Tetramines metal complexes

Tetraazaporphyrin, octaphenyl-metallation, 858 Tetraazaporphyrins synthesis, 857 Tetraethylenepentamine metal complexes, 56 Tetraglycine metal complexes, 764 Tetraketones metal complexes, 399 1,3,5,7-Tetraketones metal complexes, 400 Tetramines cyclic... 

According to the modular approach, components of the fluorosensor can be changed at will. For instance, it could be of some interest to replace the quad-ridentate receptors of systems 4 and 5 by their cyclic counterparts, to obtain 6 and 7 [8]. The reason of the interest is that, ceteris paribus, cyclic ligands form more stable metal complexes than their open-chain analogues (the thermodynamic macrocyclic effect [12]). The tetramine receptor in 6 has the skeleton of the classical 14-membered macrocycle cyclam, whereas the receptor subunit of 7 refers to the other well-known object of macrocyclic chemistry dioxocyclam. 

Figure 19 Spwtrofluorimetric titration with Zn" of a solution of 4 (triangles), 11 (diamonds) and 12 (circles) in aqueous MeCN. In the case of the disubstituted tetramines 11 and 12, metal complexation does not induce the fluorescence revival observed with 4, due to the occurrence of an intracomplex eT process.

Tetramine complexes [PdL4]X2 are also common.183 The salts [Pd(NH3)4][PdCl4] and [Pd(NH3)4][PtCl4] have a solid state structure similar to [Pt(NH3)4] [PtCl4], where the square planar molecular units are stacked vertically with short axial metal-metal distances (3.25 A),... 

The branched tetramine tren is a typical ligand for divalent transition metal cations, and forms fairly stable complexes in aqueous solution [76] (M +-I-tren = [M(tren)]2+, log/ Cu 18.5 Ni , 14.6 Zn , 14.5 Co", 12.7 Fe", 8.8), which usually exhibit a trigonal bipiramidal geometry, the fifth vacant coordination site being occupied by a solvent molecule or by a coordinating anion (Figure 5). 

Figure 6.3. Titration of H30 and Cu aq with ammonia (a) and with tetramine (trien) (b). Equilibrium diagrams for the distribution of NH3-NH4 (c) of the amino coppeifll) complexes (d) and of Cu ", Cu-trien (e). The similarity of titrating with a base and titrating a metal ion with a base (Lewis acid-base interaction) is obvious. Both neutralization reactions are used analytically for the determination of acids and metal ions. A pH or pMe indicator electrode (glass electrode for and copper electrode for Cu " ) can be used for the end point indication.

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