title: The spectroscopic characterization, photochromism of cadmium(II)-iodo complexes of 1-alkyl-2-(arylazo)imidazoles and DFT computation of representative complexes.
abstract: [Cd(Raai-C(n)H(2n+1))(μ-I)I]2 and [Cd(Raai-C(n)H(2n+1))2I2] are synthesized by the reaction of CdI2 with 1-alkyl-2-(arylazo)imidazole (Raai-C(n)H(2n+1), n=4, 6, 8) in MeOH in 1:1 and 1:2 M ratio of salt and ligands, respectively. The complexes have been characterized by spectral data (UV-Vis, IR, (1)H NMR, Mass). The coordinated Raai-C(n)H(2n+1) shows photochromism, E(trans)-to-Z(cis) isomerisation, upon UV light irradiation. The reverse process, Z-to-E, is very slow in visible light irradiation process while the reaction is sensitive to change of reaction temperature. The quantum yields (ϕE→Z) for E-to-Z and the activation energy (Ea) of Z-to-E isomerisation are calculated and found that the complexes show subordinate results compared to free ligand. DFT computations of two representative complexes were carried out to explain the spectral and photochromic phenomena.
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
authors.forename: Chandana
authors.initials: C
authors.lastname: Sen
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
authors.forename: Avijit
authors.initials: A
authors.lastname: Nandi
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
authors.forename: Debashis
authors.initials: D
authors.lastname: Mallick
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
authors.forename: Sudipa
authors.initials: S
authors.lastname: Mondal
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India.
authors.forename: Kamal Krishna
authors.initials: KK
authors.lastname: Sarker
authors.affiliation: Department of Chemistry, Inorganic Chemistry Section, Jadavpur University, Kolkata 700 032, India. Electronic address: c_r_sinha@yahoo.com.
authors.forename: Chittaranjan
authors.initials: C
authors.lastname: Sinha
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D060733:Electromagnetic Radiation; D006358:Hot Temperature; D007093:Imidazoles / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D055668:Photochemical Processes; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014466:Ultraviolet Rays
chemical_list: D007093:Imidazoles; D008024:Ligands; D002104:Cadmium; D007455:Iodine
keywords: Activation energy; Arylazoimidazoles; Cadmium(II); DFT computation; Photochromism; Quantum yield