Binuclear alkynylplatinum(ii) terpyridine complexes with flexible bridges behave as organogelators for several organic solvents

Abstract

New binuclear alkynylplatinum(ii) terpyridyl complexes with flexible bridges have been synthesized and characterized by 1H NMR, mass spectra and elemental analysis. These compounds can gelate a variety of organic solvents via multiple intermolecular interactions such as metal-metal (Pt⋯Pt) and π-π stacking interactions, hydrogen bonding interactions, and van der Waals forces, which were confirmed by ultraviolet-visible (UV-vis) absorption spectroscopy, rheological studies, temperature-dependent 1H NMR spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Moreover, compound 1b with a longer flexible bridge (-O(CH2)6O-) exhibited higher gelation ability than that of compound 1a with a shorter flexible bridge (-O (CH2)4O-). A scanning electron microscopy (SEM) investigation of the xerogels from different organic solvents gave a visual image showing that fibrillar aggregates are entangled in three-dimensional network structures.