REDUCTIVE QUENCHING OF NOVEL MIXED-LIGAND TRIS(BIPYRIDYL)RUTHENIUM(II) COMPLEXES IN AQUEOUS-SOLUTION AND INERT COLLOIDAL SUSPENSIONS

被引:35
作者
KELLY, LA [1 ]
RODGERS, MAJ [1 ]
机构
[1] BOWLING GREEN STATE UNIV,CTR PHOTOCHEM SCI,BOWLING GREEN,OH 43403
关键词
D O I
10.1021/j100076a023
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The reductive quenching of the lowest energy electronically excited state of four mixed-ligand tris(bipyridyl)ruthenium(II) complexes by anionic ascorbate and N-phenylglycine electron donors was investigated in aqueous solution at pH greater than or equal to 5.0. The central ruthenium(II) metal atom is coordinated to either two 2,2'-bipyridine (bpy) or two 4,4'-dicarboxy-2,2'-bipyridine (dcbpy) ligands to render the complexes a net 2+ ([Ru(bpy)(2)(L)](2+)) or 2- ([Ru(dcbpy)(2)(L)](2-)) charge. Reductive quenching was found to proceed with a larger bimolecular rate constant (k(q) = 1.2-7.4 x 10(8) M(-1) s(-1)) than that previously measured for the quenching of the parent Ru(bpy)(3)(2+) by ascorbate. Moderate yields (phi(ce), = 0.20-0.40) of the reduced metal complex were formed in the process. The reductive quenching of the dianionic complexes in homogeneous solution was compared with that in suspensions (pH 5.0) of inert colloidal alumina-coated silica particles, where both:the anionic donor and the chromophore are coadsorbed to the cationic particles. The apparent bimolecular rate constants were found to be enhanced by more than 1 order of magnitude in these colloidal systems, with a concomitant decrease in the yield of redox products escaping from the solvent cage.
引用
收藏
页码:6377 / 6385
页数:9
相关论文
共 38 条
[1]  
AMOUYAL E, 1989, NEW J CHEM, V13, P501
[2]  
BARD AJ, 1985, STANDARD POTENTIALS, P408
[3]  
BEVINGTON PR, 1969, DATA REDUCTION ERROR, pCH11
[4]   MECHANISM OF DISPROPORTIONATION OF ASCORBATE RADICALS [J].
BIELSKI, BHJ ;
ALLEN, AO ;
SCHWARZ, HA .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1981, 103 (12) :3516-3518
[5]   HOMOGENEOUS CATALYSIS OF THE PHOTO-REDUCTION OF WATER BY VISIBLE-LIGHT - MEDIATION BY A TRIS(2,2'-BIPYRIDINE)RUTHENIUM(II)-COBALT(II) MACROCYCLE SYSTEM [J].
BROWN, GM ;
BRUNSCHWIG, BS ;
CREUTZ, C ;
ENDICOTT, JF ;
SUTIN, N .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1979, 101 (05) :1298-1300
[6]   EXCITED-STATE PHOTOCHEMISTRY IN THE TRIS(2,2'-BIPYRIDINE)RUTHENIUM(II)-SULFITE SYSTEM [J].
CREUTZ, C ;
SUTIN, N ;
BRUNSCHWIG, BS .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1979, 101 (05) :1297-1298
[7]   ONE-ELECTRON REDUCTION OF RUTHENIUM(II)-DIIMINE COMPLEXES - CHARACTERIZATION OF REDUCED SPECIES CONTAINING 2,2'-BIPYRIDINE, 2,2'-BIPYRIMIDINE, AND 2,2'-BIPYRAZINE IN AQUEOUS-SOLUTION [J].
DANGELANTONIO, M ;
MULAZZANI, QG ;
VENTURI, M ;
CIANO, M ;
HOFFMAN, MZ .
JOURNAL OF PHYSICAL CHEMISTRY, 1991, 95 (13) :5121-5129
[8]   PHOTOINDUCED ELECTRON-TRANSFER REACTIONS OF TRANSITION-METAL COMPLEXES WITH AMINES - MECHANISTIC STUDIES OF ALTERNATE PATHWAYS TO BACK ELECTRON-TRANSFER [J].
DELAIVE, PJ ;
FOREMAN, TK ;
GIANNOTTI, C ;
WHITTEN, DG .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1980, 102 (17) :5627-5631
[9]   *UBER DIE KINETIK SEHR SCHNELL VERLAUFENDER IONENREAKTIONEN IN WASSERIGER LOSUNG [J].
EIGEN, M .
ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-FRANKFURT, 1954, 1 (3-4) :176-200
[10]   ELECTRON-TRANSFER REACTIONS MEDIATED BY ACRIDINE TRIPLET-STATE IN AQUEOUS-SOLUTIONS - TRIPLET ENERGY-TRANSFER FROM RU(BIPY)3(2+) AND PHOTOSENSITIZED ELECTRON-TRANSFER FROM PARA-SUBSTITUTED PHENOLS TO METHYL VIOLOGEN [J].
FORD, WE ;
RODGERS, MAJ .
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 1991, 59 (01) :73-80