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Sinha N, Wenger OS. Photoactive Metal-to-Ligand Charge Transfer Excited States in 3d 6 Complexes with Cr 0, Mn I, Fe II, and Co III. J Am Chem Soc 2023; 145:4903-4920. [PMID: 36808978 PMCID: PMC9999427 DOI: 10.1021/jacs.2c13432] [Citation(s) in RCA: 40] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Many coordination complexes and organometallic compounds with the 4d6 and 5d6 valence electron configurations have outstanding photophysical and photochemical properties, which stem from metal-to-ligand charge transfer (MLCT) excited states. This substance class makes extensive use of the most precious and least abundant metal elements, and consequently there has been a long-standing interest in first-row transition metal compounds with photoactive MLCT states. Semiprecious copper(I) with its completely filled 3d subshell is a relatively straightforward and well explored case, but in 3d6 complexes the partially filled d-orbitals lead to energetically low-lying metal-centered (MC) states that can cause undesirably fast MLCT excited state deactivation. Herein, we discuss recent advances made with isoelectronic Cr0, MnI, FeII, and CoIII compounds, for which long-lived MLCT states have become accessible over the past five years. Furthermore, we discuss possible future developments in the search for new first-row transition metal complexes with partially filled 3d subshells and photoactive MLCT states for next-generation applications in photophysics and photochemistry.
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Affiliation(s)
- Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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Bürgin TH, Glaser F, Wenger OS. Shedding Light on the Oxidizing Properties of Spin-Flip Excited States in a Cr III Polypyridine Complex and Their Use in Photoredox Catalysis. J Am Chem Soc 2022; 144:14181-14194. [PMID: 35913126 PMCID: PMC9376921 DOI: 10.1021/jacs.2c04465] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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The photoredox activity of well-known RuII complexes
stems from metal-to-ligand charge transfer (MLCT) excited states,
in which a ligand-based electron can initiate chemical reductions
and a metal-centered hole can trigger oxidations. CrIII polypyridines show similar photoredox properties, although they
have fundamentally different electronic structures. Their photoactive
excited state is of spin-flip nature, differing from the electronic
ground state merely by a change of one electron spin, but with otherwise
identical d-orbital occupancy. We find that the driving-force dependence
for photoinduced electron transfer from 10 different donors to a spin-flip
excited state of a CrIII complex is very similar to that
for a RuII polypyridine, and thereby validate the concept
of estimating the redox potential of d3 spin-flip excited
states in analogous manner as for the MLCT states of d6 compounds. Building on this insight, we use our CrIII complex for photocatalytic reactions not previously explored with
this compound class, including the aerobic bromination of methoxyaryls,
oxygenation of 1,1,2,2-tetraphenylethylene, aerobic hydroxylation
of arylboronic acids, and the vinylation of N-phenyl
pyrrolidine. This work contributes to understanding the fundamental
photochemical properties of first-row transition-metal complexes in
comparison to well-explored precious-metal-based photocatalysts.
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Affiliation(s)
- Tobias H Bürgin
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Felix Glaser
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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Sinha N, Pfund B, Wegeberg C, Prescimone A, Wenger OS. Cobalt(III) Carbene Complex with an Electronic Excited-State Structure Similar to Cyclometalated Iridium(III) Compounds. J Am Chem Soc 2022; 144:9859-9873. [PMID: 35623627 PMCID: PMC9490849 DOI: 10.1021/jacs.2c02592] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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Many organometallic
iridium(III) complexes have photoactive excited
states with mixed metal-to-ligand and intraligand charge transfer
(MLCT/ILCT) character, which form the basis for numerous applications
in photophysics and photochemistry. Cobalt(III) complexes with analogous
MLCT excited-state properties seem to be unknown yet, despite the
fact that iridium(III) and cobalt(III) can adopt identical low-spin
d6 valence electron configurations due to their close chemical
relationship. Using a rigid tridentate chelate ligand (LCNC), in which a central amido π-donor is flanked by two σ-donating
N-heterocyclic carbene subunits, we obtained a robust homoleptic complex
[Co(LCNC)2](PF6), featuring a photoactive
excited state with substantial MLCT character. Compared to the vast
majority of isoelectronic iron(II) complexes, the MLCT state of [Co(LCNC)2](PF6) is long-lived because it
does not deactivate as efficiently into lower-lying metal-centered
excited states; furthermore, it engages directly in photoinduced electron
transfer reactions. The comparison with [Fe(LCNC)2](PF6), as well as structural, electrochemical, and UV–vis
transient absorption studies, provides insight into new ligand design
principles for first-row transition-metal complexes with photophysical
and photochemical properties reminiscent of those known from the platinum
group metals.
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Affiliation(s)
- Narayan Sinha
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Björn Pfund
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Christina Wegeberg
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, BPR 1096, Mattenstrasse 24a, 4058 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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Chong J, Besnard C, Cruz CM, Piguet C, Jiménez JR. Heteroleptic mer-[Cr(N ∩N ∩N)(CN) 3] complexes: synthetic challenge, structural characterization and photophysical properties. Dalton Trans 2022; 51:4297-4309. [PMID: 35195140 PMCID: PMC8922558 DOI: 10.1039/d2dt00126h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The substitution of three water molecules around trivalent chromium in CrBr3·6H2O with the tridentate 2,2′:6′,2′′-terpyridine (tpy), N,N′-dimethyl-N,N′-di(pyridine-2-yl)pyridine-2,6-diamine (ddpd) or 2,6-di(quinolin-8-yl)pyridine (dqp) ligands gives the heteroleptic mer-[Cr(L)Br3] complexes. Stepwise treatments with Ag(CF3SO3) and KCN under microwave irradiations provide mer-[Cr(L)(CN)3] in moderate yields. According to their X-ray crystal structures, the associated six-coordinate meridional [CrN3C3] chromophores increasingly deviate from a pseudo-octahedral arrangement according to L = ddpd ≈ dpq ≪ tpy; a trend in line with the replacement of six-membered with five-membered chelate rings around CrIII. Room-temperature ligand-centered UV-excitation at 18 170 cm−1 (λexc = 350 nm), followed by energy transfer and intersystem crossing eventually yield microsecond metal-centered Cr(2E → 4A2) phosphorescence in the red to near infrared domain 13 150–12 650 cm−1 (760 ≤ λem ≤ 790 nm). Decreasing the temperature to liquid nitrogen (77 K) extends the emission lifetimes to reach the millisecond regime with a record of 4.02 ms for mer-[Cr(dqp)(CN)3] in frozen acetonitrile. The heteroleptic mer-[Cr(L)(CN)3] (L = tpy, ddpd, dqp) complexes with their C2v-symmetrical [CrC3N3] luminescent chromophores represent the missing links between pseudo-octahedral [CrN6] and [CrC6] units found in their well-known homoleptic parents.![]()
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Affiliation(s)
- Julien Chong
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Céline Besnard
- Laboratory of Crystallography, University of Geneva, 24 quai E. Ansermet, CH-1211 Geneva 4, Switzerland
| | - Carlos M Cruz
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Claude Piguet
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland.
| | - Juan-Ramón Jiménez
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland. .,Department of Inorganic Chemistry, University of Granada and "Unidad de Excelencia en Química" (UEQ), Avda. Fuentenueva, E-18071 Granada, España.
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Wegeberg C, Wenger OS. Luminescent First-Row Transition Metal Complexes. JACS AU 2021; 1:1860-1876. [PMID: 34841405 PMCID: PMC8611671 DOI: 10.1021/jacsau.1c00353] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Indexed: 05/25/2023]
Abstract
Precious and rare elements have traditionally dominated inorganic photophysics and photochemistry, but now we are witnessing a paradigm shift toward cheaper and more abundant metals. Even though emissive complexes based on selected first-row transition metals have long been known, recent conceptual breakthroughs revealed that a much broader range of elements in different oxidation states are useable for this purpose. Coordination compounds of V, Cr, Mn, Fe, Co, Ni, and Cu now show electronically excited states with unexpected reactivity and photoluminescence behavior. Aside from providing a compact survey of the recent conceptual key advances in this dynamic field, our Perspective identifies the main design strategies that enabled the discovery of fundamentally new types of 3d-metal-based luminophores and photosensitizers operating in solution at room temperature.
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Sinha N, Jiménez J, Pfund B, Prescimone A, Piguet C, Wenger OS. A Near-Infrared-II Emissive Chromium(III) Complex. Angew Chem Int Ed Engl 2021; 60:23722-23728. [PMID: 34125469 PMCID: PMC8597102 DOI: 10.1002/anie.202106398] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 12/25/2022]
Abstract
The combination of π-donating amido with π-accepting pyridine coordination units in a tridentate chelate ligand causes a strong nephelauxetic effect in a homoleptic CrIII complex, which shifts its luminescence to the NIR-II spectral range. Previously explored CrIII polypyridine complexes typically emit between 727 and 778 nm (in the red to NIR-I spectral region), and ligand design strategies have so far concentrated on optimizing the ligand field strength. The present work takes a fundamentally different approach and focusses on increasing metal-ligand bond covalence to shift the ruby-like 2 E emission of CrIII to 1067 nm at 77 K.
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Affiliation(s)
- Narayan Sinha
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Juan‐Ramón Jiménez
- Department of Inorganic and Analytical ChemistryUniversity of Geneva30 quai E. Ansermet1211Geneva 4Switzerland
| | - Björn Pfund
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
| | - Alessandro Prescimone
- Department of ChemistryUniversity of Basel, BPR 1096Mattenstrasse 24a4058BaselSwitzerland
| | - Claude Piguet
- Department of Inorganic and Analytical ChemistryUniversity of Geneva30 quai E. Ansermet1211Geneva 4Switzerland
| | - Oliver S. Wenger
- Department of ChemistryUniversity of BaselSt. Johanns-Ring 194056BaselSwitzerland
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Sinha N, Jiménez J, Pfund B, Prescimone A, Piguet C, Wenger OS. A Near‐Infrared‐II Emissive Chromium(III) Complex. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106398] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Narayan Sinha
- Department of Chemistry University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Juan‐Ramón Jiménez
- Department of Inorganic and Analytical Chemistry University of Geneva 30 quai E. Ansermet 1211 Geneva 4 Switzerland
| | - Björn Pfund
- Department of Chemistry University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
| | - Alessandro Prescimone
- Department of Chemistry University of Basel, BPR 1096 Mattenstrasse 24a 4058 Basel Switzerland
| | - Claude Piguet
- Department of Inorganic and Analytical Chemistry University of Geneva 30 quai E. Ansermet 1211 Geneva 4 Switzerland
| | - Oliver S. Wenger
- Department of Chemistry University of Basel St. Johanns-Ring 19 4056 Basel Switzerland
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Jiménez JR, Doistau B, Poncet M, Piguet C. Heteroleptic trivalent chromium in coordination chemistry: Novel building blocks for addressing old challenges in multimetallic luminescent complexes. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2020.213750] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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The Tyranny of Arm-Wrestling Methyls on Iron(II) Spin State in Pseudo-Octahedral [Fe(didentate)3] Complexes. CHEMISTRY 2020. [DOI: 10.3390/chemistry2020015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The connection of a sterically constrained 3-methyl-pyrazine ring to a N-methyl-benzimidazole unit to give the unsymmetrical α,α’-diimine ligand L5 has been programmed for the design of pseudo-octahedral spin-crossover [Fe(L5)3]2+ units, the transition temperature (T1/2) of which occurs in between those reported for related facial tris-didentate iron chromophores fitted with 3-methyl-pyridine-benzimidazole in a LaFe helicate (T1/2 ~ 50 K) and with 5-methyl-pyrazine-benzimidazole L2 ligands (T1/2 ~350 K). A thorough crystallographic analysis of [Fe(L5)3](ClO4)2 (I), [Ni(L5)3](ClO4)2 (II), [Ni(L5)3](BF4)2∙H2O (III), [Zn(L5)3](ClO4)2 (IV), [Ni(L5)3](BF4)2∙1.75CH3CN (V), and [Zn(L5)3](BF4)2∙1.5CH3CN (VI) shows the selective formation of pure facial [M(L5)3]2+ cations in the solvated crystals of the tetrafluoroborate salts and alternative meridional isomers in the perchlorate salts. Except for a slightly larger intra-strand interannular twist between the aromatic heterocycles in L5, the metric parameters measured in [Zn(L5)3]2+ are comparable to those reported for [Zn(L2)3]2+, where L2 is the related unconstrained ligand. This similitude is reinforced by comparable ligand-field strengths (∆oct) and nephelauxetic effects (as measured by the Racah parameters B and C) extracted from the electronic absorption spectra recorded for [Ni(L5)3]2+ and [Ni(L2)3]2+. In this context, the strictly high-spin behavior observed for [Fe(L5)3]2+ within the 5–300 K range contrasts with the close to room-temperature spin-crossover behavior of [Fe(L2)3]2+ (T1/2 = 349(5) K in acetonitrile). This can be unambiguously assigned to an intraligand arm wrestling match operating in bound L5, which prevents the contraction of the coordination sphere required for accommodating low-spin FeII. Since the analogous 3-methyl-pyridine ring in [Fe(L3)3]2+ derivatives are sometimes compatible with spin-crossover properties, the consequences of repulsive intra-strand methyl–methyl interactions are found to be amplified in [Fe(L5)3]2+ because of the much lower basicity of the 3-methyl-pyrazine ring and the resulting weaker thermodynamic compensation. The decrease of the stability constants by five orders of magnitude observed in going from [M(L2)3]2+ to [M(L5)3]2+ (M = NiII and ZnII) is diagnostic for the operation of this effect, which had been not foreseen by the authors.
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Excited-State Relaxation in Luminescent Molybdenum(0) Complexes with Isocyanide Chelate Ligands. INORGANICS 2020. [DOI: 10.3390/inorganics8020014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Diisocyanide ligands with a m-terphenyl backbone provide access to Mo0 complexes exhibiting the same type of metal-to-ligand charge transfer (MLCT) luminescence as the well-known class of isoelectronic RuII polypyridines. The luminescence quantum yields and lifetimes of the homoleptic tris(diisocyanide) Mo0 complexes depend strongly on whether methyl- or tert-butyl substituents are placed in α-position to the isocyanide groups. The bulkier tert-butyl substituents lead to a molecular structure in which the three individual diisocyanides ligated to one Mo0 center are interlocked more strongly into one another than the ligands with the sterically less demanding methyl substituents. This rigidification limits the distortion of the complex in the emissive excited-state, causing a decrease of the nonradiative relaxation rate by one order of magnitude. Compared to RuII polypyridines, the molecular distortions in the luminescent 3MLCT state relative to the electronic ground state seem to be smaller in the Mo0 complexes, presumably due to delocalization of the MLCT-excited electron over greater portions of the ligands. Temperature-dependent studies indicate that thermally activated nonradiative relaxation via metal-centered excited states is more significant in these homoleptic Mo0 tris(diisocyanide) complexes than in [Ru(2,2′-bipyridine)3]2+.
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Lawson Daku LM. Spin-state dependence of the structural and vibrational properties of solvated iron( ii) polypyridyl complexes from AIMD simulations: III. [Fe(tpen)]Cl 2 in acetonitrile. RSC Adv 2020; 10:43343-43357. [PMID: 35519674 PMCID: PMC9058091 DOI: 10.1039/d0ra09499d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 11/19/2020] [Indexed: 11/22/2022] Open
Abstract
In order to achieve an in-depth understanding of the role played by the solvent in the photoinduced low-spin (LS) → high-spin (HS) transition in solvated Fe(ii) complexes, an accurate description of the solvated complexes in the two spin states is required. To this end, we are applying state-of-the-art ab initio molecular dynamics (AIMD) simulations to the study of the structural and vibrational properties of iron(ii) polypyridyl complexes. Two aqueous LS complexes were investigated in this framework, namely, [Fe(bpy)3]2+ (bpy = 2,2′-bipyridine) [Lawson Daku and Hauser, J. Phys. Chem. Lett., 2010, 1, 1830; Lawson Daku, Phys. Chem. Chem. Phys., 2018, 20, 6236] and [Fe(tpy)2]2+ (tpy = 2,2′:6′,2′′-ter-pyridine) [Lawson Daku, Phys. Chem. Chem. Phys., 2019, 21, 650]. For aqueous [Fe(bpy)3]2+, combining the results of forefront wide-angle X-ray scattering experiments with those of the AIMD simulations allowed the visualization of the interlaced coordination and solvation spheres of the photoinduced HS state [Khakhulin et al., Phys. Chem. Chem. Phys., 2019, 21, 9277]. In this paper, we report the extension of our AIMD studies to the spin-crossover complex [Fe(tpen)]2+ (tpen = N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine) in acetonitrile (ACN). The determined LS and HS solution structures of the complex are in excellent agreement with the experimental results obtained by high-resolution transient X-ray absorption spectroscopy [Zhang et al., ACS Omega, 2019, 4, 6375]. The first solvation shell of [Fe(tpen)]2+ consists of ACN molecules located in the grooves defined by the chelating coordination motif of the tpen ligand. Upon the LS → HS change of states, the solvation number of the complex is found to increase from ≈9.2 to ≈11.9 and an inner solvation shell is formed. This inner solvation shell originates from the occupancy by about one ACN molecule of the internal cavity which results from the arrangement of the 4 pyridine rings of the tpen ligand, and which becomes accessible to the solvent molecules in the HS state only thanks to the structural changes undergone by the complex. The presence of this inner solvation shell for the solvated HS complex probably plays a key role in the spin-state dependent reactivity of [Fe(tpen)]2+ in liquid solutions. AIMD study of the SCO [Fe(tpen)]2+ complex in acetonitrile: radial distribution functions and running coordination numbers characterizing its solvation structure in the HS state.![]()
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Lawson Daku LM. Spin-state dependence of the structural and vibrational properties of solvated iron(ii) polypyridyl complexes from AIMD simulations: II. aqueous [Fe(tpy)2]Cl2. Phys Chem Chem Phys 2019; 21:650-661. [DOI: 10.1039/c8cp06671j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
LS and HS Fe–O radial distribution functions and running coordination numbers for aqueous [Fe(tpy)2]Cl2: in both spin states, the first hydration shell of [Fe(tpy)2]2+ consists in a chain of ∼15 hydrogen-bonded water molecules wrapped around the ligands.
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Abstract
In this invited Perspective, recent developments and possible future directions of research on photoactive coordination compounds made from nonprecious transition metal elements will be discussed. The focus is on conceptually new, structurally well-characterized complexes with excited-state lifetimes between 10 ps and 1 ms in fluid solution for possible applications in photosensitizing, light-harvesting, luminescence and catalysis. The key metal elements considered herein are Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, W and Ce in various oxidation states equipped with diverse ligands, giving access to long-lived excited states via a range of fundamentally different types of electronic transitions. Research performed in this area over the past five years demonstrated that a much broader spectrum of metal complexes than what was long considered relevant exhibits useful photophysics and photochemistry.
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Affiliation(s)
- Oliver S Wenger
- Department of Chemistry , University of Basel , St. Johanns-Ring 19 , 4056 Basel , Switzerland
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14
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Brown AM, McCusker CE, Carey MC, Blanco-Rodríguez AM, Towrie M, Clark IP, Vlček A, McCusker JK. Vibrational Relaxation and Redistribution Dynamics in Ruthenium(II) Polypyridyl-Based Charge-Transfer Excited States: A Combined Ultrafast Electronic and Infrared Absorption Study. J Phys Chem A 2018; 122:7941-7953. [DOI: 10.1021/acs.jpca.8b06197] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Allison M. Brown
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Catherine E. McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Monica C. Carey
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
| | - Ana Maria Blanco-Rodríguez
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Michael Towrie
- Central Laser Facility, Research Complex at Harwell, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - Ian P. Clark
- Central Laser Facility, Research Complex at Harwell, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX, United Kingdom
| | - Antonín Vlček
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
- J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejskova 3, CZ-182 23 Prague, Czech Republic
| | - James K. McCusker
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
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Büldt LA, Wenger OS. Luminescent complexes made from chelating isocyanide ligands and earth-abundant metals. Dalton Trans 2018; 46:15175-15177. [PMID: 29063087 DOI: 10.1039/c7dt03620e] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In this invited frontier article, recently discovered d6 and d10 complexes with long-lived metal-to-ligand charge transfer (MLCT) excited states are highlighted. Chelating diisocyanide ligands give access to emissive Mo(0) and Cr(0) complexes with d6 electron configuration exhibiting photophysical properties similar to those of Ru(ii) polypyridines or cyclometalated Ir(iii) complexes. With Ni(0), these ligands yield luminescent tetrahedral d10 complexes similar to isoelectronic Cu(i) bis(diimine) compounds.
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Affiliation(s)
- Laura A Büldt
- Department of Chemistry, University of Basel, St Johanns-Ring 19, 4056 Basel, Switzerland.
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Lawson Daku LM. Spin-state dependence of the structural and vibrational properties of solvated iron(ii) polypyridyl complexes from AIMD simulations: aqueous [Fe(bpy)3]Cl2, a case study. Phys Chem Chem Phys 2018; 20:6236-6253. [DOI: 10.1039/c7cp07862e] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
LS and HS IR spectra of aqueous [Fe(bpy)3]2+ and corresponding HS–LS difference IR spectrum as obtained from state-of-the-art ab initio molecular dynamics simulations applied to the determination of the structural and vibrational properties of the solvated complex.
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18
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Atkins AJ, Talotta F, Freitag L, Boggio-Pasqua M, González L. Assessing Excited State Energy Gaps with Time-Dependent Density Functional Theory on Ru(II) Complexes. J Chem Theory Comput 2017; 13:4123-4145. [DOI: 10.1021/acs.jctc.7b00379] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Andrew J. Atkins
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Francesco Talotta
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
- Laboratoire de
Chimie et Physique Quantiques (UMR5626), CNRS et Université
de Toulouse 3, 31062 Toulouse, France
| | - Leon Freitag
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
| | - Martial Boggio-Pasqua
- Laboratoire de
Chimie et Physique Quantiques (UMR5626), CNRS et Université
de Toulouse 3, 31062 Toulouse, France
| | - Leticia González
- Institute
of Theoretical Chemistry, Faculty of Chemistry, University of Vienna, Währinger Straße 17, A-1090 Vienna, Austria
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Büldt LA, Wenger OS. Isocyanid-Komplexe von Cr0
, Mo0
und W0
als Leuchtstoffe und Photosensibilisatoren mit langlebigen angeregten Zuständen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201701210] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Laura A. Büldt
- Institut für Anorganische Chemie; Universität Tübingen; Auf der Morgenstelle 18 72076 Tübingen Deutschland
| | - Oliver S. Wenger
- Departement Chemie; Universität Basel; St. Johanns-Ring 19 4056 Basel Schweiz
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20
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Büldt LA, Wenger OS. Chromium(0), Molybdenum(0), and Tungsten(0) Isocyanide Complexes as Luminophores and Photosensitizers with Long-Lived Excited States. Angew Chem Int Ed Engl 2017; 56:5676-5682. [DOI: 10.1002/anie.201701210] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Indexed: 01/30/2023]
Affiliation(s)
- Laura A. Büldt
- Institute of Inorganic Chemistry; University of Tübingen; Auf der Morgenstelle 18 72076 Tübingen Germany
| | - Oliver S. Wenger
- Department of Chemistry; University of Basel; St. Johanns-Ring 19 4056 Basel Switzerland
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21
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Büldt LA, Guo X, Vogel R, Prescimone A, Wenger OS. A Tris(diisocyanide)chromium(0) Complex Is a Luminescent Analog of Fe(2,2'-Bipyridine) 32. J Am Chem Soc 2017; 139:985-992. [PMID: 28054486 DOI: 10.1021/jacs.6b11803] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A meta-terphenyl unit was substituted with an isocyanide group on each of its two terminal aryls to afford a bidentate chelating ligand (CNtBuAr3NC) that is able to stabilize chromium in its zerovalent oxidation state. The homoleptic Cr(CNtBuAr3NC)3 complex luminesces in solution at room temperature, and its excited-state lifetime (2.2 ns in deaerated THF at 20 °C) is nearly 2 orders of magnitude longer than the current record lifetime for isoelectronic Fe(II) complexes, which are of significant interest as earth-abundant sensitizers in dye-sensitized solar cells. Due to its chelating ligands, Cr(CNtBuAr3NC)3 is more robust than Cr(0) complexes with carbonyl or monodentate isocyanides, manifesting in comparatively slow photodegradation. In the presence of excess anthracene in solution, efficient energy transfer and subsequent triplet-triplet annihilation upconversion is observed. With an excited-state oxidation potential of -2.43 V vs Fc+/Fc, the Cr(0) complex is a very strong photoreductant. The findings presented herein are relevant for replacement of precious metals in dye-sensitized solar cells and in luminescent devices by earth-abundant elements.
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Affiliation(s)
- Laura A Büldt
- Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland
| | - Xingwei Guo
- Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland
| | - Raphael Vogel
- Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland
| | - Oliver S Wenger
- Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland
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