Cyclic voltammetric studies of clusters(C_6H_5-C_2C_6 H_4-R-p)Co_2(CO)_(6-n) L_n[n=0,2; L=PPh_3,P(OEt)_3] and(RCH_2C)_2Co_2(CO_4)(PPh_3)_2 on Pt electrode are described. The primary reduction(0/-1)and oxidation (+1/0)...Cyclic voltammetric studies of clusters(C_6H_5-C_2C_6 H_4-R-p)Co_2(CO)_(6-n) L_n[n=0,2; L=PPh_3,P(OEt)_3] and(RCH_2C)_2Co_2(CO_4)(PPh_3)_2 on Pt electrode are described. The primary reduction(0/-1)and oxidation (+1/0) steps are considered as a mono-electron process for all clusters. For the clusters (C_6H_5C_2C_6H_4-R-P)Co_2(CO)_6, a good linear relation between reduction poten- tial EF_p^(red) and Hammett constant σp of R in the clusters is found. For the clusters(RC_2R′)Co_2(CO)_4L_2, their radical anions are extremely unstable at room temperature and fragment into a series of mono- nuclear species, one of which is(RC-3R′)Co(CO)_2PPh_3. The reaction of radical anions of (RC_2R’)- Co_2(CO)_(6-n) (PPh_3)_n(n=0,2) with PPh_3 also produces mononuclear species (RC_2R’)Co(CO)_2PPh_3 which has been detected by means of cyclic voltammetry and ESR. The influence of R on redox pro- perties of clusters is discussed.展开更多
基金This project was supported by the National Natural Science Foundation of China as an item of major project.
文摘Cyclic voltammetric studies of clusters(C_6H_5-C_2C_6 H_4-R-p)Co_2(CO)_(6-n) L_n[n=0,2; L=PPh_3,P(OEt)_3] and(RCH_2C)_2Co_2(CO_4)(PPh_3)_2 on Pt electrode are described. The primary reduction(0/-1)and oxidation (+1/0) steps are considered as a mono-electron process for all clusters. For the clusters (C_6H_5C_2C_6H_4-R-P)Co_2(CO)_6, a good linear relation between reduction poten- tial EF_p^(red) and Hammett constant σp of R in the clusters is found. For the clusters(RC_2R′)Co_2(CO)_4L_2, their radical anions are extremely unstable at room temperature and fragment into a series of mono- nuclear species, one of which is(RC-3R′)Co(CO)_2PPh_3. The reaction of radical anions of (RC_2R’)- Co_2(CO)_(6-n) (PPh_3)_n(n=0,2) with PPh_3 also produces mononuclear species (RC_2R’)Co(CO)_2PPh_3 which has been detected by means of cyclic voltammetry and ESR. The influence of R on redox pro- perties of clusters is discussed.
