Cesium complex

Wallace, B. A., and Ravikumar, K. (1988). The gramicidin pore Crystal structure of a cesium complex. Science 241, 182-187. 

All the cesium complex halides are easily hydrolyzed and decompose on heating under vacuum. 

Heterobinuclear complexes containing alkali or alkaline earth metal cations have been derived from mononuclear transition metal complexes of compartmental ligands (51).288 The molar conductivities of the (51)-CuLi2 series suggest that the complexes are uniunivalent electrolytes in water and so are present in solution as Li[(51b)CuLi]- H20 the corresponding di-sodium, -potassium or -cesium complexes are unibivalent electrolytes and so likely to be present in solution as M2[(51)Cu]- H20. 

Walker, B.A. and K. Rasikumar The Gramicidin Pore Crystal Structure of a Cesium Complex." Science. 183 duly 8. 1988). 

Thuery, P., Nierlich, M., Bryan, J.C. et al. 1997. Crown ether conformations in 1,3-calix[4]arene bis(crown ether) Crystal structures of a cesium complex and solvent adducts and molecular dynamics simulations. J. Chem. Soc. Dalton Trans. 1997 (22) 4191 4202. 

The structure of the tetranitro derivative was confirmed by X-ray diffraction in the solid state, this compound does not possess any symmetry element. The conformation of the calixarene structure is less symmetrical than for calix[4]arene(bis crown-6). The nitro groups appear to strongly modify the usual conformation of this calixarene, and a decrease in the preorganization toward cesium complexation can be expected. 

Figure 1. The structure of the cesium complex ofbis-calix[4]arene (5).

The rubidium and cesium complexes of [2.2.2] are isomorphous with approximate D3 symmetry and a crystallographic twofold rotation axis (41). While the rubidium cation is complexed almost without strain, the Cs+ is accommodated only by enlarging the cavity, increasing the mean C—C torsion angle to 71° (compared with 54° for the potassium cryptate). The ligand deformations required to complex Na+ and Cs + are reflected in their lower solution stability constants with respect to the K+ and Rb+ cryptates (see Section III,D). 

J Kondow, T., Inokuchi, H., Wakayama, N. Ortho-Para Hydrogen Conversion and Hydrogen-Deuterium Exchange in the Presence of Tetracyanopyrene-Cesium Complex. J. 

It must be stressed that factors such as the hydration (or solvation) of the metal ion and anion effects on the extracted complex often make it difficult to predict the order of extractability for such systems. Such factors may even influence the stoichiometry of the extracted species. Thus, the simple match of the metal to the whole concept is only of limited utility. For example, potassium, rubidium and sodium nitrates are extracted in the presence of dibenzo-18-crown-6 (2) as 1 1 1 complexes. On the other hand, cesium forms a 1 2 1 sandwich complex with this crown (metal crown nitrate) in the organic phase and this affects the extraction order for the above metal ions, with the order being dependent on ligand concentration. In contrast, for picrate as the anion the composition of the extracted cesium complex is 1 1 1 (Fig. 4.8) [27]. 

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