Zinc compounds 24-membered ring structures

FIGURE 6. 3D zinc phosphates with eight-membered rings obtained from the transformation of the ladder compound 2 (a) [C Halos-[Zn2(P04)2] (8) and (b) [C2N2H1o](Zn2(P04)2] (9). The features of the ladder structure can be dearly seen in the 3D strudure of 9. Such features are also present in 4 and 8. 

Although the structural chemistry of molybdenum and vanadium phosphates is very diverse these compounds seem to be prototypes for open framework transition and main group metal phosphates. Recent results have shown that zeolite-like compounds like zinc/cobalt phosphates [731, indium phosphates [74], nickel/aluminum phosphates [75], cobalt/boron phosphates [76], manganese and cobalt phosphonates with giant 44-membered rings forming ellipsoidal cavities [77] can be synthesized. All these examples show that the diverse chemistry of octahedral-tetrahedral framework structures is a vast field where... 

The zinc bis(tetraseleno) anion, [Zn(Se4)2]2-, has been crystallized with a number of cations, synthesized by a variety of methods, and its reactivity studied.581-584 The compound (hexaseleno) (tetraseleno)zinc (64) was synthesized from zinc acetate in the presence of lithium polyselenide and structurally characterized, demonstrating seven-membered and flve-membered ZnSen rings.585 Mixed donor neutral monomers have also been formed with imidazole A-donor ligands, ZnSe4 (A-methylimidazole)2.553... 

The structures of some complexes with perfluoroalkylzinc derivatives have also been determined by X-ray diffraction. The first fully characterized compound of this type was the pyridine adduct [(CF3)2Zn(C5H5N)2j, which presents the typical four-coordinated zinc center with a distorted tetrahedral geometry (Table 5). The tetramethyltetrazene ligand forms a four-membered chelate ring via a 1,3-coordination with (C6F5)2Zn (Figure 22). 

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