ABSTRACT: In the title compound, C(4)H(6)F(4)O(2), a partially fluorinated aliphatic diol, cooperative O-H⋯O hydrogen bonds form R(2) (2)(14) rings, which are connected into infinite layers parallel to the (100) plane by C(7) chains. A C-H⋯F link is also seen.
Project description:The title co-crystal, C4H7N5·C4H10O2, crystallizes with one mol-ecule of 6-methyl-1,3,5-triazine-2,4-diamine (DMT) and one mol-ecule of butane-1,4-diol in the asymmetric unit. The DMT mol-ecules form ribbons involving centrosymmetric R2(2)(8) dimer motifs between DMT mol-ecules along the c-axis direction. These ribbons are further hydrogen bonded to each other through butane-1,4-diol, forming sheets parallel to (121).
Project description:The diastereoselective synthesis of fluorinated building blocks that contain chiral fluorine substituents is of interest. Here we describe optimisation efforts in the synthesis of <i>anti</i>-2,3-difluorobutane-1,4-diol, as well as the synthesis of the corresponding <i>syn</i>-diastereomer. Both targets were synthesised using an epoxide opening strategy.
Project description:The asymmetric unit of the title compound, C(12)H(18)F(4)Si(2), contains two independent mol-ecules, both lying on inversion centers. The C(arene)-Si distances are significantly longer than in the analogous non-fluorinated compound. The packing of the mol-ecules results in a herringbone motif in the ac plane.
Project description:The title compound, C(20)H(14)F(4)N(4), is a flexible bis-pyridine-type ligand with an extended fluorinated spacer group between the two pyridyl functions. The centroid of the central aromatic ring is situated on a crystallographic center of inversion. The dihedral angle between the pyridine ring and the central benzene ring is 63.85?(9)°. The crystal structure exhibits inter-molecular C-H?F hydrogen-bonding inter-actions.
Project description:The title compound, C(40)H(56)Cl(2)Si(4), was synthesized by the coupling of 1,1-di-tert-butyl-1,2-dichloro-2,2-diphenyl-disilane with lithium. The asymmetric unit contains one half-mol-ecule, which is completed by an inversion centre. In the mol-ecule, the tetra-silane skeleton adopts a perfect anti conformation and the Si-Si bonds [2.4355?(5) and 2.4328?(7)?Å] are longer than the standard Si-Si bond length (2.34?Å). The Si-Si-Si angle [116.09?(2)°] is larger than the tetra-hedral bond angle (109.5°). These long bond lengths and the wide angle are favorable for reducing the steric hindrance among the tert-butyl and the phenyl groups. The dihedral angle between the phenyl rings in the asymmetric unit is 37.36?(8)°.
Project description:The title compound, C(12)H(20)N(4) (2+)·2BF(4) (-), was prepared by the anion exchange of a dibromide ionic liquid with sodium tetra-fluoro-borate. The asymmetric unit contains one half of the imidazolium cation, which lies about an inversion centre at the mid-point of the central C-C bond of the linking butyl chain. The two planar imidazole rings (r.m.s. deviation = 0.0013?Å) are strictly parallel and separated by 2.625?(7)?Å [vertical distance between the centroids of two imidazole rings], giving the mol-ecule a stepped appearance. In the crystal structure, inter-molecular C-H?F hydrogen bonds link the cations and anions, generating a three-dimensional network.
Project description:In the title compound, C18H12F4N2S2, a bis-thio-phenyl Schiff base ligand with a perifluorinated aromatic core, the complete molecule is generated by crystallographic inversion symmetry. The thio-phene and tetra-fluorinated benzene rings are oriented at a dihedral angle of 77.38?(4)°. The crystal structure exhibits C-H?F hydrogen bonds, resulting in supra-molecular chains along the c-axis direction.
Project description:The asymmetric unit of the title compound, C(18)H(22)N(4)S(2), contains one half-mol-ecule, the complete mol-ecule being generated by crystallographic inversion symmetry. The crystal structure features two inter-molecular N-H?S hydrogen-bonding inter-actions, the first generating an infinite chain along the b axis and the second an infinite chain along the a axis, together forming an inter-locking structure.
Project description:1. [(14)C]Acetoin was enzymically synthesized from [(14)C]pyruvate with a pyruvate decarboxylase preparation. Its optical activity was [alpha](20) (d)-78 degrees . 2. Large amounts (1000-fold higher than physiological concentrations) of acetoin were incubated with rat liver mince. Acetoin disappeared but very little (14)CO(2) was evolved. A compound accumulated, which was purified and identified as butane-2,3-diol. Chromatography on borate-impregnated paper indicated the presence of both the erythro and threo forms. 3. Liver extracts capable of interconverting biacetyl, acetoin and butane-2,3-diol were obtained. These interconversions were catalysed by two different enzymes: acetoin dehydrogenase (EC 184.108.40.206) and butane-2,3-diol dehydrogenase (EC 220.127.116.11), previously identified in bacteria. Both required NAD(+) or NADP(+) as cofactors and were different from alcohol dehydrogenase. The equilibrium in both cases favoured the more reduced compound. 4. The activity of butane-2,3-diol dehydrogenase was decreased by dialysis against EDTA: the addition of Co(2+), Cu(2+), Zn(2+) and other bivalent metal ions restored activity. 5. Biacetyl reductase was resolved into multiple forms by CM-Sephadex chromatography and electrophoresis.
Project description:The asymmetric unit of title compound, C(7)H(6)N(4)·C(6)H(6)O(2), contains one 5-(1H-imidazol-1-yl)pyrimidine mol-ecule and two half benzene-1,4-diol mol-ecules; the benzene-1,4-diol mol-ecules are located on individual inversion centers. In the pyrimidine mol-ecule, the imidazole ring is twisted with respect to the pyrimidine ring at a dihedral angle of 25.73?(7)°. In the crystal, O-H?N hydrogen bonds link the mol-ecules to form supra-molecular chains. ?-? stacking is also observed in the crystal, the centroid-centroid distance between parallel imdazole rings being 3.5543?(16)?Å.