Zirconium compounds amination reactions

Zirconium tetrachloride is instantly hydrolyzed in water to zirconium oxide dichloride octahydrate [13520-92-8]. Zirconium tetrachloride exchanges chlorine for 0x0 bonds in the reaction with hydroxylic ligands, forming alkoxides from alcohols (see Alkoxides, METAl). Zirconium tetrachloride combines with many Lewis bases such as dimethyl sulfoxide, phosphoms oxychloride and amines including ammonia, ethers, and ketones. The zirconium organometalLic compounds ate all derived from zirconium tetrachloride. 

Mono(cyclooctatetraenyl) lanthanide(III) compounds, synthesis and characteristics, 4, 124 Mono(cyclooctatetraenyl) zirconium(III) compounds, preparation and reactions, 4, 743 Mono(cyclopentadienyl) amido complexes alkane elimination, 4, 446 amine elimination, 4, 442 HCL elimination, 4, 446 metathesis reactions, 4, 438 miscellaneous reactions, 4, 448 properties, 4, 437... 

For the reaction of TDI with a polyether triol, bismuth or lead compounds can also be used. However, tin catalysts are preferred mainly because of their slight odor and the low amounts required to achieve high reaction rates. Carboxylic acid salts of calcium, cobalt, lead, manganese, zinc, and zirconium are employed as cocatalysts with tertiary amines, tin compounds, and tin—amine combinations. Carboxylic acid salts reduce cure time of rigid foam products. Organic mercury compounds are used in cast elastomers and in RIM systems to extend cream time, ie, the time between mixing of all ingredients and the onset of creamy appearance. 

Other classical reactions such as halogenation or amination with zirconium and boron compounds respectively are possible starting from 1,1-boriozirconocene complexes. 

Acidic transition-metal hydrides have been used to prepare metal-silicon bonded compounds by an interesting condensation reaction that proceeds with amine elimination (equation 30)66. An attempt to carry out a similar reaction between Ph3SiH and the zirconium amide Cp2Zr(NMe2)2 failed67. 

The tertiary amines, trimethylamine and triethylamine, and the secondary amines, dimethyl, diethyl, and dipropyl, react with zirconium tetrachloride to form 1 2 addition compounds, whereas primary amines undergo ammonolysis reactions (151). 

Zirconium and hafnium dialkylamides are highly reactive compounds. They undergo (i) protolytic substitution reactions with reagents such as alcohols, cyclopentadiene and bis(trimethylsilyl)amine (ii) insertion reactions with CO2, CS2, COS, nitriles, phenyl isocyanate, methyl isothiocyanate, carbodiimides and dimethyl acetylenedicarboxylate and (iii) addition reactions with metal carbonyls. These reactions are summarized with reference to Zr(NMc2)4 in Scheme 1. 

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