Crystallographic Investigations of Biotin and Carboxybiotin Derivatives a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73473/1/j.1749-6632.1985.tb18435.x.pd

4-{2-[3-(2-Ammonioacetamido)propanamido]ethyl}-1H-imidazol-3-ium dichloride

Mol­ecules of the title compound, Gly-β-Ala-Histamine dihydro­chloride, C10H19N5O2 2+·2Cl−, are linked by N—H⋯O and N—H⋯Cl hydrogen bonds into two-dimensional polymeric sheets parallel to the (011) plane, forming a stacked structure along the a axis. The parallel layers are also inter­linked alternately by different N—H⋯Cl hydrogen bonds, forming a three-dimensional framework

1-[3-(4-Nitro­phen­yl)propano­yl]urea acetic acid monosolvate

The title compound, C10H11N3O4·C2H4O2, was prepared by an electrochemical technique. In the crystal, acetic acid mol­ecules are involved in hydrogen bonding to two separate propano­ylurea mol­ecules, acting as a donor in an O—H⋯O inter­action and as an acceptor in two N—H⋯O inter­actions. The propano­ylurea mol­ecules inter­act with each other via N—H⋯O hydrogen bonds. C—H⋯O inter­actions also stabilize the crystal structure

Tricaesium tris­(pyridine-2,6-dicarboxyl­ato-κ3 O 2,N,O 6)lutetium(III) octa­hydrate

Colourless block crystals of the title compound, Cs3[Lu(dipic)3]·8H2O [dipic is dipicolinate or pyridine-2,6-dicarboxyl­ate, C7H3NO4] were synthesized by slow evaporation of the solvent. The crystal structure of this LuIII-complex, isostructural with the DyIII and EuIII complexes, was determined from a crystal twinned by inversion and consists of discrete [Lu(dipic)3]3− anions, Cs+ cations and water mol­ecules involving hydrogen bonding. The Lu atom lies on a twofold rotation axis and is coordinated by six O atoms and three N atoms of three dipicolinate ligands. One Cs atom is also on a twofold axis. The unit cell can be regarded as successive layers along the crystallographic c-axis formed by [Lu(dipic)3]3− anionic planes and [Cs+, H2O] cationic planes. In the crystal structure, although the H atoms attached to water mol­ecules could not be located, short O—O contacts clearly indicate the occurrence of an intricate hydrogen-bonded network through contacts with other water mol­ecules, Cs cations or with the O atoms of the dipicolinate ligands

1,4-Bis(4-chlorophenylseleno)-2,5-dimethoxybenzene

The title compound, C20H16Cl2O2Se2, utilizes the symmetry of the crystallographic inversion center. Molecular chains are formed through symmetric C—H...Cl interactions around inversion centers, mimicking the commonly observed symmetric hydrogen-bonded dimer pattern often found in carboxylic acids

Establishing a training set through the visual analysis of crystallization trials. Part II: crystal examples

As part of a training set for automated image analysis, crystallization screening experiments for 269 different macromolecules were visually analyzed and a set of crystal images extracted. Outcomes and trends are analyzed

Interaction between Plate Make and Protein in Protein Crystallisation Screening

Background: Protein crystallisation screening involves the parallel testing of large numbers of candidate conditions with the aim of identifying conditions suitable as a starting point for the production of diffraction quality crystals. Generally, condition screening is performed in 96-well plates. While previous studies have examined the effects of protein construct, protein purity, or crystallisation condition ingredients on protein crystallisation, few have examined the effect of the crystallisation plate