Laser photolysis studies on CuI complexes of thia-calix[3]pyridine.: Phosphorescence from the intramolecular charge-transfer excited state

Copper(I) complexes of thia-calix[3]pyridine in dichloromethane exhibit phosphorescence from the MLCT triplet states at room temperature. The phosphorescence spectrum shifts to red on going from 300 to 180 K. The laser photolysis study carried out in the temperature range 300-180 K reveals that phosphorescence originates from the two triplet states, T-H and T-L, which are in thermal equilibrium with the energy difference of ca. 5 kcal mol(-1). (C) 2003 Elsevier Science B.V. All rights reserved.