CASSCF-based explicit ligand field models clarify the ground state electronic structures of transition metal phthalocyanines (MPc; M = Mn, Fe, Co, Ni, Cu, Zn) (2016)

View/ Open
Type of Content
Journal ArticlePublisher
Canadian Science PublishingISSN
0008-40421480-3291
Language
enCollections
- Science: Journal Articles [1179]
Abstract
© 2016 Published by NRC Research Press. Multireference electronic structure methods are used to assign ground state electronic configurations for a series of metallophthalocyanines. Ligand orbital occupancies remain constant across the period and are consistent with a formal 2-charge on the ligand. The d electron configurations of some metallophthalocyanines are straightforward and can be unambiguously assigned, (dxy)2(dxz,dyz)2,2(dz2)2(dx2-y2)n, with n = 2, 1, 0, respectively, for ZnPc, CuPc, and NiPc. Controversies over ground state electronic structure assignments for other metallophthalocyanines arise due to multiple complicating factors: accidental near-degeneracies, environmental effects, and different ligand field models used in interpreting experimental spectra. We demonstrate that explicit ligand field models provide more reliable and consistent interpretations of experimental data than implicit, parameterized alternatives. On this basis, we assign gas-phase electronic ground states for MnPc, (dxy)2(dxz,dyz)1,1(dz2)1and CoPc, (dxy)2(dxz,dyz)2,2(dz2)1, and show that the ground state of FePc cannot be resolved to a single state, with two near-degenerate states that are likely spin-orbit coupled: (dxy)2(dxz,dyz)1,1(dz2)2and (dxy)2(dxz,dyz)2,1(dz2)1. Remaining differences between computational predictions and experimental observations are small and may be ascribed primarily to environmental effects but are also partly due to incomplete modelling of electron correlation.
Citation
Wallace AJ, Williamson BE, Crittenden DL (2016). CASSCF-based explicit ligand field models clarify the ground state electronic structures of transition metal phthalocyanines (MPc; M = Mn, Fe, Co, Ni, Cu, Zn). Canadian Journal of Chemistry. 94(12). 1163-1168.This citation is automatically generated and may be unreliable. Use as a guide only.
Keywords
ligand field theory; CASSCF; MRMP2; phthalocyanine; multireferenceANZSRC Fields of Research
34 - Chemical sciences::3405 - Organic chemistry::340505 - Physical organic chemistry34 - Chemical sciences::3402 - Inorganic chemistry::340209 - Organometallic chemistry
34 - Chemical sciences::3407 - Theoretical and computational chemistry::340701 - Computational chemistry
34 - Chemical sciences::3406 - Physical chemistry::340604 - Electrochemistry
Rights
All rights reserved unless otherwise statedRelated items
Showing items related by title, author, creator and subject.
-
Cyclopropenium Cations Break the Rules of Attraction to FormClosely Bound Dimers
Jayasinghe CD; Polson MIJ; Wallace, Andrew James; Curnow, Owen; Crittenden, Deborah (AMER CHEMICAL SOC, 2015)The crystal structures of tris(ethylmethylamino)-cyclopropenium chloride and tris(diethylamino)-cyclopropenium iodide reveal the presence of closely bound dicationic dimers formed from two closed-shell monomer units. The ... -
Coupled cluster calculations provide a one-to-one mapping between calculated and observed transition energies in the electronic absorption spectrum of zinc phthalocyanine
Wallace AJ; Crittenden, Deborah; Williamson, Bryce (Wiley, 2017)© 2017 Wiley Periodicals, Inc. All transitions in the experimentally designated and numbered Q, B, and N bands ( < 4.8 eV) of the electronic absorption spectrum of zinc phthalocyanine (ZnPc) are assigned on the basis of ... -
Experimental validation of a computational screening approach to predict redox potentials for a diverse variety of redox-active organic molecules
Bodman SE; Burney AM; Hughes CD; McNeill, Alexandra; Crittenden, Deborah (American Chemical Society (ACS), 2020)Organic redox flow batteries are currently the focus of intense scientific interest because they have the potential to be developed into low-cost, environmentally sustainable solutions to the energy storage problem that ...