Sensitization of luminescence of antimony(III) in complexes with 6-methylquinoline in the spectral region of the A band

The luminescence properties of complexes of antimony (III) halides with 6-methylquinoline: (C 10 H 9 NH) 4 Sb 2 Cl 10 (I), (C 10 H 9 NH) 3 SbBr 6 (II), and (C 10 H 9 NH) 4 Sb 2 I 10 (III) are studied. From analysis of data obtained by UV, photoelectron, and luminescence spectroscopy, it is concluded that the decrease in the energy gap between the highest occupied and lowest unoccupied molecular orbitals of the 6-methylquinoline molecules and antimony (III) halides is responsible for quenching of the luminescence of the 6-methylquinolinium cations and for occurrence of intrinsic luminescence of the antimony (III) ions in going from complex I to complexes II and III.