Invention relates to a single step preparation of alkali metal quinolate of general formula 1 wherein M=Lithium, sodium or potassium; R=H, alkyl (C1-C6), alkoxy, aryl, aryloxy, amino, amido or halogen (Cl, F, Br, I) which is substituted or unsubstituted with direct reaction of metal with 8-hydroxyquinoline. Substituted 8-hydroxyquinoline optionally have at least one substituent selected from the group consisting of alkyl, alkoxy, aryl, aryloxy, amino, amido at 2, 5 or 7 position. Halogen substituted 8-hydroxyquinolates are also prepared from this method in the yield of 90-95% from polar solvents like acetonitrile. These complexes are useful as light emitting and electron injecting materials in organic electronic devices. Also the doping of these materials in electron transport materials improves their electron mobility.