Oxidation behaviour of the unsaturated diruthenium species [Ru2(µsb-CO)2(CO)2{µ-(PriO)2PNEtP(OPri)2}2]
摘要:
Treatment of the formally unsaturated species [Ru-2(mu(sb)-CO)(2)(CO)(2)(mu-etipdp)(2)][sb = semi-bridging, etipdp = ((PrO)-O-i)(2)PNEtP(OPri)(2)] with silver (1) salts such as AgSbF6 or AgBF4 In MeCN or PhCN led directly to the formation of the disolvated species [Ru-2(CO)(4)(RCN)(2)(mu-etipdp)(2)]X(2) (R = Me or Ph; X = SbF6 or BF4), with no intermediates being detected. In contrast, as established spectroscopically, oxidation of this complex with silver(I) salts-in very weakly co-ordinating solvents such as acetone or methanol afforded silver adducts of the parent species. Also, reaction with the electron acceptor tcnq (7,7,8,8-tetracyano-p-quinodimethane) in tetrahydrofuran (thf) gave the electron-transfer salt [Ru-2(eta(1)-tcnq)(CO)(4)(thf)(mu-etipdp)(2)][tcnq], while with p-chloranil (tetrachloro-1,4-benzoquinone) produced [Ru-2(mu-Cl)(CO)(4)(mu-etipdp)(2)][p-OC6Cl4O](2) as a consequence of the benzoquinone functioning as a chlorinating agent as well as an electron acceptor. Cyclic voltammograms of [Ru-2(mu(sb)-CO)(2)(CO)(2)(mu etipdp)(2)] and [Ru-2(CO)(4)(RCN)(2)(mu-etipdp)(2)][SbF6](2) (R = Me or Ph) have been measured in both aceto- and benzo-nitrile and are readily interpreted in terms of the redox process [Ru-2(mu(sb)-CO)(2)(CO)(2)(mu-etipdp)(2)] + 2RCN (2e)reversible arrow(-2e) [Ru-2(CO)(4)(RCN)(2)(mu-etipdp)(2)](2+). The structure of the acetonitrile species [Ru-2(CO)(4)(MeCN)(2)(mu-etipdp)(2)][BF4](2) . CH2Cl2 has been determined X-ray crystallographically.