Crystal structure of 5-fluoro-1-(2,3,6-trideoxy-α-l-glycero-hex-2-enopyranos-4-ulosyl)uracil

The present compound crystallizes in the space groupP2₁2₁2₁ withZ=4 and cell parametersa=21.687(2),b=8.155(3),c=5.883(2)Å. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.045 for 1153 observed reflections. The N-glycosidic torsion angle _CN is in the anti-range and the pyranosyl ring adopts a distorted half-chair conformation with ₂=142.7(4)°, ₂=124.4(3)° andQ=0.456(2)Å. In the crystal packing the molecules are linked together by N-HO hydrogen bonds and C-HO contacts.     

Synthesis,Infrared Spectroscopic,and Cyclic Voltammetric Studies on 1,10-Phenanthroline and 2,2′ -Bipyridine Adducts of Bis(4-morpholinecarbodithioato-S,S′)zinc(II) and Single-Crystal Structure Determination of (2,2′ -Bipyridine)bis(4-morpholinecarbodithioato-S,S′) zinc(II)

Abstract

(1,10-Phenanthroline)bis(4-morpholinecarbodithioato-S,S′)zinc(II), [Zn(mdtc)₂(1,10-phen)] ( 1 ) and (2,2′ -bipyridine)bis(4-morpholinecarbodithioato-S,S′) zinc(II), [Zn(mdtc)₂(bipy)] ( 2 ) adducts were prepared, and the crystal structure of 2 is reported. The Zn-S distances in 2 are longer than those in [Zn(dtc)₂](dtc = dithiocarbamate) complexes. The acceptance of an additional neutral ligand by the tetrahedral dithiocarbamato complex of zinc to form an octahedral adduct causes an increase in the Zn-S bond lengths and a consequent lowering of the S-Zn-S bite angle. The cyclic voltammetric study on the complexes shows an increase of electron density on the central metal ion in the adducts compared to Zn(mdtc)₂. The use of HMDE as a working electrode in the CV studies indicate the involvement of Hg in complex formation, which is otherwise absent with a platinum working electrode. The thioureide C-N distance of 1.330 ( 4 ) Å in compound 2 is in line with the ν _C?N observed at 1465 cm^?1.     

Benzoylation of methyl acrylate. Crystal and molecular structure of (methyl-3-benzoylacrylate)bis(triphenylphosphine)nickel(0)benzene (1:1) solvate

Summary The benzoylation of methyl acrylate with benzoyl chloride and zerovalent nickel has been studied and an x-ray structural analysis of the intermediate (PPh₃)₂Ni(C₁₁H₁₀O₃) · C₆H₆ complex solvate (1:1) has been carried out. The crystals are triclinic with unit cell dimensions:a 12.488(5),b 20.569(7),c 9.733(4)Å; 9().08(5), 65.54(5), 75.85(5)°; space group P ; finalR factor 0.040. The nickel is in a trigonal environment and the olefinic fragment of the methyl 3-benzoylacrylate involved in the coordination is twisted from the plane formed by the metal and the phosphorus by 8.5°. An expected C=C lengthening in the organic ligand is observed.