Ferrocene in Conjugation with a Fischer Carbene:  Synthesis, NLO, and Electrochemical Behavior of a Novel Organometallic Push−Pull System

Abstract

Using an iterative sequence of Wittig olefination, reduction, oxidation, and condensation of an active methylene group to carbonyl, it was possible to prepare a series of organometallic push-pull molecules [(COin which ferrocene is the donor element and a Fisher carbene moeity is the acceptor group. The molecular first hyperpolarizability β was determined by hyper-Rayleigh scattering experiments. The β values ranged from 110 × 10 -30 to 2420 × 10 -30 esu in acetonitrile, and they are among the highest reported for organometallic molecules so far. Electrochemical measurements are consistent with the push-pull nature of these compounds.# Dedicated to Professor D. Nasipuri on the occasion of his 75th birthday.

New pyridinium conjugated ferrocenes: Synthesis and electrochemical properties

“…The research for new conjugated ferrocenic compounds has not stopped because of the interest of these compounds in catalysis reactions, triggering electron transfer [1][2][3][4], as well as bringing interesting perspectives in the field of non-dipolar NLO [5][6][7][8][9]. In fact, with its almost always reversible one electron system, the ferrocene moiety can be switched from a good donor in the reduced state, to a weak attractor in the oxidized one.…”

A facile organolithium route to ferrocene-based triarylmethyl dyes with substantial near IR and NLO properties

“…0022 A variety of electron-accepting groups have been employed so far. These include the ordinary EWGÕs, i.e., -NO 2 , -CN, -CH@O, -CO 2 CH 3 [6], as well as other, more novel electron-withdrawing functionalities. The latter category contains groups derived from 3-(dicyanomethylidene)-2,3-dihydrobenzothiophene-1,1-dioxide, 1,3-diethyl-2-thiobarbituric acid, 4-methyl-(2-phenyl)-thioflavilium perchlorate [7], the tropylium cation as well as a number of organometallic moieties [8].…”

“…A particularly effective EWG was shown to be a tungsten Fischer carbene moiety in conjugation with a ferrocenyl group through four double bonds. In fact, this molecule was shown to exhibit a record high second-order nonlinearity and a remarkable solvent effect [6]. In an attempt to assess the effect of a carbenium ion centre on the NLO properties of certain stilbenes, we synthesized a number of triaryl carbinols with stilbenyl chromophores [9], and the NLO properties of the corresponding dyes have been measured by the hyper-Rayleigh scattering (HRS) technique [10].…”

Recent advances in the field of multicarbene and multimetal carbene complexes of the Fischer-type

“…In the field of non-linear optics, conjugated unsaturated systems with a transition metal moiety have been employed for their electron delocalization and so-called 'push-pull' characteristics [134,213,214], and the magnetic spin cross-over properties of such carbene-containing molecular wires examined [106,215]. The engineering of designer surfaces functionalized with carbenes [50,51,[216][217][218], and the redox properties and intervalence charge transfer of such organometallic systems on electrode surfaces [219] are other rapidly expanding focus areas.…”