1
|
Ash R, Zhang K, Vura-Weis J. Photoinduced valence tautomerism of a cobalt-dioxolene complex revealed with femtosecond M-edge XANES. J Chem Phys 2019; 151:104201. [PMID: 31521068 DOI: 10.1063/1.5115227] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cobalt complexes that undergo charge-transfer induced spin-transitions or valence tautomerism from low spin CoIII to high spin (HS) CoII are potential candidates for magneto-optical switches. We use M2,3-edge X-ray absorption near-edge structure (XANES) spectroscopy with 40 fs time resolution to measure the excited-state dynamics of CoIII(Cat-N-SQ)(Cat-N-BQ), where Cat-N-BQ and Cat-N-SQ are the singly and doubly reduced forms of the 2-(2-hydroxy-3,5-di-tert-butylphenyl-imino)-4,6-di-tert-butylcyclohexa-3,5-dienone ligand. The extreme ultraviolet probe pulses, produced using a tabletop high-harmonic generation light source, measure 3p → 3d transitions and are sensitive to the spin and oxidation state of the Co center. Photoexcitation at 525 nm produces a low-spin CoII ligand-to-metal charge transfer state which undergoes intersystem crossing to high-spin CoII in 67 fs. Vibrational cooling from this hot HS CoII state competes on the hundreds-of-fs time scale with back-intersystem crossing to the ground state, with 60% of the population trapped in a cold HS CoII state for 24 ps. Ligand field multiplet simulations accurately reproduce the ground-state spectra and support the excited-state assignments. This work demonstrates the ability of M2,3-edge XANES to measure ultrafast photophysics of molecular Co complexes.
Collapse
Affiliation(s)
- Ryan Ash
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3028, USA
| | - Kaili Zhang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3028, USA
| | - Josh Vura-Weis
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3028, USA
| |
Collapse
|
2
|
Kucheryavy P, Lahanas N, Lockard JV. Spectroscopic Evidence of Pore Geometry Effect on Axial Coordination of Guest Molecules in Metalloporphyrin-Based Metal Organic Frameworks. Inorg Chem 2018; 57:3339-3347. [PMID: 29493232 DOI: 10.1021/acs.inorgchem.8b00117] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A systematic comparison of host-guest interactions in two iron porphyrin-based metal-organic frameworks (MOFs), FeCl-PCN222 and FeCl-PCN224, with drastically different pore sizes and geometries is reported in this fundamental spectroscopy study. Guest molecules (acetone, imidazole, and piperidine) of different sizes, axial binding strengths, and reactivity with the iron porphyrin centers are employed to demonstrate the range of possible interactions that occur at the porphyrin sites inside the pores of the MOF. Binding patterns of these guest species under the constraints of the pore geometries in the two frameworks are established using multiple spectroscopy methods, including UV-vis diffuse reflectance, Raman, X-ray absorption, and X-ray emission spectroscopy. Line shape analysis applied to the latter method provides quantitative information on axial ligation through its spin state sensitivity. The observed coordination behaviors derived from the spectroscopic analyses of the two MOF systems are compared to those predicted using space-filling models and relevant iron porphyrin molecular analogues. While the space-filling models show the ideal axial coordination behavior associated with these systems, the spectroscopic results provide powerful insight into the actual binding interactions that occur in practice. Evidence for potential side reactions occurring within the pores that may be responsible for the observed deviation from model coordination behavior in one of the MOF/guest molecule combinations is presented and discussed in the context of literature precedent.
Collapse
Affiliation(s)
- Pavel Kucheryavy
- Department of Chemistry , Rutgers University - Newark , Newark , New Jersey 07102 , United States
| | - Nicole Lahanas
- Department of Chemistry , Rutgers University - Newark , Newark , New Jersey 07102 , United States
| | - Jenny V Lockard
- Department of Chemistry , Rutgers University - Newark , Newark , New Jersey 07102 , United States
| |
Collapse
|
3
|
Nelson DJ, Nolan SP. Hydroxide complexes of the late transition metals: Organometallic chemistry and catalysis. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
4
|
Chuang YC, Sheu CF, Lee GH, Chen YS, Wang Y. Charge density studies of 3d metal (Ni/Cu) complexes with a non-innocent ligand. ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2017; 73:634-642. [PMID: 28762973 DOI: 10.1107/s2052520617007119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/13/2017] [Indexed: 06/07/2023]
Abstract
High-resolution X-ray diffraction experiments and atom-specific X-ray absorption experiments are applied to investigate a series of square planar complexes with the non-innocent ligand of maleonitriledithiolate (mnt), [S2C2(CN)2]z-, containing M-S bonds. Four complexes of (PyH)z[M(mnt)2]z-, where M = Ni or Cu, z = 2 or 1 and PyH+ = C5NH6+, were studied in order to clarify whether such one-electron oxidation-reduction, [M(mnt)2]2-/[M(mnt)2]1-, is taking place at the metal or the ligand site. Combining the techniques of metal K-, L-edge and S K-edge X-ray absorption spectroscopy with high-resolution X-ray charge density studies, it is unambiguously demonstrated that the electron redox reaction is ligand based and metal based for Ni and Cu pairs, respectively. The bonding characters in terms of topological properties associated with the bond critical points are compared between the oxidized form [ML]- and the reduced form [ML]2-. In the case of Ni complexes, the formal oxidation state of Ni remains as Ni2+ and each mnt ligand carries a 2- charge in [Ni(mnt)2]2-, but only one of the ligands is formally oxidized in [Ni(mnt)2]1-. In contrast, in the case of Cu complexes, the mnt remains as 2- in both complexes, but the formal oxidation states of the metal are Cu2+ and Cu3+. Bond characterizations and d-orbital populations will be presented. The complementary results of XAS, XRD and DFT calculations will be discussed. The conclusion on the redox reactions in these complexes can be firmly established.
Collapse
Affiliation(s)
- Yu Chun Chuang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chou Fu Sheu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Gene Hsiang Lee
- Instrumentation Center, National Taiwan University, Taipei 10617, Taiwan
| | - Yu Sheng Chen
- ChemMatCARS Beamline, The University of Chicago, Advanced Photon Source, Argonne, Illinois 60439, USA
| | - Yu Wang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| |
Collapse
|
5
|
|
6
|
Schwalenstocker K, Paudel J, Kohn AW, Dong C, Van Heuvelen KM, Farquhar ER, Li F. Cobalt Kβ valence-to-core X-ray emission spectroscopy: a study of low-spin octahedral cobalt(iii) complexes. Dalton Trans 2016; 45:14191-202. [PMID: 27533922 PMCID: PMC5021618 DOI: 10.1039/c6dt02413k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Kβ valence-to-core (V2C) X-emission spectroscopy (XES) has gained prominence as a tool for molecular inorganic chemists to probe the occupied valence orbitals of coordination complexes, as illustrated by recent evaluation of Kβ V2C XES ranging from titanium to iron. However, cobalt Kβ V2C XES has not been studied in detail, limiting the application of this technique to probe cobalt coordination in molecular catalysts and bioinorganic systems. In addition, the community still lacks a complete understanding of all factors that dictate the V2C peak area. In this manuscript, we report experimental cobalt Kβ V2C XES spectra of low-spin octahedral Co(iii) complexes with different ligand donors, in conjunction with DFT calculations. Cobalt Kβ V2C XES was demonstrated to be sensitive to cobalt-ligand coordination environments. Notably, we recognize here for the first time that there is a linear correlation between the V2C area and the spectrochemical series for low-spin octahedral cobalt(iii) complexes, with strong field π acceptor ligands giving rise to the largest V2C area. This unprecedented correlation is explained by invoking different levels of π-interaction between cobalt p orbitals and ligand orbitals that modulate the percentage of cobalt p orbital character in donor MOs, in combination with changes in the average cobalt-ligand distance.
Collapse
Affiliation(s)
| | - Jaya Paudel
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces NM 88003
| | | | - Chao Dong
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces NM 88003
| | | | - Erik R. Farquhar
- CWRU Center for Synchrotron Biosciences, Brookhaven National Laboratory, Upton, NY 11973
| | - Feifei Li
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces NM 88003
| |
Collapse
|
7
|
Shin JW, Jeong AR, Lee SY, Kim C, Hayami S, Min KS. Trinuclear nickel and cobalt complexes containing unsymmetrical tripodal tetradentate ligands: syntheses, structural, magnetic, and catalytic properties. Dalton Trans 2016; 45:14089-100. [PMID: 27503766 DOI: 10.1039/c6dt02701f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The coordination chemistries of the tetradentate N2O2-type ligands N-(2-pyridylmethyl)iminodiethanol (H2pmide) and N-(2-pyridylmethyl)iminodiisopropanol (H2pmidip) have been investigated with nickel(ii) and cobalt(ii/iii) ions. Three novel complexes prepared and characterized are [(Hpmide)2Ni3(CH3COO)4] (1), [(Hpmide)2Co3(CH3COO)4] (2), and [(pmidip)2Co3(CH3COO)4] (3). In 1 and 2, two terminal nickel(ii)/cobalt(ii) units are coordinated to one Hpmide(-) and two CH3CO2(-). The terminal units are each connected to a central nickel(ii)/cobalt(ii) cation through one oxygen atom of Hpmide(-) and two oxygen atoms of acetate ions, giving rise to nickel(ii) and cobalt(ii) trinuclear complexes, respectively. Trinuclear complexes 1 and 2 are isomorphous. In 3, two terminal cobalt(iii) units are coordinated to pmidip(2-) and two CH3CO2(-). The terminal units are each linked to a central cobalt(ii) cation through two oxygen atoms of pmidip(2-) and one oxygen atom of a bidentate acetate ion, resulting in a linear trinuclear mixed-valence cobalt complex. 1 shows a weak ferromagnetic interaction with the ethoxo and acetato groups between the nickel(ii) ions (g = 2.24, J = 2.35 cm(-1)). However, 2 indicates a weak antiferromagnetic coupling with the ethoxo and acetato groups between the cobalt(ii) ions (g = 2.37, J = -0.5 cm(-1)). Additionally, 3 behaves as a paramagnetic cobalt(ii) monomer, due to the diamagnetic cobalt(iii) ions in the terminal units (g = 2.53, |D| = 36.0 cm(-1)). No catalytic activity was observed in 1. However, 2 and 3 showed significant catalytic activities toward various olefins with modest to good yields. 3 was slightly less efficient toward olefin epoxidation reaction than 2. Also 2 was used for terminal olefin oxidation reaction and was oxidised to the corresponding epoxides in moderate yields (34-75%) with conversions ranging from 47-100%. The cobalt complexes 2 and 3 promoted the O-O bond cleavage to ∼75% heterolysis and ∼25% homolysis.
Collapse
Affiliation(s)
- Jong Won Shin
- Department of Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea
| | | | | | | | | | | |
Collapse
|
8
|
Kucheryavy P, Lahanas N, Velasco E, Sun CJ, Lockard JV. Probing Framework-Restricted Metal Axial Ligation and Spin State Patterns in a Post-Synthetically Reduced Iron-Porphyrin-Based Metal-Organic Framework. J Phys Chem Lett 2016; 7:1109-1115. [PMID: 26950260 DOI: 10.1021/acs.jpclett.6b00302] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An iron-porphyrin-based metal organic framework PCN-222(Fe) is investigated upon postsynthetic reduction with piperidine. Fe K-edge X-ray absorption and Kβ mainline emission spectroscopy measurements reveal the local coordination geometry, oxidation, and spin state changes experienced by the Fe sites upon reaction with this axially coordinating reducing agent. Analysis and fitting of these data confirm the binding pattern predicted by a space-filling model of the structurally constrained pore environments. These results are further supported by UV-vis diffuse reflectance, IR, and resonance Raman spectroscopy data.
Collapse
Affiliation(s)
- Pavel Kucheryavy
- Department of Chemistry, Rutgers University , Newark, New Jersey 07102, United States
| | - Nicole Lahanas
- Department of Chemistry, Rutgers University , Newark, New Jersey 07102, United States
| | - Ever Velasco
- Department of Chemistry, Rutgers University , Newark, New Jersey 07102, United States
| | - Cheng-Jun Sun
- X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Jenny V Lockard
- Department of Chemistry, Rutgers University , Newark, New Jersey 07102, United States
| |
Collapse
|
9
|
Wajda-Hermanowicz K, Pieniążczak D, Zatajska A, Wróbel R, Drabent K, Ciunik Z. A Study on the Condensation Reaction of 4-Amino-3,5-dimethyl-1,2,4-triazole with Benzaldehydes: Structure and Spectroscopic Properties of Some New Stable Hemiaminals. Molecules 2015; 20:17109-31. [PMID: 26393552 PMCID: PMC6332017 DOI: 10.3390/molecules200917109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 11/26/2022] Open
Abstract
Studies on the stable hemiaminals and Schiff bases formation in the reaction of substituted benzaldehydes with primary 3,5-dimethyl-1,2,4-triazole 4-amine were carried out under neutral conditions. These products were investigated by IR, Raman, MS, 1H- and 13C-NMR spectra as well as by X-ray crystallography. The effect of reaction conditions: temperature, polarity of the solvents utilized, substrate concentration and the ortho and para benzaldehyde substituents on the yield of products was also examined.
Collapse
Affiliation(s)
| | - Damian Pieniążczak
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wrocław 50-383, Poland.
| | - Aleksandra Zatajska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wrocław 50-383, Poland.
| | - Robert Wróbel
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wrocław 50-383, Poland.
| | - Krzysztof Drabent
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wrocław 50-383, Poland.
| | - Zbigniew Ciunik
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, Wrocław 50-383, Poland.
| |
Collapse
|
10
|
Shin JW, Jeong AR, Hayami S, Moon D, Min KS. Synthesis, structure, and magnetic properties of dicopper and tricobalt complexes based on N-(2-pyridylmethyl)iminodiethanol. Inorg Chem Front 2015. [DOI: 10.1039/c5qi00088b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A novel unsymmetrical dinuclear copper complex [Cu(H2pmide)(NO3)Cu(Hpmide)](NO3)2 (1) and a mixed-valence trinuclear cobalt compound [(pmide)2Co3(CH3CO2)2(NCS)2]·4CH3OH (2) have been prepared and characterized using structure and molecular magnetism.
Collapse
Affiliation(s)
- Jong Won Shin
- Beamline Department
- Pohang Accelerator Laboratory/POSTECH
- Pohang
- Republic of Korea
| | - Ah Rim Jeong
- Department of Chemistry
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
| | - Shinya Hayami
- Department of Chemistry
- Graduate School of Science and Technology
- Kumamoto University
- Kumamoto 860-8555
- Japan
| | - Dohyun Moon
- Beamline Department
- Pohang Accelerator Laboratory/POSTECH
- Pohang
- Republic of Korea
| | - Kil Sik Min
- Department of Chemistry Education and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu 702-701
- Republic of Korea
| |
Collapse
|
11
|
Wu LC, Thomsen MK, Madsen SR, Schmoekel M, Jørgensen MRV, Cheng MC, Peng SM, Chen YS, Overgaard J, Iversen BB. Chemical Bonding in a Linear Chromium Metal String Complex. Inorg Chem 2014; 53:12489-98. [DOI: 10.1021/ic501603x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Lai-Chin Wu
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Maja K. Thomsen
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Solveig R. Madsen
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Mette Schmoekel
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Mads R. V. Jørgensen
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | | | - Shie-Ming Peng
- Department
of Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yu-Sheng Chen
- ChemMatCARS Beamline, Advanced Photon Source, The University of Chicago, Argonne, Illinois 60439, United States
| | - Jacob Overgaard
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Bo B. Iversen
- Center
for Materials Crystallography, Department of Chemistry and iNANO, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| |
Collapse
|