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.