The preparation of allenes by the condensation of an acyl chloride with a phosphonium ylid and subsequent elimination of an acid salt and a phosphonium oxide has been established by Bestmann and Hartung. It was felt that this process could be expanded to include the synthesis of butatrienes. Butatrienes are stabilized by aromatic substituents while aromatic substituents decrease the nucleophilicity and reactivity of the phosphonium ylids to be used in the synthesis of the butatrienes. The ylids employed were carbomethoxyphenylmethylenetriphenyl phosphorane, and a new compound, carbethoxyphenylmethylenetriphenyl phosphorane, both of which failed to form alkylated condensation products. Both ylids were prepared by the "melt" method which gave better yields than comparable processes in dry benzene. The salt of a third ylid, carbethoxyphenylmethylenetrimethylphosphonium chloride - a new compound, was also prepared. However, the process for the preparation of this salt was not consistently reproducable and gave only low yields. A previously unreported reaction involving the condensation of ethyl diethylphosphonoacetate and benzoyl chloride was carried out and led to the formation of ethyl phenylpropynoate as was proposed.

The synthesis and reactions of hydrotris(pyrazolyl)borate, (TpR,R) supported ytterbium(II) borohydride and lanthanide(III) dialkyl (Ln = Yb, Lu) complexes were investigated. The lanthanide(III) dialkyl complexes were found to undergo both hydrogenolysis reaction and protonolysis reaction with terminal alkynes. Reaction of [(TptBu,Me)YbH]2 (1) with NH3BH3 and (TptBu,Me)YbI(THF) (2) with NaBH4 afforded the corresponding mono-ligand complexes, (TptBu,Me)Yb(BH4) (3) and (TptBu,Me)Yb(BH4)(THF) (4), respectively. Compounds 3 and 4 represent rare examples of lanthanide(II) tetrahydroborate complexes. IR spectroscopy data, in the B-H stretching region are consistent with the 3-BH4 bonding mode found in the solid state of compound 4 and the corresponding deuterium labelled BD4 analogue of 4 shows the expected IR isotope shifts. Mono-ligand lanthanide dialkyl complexes, (TpR,R)Ln(CH2SiMe2R)2(THF)0/1 (5-9) were synthesized from the homoleptic Ln(CH2SiMe2R)3(THF)2 (Ln = Yb, Lu; R = Me, Ph) complexes by two alternative and complementary methods: alkyl abstraction with the thallium salts of the ligands, TlTpR,R and protonolysis using the acid form of the ligands, HTpR,R. Hydrogenolysis of the dialkyl complexes (TpMe2)Ln(CH2SiMe3)2(THF) (7a, Yb; 8a, Lu) afforded the corresponding tetranuclear hydride complexes, [(TpMe2)LnH2]4 (11, Yb; 12, Lu). Similarly, hydrogenolysis of (Tp)Yb(CH2SiMe3)2(THF) (9) afforded the hexanuclear hydride [(Tp)YbH2]6 (13). When treated with a variety of terminal alkynes, the dialkyl complexes, (TpR,Me)Ln(CH2SiMe3)2(THF) (14a, Y; 8a, Lu), gave the corresponding bis-alkynide complexes, (TpR,Me)Ln(CCR)2 (15-27). The structures of the complexes depend on the steric size of both the alkyne substituents and the substituent on position 3 of the pyrazolyl ring. Except for the bulkiest substituents, the compounds are dimeric with two asymmetric 2-alkynide bridging groups and a coupled alkynide unit bridging the two lanthanide centers via an unusual enyne bonding motif. The synthesis of Lu(CH2Ph-4-R)3(THF)3 (R = H, 28a; R = Me, 28b) was achieved by salt metathesis reactions between KCH2Ph-4-R and LuCl3. Variable temperature NMR studies in THF shows that the formation of these complexes is accompanied by a small amount of the anionic ate K[Lu(CH2PH-4-R)4(THF)n] (30) complexes, which can be prepared independently by reaction of pure Lu(CH2Ph-4-R)3(THF)3 with one equiv. of KCH2Ph-4-R. One of the coordinated THF of 28a could be removed by trituration with toluene to give Lu(CH2Ph-4-R)3(THF)2 (29a). Protonolysis reaction with HTpR,R afforded the corresponding dibenzyl complexes, (TpR,R)Ln(CH2Ph-4-R)2(THF)n (31-33). X-ray crystal structures of complex 4, the dialkyl complexes 5b, 6b, 7 and 8; dihydride complexes 11, 12 and 13; bis-alkynide complexes 15, 16, 17, 21, 22 and 24 as well as the tribenzyl compounds 28a and 29a and dibenzyl complexes 31-33 were determined. The solution behaviour, solid state structures and structural diversity of these complexes are discussed.

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