An empirical formula is suggested to describe the mutuaJ dependence of the length of the bonds formed by a central atom in systems built up from equivalent carbon atoms, e.g. diamond, graphite, the cumulene and polyyne chains and intermediate structures between them. A geometrical representation of the relationship is a regular tetrahedron. A point of this tetrahedron characterizes the arrangem...

The title compound, C(12)H(18)N(2)O(4)·H(2)O, was obtained as a product of the reaction of hydro-quinone with n-propanol amine. The compound crystallizes as a monohydrate, integrating water into its hydrogen-bonded network. Each diamino-quinone moiety forms two centrosymmetric 10-membered rings through C=O⋯H-N bonds. The resulting bands along [102] are inter-linked through hy-droxy groups and w...

Desferrioxamine B (DFOB) was biotinylated at the pendant amine using solid-phase organic synthesis (SPOS) on a matrix used conventionally for metal affinity chromatography. The strength of the DFOB-matrix coordinate bonds was functionally equivalent to a covalent bond which underpinned the veracity of the SPOS format. After washing excess reagents, biotin-DFOB was eluted from the matrix with wa...

Amidine-type peptide bond isosteres were designed based on the substitution of the peptide bond carbonyl (C=O) group with an imino (C=NH) group. The positively-charged property of the isosteric part resembles a reduced amide-type peptidomimetic. The peptidyl amidine units were synthesized by the reduction of a key amidoxime (N-hydroxyamidine) precursor, which was prepared from nitrile oxide com...

hydroquinazoline-2,5-dione was obtained from Biginelli-type cyclocondensation1 of 5,5-dimethylcyclohexane-1,3-dione with urea and 4-bromobenzaldehyde: yield 1.16 g (62.19%), m.p. 174 – 175 ̊C. A summary of the key crystallographic information is given in Table 1. The atomic coordinates and equivalent isotropic displacement parameters with estimated standard deviations for atoms except H are list...

Molecular dynamics (MD) simulations of chloroform vapor and liquid at normal temperature and pressure and liquid under hydrostatic pressure are presented, giving bond lengths and vibrational frequencies as functions of pressure. The change in bond lengths between vapor and liquid at normal temperature and pressure is consistent with a pressure equivalent to the cohesive energy density (CED) of ...

In the title compound, C28H19BrF2O2, the C=C double bond is E-configured. In the crystal, C-H⋯O and C-H⋯F contacts connect mol-ecules into planes perpendicular to the c axis. The shortest centroid-centroid distance between two aromatic systems is 3.6745 (12) Å between one of the para-fluoro-phenyl rings and its symmetry-generated equivalent.

Di[dihydroxotin(IV)] Tröger's base bis-porphyrin 1, a host molecule with two internal and two external guest interaction sites, binds <or= 1 equivalent of dicarboxylic acid quantitatively within the chiral cavity, a regioselectivity amplified by initial ditopic H-bond formation, followed by kinetic trapping.