Square-planar d⁸ metal push-pull dithiolene complexes: Synthesis and characterization of [Pd(Me₂pipdt)(dmit)]

Experimental and theoretical results on the novel [Pd(Me₂pipdt)(dmit)] complex (1) based on the push Me₂pipdt (1,4-dimethyl-piperazine-3,2-dithione) and pull dmit (1,3-dithiolo-2-thione-4,5-dithiolato), show that an unbalanced electron distribution at the dithiolene core occurs. The presence of a solvatochromic absorption at low energy, shifted to higher frequency when compared to the corresponding nickel case, points out that these complexes are potential second-order non-linear chromophores, whose properties are tunable with the metal.