Behavior of Supramolecular Polymerization of Alkynylplatinum(II) Complex in Different Compositions of DMSO and Water

Abstract

We report the self-assembling behavior of a terpyridine-based alkyne platinum(II) complex (R-L-Pt-BP) under varying composition ratios of DMSO and H2O. The resulting self-assemblies exhibited distinct photoluminescence and circular dichroism (CD) properties depending on the solvent conditions. Notably, strong positive CD signals were observed for the self-assembled R-L-Pt-BP in DMSO and H2O (2:8 v/v), accompanied by a red-shift in emission wavelength. In contrast, a negative CD signal was observed for the self-assembled R-L-Pt-BP in DMSO and H2O (5:5 v/v), along with a blue shift in photoluminescence (PL). The self-assembly formed in DMSO and H2O (2:8 v/v) followed a cooperative model characterized by a nucleation-elongation mechanism, whereas those formed in DMSO and H2O (5:5 and 8:2 v/v) adhered to an isodesmic model. Thermodynamic parameters were determined using EQ model of the heating curves. The Gibbs free energy (Delta G) of the self-assemblies formed in DMSO and H2O (5:5 and 2:8 v/v) was found to be higher than that formed in DMSO and H2O (8:2 v/v).