A novel blue-emitting indium(III) complex: Synthesis, crystal structure, and effect of solvents and temperature on the luminescent properties

A novel indium complex [{InL(NO3)(OH)] center dot NO3 center dot CH3OH}(2) (1) is isolated from the refluxing reaction of a tetradentate Schiff base ligand, N,N '-bis(2-pyridinylmethylene)cyclohexane-1,2-diamine (L), and In(III) nitrate hydrate. The room temperature (298 K) and cryogenic temperature (77 K) emission spectra of 1 are recorded in solid state and different solvents (CH3OH, CHCl3, CH3CN and DMSO). Complex 1 exhibits a pronounced bathochromic shift in emission spectra as solvent polarity increases (polarity order: DMSO > CH3CN > CHCl3), indicating a change in dipole moment of 1 upon excitation. Further bathochromic shift exists in CH3OH (467 nm) solution. An extended work is developed to discuss on maximum emission and lunminescent lifetime of 1 dispersed in the deuterated reagents (CD3OD, CDCl3, CD3CN and DMSO-d(6)). The results exhibit that the similar emission also exists in deuterated reagents and the longer lifetime is observed due to the scarcity of O - H, N - H, and C - H oscillators. The quantum yield of 1 decreases with increasing polarity of solvent within the region of 7.8-15.4%. Commission Internationale de L'Eclairage (CIE) 1931 demonstrates that the color gamut of 1 is blue. (C) 2014 Elsevier B.V. All rights reserved.