Fabrication of nanoscale photochromic materials by vapor deposition method

Vapor deposition method was used to obtain nanocrystals of N-(3,5-di-tert-butylsalicylidene)-4-aminopyridine (1) and N-(3,5-di-tert- butylsalicylidene)-4-iodoaniline (2), and nanoscale thin layers (65 nm thick) of cis-1,2-dicyano-1,2-bis(2,4,5-trimethyl-3-thienyl)ethene (3). Compound 3 was also deposited on a substrate previously covered by gold nanoparticles (Ø = 100nm). Nanoscale crystals of 1 and 2 showed similarities with bulk crystals: they exhibit photochromic properties and they have similar shapes according to Atomic force microscopy (AFM) investigations. The thin layers of 3, with and without gold nanoparticles, showed light-induced absorption change in the visible.