nitroacetophenone, nitromesitylene, and 2,4,6-tri-tert-butylnitrobenzene. No obvious correlations of the delta(ii) values with traditional reactivity parameters were observed. The CS tensor components change significantly for the para-substituted nitrobenzenes, but these variations nearly cancel to yield isotropic shifts that fall in a range of only 3 ppm. Ab initio calculations of the delta(ii) values at the HF level are in poor agreement with the experimental values, whereas MP2 calculations and DFT calculations employing the B3LYP functional are in better agreement with experiment. The calculated (B3LYP/6-311G) delta(ii) values follow a trend in which delta(11) and delta(33) increase while delta(22) decreases with the accepted electron withdrawing ability of the para substituent. These changes tend to cancel yielding a variation in delta(iso) of only 4 ppm. These calculations indicate that the CS tensor has the same orientation as the carbon CS tensor in the isoelectronic benzoate anion: delta(11) bisects the O-N-O angle, delta(33) is perpendicular to the NO(2) plane, and delta(22) is in the NO(2) plane and perpendicular to delta(11).
Collapse
Affiliation(s)
- Glenn H Penner
- Department of Chemistry, University of Guelph, Ontario, Canada N1G 2W1.
| | | | | | | | | |
Collapse
|
47
|
Eichele K, Wasylishen RE, Corrigan JF, Taylor NJ, Carty AJ, Feindel KW, Bernard GM. Phosphorus chemical shift tensors of phosphido ligands in ruthenium carbonyl compounds: (31)P NMR spectroscopy of single-crystal and powder samples and ab initio calculations. J Am Chem Soc 2002; 124:1541-52. [PMID: 11841326 DOI: 10.1021/ja0122041] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The phosphorus chemical shift (CS) tensors of several ruthenium carbonyl compounds containing a phosphido ligand, micro), bridging a Ru [bond] Ru bond were characterized by solid-state (31)P NMR spectroscopy. As well, an analogous osmium compound was examined. The structures of most of the clusters investigated have approximate local C(2v) symmetry about the phosphorus atom. Compared to the "isolated" PH(2)(-) anion, the phosphorus nucleus of a bridging phosphido ligand exhibits considerable deshielding. The phosphorus CS tensors of most of the compounds have spans ranging from 230 to 350 ppm and skews of approximately zero. Single-crystal NMR was used to investigate the orientation of the phosphorus CS tensors for two of the compounds, Ru(2)(CO)(6)(mu(2)-C [triple bond] C [bond] Ph)(mu(2)-PPh(2)) and Ru(3)(CO)(9)(mu(2)-H)(mu(2)-PPh(2)). The intermediate component of the phosphorus CS tensor, delta(22), lies along the local C(2) axis in both compounds. The least shielded component, delta(11), lies perpendicular to the Ru [bond] P [bond] Ru plane while the most shielded component, delta(33), lies perpendicular to the C [bond]P [bond] C plane. The orientation of the phosphorus CS tensor for a third compound, Ru(2)(CO)(6)(mu(2)-PPh(2))(2), was investigated by the dipolar-chemical shift NMR technique and was found to be analogous, suggesting it to be the same in all compounds. Ab initio calculations of phosphorus magnetic shielding tensors have been carried out and reproduce the orientations found experimentally. The orientation of the CS tensor has been rationalized using simple frontier MO theory. Splittings due to (99,101)Ru [bond] (31)P spin-spin coupling have been observed for several of the complexes. A rare example of (189)Os [bond] (31)P spin-spin splittings is observed in the (31)P MAS NMR spectrum of the osmium cluster, where (1)J((189)Os, (31)P) is 367 Hz. For this complex, the (189)Os nuclear quadrupolar coupling constant is on the order of several hundred megahertz.
Collapse
Affiliation(s)
- Klaus Eichele
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3
| | | | | | | | | | | | | |
Collapse
|
48
|
Bernard GM, Wasylishen RE. A 13C solid-state NMR investigation of the alkynyl carbon chemical shift tensors for 2-butyne-1,4-diol. Solid State Nucl Magn Reson 2002; 21:86-104. [PMID: 11949820 DOI: 10.1006/snmr.2001.0050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The alkynyl carbon chemical shift (CS) tensors for 2-butyne-1,4-diol are reported, based on analyses of the carbon-13 NMR spectra of stationary-powder and slow magic-angle spinning (MAS) samples for which the alkynyl carbon nuclei are enriched in 13C. NMR spectra of slow MAS samples exhibit spinning-frequency-dependent fine structure typical of crystallographically equivalent but magnetically distinct nuclei. Simulated spectra of slow MAS samples of this two-spin system are particularly sensitive to the relative orientations of the CS tensors. In addition, the value of 1J(13C, 13C), +175 +/- 10 Hz, is determined by examination of the total NMR lineshape of slow MAS samples. The CS tensors are almost axially symmetric, delta11 = 158.9 +/- 1.0 ppm and delta22 = 155.7 +/- 1.0 ppm; the direction of greatest shielding is approximately along the alkynyl C-C bond, delta33 = -57.8 +/- 2.0 ppm. Both the magnitudes of the principal components of the CS tensors and their orientations are in agreement with those predicted from first-principles calculations at the HF and MP2 levels of theory. This study demonstrates the importance of examining the NMR spectra of homonuclear two-spin systems with and without MAS under a variety of conditions (e.g., two or more applied magnetic fields and slow MAS).
Collapse
Affiliation(s)
- Guy M Bernard
- Department of Chemistry, University of Alberta, Edmonton, Canada
| | | |
Collapse
|
49
|
Bernard GM, Wasylishen RE, Phillips AD. A Carbon-13 and Deuterium NMR Investigation of Solid Platinum−Ethylene Complexes: Zeise's Salt and Pt(η2-C2H4)(PPh3)2. J Phys Chem A 2000. [DOI: 10.1021/jp994439t] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guy M. Bernard
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3
| | | | - Andrew D. Phillips
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4J3
| |
Collapse
|
50
|
Bernard GM, Eichele K, Wu G, Kirby CW, Wasylishen RE. Nuclear magnetic shielding tensors for the carbon, nitrogen, and selenium nuclei of selenocyanates - a combined experimental and theoretical approach. CAN J CHEM 2000. [DOI: 10.1139/v00-046] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The principal components of the carbon, nitrogen, and selenium chemical shift (CS) tensors for several solid selenocyanate salts have been determined by NMR measurements on stationary or slow magic-angle-spinning powder samples. Within experimental error, all three CS tensors are axially symmetric, consistent with the expected linear geometry of these anions. The spans (Ω) of the carbon and selenium CS tensors for the selenocyanate anion (SeCN-) are approximately 300 and 800 ppm, respectively, much less than the corresponding values for carbon diselenide (CSe2). This difference is a consequence of the difference in the CS tensor components perpendicular to the C infiniti symmetry axes in these systems. Ab initio calculations show that the orbital symmetries of these compounds are a significant factor in the shielding. For CSe2, efficient mixing of the σ and π orbitals results in a large paramagnetic contribution to the total shielding of the chemical shielding tensor components perpendicular to the molecular axis. Such mixing is less efficient for the SeCN-, resulting in a smaller paramagnetic contribution and hence in greater shielding in directions perpendicular to the molecular axis.Key words: selenocyanates, solid-state NMR, carbon shielding tensors, nitrogen shielding tensors, selenium shielding tensors, ab initio calculations.
Collapse
|