No abstract

No abstract

Rearrangement of the W(0) d6 ^-alkyne complex /ac-(dppe)(OC)3W(j/2-PhC=CH) (dppe = Ph2PCH2CH2PPh2) yields a meridional tricarbonyl tungsten vinylidene complex, zner-(dppe) (OC)3W=C=CHPh, which provides an M-C-C framework for further ligand-based transformations. Electrophilic addition at the 0-carbon of the vinylidene ligand generates a cationic tungsten carbyne, [wr-(dppe)(OC)3W5=CCH2Ph] [BF4]. This carbyne cation undergoes carbon monoxide substitution

Synthetic procedures are described for the preparation of cationic derivatives of the formula [( ' )2(82 2)(µ-8)(µ-8 )]+, where Cp' = C6H5 (a), C5H4Me (b), or C5Mes (c). Spectroscopic data for the protonated complexes are reported, and p values for the µ-SH ligands have been determined in acetonitrile. Oxidation of the protonated complexes results in the formation of a dicationic derivative of the formula [( ' (µ-8))282 2]22+, 2. Both the triflate and tetrafluoroborate salts of 2b have been characterized by X-ray diffraction studies. The triflate salt crystallized in space group C2/c with o = 35.498 (10) A,b = 14.823 (7) Á, c = 17.246 (5) Á, and ß = 115.51 (2)°. The tetrafluoroborate salt crystallized in space group P2Jn with o = 11.476 (5) A, b = 13.843 (6) A, c = 12.577 (4) A, and ß = 112.97 (3)°. The structures confirm that two dinuclear units have interacted through formation of a S-S bond between µ-sulfido ligands. The reaction of hydrogen (1 atm) with 2 at room temperature resulted in the hydrogenolysis of the intermolecular S-S bond and the formation of 1. Other reactions of 2 have been Characterized that indicate that 2 functions as an effective hydrogen atom acceptor. listings of observed and calculated structure factors (35 pages). Ordering information is given on any current masthead page. NMR and X-ray Studies of Renta-and Hexaborane Alkyl Derivatives Involving [3.3.1] and [3.3.2] Ring Systems

No abstract