Synthesis, crystal structures and third-order nonlinear optical properties of two novel ferrocenyl Schiff-base complexes [Ag(L)2](NO3)(MeOH)(EtOH) and [HgI2(L)] {L=1,2-bis[(ferrocen-1-ylmethylene)amino]ethane}

Two novel ferrocenyl complexes [Ag(L)(2)](NO3)(.)(MeOH)(.)(EtOH)(.) (1) and [HgI2(L)] (2) {L = 1,2-bis[(ferrocen-1-ylmethylene) amino]ethane} have been prepared and structurally characterized by means of X-ray single crystal diffraction. The central ion, silver(I) or mercury(II), has a distorted tetrahedral environment, the silver(I) ion coordinates with two L, and the mercury(II) ion binds one L and two iodine atoms. Their third-order nonlinear optical (NLO) properties were determined by Z-scan techniques in DMF solution. The results indicate that the two complexes exhibit very strong NLO absorption and strong self-focusing effects. The third-order NLO absorptive coefficients alpha(2) are 1.34 x 10(-8) in W-1 for 1 and 3.1 x 10(-9) in W-1 for 2. The refractive indexes n(2) for the two complexes are 1.15 x 10(-18) and 8.02 x 10(-19) m(2) W-1, respectively. The hyperpolarizability gamma values are calculated to be 2.68 x 10(-30) esu for 1 and 1.44 x 10(-30) esu for 2. The gamma values are several orders of magnitude larger than those of the reported aryl and vinyl derivatives of ferrocene. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).