Ranking solvent interactions and dielectric constants with [Pt(mesBIAN)(tda)]: A cautionary tale for polarity determinations in ionic liquids.

The solvatochromic properties of [Pt(mesBIAN)(tda)] are studied in traditional molecular solvents and ionic liquids and duly compared along established empirical solvent parameter scales. The charge-transfer absorption band of [Pt(mesBIAN)(tda)] is determined to be primarily dependent upon solvent acidity and dipolarity. Notably, ionic liquids do not obey the same well-behaved trend as molecular solvents, highlighting the complexity and domain (nano)segregation inherent to ionic liquids.