The Aggregations and Strong Emissions of d8and d10Metal−8-Hydroxyquinaldine Complexes.

Five new d 8and d 10metal complexes, Pd(8-hq) 2( 1), [Ag(8-Hhq) 2]NO 3( 2), Ag(8-hq)(8-Hhq) ( 3), [(8-H 2hq) 2PdCl 4]·2H 2O ( 4), and Pt(8-hq)(tht)Cl ( 5) (tht = tetrahydrothiophene), all with a fluorogenic chelating agent, 8-hydroxyquinaldine (8-Hhq), have been synthesized and characterized. The aggregations of their photoactive metal centers through π−π stacking and hydrogen bonding interactions construct the interesting frameworks. The strong emissions of 1− 3and 5in solid states with orange, cyan, and green luminescences originating from metal··· metal and π−π interactions are assigned as metal to ligand charge transfer/metal–metal to ligand charge transfer/intraligand emissions. The solvent effects on their photophysical properties are examined, which exhibit a wide range of strong luminescences in the different organic solvents. In addition, time-dependent density functional theory calculations using the B3LYP functional on 1are in good agreement with the experiments. Thermogravimetric analyses and UV/vis spectra with composition of certain simulated results are also reported. [ABSTRACT FROM AUTHOR]