Redetermination of 3-deazauracil
نویسنده
چکیده
The crystal structure of the title compound, 4-hydr-oxy-2-pyridone, C(5)H(5)NO(2), which has been the subject of several determinations using X-rays and neutron diffraction, was first reported by Low & Wilson [Acta Cryst. (1983). C39, 1688-1690]. It has been redetermined, providing a significant increase in the precision of the derived geometric parameters. The asymmetric unit comprises a planar 4-enol tautomer having some degree of delocalization of π-electron density through the mol-ecule. In the crystal structure, the mol-ecules are connected into chains by two strong O-H⋯O and N-H⋯O hydrogen bonds between the OH and NH groups and the carbonyl O atom.
منابع مشابه
Redetermination of 3-methylisoquinoline at 150 K
The structure of the title compound, C(19)H(9)O, has been redetermined at 150 K. The redetermination is of significantly higher precision than a previous room-temperature structure [Ribar et al. (1974 ▶). Cryst. Struct. Commun.3, 323-325]. The C-N bond lengths for this redetermination are much closer to those observed in comparable structures, and the orientation of the methyl group with respec...
متن کاملRedetermination of Crystal Structure of N,N'-bis (2-Hydroxybenzylidene)-2,2-Dimethyl-1,3-Propanediamine
The structure of N,N'-bis(2-hydroxybenzylidene)-2,2-dimethyl-1,3-propanediamine, C19H22N2O2, has been studied at low temperature (120K) by means of single-crystal X-ray diffraction. Solving the structure shows an orthorhombic unit cell, with P212121 space group, Z = 4, a = 6.1046 (4) Å, b = 15.8349 (11)</e...
متن کاملRedetermination of tetrakis(trimethylstannyl)germane
Redetermination of the structure of the title compound, [Ge(SnMe(3))(4)] or [GeSn(4)(CH(3))(12)], previously refined from powder diffraction data only [Dinnebier, Bernatowicz, Helluy, Sebald, Wunschel, Fitch & van Smaalen et al. (2002 ▶). Acta Cryst. B58, 52-61], confirms that four bulky trimethyl-stannyl ligands surround the central Ge atom (site symmetry 1) in a tetra-hedral coordination.
متن کاملRedetermination of β-Ba(PO3)2
In comparison with the previous structure determination of the β-modification of barium catena-polyphosphate that was based on Weissenberg film data [Grenier et al. (1967 ▶). Bull. Soc. Fr. Minéral. Cristallogr. 90, 24-31], the current CCD-data-based redetermination reveals all atoms with anisotropic displacement parameters, standard uncertainties for the atomic coordinates, and the determinati...
متن کاملRedetermination of the perovskite-type compound YRh3B revealing a Rh deficiency
In contrast with previous structural studies of ytterbium trirhodium boride, YbRh(3)B, that suggest a boron deficiency, the current redetermination of the crystal structure of YbRh(3)B revealed instead a rhodium deficiency with a refined composition of YbRh(2.67 (2))B. In the ABX(3) perovskite-type structure, Yb, B and Rh are located on the A, B and X positions, respectively, with site symmetri...
متن کامل