THE PHOTOCHEMICAL PRODUCTION OF NICKEL FILMS FROM THIN-FILMS OF THE INORGANIC NICKEL-COMPLEXES TRANS-NIN4X2 (N2-EQUIVALENT-TO-ET2NC2H4NH2, MEHNC2H4NMEH X-EQUIVALENT-TO-NO2, NO3, NCS)

The solid state photochemistry of trans-NiN4X2 (N2 = Et2NC2H4NH2, MeHNC2H4NMeH; X = NO2, NO3, NCS) was studied. All these molecules undergo photoinduced loss of X or X- as the primary photoprocess. The complexes trans-Ni(MeHNC2H4NMeH)2(X)2 (X = NCS, NO3) undergo loss of X as an anion to yield thermally stable ion pairs of the type [Ni(MeHNC2H4NMeH)2X][X]. These ionic products are photosensitive, decaying with loss of all ligands to form metal films. The remaining complexes trans-NiN4X2 (N2 = Et2NC2H4NH2, X = NO2, NO3, NCS, N2 = MeHNC2H4NMeH; X = NO2) undergo photoextrusion of X as a radical. This primary photoprocess does not yield stable intermediates and the resultant Ni(I) complexes decompose in a rapid thermal reaction. These results are interpreted in terms of charge transfer reactivity which results in radical loss, or ligand field reactivity which results in loss of the ion. Either type of reactivity results in the loss of all ligands and the formation of metal films.