ETHYNYL AND BUTADIYNYL COMPLEXES OF IRON AND RUTHENIUM WITH TERMINAL MAIN-GROUP ELEMENT SUBSTITUENTS, CP-ASTERISK-FE(PH2PCH(X)CH2PPH2)C-CY(X = H, PPH2, Y = H, PPH2, P(-CC-CSIME3 (X = CL, C-CC-CSIME3)()PH2ME) AND RU(PH2PCH2)(2)(X)C)

Treatment of Cp Fe(dppe)C = CH (dppe = Ph2PCH2CH2PPh2), 1, with an eq uimolar quantity of t-BuLi or with 2.5 equivalents of MeLi, followed b y addition of ClPPh2, yielded Cp Fe(dppe)C = CPPh2, 2. With excess t- or n-BuLi, the ethylene bridge of the dppe ligand in 1 was also metal lated, and further reaction with ClPPh2 resulted in Cp Fe(tppe)C = CP Ph2 (tppe = Ph2PCH(PPh2)CH2PPh2), 3. Quaternization of 3 by Mel smooth ly produced the phosphoniumethynyl derivative [Cp Fe(tppe)C = CPPh2Me ]I, 4. Reactions of cis-Ru(dppm)(2)Cl-2 (dppm = Ph2PCH2PPh2) with LiC = CC = CSiMe3, in situ generated from Me3SiC = CC = CSiMe3 and MeLi/Li Br in THF, gave cis-Ru(dppm),(C = CC = CSiMe3)(2), 5, trans-Ru(dppm)(2 )(C = CC = CSiMe3)(2), 6, and trans-Ru(dppm)(2)(Cl)C = CC = CSiMe3, 7, depending on the solvent (ether or THF) and the molar ratios of the r eactants. According to an X-ray structure analysis, the ethynyl ligand of 1 is structurally characterized by d(Fe-C), 1.876(13) and d(C = C) , 1.206(15) Angstrom, the value of the angle Fe-C = C being 176.3(11)d egrees.