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

## TL;DR

This study explores how a platinum complex self-assembles and changes its light properties in different mixtures of DMSO and water.

## Contribution

The paper reveals solvent-dependent self-assembly mechanisms and optical properties of an alkynylplatinum(II) complex.

## Key findings

- Strong positive CD signals and red-shifted emission were observed in 2:8 DMSO/H2O mixtures.
- Negative CD signals and blue-shifted emission were observed in 5:5 DMSO/H2O mixtures.
- The self-assembly mechanism varied between cooperative and isodesmic models depending on solvent composition.

## 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 (ΔG) 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).

The self‐assembly of R‐L‐Pt‐BP in DMSO/H2O showed solvent‐dependent CD and photoluminescence (PL). A cooperative mechanism with red‐shifted emission and higher ΔG appeared in 2:8 mixtures; whereas 5:5 and 8:2 followed an isodesmic model with opposite CD signals.