Chemistry | 2019
Do Anionic π-Molecules Aggregate Together in Solution? - Case Study with Multi-interactive Ligand and the Network Formation.
Abstract
An anionic π-molecule can aggregate together when a multi-interactivity is introduced, in sharp contrast to common anionic molecules that are generally difficult to stack on each other. We found that a multi-interactive ligand, TPHAP - , (2,5,8-tri(4 -pyridyl)-1,3,4,6,7,9-hexaazaphenalenate) exhibited a large Stokes shift and an intramolecular charge transfer, both of which were sensitive to hydrogen-bonding media. An anionic potassium salt of TPHAP - in methanol formed various aggregation states depending on the concentration examined, revealed by the steady-state spectroscopic and fluorescence lifetime measurements. Self-assembling cadmium ions and the ligands can create several morphological crystals controlled by the ligand concentration, among which three new structures were determined by single crystal analysis. The X-ray structures obtained suggest that the aggregation states of the ligand in solution can be transferred to the solid system of the porous coordination networks.