title: Synthesis, spectroscopy and photochemistry of nitro-azobenzene dyes bearing benzophenone parts.
abstract: Novel nitro-azobenzene dyes bearing one or two benzophenone branches were proposed and synthesized to improve their photophysical and photochemical properties. The new dyes exhibited double UV/visible bands, and they displayed weak fluorescence emission as excited at 350 nm. Single crystal X-ray diffraction data showed that two phenyl rings of azobenzene was almost coplanar, and the benzophenone part was neither coplanar nor linear connection with azobenzene via ether bridged bond, which have good fit with molecular geometry optimization calculation results. The cyclic voltammeric results of nitro-azobenzene dyes were firstly reported in this paper, which demonstrated that the electrochemical properties of nitro-azobenzene dyes was altered by the substitution of benzophenone part. Thermal stabilities of the new dyes were studied by the analysis of differential scanning calorimetry (DSC) and thermograving (TG) in this paper. Efficient visible-light photoinitiating polymerization of methyl methacrylate (MMA) by the novel nitro-azobenzene dyes was presented and discussed.
authors.affiliation: College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China. fanggao1971@gmail.com
authors.forename: Fang
authors.initials: F
authors.lastname: Gao
authors.forename: Jianchao
authors.initials: J
authors.lastname: Wang
authors.forename: XiaoJiao
authors.initials: X
authors.lastname: Liu
authors.forename: Long
authors.initials: L
authors.lastname: Yang
authors.forename: Nvdan
authors.initials: N
authors.lastname: Hu
authors.forename: Ting
authors.initials: T
authors.lastname: Xie
authors.forename: Hongru
authors.initials: H
authors.lastname: Li
authors.forename: Shengtao
authors.initials: S
authors.lastname: Zhang
mesh_terms: D001391:Azo Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D055668:Photochemical Processes; D011108:Polymers / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D001391:Azo Compounds; D005456:Fluorescent Dyes; D011108:Polymers; C034531:4-nitroazobenzene