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M.R. Udupa

Bio: M.R. Udupa is an academic researcher from University of Göttingen. The author has contributed to research in topics: Monoclinic crystal system & Crystal structure. The author has an hindex of 2, co-authored 2 publications receiving 72 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the crystal and molecular structure of creatinininium tetrachlorocuprate (II) was described and the structure was solved by X-ray diffraction studies and was refined by least-squares methods to R = 0.041 for 1344 reflections.

40 citations

Journal ArticleDOI
TL;DR: Tris(thiourea)silver(I) perchlorate, Ag[SC(NH2)2]3ClO4, was determined from three-dimensional diffractometer data and refined by least-squares methods with anisotropic thermal parameters to a conventional R factor of 0.048 for 2202 observed reflections as mentioned in this paper.

32 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the polarized X-ray absorption cross section of the ls → 3d transition in a square planar CuCl2−4 complex has been measured with respect to rotation about an axis normal to the CuCl4.

204 citations

Journal ArticleDOI
TL;DR: In this article, the origin of the shoulder structure in the X-ray absorption spectra of a single crystal of (creatinium)2CuCl4 was found to be exclusively polarized in the direction normal to the molecular plane of the CuCl42− ion.

143 citations

Journal ArticleDOI
TL;DR: Examination of the major components of human urine in this assay confirms that at physiological concentrations, urate protects against both types of oxygen radicals, and 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.
Abstract: 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.

83 citations

Journal ArticleDOI
TL;DR: The syntheses and crystal structures of the first cyanide, sulfur mixed ligand copper(I) complexes are reported and the difference between the polymorphs is that 5 has a zig-zag chain with a repeat unit of two while 6 has a 4-fold helix.
Abstract: 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...

75 citations