TY - JOUR
T1 - Theoretical study on second hyperpolarizabilities of singlet diradical square planar nickel complexes involving o-semiquinonato type ligands
AU - Fukui, Hitoshi
AU - Kishi, Ryohei
AU - Minami, Takuya
AU - Nagai, Hiroshi
AU - Takahashi, Hideaki
AU - Kubo, Takashi
AU - Kamada, Kenji
AU - Ohta, Koji
AU - Champagne, Benoît
AU - Botek, Edith
AU - Nakano, Masayoshi
PY - 2008/9/11
Y1 - 2008/9/11
N2 - Hybrid density functional theory method is applied for investigating the diradical character dependence of the second hyperpolarizability (γ) of square planar nickel complexes involving several types of bidentate ligands [o-C6H4XY, where X = Y = O, NH, S, Se, and PH as well as (X, Y) = (NH, NH2) and (S, NH2)]. It is found that, as a function of the donor atoms, the diradical character of these complexes varies from 0.0 to 0.884 and is associated with substantial variations of γ ranging from 14 × 103 to 819 × 103 au. In particular, the largest γ values are associated with intermediate diradical characters in good agreement with the structure-property relationship obtained for pure hydrocarbon systems. Increasing the electronegativity of the X and Y donor groups of the ligands leads to larger diradical characters as a result of the enhancement of the double bond nature of the C=X(Y) bonds, which further stabilizes the diradicals on both-end benzene rings. This demonstrates that the electronegativities of the donor atoms of the ligands become a tuning parameter of the diradical character and then of the γ values of these complexes.
AB - Hybrid density functional theory method is applied for investigating the diradical character dependence of the second hyperpolarizability (γ) of square planar nickel complexes involving several types of bidentate ligands [o-C6H4XY, where X = Y = O, NH, S, Se, and PH as well as (X, Y) = (NH, NH2) and (S, NH2)]. It is found that, as a function of the donor atoms, the diradical character of these complexes varies from 0.0 to 0.884 and is associated with substantial variations of γ ranging from 14 × 103 to 819 × 103 au. In particular, the largest γ values are associated with intermediate diradical characters in good agreement with the structure-property relationship obtained for pure hydrocarbon systems. Increasing the electronegativity of the X and Y donor groups of the ligands leads to larger diradical characters as a result of the enhancement of the double bond nature of the C=X(Y) bonds, which further stabilizes the diradicals on both-end benzene rings. This demonstrates that the electronegativities of the donor atoms of the ligands become a tuning parameter of the diradical character and then of the γ values of these complexes.
UR - http://www.scopus.com/inward/record.url?scp=52349085801&partnerID=8YFLogxK
U2 - 10.1021/jp804400s
DO - 10.1021/jp804400s
M3 - Article
C2 - 18700736
AN - SCOPUS:52349085801
SN - 1089-5639
VL - 112
SP - 8423
EP - 8429
JO - Journal of physical chemistry A
JF - Journal of physical chemistry A
IS - 36
ER -