Kupferkomplexe von Bisamiden, IV UV.‐Banden binuclearer Koordinationsverbindungen ohne Cu‐Cu‐Bindung

Abstract

Summary. Cupric copper and N, N'-Bis-(2-dimethylaminoethy1)-oxamid form in aqueous solution six complexes, three of them being binuclear. Potentiometric and spectrophotometric data were used to obtain stability constants and concentration of each complex, and t o calculate their electronic absorption spectra. The binuclear compounds show strong absorption bands in the near UV., in analogy to the quite differently structured dimeric copper acetate. It is proposed that all these bands near to 370 nm are of charge transfer type.

Bicyclam [6,6′-bi(1,4,8,11-tetra-azacyclotetradecane)]: a ditopic receptor for homo- and hetero-bimetallic complexes

“…In pure thf the reaction does not take place since L' is practically insoluble in this solvent, but addition of bis(2methoxyethyl) ether in which L' is partially soluble helps The absorption spectra of these compounds together with those of the mononuclear complexes with cyclam are given in Table 1 Since it is known that macrocyclic Ni2+ complexes exist in a blue and in a yellow form [see equation (2)] it was interesting (Table 2). In addition the temperature dependence of the spectrum also allows the determination of K, at different (Figure 3) and from these the thermodynamic parameters can be calculated ( (Figure 4) and typical of axial symmetry, with gll split by the hyperfine coupling constant into a quartet.…”

“…The absorption spectra of these compounds together with those of the mononuclear complexes with cyclam are given in Since it is known that macrocyclic Ni2+ complexes exist in a blue and in a yellow form [see equation (2)] it was interesting was determined by adding large amounts of CaCl, to the solution (Figure 2). From this value the equilibrium constant K, at 25 "C and I = 0.2 mol dm-3 can be calculated (Table 2).…”