Chiral organometallic chromophores for nonlinear optics derived from [Fe2(η5-C5H5)2(CO)2(μ-CO)(μ-C-CH3)]+ [BF4]-

Two series of chiral organometallic Donor-pi-Acceptor chromophores derived from [Fe-2(eta(5)-C5H5)(2)(CO)(2)(mu-CO)(mu-C-CH3)](+) [BF4](-) have been synthesised. In the first series (S)-(-)-2-methoxymethyl pyrrolidine acts as the chiral donor end group and in the second series 1,1'-binaphthyl acts as the chiral pi-bridging unit. The nonlinear optical properties of these compounds were measured by the Kurtz powder technique and by hyper-Raleigh scattering. beta-values of up to 964 x 10(-30) esu were obtained for a member of the first series. Single crystal X-ray studies of [Fe-2(eta(5)-C5H5)(2)(CO)(2)(mu-CO)(mu-C-CH3)](+) [BF4](-). [Fe-2(eta(5)-C5H4CH3)(2)(CO)(2)(mu-CO)(mu-(E)-C-CH=CH-2-(5-piperidin-1-yl-thiophene))](+) [BF4](-) and [Fe-2(eta(5)-C5H4CH3)(2)(CO)(2)(mu-CO)(mu-(E)-C-CH=CH-2-(naphthalene))](+) [BF4](-) are reported. (C) 2002 Elsevier Science B.V. All rights reserved.