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The effect of the functional, basis set, and solvent in the simulation of the geometry and spectroscopic properties of V IV O 2+ complexes. chemical and biological applications
Author(s) -
Micera Giovanni,
Garribba Eugenio
Publication year - 2011
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.23237
Subject(s) - bond length , polarizability , basis set , molecular geometry , chemistry , polarizable continuum model , density functional theory , hybrid functional , standard deviation , geometry , triple bond , crystallography , computational chemistry , solvent , molecule , solvent effects , mathematics , double bond , crystal structure , statistics , organic chemistry , polymer chemistry
The geometry of 32 V IV O 2+ complexes with different donor set, electric charge, geometry, arrangement of the ligands with respect to the VO bond and type of ligand was calculated by density functional theory methods. 32 VO, 45 VO, 16 VOH, 40 VN, 24 VS, and 14 VCl bonds were examined. The performance of several functionals (B3LYP, B3P86, B3PW91, HCTH, TPSS, PBE0, and MPW1PW91), keeping constant the Pople triple‐zeta basis sets 6‐311g, was tested. The order of accuracy of the functional in the prediction of the bond distances, expressed in terms of mean of the deviation Δ d (Δ d = d calcd − d exptl ) and absolute deviation |Δ d | (|Δ d | = | d calcd − d exptl |) from the experimental values and of the corresponding standard deviations (SD(Δ d ) and SD(|Δ d |)), is: B3P86 ∼ PBE0 ∼ MPW1PW91 > B3PW91 ≫ TPSS > B3LYP ≫ HCTH. In the gas phase the prediction of VO, VO, VN bond lengths is rather good, but that of VOH, VS and VCl distances is by far worse. An improvement in the optimization of VS and VCl lengths is reached by adding polarization and diffuse functions on the sulfur and chlorine atoms. Finally, a general improvement in the prediction of all the calculated bond lengths and angles is obtained by simulating the structures in the solvent where they are isolated within the framework of the polarizable continuum model. The last choice allows also to improve the prediction of structural (the deviation of a penta‐coordinate geometry toward the trigonal bipyramid) and spectroscopic parameters ( 51 V and 14 N hyperfine coupling constants and 14 N nuclear quadrupolar coupling constant). In most of the cases, the structures optimized in solution closely approach the experimental ones and this can be of great help in the simulations of naturally occurring vanadium compounds and metal site of V‐proteins, like amavadin and the reduced form of vanadium bromoperoxidase (VBrPO). © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011