V. Catalano, R. Kurtaran, Ryan A Heck
Mar 15, 1999
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0
Influential Citations
24
Citations
Journal
Inorganica Chimica Acta
Abstract
The complexes, [Ru(bdmpp)(bpy)Cl](PF 6 ) ( 1a ), [Ru(bdmpp)(phen)Cl](PF 6 ) ( 2a ), and [Ru(bdmpp)(Me 2 bpy)Cl](PF 6 ) ( 3a ) (where bdmpp is 2,6-bis(3,5-dimethyl- N -pyrazoyl)pyridine, bpy is 2,2′-bipyridine, phen is 1,10-phenanthroline and Me 2 bpy is 4,4′-dimethyl-2,2′-dipyridyl) were synthesized and characterized by 1 H NMR, electronic absorption spectroscopy and cyclic voltammetry. 1a and 3a were also characterized by X-ray crystallography. The chloride salt of 1a , [Ru(bdmpp)(bpy)Cl]Cl · 1.25CHCl 3 , crystallizes in the monoclinic space group P 2 1 / n with Z =4, a =13.551(2), b =8.556(1), c =29.994(3) A, β =100.28(1)°, V =3421.8(7) A 3 with 4486 unique data yielding R 1 =0.0715 ( I >2 σ ( I )). The chloride salt of 3a crystallizes in the triclinic space group P with 1.25 chloroform solvate and a =8.656(1), b =10.685(2), c =18.729(3) A, α =94.394(6), β =99.72(1), γ =98.61(1)°, V =1679.0(4) A 3 , Z =2, and R 1 =0.066 ( I >2 σ ( I )) with 4403 unique reflections. Compounds 1a , 2a , and 3a are converted to their corresponding aqua complexes, 1b , 2b , and 3b upon treatment with aqueous silver ion, and to the acetonitrile species, 1c , 2c , and 3c , by dissolution in acetonitrile. Cyclic voltammograms in acetonitrile of 1a , 2a , and 3a display one-electron oxidations at 0.72, 0.71, 0.63 V, respectively, consistent with a Ru(III/II) couple. Compounds 1b , 2b , and 3b show a pH independent couple at pH<2 and a pH dependent couple consistent with a one-electron, one-proton process at pH values from ca. 2 to 11. Past pH 11 this redox process becomes pH independent again, and the compounds become unstable. The one-electron nature was verified by bulk electrolysis and spectroelectrochemical measurements.