Alkynyl ligands structure

The tendency to form ate complexes observed for yttrium is also seen in the preparation of a novel zirconium alkynyl complex. Reaction of Zr(Por)Cl2 (Por = OEP or TPP) with either two or three equivalents of LiC=CR (R = Ph or SiMe ) gives the trisalkynyl complexes Zr(Por)(C=CR)3Li(TFIF). An X-ray crystal structure of Zr(OEP)(C=CPh)2Li(THF) shows that all three alkynyl ligands are on... 

The first polynuclear structures with gold(i) centers coordinated to isocyanide and alkynyl groups were prepared through a novel exchange of alkynyl ligands. This special route became necessary, because the coupling of certain complexes proved elusive (Equation (40)) AuCl complexes of isocyanides with terminal alkynyl groups are subject to decomposition upon treatment with a variety of auxiliary bases. 

Li, X.-L., Shi, L.-X., Zhang, L.-Y, et al (2007) Syntheses, structures, and sensitized lanthanide luminescence by Pt- Ln (Ln = Eu, Nd, Yb) energy transfer for heteronuclear PtLn2 and R2Ln4 complexes with a terpyridyl-functionalized alkynyl ligand. Inorganic Chemistry, 46, 10892. 

The purpose of this review is to attempt to discern, from consideration of the full range of data from these techniques, which metrical and vibrational-spectroscopic parameters may be meritoriously applied to the discussion of the electronic structures of metal-alkynyl complexes, and what conclusions may be drawn from them. Because this review aims to extract the intrinsic parameters that characterize M—C=C—R bonding, the discussion is limited in scope to compounds possessing terminal (rj ) alkynyl ligands bound to a single metal center (2) complexes, clusters, oligomers. 

The reaction of (OEP)ZrCl2 with 3equiv. of LiC=CPh produces the alkynyl (OEP)Zr(lv) porphyrin complex (OEP)Zr(7]1-C=CPh)3Li(THF) 242194 (Equation (18)). The molecular structure shows that three alkynyl ligands are coordinated to the Zr center in a piano-stool fashion and that the lithium cation is bound to the pocket formed by three alkynyl ligands. Treatment of complex 242 with anhydrous HC1 produces a C-C bond-coupled product H2C=C(Ph)=CPh and HC=CPh quantitatively. This example shows different reactivity of the zirconium porphyrin from that of analogous metallocene complexes. 

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