Homoleptic complexes zirconium

Homoleptic anionic zirconium and hafnium phosphine complexes have recently been prepared using bisphosphinine ligands, which are phosphine analogs of the ubiquitous bipyridyl ligand. Structure determinations of the Li3(solv)Cl salts were performed (solv = DME for M = Zr and THF for M = Hf) show the overall geometry around the metal center to be trigonal prismatic. Disruption of the aromaticity is... 

Other homoleptic Lu(III) sandwich complexes 23, 25 (78), and 27 (34), have been prepared accordingly, as in Scheme 6. Zirconium sandwich complexes have been prepared by the method employed by Kim et al. (80) for the synthesis of zirconium porphyrin double deckers reaction of Zr(lV-Et2)4 with the pz ligands 24 (35%) and 26 (61%) produced the corresponding sandwich complexes (28 and 29) (Scheme 6). 

No homoleptic isocyanide complexes of niobium, tantalum, titanium, zirconium, and halfnium have yet been synthesized. The vanadium cation... 

Cavell also reported alkyl derivatives. Tetrabenzyl zirconium was found to react separately with one molar equivalent of two parent methanes to afford complexes 135 and 136 in excellent yields.66 The 13C NMR chemical shifts of the methandiide centres in 135 (Ad = adamantyl) and 136 of 82.8 and 84.4 ppm are clearly different from the dichloride congeners and reflect the substitution of the chlorides by alkyls. The corresponding hafnium dialkyl 137 was also prepared from 133 and neopentyl lithium and the methanide resonance for this complex appeared at 71.6 ppm in its 13C NMR spectrum.63 Noteably, these alkyls displayed far greater stability than their homoleptic tetraalkyl cousins. 

Zirconium-Containing Homoleptic Phosphinoamide Dynamic Complexes. .. 97... 

Sulfenamide. A homoleptic sulfenamido complex of uranium has been isolated from the reaction of Li(Bu NSPh) with UCI4 in the presence of PMe3 in toluene.The complex U(PhS=N-Bu )4 possesses two ry -coordinated sulfenamide ligands, and is nearly isostructural with the analogous zirconium complex. 

Rosen CT, Kristin K, Giolando MD. Homoleptic phenolate complexes of zirconium (IV) syntheses and structural characterization of the first six coordinate complexes. J Chem Soc Dalton Trans 2003 120-5. 

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