SYNTHESIS, CHARACTERIZATION AND ELECTROCHEMICAL STUDIES OF 1',6'-BIS(ETHYNYL)BIFERROCENE AND SOME METAL-COMPLEXES - NOVEL HETEROMETALLIC COMPOUNDS TOWARDS NONLINEAR OPTICS

The reaction of trimethylsilylacetylene and 1',6'-diiodoferrocene (1) resulted in the formation of 1',6'-bis(trimethylsilylethynyl)biferroc (2) and, with subsequent desilylation, 1',6'-bis(ethynyl)biferrocene ( 3), in excellent yields. The novel difunctional ligand 3 lends itself to metal coordination, and the multimetallic complexes 1',6'-bis (I)tr icarbonyl[1,2-bis(diphenylphosphino)methane]} biferrocene (4) and 1',6 '-bis(rutheniumbis [1,2-bis(diphenylphosphino)methane]chloride) biferr ocene (5) were formed from arbonyl[1,2-bis(diphenylphosphino)methane]b romide) and bis[1,2-bis(diphenylphosphino)methane]dichloride}, respect ively. All the compounds have been fully characterized by analytical a nd spectroscopic methods. Cyclic voltammetry experiments indicate that there is a large electron delocalization between the iron atoms of th e biferrocene moiety and the metal centres in the one-electron-oxidize d complexes. Additionally, results show that the ruthenium and mangane se centres donates electron density through the acetylene linkage to t he (FeCp(2))(2) ligand.