Ferrocene-based nonlinear optical

Ferrocenyl-based polymers are established as useful materials for the modification of electrodes, as electrochemical biosensors, and as nonlinear optical systems. The redox behavior of ferrocene can be tuned by substituent effects and novel properties can result for example, permethylation of the cyclopentadienyl rings lowers the oxidation potential, and the chaige transfer salt of decamethylfer-rocene with tetracyanocthylene, [FeCpJ]" (TCNE], is a ferromagnet below = 4.8 K, and electrode surfaces modified with a pentamethylferrocene derivative have been used as sensors for cytochrome c These diverse properties have provided an added impetus to studies on ferrocene dendrimers. 

Synthetic Approaches to Polymeric Nonlinear Optical Materials Based on Ferrocene Systems... 

More recently, a soluble polymer (32) was prepared via reaction of l,l -ferrocenedimethanol with 4,4 -biphenyltetraamine in the presence of [RuCl2(P(C6115)3)3] (70). Approximately 20% of the iron centers were foimd to be in the Fe(III) state as a result of oxidation by ruthenium complexes formed during the polycondensation reaction. Wright and co-workers have reported the synthesis of ferrocene-based polymers possessing nonlinear optical properties (33) (71-73). These polymers were formed by polycondensation of a difunctionabzed ferrocene monomer (71). 

Sidechain ferrocene-based polymers possessing nonlinear optical properties have been described by Wright and coworkers as shown in Scheme The copolymerization of 5 mol% of the ferrocenyl functionalized monomer 28 with methyl methacrylate 29 resulted in an organometallic polymer (30) displaying second-harmonic-generation activity. The Tg and T values of this organometallic polymer were 120 and 225°C, respectively, which are similar to those of poly(methyl methacrylate). 

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