Zirconium complexes acetonitrile

By treatment of 159 and 164 with methyllithium, Erker obtained 167 and 168 in 57% and 80% yield, respectively the latter was also characterized by X-ray-crystallography (Scheme 27). Treatment of 167 and 168 with 1 equiv of tris(pentafluorophenyl)-borane caused a methyl transfer with formation of cationic zirconium complexes 169 (91%) and 170 (95%) 169 was also structurally characterized. Addition of a second equivalent of the borane gave dicationic 171 in 93% yield. Treatment of 171 with dichloromethane resulted in an immediate reaction to give 172, which also was structurally characterized. The similar complex 173 was obtained by treatment of 164 with tris(pentafluorophenyl)borane (88%). Addition of acetonitrile to 171 gave 174 (89%), and with 2,6-dimethylphenylisonitrile, 175 was formed in 81% yield. Complexes 169, 170, and 172 show an interesting dynamic NMR behavior corresponding to... 

CF2)2C2(AsMe2)2 (tfars), in acetonitrile (sealed tube, eight days at 100 °C, six months at room temperature) yields [ZrCl3(tfars)] -MeCN as a brown solid. A weak IR band at 2255 cm-1 indicates that the acetonitrile is not coordinated to the metal. This compound is a nonelectrolyte in acetonitrile and exhibits a magnetic moment at room temperature of 1.73 BM. It appears to be the first magnetically dilute zirconium(III) complex to have been reported.20... 

Zirconium(IV) and hafnium(IV) chlorides and bromides form 1 2 adducts of the type [ZrX4(RCN)2] (R = Me, Et, Pr or Ph X = Cl or Br) and [HfX4(MeCN)2] (X = Cl or Br).11SM24 These complexes may be prepared by (i) direct reaction of the metal tetrahalide with an excess of the nitrile120 123 or (ii) electrochemical oxidation of zirconium or hafnium metal in the presence of a solution of chlorine or bromine in acetonitrile.118 The adducts are moisture-sensitive, white solids, insoluble in nonpolar solvents, but soluble in acetonitrile. In the later solvent, [ZrBr4(MeCN)2 behaves as a nonelectrolyte.122... 

Group IV ligands, 364 nitrogen ligands, 366 tris(l,10-phenanthrolme), 366 Zirconium(III) complexes, 366-370 acetonitrile, 366 ammines, 366 aqua,370... 

It has been found that most of the acceptor chlorides accept one chloride ion from triphenylchloromethane in a solution of acetonitrile, including the tetrachlorides of titanium(IV) and tin(IV). Zirconium(IV) and germanium(IV)-chlorides were, however, found to accept two chloride ions to produce the hexa-chlorometallates. A careful analysis of the data has revealed that inner-sphere complexes are formed in which the undissociated ion pairs are not separated by solvation shells ... 

Epoxide ring opening by thiophene was catalysed by 10 mol% of bis(cyclo-pentadienyl)zirconium dichloride complex. The reaction was performed in acetonitrile and, rather surprisingly, the 3-alkylated thiophene 17 was isolated in 71% yield (Scheme 25) [46]. 

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