TY - JOUR
T1 - Photochemistry of Metal-Metal Bonded Complexes. II. The Photochemistry of Rhenium and Manganese Carbonyl Complexes Containing a Metal-Metal Bond
AU - Wrighton, Mark S.
AU - Ginley, David S.
PY - 1975/4/1
Y1 - 1975/4/1
N2 - The photochemistry of Mn2(CO)10, Mn2(CO)9PPh3, Mn2(CO)8(PPh3)2, Re2(CO)10, and MnRe(CO)10, I, II, III, IV, and V, respectively, is reported. Photolysis at 366 nm of I-V in CCU yields the corresponding mononuclear metal carbonyl chloride with high (∼0.5) quantum efficiencies and with stoichiometries consistent with symmetrical metal-metal bond cleavage. Photolysis of I, IV, or V in the presence of ∼10-3 M I2 yields the expected M(CO)sI species with an essentially quantitative chemical yield and quantum yields comparable to those for reaction in pure CCl4. Photolysis of I or IV in the presence of PhCH2Cl or PH3CCI gives good yields of bibenzyl or PH3C· radicals, respectively. Complexes I and IV are formed in ∼1:1 yield upon flash photolysis of V; I and III are formed in —-1:1 yield upon flash photolysis of II in pure isooctane; and V is formed from the photolysis of a mixture of I and IV. Complex III is found to be the principal primary photoproduct upon 366-nm photolysis of I in isooctane solutions of 0.1 PPH3. All of the observed photochemistry can be interpreted as arising from homolytic metal-metal bond cleavage occurring from an excited state derived from σb → σ* oneelectron transition associated with the metal-metal bond. Each of I-V exhibits a near-uv absorption corresponding to this transition.
AB - The photochemistry of Mn2(CO)10, Mn2(CO)9PPh3, Mn2(CO)8(PPh3)2, Re2(CO)10, and MnRe(CO)10, I, II, III, IV, and V, respectively, is reported. Photolysis at 366 nm of I-V in CCU yields the corresponding mononuclear metal carbonyl chloride with high (∼0.5) quantum efficiencies and with stoichiometries consistent with symmetrical metal-metal bond cleavage. Photolysis of I, IV, or V in the presence of ∼10-3 M I2 yields the expected M(CO)sI species with an essentially quantitative chemical yield and quantum yields comparable to those for reaction in pure CCl4. Photolysis of I or IV in the presence of PhCH2Cl or PH3CCI gives good yields of bibenzyl or PH3C· radicals, respectively. Complexes I and IV are formed in ∼1:1 yield upon flash photolysis of V; I and III are formed in —-1:1 yield upon flash photolysis of II in pure isooctane; and V is formed from the photolysis of a mixture of I and IV. Complex III is found to be the principal primary photoproduct upon 366-nm photolysis of I in isooctane solutions of 0.1 PPH3. All of the observed photochemistry can be interpreted as arising from homolytic metal-metal bond cleavage occurring from an excited state derived from σb → σ* oneelectron transition associated with the metal-metal bond. Each of I-V exhibits a near-uv absorption corresponding to this transition.
UR - https://www.scopus.com/pages/publications/0001366582
U2 - 10.1021/ja00841a012
DO - 10.1021/ja00841a012
M3 - Article
AN - SCOPUS:0001366582
SN - 0002-7863
VL - 97
SP - 2065
EP - 2072
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 8
ER -