341495-45-2Relevant academic research and scientific papers
Synthesis, spectral characterization and electrochemical studies of mixed-ligand complexes of platinum(II) with 2-(arylazo)pyridines and catechols. Single-crystal X-ray structure of dichloro{2-(phenylazo) pyridine}platinum(II)
Rauth, Goutam Kumar,Pal, Sanjib,Das, Debasis,Sinha, Chittaranjan,Slawin, Alexander M.Z.,Woollins
, p. 363 - 372 (2008/10/08)
The reaction of 2-(arylazo)pyridines, RH4C6N=NC5H4N (aap, 1 where R = H (pap). p-Me (p-tap). p-Cl (p-Clpap)) with K2PtCl4 in 1:2 boiling acetonitrile - water affords orange - red complexes of the type Pt(aap)Cl2 (2). The IR spectrum shows two r(Pt-Cl) stretches suggesting cis-PtCl2 configuration. The structural confirmation was carried out by an X-ray diffraction study of Pt(pap)Cl2 (2a). The addition of catechols to a chloroform-methanol solution of Pt(aap)Cl2 in the presence of Et3N yielded green colored mixed-ligand complexes of the formula Pt(aap)(O,O) (O,O = catecholate (cat) (3), 4-tert-butylcatecholate (tbcat), (4), 3,5-di-tert-butylcatecholate (dtbcat) (5) and tetrachlorocatecholate (tccat) (6)). The complexes were characterized by elemental analyses, IR, UV - Vis - NIR and 1H NMR spectral data. Electronic spectra exhibit a ligand-ligand charge transfer (LLCT) transition at NIR region: the position and symmetry of the band depend on the type of substituent on the catechol frame. This is qualitatively assigned as 3b1(cat) → π*(aap) transition. Cyclic voltammogram of the complexes show four successive redox responses: two couples positive to SCE are referred to as oxidation of catechol to semiquinone and semiquinone to quinone, respectively and two couples negative to SCE correspond to azo reductions.
