Homoatomare d10‐d10‐Wechselwirkungen — Auswirkungen auf Struktur‐ und Stoffeigenschaften

Observation of an electric quadrupole transition in the X-ray absorption spectrum of a Cu(II) complex

Polarized Cu K-edge XANES of square planar CuCl42− ion. Experimental and theoretical evidence for shake-down phenomena

Attack by reactive oxygen species leads to a decay in phycoerythrin fluorescence emission. This phenomenon provides a versatile new assay for small molecules and macromolecules that can function as protective compounds. With 1-2 x 10(-8) M phycoerythrin, under conditions where peroxyl radical generation is rate-limiting, the fluorescence decay follows apparent zero-order kinetics. On reaction with HO., generated with the ascorbate-Cu2+ system, the fluorescence decays with apparent first-order kinetics. Examination of the major components of human urine in this assay confirms that at physiological concentrations, urate protects against both types of oxygen radicals. A novel finding is that creatinine protects efficiently by a chelation mechanism against radical damage in the ascorbate-Cu2+ system at creatinine, ascorbate, and Cu2+ concentrations comparable to those in normal urine. Urate and creatinine provide complementary modes of protection against reactive oxygen species in the urinary tract.

Fluorescence-based assay for reactive oxygen species: a protective role for creatinine.

The syntheses and crystal structures of a family of silver cyanide complexes of thiourea and substituted thioureas are reported. The sulfur ligands include thiourea (tu), 1-methyl-2-thiourea (mtu), 1,3-dimethyl-2-thiourea (dmtu), 1,1,3,3-tetramethyl-2-thiourea (tmtu), and 2-imidazolidinethione (N,N‘-ethylenethiourea, etu). Synthesis was effected by dissolving AgCN in an aqueous solution of ligand. Two different complexes were obtained by the reaction of AgCN with tu. Complex 1a:  (AgCN)(tu), monoclinic, P21/c, a = 9.3851 (6) A, b = 8.2782 (5) A, c = 7.1178 (5) A, β = 94.591 (1)°, and Z = 4. Complex 1b:  (AgCN)(tu)2, triclinic, P1, a = 7.9485 (14) A, b = 9.431 (2) A, c = 12.771 (2) A, α = 85.695 (3)°, β = 81.210 (4)°, γ = 77.987 (2)°, and Z = 4. Complex 2:  (AgCN)(mtu), triclinic, P1, a = 4.113 (2) A, b = 9.472 (4) A, c = 9.679 (4) A, α = 113.918 (5)°, β = 98.188 (6)°, γ = 97.725 (6)°, and Z = 2. Complex 3 (AgCN)2(dmtu)2, monoclinic, P21/m, a = 7.1482 (7) A, b = 14.776 (2) A, c = 7.3366 (7) A, β = 92.418...

M.R. Udupa

Papers

Crystal and molecular structure of creatininium tetrachlorocuprate(II)

The crystal and molecular structure of tris(thiourea)silver(I) perchlorate