title: Tuning the Electronic Properties of 2-Cyano-3-phenylacrylamide Derivatives.
abstract: We are the first to report the synthesis of a new class of 2-cyanoarylacrylamide (2-CAA) derivatives and observe that the synthesized 2-CAA shows fluorescence properties due to the formation of a dimeric interaction of hydrogen bonds between carbonyl oxygens and amide hydrogens (C═O···H-N-C═O···H-N···); i.e., dimers are linked through dimeric N-H···O hydrogen bonds. The single-crystal X-ray structure shows molecules to be hydrogen-bonded dimers, which further form a parallel stacking arrangement, mediated by significant π-π interactions. The (1)H NMR and fluorescence spectral studies indicate the coexistence of amide and iminol tautomers in solution, which can be influenced by the nature of the solvent. Further, the excitation-wavelength-dependent fluorescence spectrum and the biexponential fluorescence decay profiles suggest the presence of more than one emitting species; i.e., amide and iminol tautomers coexists in solution. We have also shown that the equilibrium between the two tautomers can be tuned by the judicious choice of electron-donating or -withdrawing substituents.
authors.affiliation: Chemistry Division, School of Advanced Sciences, VIT University , Vellore 632014, India.|Research Center for Materials Science and the Department of Chemistry, Nagoya University , Chikusa, Nagoya 464-8602, Japan.
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Gunasekar
authors.affiliation: Chemical Laboratory, CSIR-Central Leather Research Institute , Adyar, Chennai 600020, India.
authors.forename: Pichandi
authors.initials: P
authors.lastname: Thamaraiselvi
authors.affiliation: Department of Biotechnology, School of Life Sciences, University of Hyderabad , Hyderabad 500046, India.
authors.forename: Ravindranath S
authors.initials: RS
authors.lastname: Rathore
authors.affiliation: Chemistry Division, School of Advanced Sciences, VIT University , Vellore 632014, India.
authors.forename: Kulathu Iyer
authors.initials: KI
authors.lastname: Sathiyanarayanan
authors.affiliation: Chemical Laboratory, CSIR-Central Leather Research Institute , Adyar, Chennai 600020, India.
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Easwaramoorthi