Study of the thermal behaviour of ordered bimetallic EDTA complexes

Abstract The study of the thermal behaviour of a family of isostructural ordered bimetallic MM'(EDTA)·6H 2 O complexes has been performed using TG and DTA. Formal kinetic analysis of the dehydration step has been approached using non-isothermal procedures. The resulting correlation among the calculated E a values and the cationic sizes implies a common dehydration mechanism. Copper-containing complexes show distinctive behaviour during the ligand pyrolysis processes. A mechanistic interpretation involving formation of Cu(I) and Cu(0) intermediates is furnished. The evolution of the inorganic residues in systems containing both Co and Ni is especially considered given the interest in the (Co…

Vanadyl phosphate dihydrate, a solid acid: the role of water in VOPO4�2H2O and its sodium derivatives Na x (VIV x VV 1?x O)PO4�(2?x)H2O

Sodium-containing intercalates having as general formula Na x VOPOP4·(2−x)H2O (0.25≤x<0.50) have been obtained and characterized. Orthorhombic phases, which essentially maintain the structure of the layered oxide hydrate VOPO4·2H2O result. Intercalated sodium ions act as ‘pillars’. The presence of H3O+ ions in the parent VOPO4·2H2O and also in some reduced phases, is detected. The understanding of the structural role of the water molecules is advanced and the topotactic dehydration/rehydration processes are studied. The formation of a new metastable VOPO4·H2O phase is established.

Kineticversus thermodynamic synthesis pathways of solid bimetallic coordination compounds ? Synthesis and crystal structure of some bimetallic compounds of glycineN,N?-1,2-cyclohexanedylbis[N-(carboxymethyl)]

Crystal structure and spectroscopic study of [Cu(BPCA)(OH2)(O2CCH3)·H2O complex; BPC = N-2-pyridinylcarbonyl-2-pyridinecarboximidate anion

Abstract The crystal and molecular structure of the [Cu(BPCA)(OH2)(O 2CCH3]·H2O complex (BPCA = N-2-pyridinylcarbonyl-2-pyridinecarboximidate anion) has been determined by X-ray diffraction methods. It crystallizes in the triclinic space group P l with two formula units in a cell of dimensions: a = 7.416(2), b = 8.632(4), c = 13.034(3) A, α = 74.55(3), β = 84.84(3), γ = 81.04(5)°. Least-squares refinement of 2534 reflections with I > 2.5σ(I) and 218 parameters gave a final R = 0.047 and Rw = 0.049. The structure consists of discrete [Cu(BPCA)(OH2)(O2CCH3)] neutral units linked through hydrogen bonding. The coordination geometry around copper ions can be described as tetragonal square pyrami…