Heteroleptic dithiolenes

There is a large number of heteroleptic dithiolene complexes—complexes that contain at least one dithiolene and at least one other ligand. This chapter is focused on mononuclear and relatively simple dinuclear complexes. The electrochemistry of heteroleptic dithiolene complexes is only briefly discussed in view of the limited amount of data available. Oxodithiolene complexes are often studied as structural models for Mo and W enzymes and are reviewed in Chapter 10 in this volume (113). Focused here is the chemical reactivity of selected types of heteroleptic dithiolene complexes. 

It is clear, however, that unsymmetrical homoleptic (20-23) (Scheme 23), or heteroleptic dithiolene complexes (24-27) (Scheme 24), which have a nonzero dipole moment, seem to be better candidate systems for SHG application than... 

Some heteroleptic dithiolene complexes studied for their third-order NLO properties and involving the dmit or the mnt ligands are shown in Scheme 27 (455, 456). Only the dmit-containing complexes exhibit a large third-order optical nonlinearity, due to their larger planar conjugated system compared to the mnt analogues. 

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