Synthesis and characterisation of alkyl-N,N′-bis(salicylidene)ethylenediamino- and alkyl-N,N′-bis(salicylidene)-1,2-phenylenediaminogallium or indium complexes: crystal structure of methyl-N,N′-bis(salicylidene)-1,2-phenylenediaminoindium

The reaction of trialkylgallium or indium R₃M (M=In, Ga; R=Me, Et) with N,N′-ethylenebis(salicylideneimine) or 1,2-N,N′-phenylenebis(salicylideneimine) yields seven intramolecularly coordinated organogallium or organoindium complexes. Two hydroxyl protons in the ligands react with both trialkylindium and trimethylgallium, while one hydroxyl group reacts exclusively with triethylgallium. The complexes obtained have been fully characterised by elemental analysis, ¹H-NMR, IR and mass spectroscopy. The structure of methyl-N,N′-bis(salicylidene)-1,2-phenylenediaminoindium (1) has been determined by single-crystal X-ray analysis. The In atom is five coordinate in the structure. Fluorescence spectroscopy has shown that the maximum emission wavelength of 1 is 499 nm upon radiation by UV light.