Theoretical studies on linear and nonlinear optical characterization and optical limiting property of Pb(II), In(III) chloride, Ni(II) metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines

To provide an insight into the optical limiting ( OL) behavior of a series of 3 metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines; the third-order nonlinear optical ( NLO) properties, one-photon absorption ( OPA) and two-photon absorption ( TPA) characterizations have been theoretically investigated by means of AM1, ZINDO and configuration interaction ( CI) methods. The highest values for the TPA cross-section ( delta(omega)) are exhibited by derivatives metallated with indium and lead. It is also seen that the nickel-metallated compound might be a passive optical limiter of the series, indicating the weakest delta(omega) and second hyperpolarizability (gamma). Our calculated results are in good agreement with the previous experimental observations on the examined molecules.