0000000000231076
AUTHOR
Jean Michel Barbe
Synthesis and crystal structures of palladium(II) complexes of 1,11-bis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione
The two palladium(II) complexes, [PdL22222][ClO4]2·H2O 1 and [Pd(H−2L22222)]·H2O 2 with 1,11-bis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane-5,7-dione, L22222, were prepared and characterized by X-ray crystallography and UV-visible spectroscopy. In 1 the palladium centre is co-ordinated by the tertiary amines of the macrocycle and the two pyridylmethyl nitrogens, forming a square-planar geometry in which two amide nitrogen groups remain protonated and do not take part in co-ordination. Moreover, there is a weak interaction between palladium and H(–N(8)) [d(PdII ⋯ H) = 2.90 A]. In contrast, 2 isolated under basic conditions has a square-planar geometry but the palladium ion is co-ordi…
Synthesis and characterization of a 1,8-difunctionalized dissymmetrical cyclam copper(II) complex bearing pyridylmethyl and N,N-dimethylcarbamoylmethyl groups
The new dissymmetrical ligand 1-(N,N-dimethylcarbamoylmethyl)-8-(2-pyridylmethyl)-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane, 5, was synthesized and the physicochemical properties of its copper(II) complex, [CuII(5)](ClO4)2·CH3CN, were determined. UV–Vis, IR, ESR experiments, and X-ray analysis of [CuII(5)](ClO4)2·CH3CN were carried out. The X-ray structure of [CuII(5)](ClO4)2·CH3CN revealed a distorted square pyramid with the four coordinating nitrogen atoms of the macrocycle lying in the basal position. Curiously, the fifth ligand is the N,N-dimethylcarbamoylmethyl group through the oxygen atom and not the pyridylmethyl moiety.
Effect of axially bound anions on the electroreduction of tin(IV) porphyrins in tetrahydrofuran
The spectroscopic characterization and electrochemistry of SnL(X)2 is presented where L is the dianion of tetra-p-tolylporphyrin or tetra-m-tolylporphyrin and X is ClO4–, Br–, Cl–, F–, or OH–. In all cases, electroreduction leads to porphyrin π anion radicals and dianions which were characterized in tetrahydrofuran by spectroelectrochemistry and e.s.r. spectroscopy. Dissociation of one ClO4– ion from SnL(ClO4)2 occurs before electroreduction of the complex but no dissociation is observed either before or after electroreduction of SnL(F)2 or SnL(OH)2. In contrast, one Br– ion dissociates after the first electron addition to SnL(Br)2 while one Cl– ion dissociates from SnL(Cl)2 after the secon…
ChemInform Abstract: Synthesis and Electrode Reactions of Difluorogermanium(IV) Porphyrins. Molecular Stereochemistry and Crystal Structure of Difluoro-(2,3,7,8,12,13,17,18-octaethylporphyrinato)germanium(IV).
The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethylporphyrinate(2–)(oep), 5,10,15,20-tetraphenylporphyrinate(2–)(tpp), or 5,10,15,20-tetra-p-tolylporphyrinate(2–)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate dichloro derivative [GeCl2(P)]. The complexes were characterized by elemental analysis, 1H n.m.r., i.r., and u.v.–visible spectroscopy. The electrochemical behaviour was investigated in non-aqueous media while spectroelectrochemistry and e.s.r. were used to characterize the oxidized and reduced complexes. Each complex could be reversibly oxidized or reduced by one electron. In each case these electron additions or abstractions…
Synthesis and electrode reactions of difluorogermanium(IV) porphyrins. Molecular stereochemistry and crystal structure of difluoro-(2,3,7,8,12,13,17,18-octaethylporphyrinato)germanium(IV)
The difluorogermanium(IV) porphyrins [GeF2(P)][P = 2,3,7,8,12,13,17,18-octaethylporphyrinate(2–)(oep), 5,10,15,20-tetraphenylporphyrinate(2–)(tpp), or 5,10,15,20-tetra-p-tolylporphyrinate(2–)(tptp)] have been prepared by reacting hydrogen fluoride with the appropriate dichloro derivative [GeCl2(P)]. The complexes were characterized by elemental analysis, 1H n.m.r., i.r., and u.v.–visible spectroscopy. The electrochemical behaviour was investigated in non-aqueous media while spectroelectrochemistry and e.s.r. were used to characterize the oxidized and reduced complexes. Each complex could be reversibly oxidized or reduced by one electron. In each case these electron additions or abstractions…