The air-stable unsymmetrical complexes Ni(dt)(dmit), Ni(dt)(dmio), Ni(tmdt)(dmit), Ni(tmdt)(dmio), Ni(etdt)(dmit), Ni(etdt)(dmio), Ni(ptdt)(dmit), and Ni(ptdt)(dmio) (where dmit is 1,3-dithiol-2-thione-4,5-dithiolate, dmio is 1,3-dithiol-2-one-4,5-dithiolate, dt is tetrathiafulvalendithiolate, tmdt is trimethylenetetrathiafulvalenedithiolate, etdt is ethylenedithiotetrathiafulvalenedithiolate, and ptdt is propylenedithiotetrathiafulvalenedithiolate) were prepared and characterized analytically, electrochemically and spectroscopically. In the solid state, the compounds exhibit optical absorption edges between 0.70 and 0.82 eV. Their LUMO and HOMO levels occur at ca. 4.5 and 5.3 eV, respectively.
The unsymmetrical complexes Ni(dmdt)(dmio) and Ni(dmstfdt)(dmio) (dmdt = dimethyltetrathiafulvalenedithiolate, dmstfdt = dimethyldiselenadithiafulvalenedithiolate, dmio = 1,3-dithiol-2-one- 4,5-dithiolate) were prepared and characterized analytically and spectroscopically. The complexes exhibit strong third-order nonlinear optical response in the visible and near-infrared spectral regions.