Syntheses, structures and electrochemical study of π-acetylene complexes of cobalt
摘要:
The preparation and characterisation of the complexes [Co-2(CO)(4)(PMe3)(2)][Co-2(CO)(6)](Me3SiC2C2SiMe3) (4), [Co-2(CO)(4)(dppm)] [Co-2(CO)(6)](Me3SiC2C2H) (5), [Co-2(CO)(4)(dppa)][Co-2(CO)(6)](Me3SiC2C2SiMe3) (6), [Co-2(CO)(4)(dppm)](2) [Co-2(CO)(6)](Me(3)SiC(2)Cdrop CC2C2SiMe3) (7) and [{SiMe3(Co-2(CO)(4)(dppm))C-2}(2)(HCdropC)(1,3,5-C6H3)] (8) are described. An electrochemical study of the complexes 5-8 and of the related [Co-2(CO)(4)(dppm)](2)(Me3SiC2-(CdropC)(2)C2SiMe3) (1), [Co-2(CO)(4)(dppa)](2)(Me3SiC2C2SiMe3) (2) and [{SiMe3(Co-2(CO)(4)(dppm))C-2}(HCdropC)(2)(1,3, 5-C6H3)] (3) is presented by means of the cyclic and square-wave voltammetry techniques. Crystals of 8 suitable for single-crystal X-ray diffraction were grown and the molecular structure of this compound is discussed. (C) 2003 Elsevier B.V. All rights reserved.
Alkynyl cobalt complexes. An electrochemical study
摘要:
The preparation and characterisation of the complexes Co-2(CO)(5)(PMe3)(mu-eta (2)-Me3SiC2C=CSiMe3) (2) and Co-2(CO)(4)(PMe3)(2)(mu-eta (2)-Me3SiC2C=CSiMe3) (3) are described. A comparative electrochemical study of the complexes Co-2(CO)(6-n)L-n(mu-eta (2)-Me3SiC2C=CSiMe3) (n = 0 (1); n = 1, L = PMe3 (2); n = 2, L = PMe3 (3), PPh2Me (4), dppa (5), dppm (6)) is presented by means of the cyclic and square-wave voltammetry techniques. Substitution of CO by phosphine ligands transforms the Co2C2 redox centre from a readily reducible to an easily oxidisable centre and contributes to the stabilisation of the Go-Co bond increasing the lifetime of the radical cations and anions. (C) 2001 Elsevier Science B.V. All rights reserved.