Tetravalent tin complex with high electron affinity for electroluminescentapplications

We report the synthesis and electroluminescent properties of the organometa llic complex diphenyltin bis-hydroxyquinoline (Sph(2)q(2)). The complex was prepared by the reaction of diphenyltin dichloride with 8-hydroxyquinoline and shows an absorption cutoff wavelength of 460 nm and bright photolumine scence with a peak wavelength at 508 nm. The ionization potential of Sph(2) q(2) was determined to be similar to 6.0 eV by photoemission apparatus, and the electron affinity is estimated to be 3.3 eV. Sph(2)q(2) was used as an emitting and electron injection layer in bilayer devices. The electrolumin escence (EL) properties and charge injection properties of Sph(2)q(2) are c haracterized. Sph(2)q(2) is easily soluble in common organic solvents and f urther modification of its properties is possible. The results indicate tha t tetravalent tin complexes are potential emitting and charge injection mat erials for EL applications. (C) 2000 American Institute of Physics. [S0003- 6951(00)03124-7].