On the Role of Chalcogen Donor Atoms in Diimine-Dichalcogenolate Pt super(II) SONLO Chromophores: Is It Worth Replacing Sulfur with Selenium?

Two new diimine-diselenolate Pt super(II) chromophores [Pt(bipy)(Me-dset)] (1) and [Pt(phen)(Me-dset)] (2) (Me-dset super(2-) = N-methyl-2-thioxothiazoline-4,5-diselenolate) were synthesized and characterized. The effect of replacing sulfur with selenium was investigated by comparing the UV/Vis spectroscopic and electrochemical properties of 1 and 2 with those of the corresponding sulfur analogues, [Pt(bipy)(Me-dmet)] (3) and [Pt(phen)(Me-dmet)] (4), with a particular focus on their linear and nonlinear optical properties. The effect of replacing sulfur with selenium as the donor atoms in the class of SONLO chromophores [Pt(NN)(EE)] (EE = N-methyl-2-thioxothiazoline-4,5-dichalcogenolate; NN = bipy, phen) was investigated by comparatively investigating their UV/Vis spectroscopic, electrochemical, and SONLO properties.