Benzotriazole zinc complexes

Barbituric acid, methyl-5-nitroso-zinc complexes, 958 Bayldonite, 960 Benzeneselenic acid metal complexes, 977 Benzimidazole metal complexes, 949 Benzoquinoline zinc complexes, 953 Benzothiazole zinc complexes, 981 Benzotriazole zinc complexes, 950 Benzoxazole metal complexes, 951 Berry twist... 

In all cases there was a small amount of the cyclic carbonate formed. It was observed that the monometallic complex Zr(L )(0 Pr)2 was inactive for the polymerisation. This suggests that the bimetallic nature of the complex is important, which has previously been shown for zinc(ii) complexes. Ko has also screened a series of benzotriazole phenolate zirconium complexes. Figure 8.10. Zr(L)2(0 Pr)2, where R=H was by far the most active (pC02 = 600 psi, T= 100 °C, 16 h) giving an 87% conversion of CHO, with a 99% selectivity to polymer with 90% carbonate linkages. Although these results are inferior to the more established systems they do show promise and this is an area of future investigation. 

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