Dimerisation and reactivity of HCtriple bond; length of mdashCCtriple bond; length of mdashCFc at ruthenium centres

In contrast to the simple diynyl complexes formed in reactions between HCtriple bond; length of mdashCCtriple bond; length of mdashCFc and MCl(dppe)Cp∗; (M = Fe, Ru), an analogous reaction with RuCl(PPh3)2Cp∗; in the presence of KPF6 and dbu resulted in dimerisation of the diyne at the Ru centre to afford a mixture of [Ru{η1,η2-C(Ctriple bond; length of mdashCFc)double bond; length as m-dashC(L)CHdouble bond; length as m-dashCCdouble bond; length as m-dashCHFc}(PPh3)Cp∗]PF6 (L = dbu 1, PPh32). Similar reactions with RuCl(PR3)2L gave [Ru{η1,η2-C(Ctriple bond; length of mdashCFc)double bond; length as m-dashC(dbu)CHdouble bond; length as m-dashCCdouble bond; length as m-dashCHFc}(PR3)L]PF6 (L = Cp, R = Ph 3, m-tol 4; L = η5-C9H7, R = Ph 5). The reaction between 3 and I2, followed by crystallization of the paramagnetic product from MeOH, afforded the dicationic [Ru{C(Ctriple bond; length of mdashCFc)C(dbu)CHdouble bond; length as m-dashC(OMe)C(OMe)double bond; length as m-dashCHFc}(PPh3)Cp](I3)26. The molecular structures of 2·2CH2Cl2 and 6.S (S = 2CH2Cl2, C6H6) were determined by single-crystal XRD studies.