title: J-aggregates in matrix stabilized two-dimensional azobenzene derivatives.
abstract: A two-component film technique at the air-water interface has been used for fabricating matrix stabilized azobenzene J-aggregates. Langmuir monolayers of (E)-1-(3-chloro-4-(alkyloxy)phenyl)-2-phenyldiazene (CnCD, n=8,10,12) have been prepared with stearic acid (STA) as the two-dimensional matrix. Miscibility studies at a molecular level, explored from the monolayer pressure-area isotherms revealed a phase separation of the CnCD from the stearic acid matrix at a compression pressure of 10 mN/m. A 43-nm strong red shift in the 350 nm pi-pi * absorption feature implied formation of highly ordered J-aggregates of CnCDs in conformity with atomic force microscopy and micro-Raman spectral characteristics. While a one-component CnCD failed to form a 2D monolayer, the STA supported CnCD binary system crossed a mixed monolayer phase followed by compression, leading to the formation of matrix stabilized CnCD J-aggregates.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India.
authors.forename: B Vijai
authors.initials: BV
authors.lastname: Shankar
authors.forename: Archita
authors.initials: A
authors.lastname: Patnaik
mesh_terms: D000388:Air; D001391:Azo Compounds / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D010316:Particle Size; D012995:Solubility; D013229:Stearic Acids / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001391:Azo Compounds; D013229:Stearic Acids; D014867:Water; C031183:stearic acid; C009850:azobenzene