927669-22-5Relevant academic research and scientific papers
Molecular and electronic structure of square planar complexes [Pd II(tbpy)(LN,OIP)]0, [PdII(tbpy)(LN,OISQ](PF 6), and [PdII(tbpy)(LN,O IBQ](PF6)(BF4)·2CH2Cl 2
Kokatam, Swarna-Latha,Chaudhuri, Phalguni,Weyhermueller, Thomas,Wieghardt, Karl
, p. 373 - 378 (2007)
Three PdII complexes which are members of the same electron-transfer series have been synthesized. Refluxing of the reaction mixture containing equimolar amounts of PdCl2, 2-(2-trifluoromethyl) anilino-4,6-di-tert-butylphenol (H2LN,O), 4,4′-di-tert-butyl-2,2′-dipyridyl (tbpy), and 3 equiv of triethylamine in MeOH under an argon atmosphere followed by exposure to air and addition of KPF6 after cooling to room temperature yields reddish brown crystals of paramagnetic (S = 1/2) [Pd(LISQN,O)(tbpy)](PF 6) (2). Reaction of 2 with one equiv of [CoCp2] in dry and degassed CH2Cl2 using anaerobic conditions gives diamagnetic [Pd(LIPN,O)(tbpy)] (1), which is the one-electron reduced form of 2. One-electron oxidation of 2 in CH2Cl2 under argon with one equiv of NOBF4 affords diamagnetic [Pd(LIBQN,O)( tbpy)](PF6)(BF4)·2CH2Cl 2 (3). Complexes 1, 2, and 3 constitute three members of the same electron-transfer series. They are ideally suited to distinctly distinguish the geometrical and spectroscopic features of the N,O-coordinated, closed-shell, diamagnetic o-iminophenolate (LIPN,O)2-, the corresponding open-shell π-radical o-iminobenzosemiquinonate (LISQN,O)1- (Srad = 1/2), and the closed-shell o-iminobenzoquinone (LIBQN,O)0 forms. All complexes were characterized by X-ray crystallography (100 K), cyclic voltammetry, EPR, and UV-vis spectroscopy. Complex 2 exhibits three reversible electron transfer waves in the cyclic voltammogram. Structural characterization of complex 3 reveals an interesting strong ion pairing between the BF 4 anion and the complex dication with a short C-F distance of 2.7 A. The Royal Society of Chemistry.
