Synthesis, structural characterization and electroluminescence study of alkylgallium derivatives of thiobenzhydrazones

Six dimethylgallium complexes of type Me2GaL [L=N-benzylidenethiobenzahydrazonato (1), N-(4-methoxy)benzylidenethiobenzahydrazonato (2), N-(3,4-dimethoxy)benzylidenethiobenzahydrazonato (3), N-(4-N,N-dimethylamino)benzylidenethiobenzahydrazonato (4), N-(2-naphthyl)methylenethiobenzahydrazonato (5) and N-(9-anthryl)methylenethiobenzahydrazonato (6)] have been synthesized by reaction of trimethylgallium with appropriate N-arylmethylenethiobenzahydrazones. The complexes obtained have been characterized by elemental analysis, 1H-NMR, IR and mass spectroscopy. Structure of 2 has been determined by X-ray single-crystal analysis, in which Ga atom is four-coordinated. Compounds 2–4 emit blue colors at λmax=432–479 nm when irradiated by UV light. The electroluminescent (EL) properties of 2, 3 and 4 were examined by fabricating EL devices using 2, 3 and 4 as emitter, respectively. The EL bands are located in the blue region (451, 454 and 479 nm for complexes 2, 3 and 4, respectively).