Water-Molecule-Driven Vapochromic Behavior of a Mononuclear Platinum(II) System with Mixed Bipyridine and Thioglucose

A mononuclear platinum(II) complex with mixed bpy and H4tg– ligands, [Pt(H4tg-S)2(bpy)]·2H2O (1a; bpy = 2,2′-bipyridine and H5tg = 1-thio-β-d-glucose), is photoluminescent in the solid state and undergoes facile and reversible removal of solvated water molecules accompanied by changes in its absorption and emission wavelengths. The analogous dmbpy complex, [Pt(H4tg-S)2(dmbpy)]·H2O (2a; dmbpy = 4,4′-dimethyl-2,2′-bipyridine), is also emissive in the solid state, but its absorption and emission spectra remain unchanged after dehydration. X-ray crystallographic analyses revealed that the difference in the chromism of 1a and 2a is due to the difference in their hydrogen-bonding networks, which involve solvated water molecules.