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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

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Scheme II and -0.38 V (vs. the standard hydrogen electrode) for the nitro-capped complex 5 and the amino derivative 8, respectively, and both reductions were quasi-reversible. The potentials are higher than that found for the macrotricyclic ion 6 (E = -0.51 V9), but it is clear from a comparison of the structures of 5 (Figure 1) and 61 that the additional methylene bridge in 5 induces a further distortion of the nitrogen donor atoms over the cobalt sphere without significantly increasing the CoN6 core size (Co-N distances are similar). This effectively opens up one side of 5 relative to the equivalent side of the macrotricyclic cage 6 and could be conceived to allow more favorable accommodation of the larger but more readily distorted Co2+ ion.

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NMR methods have provided additional molecular and electronic structural characterization of Cu(ll) and Ag(II) complexes of tetraphenylporphyrin, octaethylporphyrin, etioporphyrin(1)‐ and their one‐electron oxidation products.