341495-00-9Relevant academic research and scientific papers
Photoactive Platinum(II) Azopyridine Complexes?
Farley, Sarah J.,Salassa, Luca,Pizarro, Ana M.,Sadler, Peter J.
, p. 92 - 101 (2022)
Platinum(II) complexes containing the strong π-acceptor N,N-chelating ligand phenylazopyridine (Ph-azpy) [Pt(p-R-Ph-azpy)X2], R = H, NMe2 or OH, X = Cl or N3, have been synthesized and characterized to explore the effects of monodentate ligands and phenyl substituents on their absorption spectra and photoactivation. Time-dependent density functional theory calculations showed that the complexes have a low-lying unoccupied orbital with strong σ-antibonding character toward the majority of the coordination bonds. The UV–visible absorption bands were assigned as mainly ligand-centered or metal-to-ligand charge-transfer transitions, with strong contributions from the chlorido and azido groups. In complexes with substituted Ph-azpy ligands, σ-donation from NMe2 and OH/O– groups results in a redshift of the main absorption bands compared with unsubstituted Ph-azpy complexes. The diazido complexes are photoactive in solution upon irradiation with either UVA or visible light for R = H or NMe2, or UVA only when R = OH/O–. Intriguingly, the phenolate group of the latter complex undergoes very slow protonation in solution. Biological screening was limited by poor solubility; however, initial tests showed that the phenolato diazido complex is rapidly taken up into the nuclei of HaCaT keratinocytes, which are stained intensely blue, and its cytotoxicity is increased upon irradiation with UVA light.
Structures, redox and spectroscopic properties of PdII and PtII complexes containing an azo functionality
Roy, Sayak,Hartenbach, Ingo,Sarkar, Biprajit
, p. 2553 - 2558 (2009/12/02)
The complexes [PdCl2(pap)] (1) and [PtCl2(pap)] (2; pap = 2-phenylazopyridine) were synthesized, by treating PdCl2 or K 2PtCl4, respectively, with pap and characterized by 1HNMR spectroscopy and eleme
Platinum complexes of diazo ligands. Studies of regioselective aromatic ring amination, oxidative halogen addition and reductive halogen elimination reactions
Panda, Manashi,Das, Srijit,Mostafa, Golam,Castineiras, Alfonso,Goswami, Sreebrata
, p. 1249 - 1255 (2007/10/03)
2-(Arylazo)pyridine ligands, L1a-1c react with the salt K 2[PtCl4] to give the mononuclear complexes [PtCl 2(L1)] (1), which readily react with ArNH2 to yield the monochloro complexes of ty
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.
