Conjugated bridging bimetallic complexes

Recent studies have shown that o-acetylide metal complexes exhibit very encouraging third-order nonlinear optical (NLO) properties [85,86]. Hence, there is considerable current interest in o-acetylide complexes and conjugated, bridging, bimetallic systems. 

Electron transfer is an appealing process allowing the same transformation as in photochemistry, i.e., cyclization-reopening. In this context, the DTE unit has proven to be useful for the elaboration of photo and/or electrochromic metal-based systems specially devoted to the control of the electronic communication in bimetallic complexes. Organometallic complexes crmsisting of Jt-conjugated system bridging two redox active metal centers have proven to be efficient molecular wires (Fig. 11). 

Bimetallic molybdenum nitrosyl complexes, (containing Mo(I), i.e. a 17e species) with conjugated bridging ligands of the bispyridine family, or the bisphenolate family, present widely separated reduction waves, as shown by McCleverty, Ward, and others [86], The separation can be observed with spacers containing up to four double bonds, or four phenylene units. 

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