TY - JOUR
T1 - Comparison of thermodynamic and kinetic aspects of oxidative addition of PhE-EPh (E = S, Se, Te) to Mo(CO)3(PR3)2, W(CO)3(PR3)2, and Mo(N[tBu]Ar) 3 complexes. The role of oxidation state and ancillary ligands in metal complex induced chalcogenyl radical generation
AU - McDonough, James E.
AU - Weir, John J.
AU - Sukcharoenphon, Kengkaj
AU - Hoff, Carl D.
AU - Kryatova, Olga P.
AU - Rybak-Akimova, Elena V.
AU - Scott, Brian L.
AU - Kubas, Gregory J.
AU - Mendiratta, Arjun
AU - Cummins, Christopher C.
PY - 2006/8/9
Y1 - 2006/8/9
N2 - Enthalpies of oxidative addition of PhE-EPh (E = S, Se, Te) to the M(0) complexes M(PiPr3)2- (CO)3 (M = Mo, W) to form stable complexes M(•EPh)(Pir 3)2(CO)3 are reported and compared to analogous data for addition to the Mo(III) complexes Mo(N[tBu]Ar)3 (Ar = 3,5-C6H3Me2) to form diamagnetic Mo(IV) phenyl chalcogenide complexes Mo(N[tBu]Ar)3(EPh). Reactions are increasingly exothermic based on metal complex, Mo(P iPr3)2(CO)3 < W(P iPr3)2(CO)3 < Mo(N[ tBu]Ar)3, and in terms of chalcogenide, PhTe-TePh < PhSe-SePh < PhS-SPh. These data are used to calculate L0M-EPh bond strengths, which are used to estimate the energetics of production of a free •EPh radical when a dichalcogenide interacts with a specific metal complex. To test these data, reactions of Mo(N[tBu]Ar) 3 and Mo(PiPr3)2(CO)3 with PhSe-SePh were studied by stopped-flow kinetics. First- and second-order dependence on metal ion concentration was determined for these two complexes, respectively, in keeping with predictions based on thermochemical data. ESR data are reported for the full set of bound chalcogenyl radical complexes (PhE •)M(PiPr3)2(CO)3; g values increase on going from S to Se, to Te, and from Mo to W. Calculations of electron densities of the SOMO show increasing electron density on the chalcogen atom on going from S to Se to Te. The crystal structure of W( •TePh)(PiPr3)2(CO)3 is reported.
AB - Enthalpies of oxidative addition of PhE-EPh (E = S, Se, Te) to the M(0) complexes M(PiPr3)2- (CO)3 (M = Mo, W) to form stable complexes M(•EPh)(Pir 3)2(CO)3 are reported and compared to analogous data for addition to the Mo(III) complexes Mo(N[tBu]Ar)3 (Ar = 3,5-C6H3Me2) to form diamagnetic Mo(IV) phenyl chalcogenide complexes Mo(N[tBu]Ar)3(EPh). Reactions are increasingly exothermic based on metal complex, Mo(P iPr3)2(CO)3 < W(P iPr3)2(CO)3 < Mo(N[ tBu]Ar)3, and in terms of chalcogenide, PhTe-TePh < PhSe-SePh < PhS-SPh. These data are used to calculate L0M-EPh bond strengths, which are used to estimate the energetics of production of a free •EPh radical when a dichalcogenide interacts with a specific metal complex. To test these data, reactions of Mo(N[tBu]Ar) 3 and Mo(PiPr3)2(CO)3 with PhSe-SePh were studied by stopped-flow kinetics. First- and second-order dependence on metal ion concentration was determined for these two complexes, respectively, in keeping with predictions based on thermochemical data. ESR data are reported for the full set of bound chalcogenyl radical complexes (PhE •)M(PiPr3)2(CO)3; g values increase on going from S to Se, to Te, and from Mo to W. Calculations of electron densities of the SOMO show increasing electron density on the chalcogen atom on going from S to Se to Te. The crystal structure of W( •TePh)(PiPr3)2(CO)3 is reported.
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U2 - 10.1021/ja063250+
DO - 10.1021/ja063250+
M3 - Article
C2 - 16881661
AN - SCOPUS:33746889433
VL - 128
SP - 10295
EP - 10303
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 31
ER -