title: Effect of solvent hydrogen bonding on the photophysical properties of intramolecular charge transfer probe trans-ethyl p-(dimethylamino) cinamate and its derivative.
abstract: Intramolecular charge transfer (ICT) behavior of trans-ethyl p-(dimethylamino) cinamate (EDAC) and 4-(dimethylamino) cinnamic acid (DMACA) were studied by steady state absorption and emission, picosecond time-resolved fluorescence experiments in various pure and mixed solvent systems. The large fluorescence spectral shift in more polar solvents indicates an efficient charge transfer from the donor site to the acceptor moiety in the excited state compared to the ground state. The energy for 0,0 transition (nu(0,0)) for EDAC shows very good linear correlation with static solvent dielectric property; however, fluorescence emission maximum, stokes shift and fluorescence quantum yield show significant deviation from linearity in polar protic solvents, indicating a large contribution of solvent hydrogen bonding on the excited state relaxation mechanism. A quantitative estimation of contribution from different solvatochromic parameters was made using linear free energy relationship based on Kamlet-Taft equation.
authors.affiliation: Department of Chemistry, North-Eastern Hill University, Shillong 793022, India.
authors.forename: T Sanjoy
authors.initials: TS
authors.lastname: Singh
authors.forename: N S
authors.initials: NS
authors.lastname: Moyon
authors.forename: Sivaprasad
authors.initials: S
authors.lastname: Mitra
mesh_terms: D002934:Cinnamates / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D010777:Photochemistry; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
chemical_list: C481008:4-(dimethylamino)cinnamic acid; D002934:Cinnamates; D005456:Fluorescent Dyes; D012997:Solvents; C522564:ethyl 4-(dimethylamino)cinnamate