NEW SOLUBLE BIS[NONA-METHYLFERROCENES, OCTA-METHYLFERROCENES, AND PENTAMETHYLFERROCENES] AS MOLECULAR WIRES WITH A METAL-TO-METAL DISTANCE OF UP TO 40-ANGSTROM
A. Hradsky et al., NEW SOLUBLE BIS[NONA-METHYLFERROCENES, OCTA-METHYLFERROCENES, AND PENTAMETHYLFERROCENES] AS MOLECULAR WIRES WITH A METAL-TO-METAL DISTANCE OF UP TO 40-ANGSTROM, Organometallics, 16(3), 1997, pp. 392-402
Methylated ferrocenes are useful building blocks for navel materials i
n molecular electronics with advantageous properties in comparison to
normal ferrocene derivatives. The presence of nine, eight, or five met
hyl substituents leads to (i) a decrease in oxidation potential, (ii)
amplified donor capacity with correspondingly increased stability of t
he ferrocenium salts, and, most significantly, (iii) increased solubil
ity. A modular synthetic approach based on standard Wittig chemistry a
ffords pi-conjugated soluble nona-, octa-, and pentamethylated biferro
cenes, bridged by up to five vinylene-phenylene subunits. These biferr
ocenes with spacers are ''molecular wires'' with a metal-to-metal dist
ance of up to 40 Angstrom and an effective conjugation pathway of up t
o 50 Angstrom.