Synthesis and characterization of CpMn(dfepe)(L) complexes (dfepe=(C2F5)2PCH2CH2P(C2F5)2; L=CO, H2, N2): an unusual example of a dihydride to dihydrogen photochemical conversion
摘要:
The synthesis and properties of perfluoroalkylphosphine manganese complexes CpMn(dfepe)(L) (dfepe = (C2F5)(2)-PCH2CH2P(C2F5)(2); L = CO, H-2, N-2) are reported. CpMn(dcepe)(CO) (1) was prepared by treatment of CpMn(CO)(2)(thf) with excess dfepe. The observed v(CO) (1934 cm(-1)) and E-1/2(ox) (+1.09 V) values confirm the very electron-deficient nature of the CpMn(dfepe) moiety. Photolysis of 1 under a H-2 purge produced a 6:1 equilibrium isomeric mixture of the hydride complexes CpMn(dfepe)(H)2 (2a) and CpMn(dfepe)(eta(2)-H-2)(2b). Photolysis of a mixture of 2a and 2b in benzene resulted in complete conversion of 2a to 2b, which slowly thermally reconverted to an equilibrium mixture (k similar to 2.3 x 10(-4) s(-1)). The dihydrogen complex 2b reacts with N-2 gas to produce CpMn(dfepe)(N-2) (3) (v(N-2) = 2113 cm(-1)). Attempts to isolate 3 resulted in production of the corresponding N-2-bridged dimer, [CpMn(dfepe)](2)(mu-N-2) (4) (Raman: v(N-2) = 2015 cm(-1)). (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis and characterization of CpMn(dfepe)(L) complexes (dfepe=(C2F5)2PCH2CH2P(C2F5)2; L=CO, H2, N2): an unusual example of a dihydride to dihydrogen photochemical conversion
摘要:
The synthesis and properties of perfluoroalkylphosphine manganese complexes CpMn(dfepe)(L) (dfepe = (C2F5)(2)-PCH2CH2P(C2F5)(2); L = CO, H-2, N-2) are reported. CpMn(dcepe)(CO) (1) was prepared by treatment of CpMn(CO)(2)(thf) with excess dfepe. The observed v(CO) (1934 cm(-1)) and E-1/2(ox) (+1.09 V) values confirm the very electron-deficient nature of the CpMn(dfepe) moiety. Photolysis of 1 under a H-2 purge produced a 6:1 equilibrium isomeric mixture of the hydride complexes CpMn(dfepe)(H)2 (2a) and CpMn(dfepe)(eta(2)-H-2)(2b). Photolysis of a mixture of 2a and 2b in benzene resulted in complete conversion of 2a to 2b, which slowly thermally reconverted to an equilibrium mixture (k similar to 2.3 x 10(-4) s(-1)). The dihydrogen complex 2b reacts with N-2 gas to produce CpMn(dfepe)(N-2) (3) (v(N-2) = 2113 cm(-1)). Attempts to isolate 3 resulted in production of the corresponding N-2-bridged dimer, [CpMn(dfepe)](2)(mu-N-2) (4) (Raman: v(N-2) = 2015 cm(-1)). (C) 2004 Elsevier Ltd. All rights reserved.