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Kidd SR, Zhou W, Warren JJ, Leznoff DB. Inducing ring distortions in unsubstituted metallophthalocyanines using axial N-heterocyclic carbenes. Dalton Trans 2024; 53:6537-6546. [PMID: 38498318 DOI: 10.1039/d4dt00528g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
A series of metallophthalocyanine (PcM) complexes with axial N-heterocyclic carbene ligands (NHC; 1,3-diisopropylimidazol-2-ylidene (DIP) and 1,3-dimethylbenzimidazol-2-ylidene (DMB)) were prepared and structurally characterized. PcCoII(DIP), PcZnII(DIP), and PcZnII(DMB) are five-coordinate complexes with mild dome-type Pc-ring distortions, while PcFeII(DIP)2 is six-coordinate and has a very large ruffle-type ring-distortion with respect to typical PcM(L)2 systems. The distortion is induced by the highly steric axial DIP ligands. The distortions were quantified and classified by their bond lengths and torsion angles, and according to the normal-coordinate structural decomposition (NSD) analysis. Upon ligation of the NHC, the insoluble PcM materials were solublized in common organic solvents, with typical UV-visible Q-band maxima observable between 658 and 677 nm; the increased solubility is rationalized in terms of the reduced solid-state aggregation of the complexes, attributable to the axial ligation.
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Affiliation(s)
- Steven R Kidd
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Wen Zhou
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Jeffrey J Warren
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
| | - Daniel B Leznoff
- Simon Fraser University, Department of Chemistry, 8888 University Drive, Burnaby BC V5A 1S6, Canada.
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Ziegler CJ, Nemykin VN. The fascinating story of axial ligand dependent spectroscopy and redox-properties in iron(II) phthalocyanines. Dalton Trans 2023; 52:15647-15655. [PMID: 37721022 DOI: 10.1039/d3dt02565a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Iron phthalocyanines play crucial fundamental and applied roles ranging from bulk colorants to components of advanced materials. In this Frontier article, we discuss four aspects concerning the influence of the axial ligands on spectroscopic and redox properties of iron(II) phthalocyanines: (i) iron versus macrocycle oxidation cite as a function of Lever's EL parameter; (ii) energy of the metal-to-ligand charge-transfer transitions as a function of Lever's EL parameter; (iii) iron versus macrocycle reduction in iron(II) phthalocyanines; (iv) Mössbauer quadrupole splitting as a function of axial ligand binding through the prism of dz2 orbital population.
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Affiliation(s)
| | - Victor N Nemykin
- Department of Chemistry, University of Tennessee, Knoxville, TN 37996, USA.
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Schrage BR, Zhou W, Harrison LA, Nevonen DE, Thompson JR, Prosser KE, Walsby CJ, Ziegler CJ, Leznoff DB, Nemykin VN. Resolving a Half-Century-Long Controversy between (Magneto)optical and EPR Spectra of Single-Electron-Reduced [PcFe] −, [PcFeL] −, and [PcFeX] 2– Complexes: Story of a Double Flip. Inorg Chem 2022; 61:20177-20199. [DOI: 10.1021/acs.inorgchem.2c03456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Briana R. Schrage
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Wen Zhou
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | - Laurel A. Harrison
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - Dustin E. Nevonen
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
| | - John R. Thompson
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | - Kathleen E. Prosser
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | - Charles J. Walsby
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | | | - Daniel B. Leznoff
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | - Victor N. Nemykin
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee37996, United States
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Nevonen DE, Ferch LS, Schrage BR, Nemykin VN. Charge-Transfer Spectroscopy of Bisaxially Coordinated Iron(II) Phthalocyanines through the Prism of the Lever's EL Parameters Scale, MCD Spectroscopy, and TDDFT Calculations. Inorg Chem 2022; 61:8250-8266. [PMID: 35549169 DOI: 10.1021/acs.inorgchem.2c00721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The position of the experimentally observed (in the UV-vis and magnetic circular dichroism (MCD) spectra) low-energy metal-to-ligand charge-transfer (MLCT) band in low-spin iron(II) phthalocyanine complexes of general formula PcFeL2, PcFeL'L″, and [PcFeX2]2- (L, L', or L″ are neutral and X- is an anionic axial ligand) was correlated with the Lever's electrochemical EL scale values for the axial ligands. The time-dependent density functional theory (TDDFT)-predicted UV-vis spectra are in very good agreement with the experimental data for all complexes. In the majority of compounds, TDDFT predicts that the first degenerate MLCT band that correlates with the MCD A-term observed between 360 and 480 nm is dominated by an eg (Fe, dπ) → b1u (Pc, π*) single-electron excitation (in traditional D4h point group notation) and agrees well with the previous assignment discussed by Stillman and co-workers[ Inorg. Chem. 1994, 33, 573-583]. The TDDFT calculations also suggest a small energy gap for b1u/b2u (Pc, π*) orbital splitting and closeness of the MLCT1 eg (Fe, dπ) → b1u (Pc, π*) and MLCT2 eg (Fe, dπ) → b2u (Pc, π*) transitions. In the case of the PcFeL2 complexes with phosphines as the axial ligands, additional degenerate charge-transfer transitions were observed between 450 and 500 nm. These transitions are dominated by a2u (Pc + L, π) → eg (Pc, π*) single-electron excitations and are unique for the PcFe(PR3)2 complexes. The energy of the phthalocyanine-based a2u orbital has large axial ligand dependency and is the reason for a large energy deviation for B1 a2u (Pc + L, π) → eg (Pc, π*) transition. The energies of the axial ligand-to-iron, axial ligand-to-phthalocyanine, iron-to-axial ligand, and phthalocyanine-to-axial ligand charge-transfer transitions were discussed on the basis of TDDFT calculations.
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Affiliation(s)
- Dustin E Nevonen
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Laura S Ferch
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Briana R Schrage
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Victor N Nemykin
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.,Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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Tyulyaeva EY, Bichan NG, Lomova TN. Generation and Spectral Properties of Oxidized Forms of Iridium and Rhenium Porphyrin Complexes. RUSS J INORG CHEM+ 2022. [DOI: 10.1134/s0036023622030147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Nemykin VN, Nevonen DE, Osterloh WR, Ferch LS, Harrison LA, Marx BS, Kadish KM. Application of Lever's EL Parameter Scale toward Fe(II)/Fe(III) versus Pc(2-)/Pc(1-) Oxidation Process Crossover Point in Axially Coordinated Iron(II) Phthalocyanine Complexes. Inorg Chem 2021; 60:16626-16644. [PMID: 34644056 DOI: 10.1021/acs.inorgchem.1c02520] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structures and, particularly, the nature of the HOMO in a series of PcFeL2, PcFeL'L″, and [PcFeX2]2- complexes (Pc = phthalocyaninato(2-) ligand; L = NH3, n-BuNH2, imidazole (Im), pyridine (Py), PMe3, PBu3, t-BuNC, P(OBu)3, and DMSO; L' = CO; L″ = NH3 or n-BuNH2; X = NCO-, NCS-, CN-, imidazolate (Im-), or 1,2,4-triazolate(Tz-)) were probed by electrochemical, spectroelectrochemical, and chemical oxidation as well as theoretical (density functional theory, DFT) studies. In general, energies of the metal-centered occupied orbitals in various six-coordinate iron phthalocyanine complexes correlate well with Lever Electrochemical Parameter EL and intercross the phthalocyanine-centered a1u orbital in several compounds with moderate-to-strong π-accepting axial ligands. In these cases, an oxidation of the phthalocyanine macrocycle (Pc(2-)/Pc(1-)) rather than the central metal ion (Fe(II)/Fe(III)) was theoretically predicted and experimentally confirmed.
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Affiliation(s)
- Victor N Nemykin
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States.,Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Dustin E Nevonen
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - W Ryan Osterloh
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
| | - Laura S Ferch
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Laurel A Harrison
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Benjamin S Marx
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Karl M Kadish
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States
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Nemykin VN, Nevonen DE, Ferch LS, Shepit M, Herbert DE, van Lierop J. Accurate Prediction of Mössbauer Hyperfine Parameters in Bis-Axially Coordinated Iron(II) Phthalocyanines Using Density Functional Theory Calculations: A Story of a Single Orbital Revealed by Natural Bond Orbital Analysis. Inorg Chem 2021; 60:3690-3706. [PMID: 33651595 DOI: 10.1021/acs.inorgchem.0c03373] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Density Functional Theory (DFT) calculations coupled with several exchange-correlation functionals were used for the prediction of Mössbauer hyperfine parameters of 36 bis-axially coordinated iron(II) phthalocyanine complexes with the general formulas PcFeL2, PcFeL'L″, and [PcFeX2]2-, including four new compounds. Both gas-phase and PCM calculations using BPW91 and MN12L exchange-correlation functionals were found to accurately predict both Mössbauer quadrupole splittings and the correct trends in experimentally observed isomer shifts. In comparison, hybrid exchange-correlation functionals underestimated quadrupole splittings, while still accurately predicted isomer shifts. Out of ∼40 exchange-correlation functionals tested, only MN12L was found to correctly reproduce quadrupole splitting trends in the PcFeL2 complexes coordinated with phosphorus-donor axial ligands (i.e., P(OnBu)3 ≈ P(OEt)3 < PMe3 < P[(CH2O)2CH2]-p-C6H4NO2 < PEt3 ≈ PnBu3). Natural Bond Orbital (NBO) analysis was successfully used to explain the general trends in the observed quadrupole splitting for all compounds of interest. In particular, the general trends in the quadrupole splitting correlate well with the axial ligand dependent, NBO-predicted population of the 3dz2 orbital of the Fe ion and are reflective of the hypothesis proposed by Ohya and co-workers ( Inorg. Chem., 1984, 23, 1303) on the adaptability of the phthalocyanine's π-system toward Fe-Lax interactions. The first X-ray crystal structure of a PcFeL2 complex with axial phosphine ligands is also reported.
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Affiliation(s)
- Victor N Nemykin
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Dustin E Nevonen
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Laura S Ferch
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Michael Shepit
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - David E Herbert
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Johan van Lierop
- Department of Physics and Astronomy, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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