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

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 H 2 O. 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 H 2 O (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 H 2 O (5:5 v/v), along with a blue shift in photoluminescence (PL). The self‐assembly formed in DMSO and H 2 O (2:8 v/v) followed a cooperative model characterized by a nucleation–elongation mechanism, whereas those formed in DMSO and H 2 O (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 (Δ G ) of the self‐assemblies formed in DMSO and H 2 O (5:5 and 2:8 v/v) was found to be higher than that formed in DMSO and H 2 O (8:2 v/v).