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Quantum Chemical Study of the Reaction between Ni + and H 2 S
Author(s) -
Lakuntza Oier,
Matxain Jon M.,
Ugalde Jesus M.
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200901020
Subject(s) - intersystem crossing , chemistry , exothermic reaction , endothermic process , transition state , ground state , atomic physics , excited state , ligand (biochemistry) , potential energy surface , computational chemistry , photochemistry , molecule , physics , adsorption , biochemistry , receptor , organic chemistry , singlet state , catalysis
The reaction between the Ni + cation and H 2 S is studied by considering both the doublet ground state and the lowest‐lying quartet state. For the doublet state the reaction is endothermic, whereas it is exothermic for the quartet state. Both CCSD(T)//B3LYP and B3LYP levels of theory, combined with the triple‐zeta quality TZVP++G(3df,2p), predict that there are three spin crossings along the characterized reaction path. The first one is located after the first transition state, and the second and third ones before and after the second transition state. On the quartet potential energy surface, both transition states are close in energy to the reactants, while on the doublet surface both lie quite higher in energy. The doublet and quartet states of the HNiSH + four‐membered intermediate lie very close in energy and their corresponding electronic configurations are connected by a single electron flip. This suggests that the ‐SH ligand would not prevent a facile intersystem crossing at this intermediate molecule, in contrast to the larger protection provided by the more electronegative OH ligand.