Thermal- and light-induced nanocluster formation in silver–mesogenic cyanophenyl condensed films

Thermal- and light-induced formation of nanoclusters has been studied by ESR spectroscopy in silver–mesogenic cyanobiphenyl films obtained via low temperature co-deposition of metal and organic component vapors—long chain alkyl(alkoxy)cyanobiphenyls (CB): CnH2n+1–C6H5–C6H5–CN, where n=5 (5CB), 8 (8CB) and CnH2n+1O–C6H5–C6H5–CN, n=8 (8OCB). The combination of the results of IR, UV–Vis and ESR spectroscopy of silver–cyanobiphenyl co-condensate films shows the formation of metastable Ag(CB)2 complexes at 90–200 K. Both thermal degradation of the complexes by annealing of the film samples up to 200–300 K and by light irradiation at lower temperatures lead to the formation of silver nanoclusters and their further aggregation in anisotropic matrix resulted in the production of anisotropic metal–mesogenic nanostructures.