Do Anionic π Molecules Aggregate in Solution? A Case Study with Multi‐interactive Ligands and Network Formation.

Nakanishi, Keisuke; Ohtsu, Hiroyoshi; Fukuhara, Gaku; Kawano, Masaki

An anionic π molecule can form an aggregate 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, 2,5,8‐tri(4′‐pyridyl)‐1,3,4,6,7,9‐hexaazaphenalenate (TPHAP−) 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; this was revealed by steady‐state spectroscopic and fluorescence lifetime measurements. Self‐assembling cadmium ions and the ligands can create several morphological crystals that are 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.

INTRAMOLECULAR charge transfer; STOKES shift; LIGANDS (Chemistry); INTRAMOLECULAR proton transfer reactions; MOLECULES; POTASSIUM salts

Chemistry - A European Journal, 2019, Vol 25, Issue 66, p15182

0947-6539

Academic Journal

10.1002/chem.201903764