Self-assembly and luminescence properties of alkyl ammonium gold(I) iso-maleonitriledithiolate coordination polymers

This thesis focuses on the design of tunable photoluminescence, control of supramolecular packing, and the preparation of stimuli-responsive gold(I) coordination polymers. This is explored via gold(I) isomaleonitriledithiolate, [Au2(i-mnt)2]2- as the anionic building block, with soft cations containing long alkyl chains in the form of tetraalkylammonium, [(CnH2n+1)4N]+ and alkyltrimethylammonium, [RMe3N]+ (where n = 5, 7, 8 and R = C4H9, C8H17, C10H21, C16H33). These structures were synthesized and displayed luminescent properties, with the emission colour ranging between green, orange, and red at room temperature due to the presence of aurophilic interactions. Modifications in the alkyl chain-length in [RMe3N]2[Au2(i-mnt)2] resulted in changes in supramolecular packing - from columnar to smectic C–like structures with [C16Me3N]2[Au2(i-mnt)2]. Notably, the C16-containing structure shows mechanical softness inherent from the parent surfactant cation [C16Me3N]+, where alterations in structural and emission properties occur upon applying mild pressure from the tip of a spatula.