Grj. Williams, EXCITED-STATE ABSORPTION AND HYPERPOLARIZABILITY IN SILICON NAPHTHALOCYANINES, Journal of molecular structure. Theochem, 332(1-2), 1995, pp. 137-140
The excited-state absorption (ESA) from the first excited singlet, S-1
, and lowest energy excited triplet, T-1, state of a model silicon nap
hthalocyanine has been calculated using a multiconfiguration-interacti
on (MECI) procedure, in conjunction with semiempirical molecular orbit
al theory. The calculations indicate that the ESA from these states ef
fectively covers the whole of the visible region when bandwidths are t
aken into consideration, thus making silicon naphthalocyanines attract
ive candidates for optical limiting applications. The nonlinear optica
l susceptibility (molecular second hyperpolarizability) of the ground
state, and the S-1 and T-1 excited states, was also calculated, with t
he excited slates exhibiting a considerable enhancement in the magnitu
de of the calculated nonlinear susceptability, in comparison with the
value obtained for the ground state.