Integrated Weissenberg Photographs Research Articles

Poly[di-μ2-acetato-κ4O:O′-μ3-thiourea-κ3S:S:S-lead(II)]: a redetermination

The structure of the title polymeric lead(II) thiourea complex, [Pb(CH3O)2{SC(NH2)2}]n, has been redetermined at significantly higher precision using diffractometer data at 100 K. The previous determination used data obtained from multiple-film integrated Weissenberg photographs [Nardelliet al.(1960).Acta Cryst.13, 898–904]. The main difference between the two models is in the precision of the bond lengths, angles and cell parameters. In the crystal, the eight-coordinate PbIIatom is chelated by two carboxylate groups and bridged by three S atoms from thiourea ligands. The coordination sphere is completed by an O atom from a third carboxylate group, the second O atom of which binds to a neighbouring PbIIatom, forming a polymeric chain that runs theaaxis. Two of these chains are related by centres of symmetry. Intermolecular hydrogen bonds connect neighbouring chains to one another, generating a three-dimensional network.

The crystal and molecular structure of Bis( ortho-aminobenzoato)zinc(II), Zn(H 2NC 6H 4COO) 2

Abstract Bis (ortho-aminobenzoato)copper (II), Cu(H2NC6H4COO)2, crystallizes in the monoclinic space group P2 1 c with cell dimensions a = 12.95 (1), b = 5.25 (1), c = 9.39 (1) A, and β = 93.3 (1)°. The structure was determined using three-dimensional X-ray diffraction data gathered on multiple-film, equi-inclination, integrated Weissenberg photographs taken about two crystal axes. Refinement, with anisotropic temperature factors, led to R = 3.1%. Coordination about the copper is that of a distorted octahedron. Four equatorial positions are occupied by two amino nitrogens and two carboxylate oxygens with both the nitrogens and oxygens in trans positions. The octahedral coordination is completed in the axial positions by two carbonyl oxygens which do not originate from the same ligands that occupy the equatorial sites. Each copper in the (100) plane is attached to four other coppers via carboxylate bridges to give a two-dimensional polymeric network coincident with the (100) plane. Significant hydrogen bonding occurs to strengthen the two-dimensional network, which, it is suggested, accounts for the extreme insolubility and high thermal stability of the compound.

The Crystal and Molecular Structure of an Anti-inflammatory Agent, 1-(Cyclopropylmethyl)-4-phenyl-6-methoxy-2(1H)-quinazolinone(SL-573)

Abstract The crystal structure of the title compound (SL-573), crystallized from an ethyl acetate solution, has been determined by the single-crystal X-ray diffraction method. The crystals are monoclinic, with the space group P21/a, and these cell constants: a=17.395(11), b=8.371(5), c=10.871(7) Å, β=99°56(4)′, and Z=4. The intensities were measured visually from equi-inclination integrated Weissenberg photographs taken with Cu Kα radiation. The structure was solved by the symbolic addition method. The final R factor was 0.119 for 3284 reflections. The molecules are placed in pairs around the centers of symmetry and are linked by van der Waals’ distances less than 3.94 Å. The dihedral angle between the quinazoline and phenyl ring planes was found to be 42.8°.

The crystal and molecular structure of bis( ortho-aminobenzoato)copper-( II), Cu(H 2NC 6H 4COO) 2

Bis ( ortho-aminobenzoato)copper ( II), Cu(H 2NC 6H 4COO) 2, crystallizes in the monoclinic space group P2 1 c with cell dimensions a = 12.95 (1), b = 5.25 (1), c = 9.39 (1) Å, and β = 93.3 (1)°. The structure was determined using three-dimensional X-ray diffraction data gathered on multiple-film, equi-inclination, integrated Weissenberg photographs taken about two crystal axes. Refinement, with anisotropic temperature factors, led to R = 3.1%. Coordination about the copper is that of a distorted octahedron. Four equatorial positions are occupied by two amino nitrogens and two carboxylate oxygens with both the nitrogens and oxygens in trans positions. The octahedral coordination is completed in the axial positions by two carbonyl oxygens which do not originate from the same ligands that occupy the equatorial sites. Each copper in the (100) plane is attached to four other coppers via carboxylate bridges to give a two-dimensional polymeric network coincident with the (100) plane. Significant hydrogen bonding occurs to strengthen the two-dimensional network, which, it is suggested, accounts for the extreme insolubility and high thermal stability of the compound.

Crystal structures of S-benzylisothiouronium hexachloroplatinate (IV) and tetrachloroaurate (III)

The crystal structures of two S-benzylisothiouronium salts, [C6H5. CH2. S. C (NH2)2 ]2 PtCl6 and C6H5. CH2 S. C (NH2)2AuCl4, have been determined from three-dimensional X-ray data obtained from integrated Weissenberg photographs. Both structures were refined by full-matrix least squares toR = 0.11. The packing in both structures occurs in alternating sheets representing polar and apolar regions. The ion pairs are held together by ionic forces and a large number of hydrogen bonds.

ChemInform Abstract: THE CRYSTAL STRUCTURE OF DL‐1,2,3,4,5,6‐HEXAHYDRO‐6,11,12,12‐TETRAMETHYL‐2,6‐METHANO‐3,11‐PROPANO‐3‐BENZAZOCINE HYDROCHLORIDE MONOHYDRATE

The structure of the title crystal (C19H27N·HCl·H2O) has been determined by X-ray diffraction method. The racemate crystallizes in monoclinic, space group P21/c with a=14.30, b=15.74, c=7.79A, β=98°58′ and Z=4. The reflection intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKx radiation. The structure was solved by the direct method of phase determination. The final R factor was 0.113. The molecules are linked in endless chains along c-axis by N+···Cl− and Cl−···H2O···Cl− hydrogen bonds. Two piperidine rings in the molecule have the chair conformation. This product which shows analgesic activity has a new molecular structure having a four-ring system, part of which is a benzomorphan nucleus.

The Crystal Structure of dl-1,2,3,4,5,6-Hexahydro-6,11,12,12-tetramethyl-2,6-methano-3,11-propano-3-benzazocine Hydrochloride Monohydrate

Abstract The structure of the title crystal (C19H27N·HCl·H2O) has been determined by X-ray diffraction method. The racemate crystallizes in monoclinic, space group P21/c with a=14.30, b=15.74, c=7.79Å, β=98°58′ and Z=4. The reflection intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKx radiation. The structure was solved by the direct method of phase determination. The final R factor was 0.113. The molecules are linked in endless chains along c-axis by N+···Cl− and Cl−···H2O···Cl− hydrogen bonds. Two piperidine rings in the molecule have the chair conformation. This product which shows analgesic activity has a new molecular structure having a four-ring system, part of which is a benzomorphan nucleus.

Refinement of the crystal structure of beryllonite, NaBePO4

The refined lattice parameters of beryllonite are:a=8.178 (3) A,b=7.818 (2) A,c=14.114 (6) A, β=90.00° (2); space groupP21/n,Z=12. Integrated Weissenberg photographs were taken by using CuK α radiation and multiple film packs. The anisotropic refinement of the crystal structure by means of least-square methods gave a finalR value of 0.063 for the 1388 observed reflections. In the crystal structure PO4 and BeO4 tetrahedra, linked by shared oxygen atoms in a three-dimensional network, form pseudo-ditrigonal rings perpendicular to theb axis. The independent Na atoms lying in the channels formed by the rings are coordinated as an irregular “nine-cornered” polyhedron and as distorted octahedra.

The Molecular and Crystal Structures of Two Isomeric Dihydrofukinolidol Sulfites, C15H22O5S

Abstract The molecular and crystal structures of two isomeric dihydrofukinolidol sulfites, C15H22O5S, have been studied by means of an X-ray analysis. The two sulfites, called S-1 and S-2, both crystallize in the orthorhombic space group P212121, with four molecules in each unit cell. The cell dimensions are a=12.544, b=14.457, and c=8.545 Å for S-1, and a=12.919, b=14.375, and c=8.496 Å for S-2. The reflection intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKα radiation. The structures were solved by the tangent formula procedure and refined by the block-diagonal-matrix least-squares method, the anisotropic thermal motions being assumed for all the atoms. The final R factor was 10.8% for S-1 and 11.2% for S-2. The absolute configurations of the molecules were determined by using the anomalous dispersion effects of the sulfur atoms for CuKα radiation. It was found that the six-membered ring containing the sulfite group in S-1 takes the chair conformation, while the same ring in S-2 has the twist boat form. The exocyclic S–O bond in the two sulfites are both axially oriented, and the other corresponding parts of the two isomers are closely similar to each other.

The crystal structure of ammonium sulfamate

The crystal and molecular structures of ammonium sulfamate, NH 4 SO 3 NH 2 , have been determined using the intensities of 560 independent reflections measured from integrated Weissenberg photographs obtained with Cu Kα radiation. The compound crystallizes in the orthorhombic system with space group Pbca . The unit-cell dimensions are: a = 7.443 ± 0.001 Å, b = 7.739 ± 0.001 Å, and c = 14.281 ± 0.002 Å; ϱ obs = 1.81 g cm −3 and ϱ calc = 1.84 g cm −3 for Z = 8. The sulfamate ion is essentially tetrahedral, with all angles being 109 ± 4°, and has bond lengths of 1.44 Å for S–O and 1.64 Å for S–N. Anisotropic refinement of three-dimensional data by least squares led to a final unweighted R factor of 9.7%. The S–N bond length is shorter than that found in sulfamic acid and is ascribed to non-zwitterionic character. Extensive hydrogen bonding is proposed but the hydrogen atoms were not located in the structure analysis.

Structure analysis of twinned crystals of tris(N,N-di-n-butyldiselenocarbamato)nickel(IV) bromide

The crystal structure of tris(N,N-di-n-butyldiselenocarbamato)nickel(IV) bromide, Ni(Se2CN-(C4H9)2)3Br, has been determined by three-dimensional X-ray methods. The Laue symmetry is 6/mmm, but the structure could be solved only in space groupP¯31c. The crystals were, therefore, regarded as being microtwinned on (001). The unit cell dimensions area =b = 14·69(3) andc = 10·91(3) Å. From integrated Weissenberg photographs, 307 non-zero symmetry-independent reflexions were measured photometrically. The structural parameters were refined by least-squares methods to a conventionalR factor of 0·10. The quadrivalent nickel atom is octahedrally coordinated by six selenium atoms. The Ni-Se distance is 2·391(5) Å; the Se-Se distance within one diselenocarbamate ligand is 3·00(1) Å; Se-Se distances between different ligands are 3·51(1), 3·52(1) and 3·55(1) Å.

The Crystal and Molecular Structure of Bromoanhydrotetrodoic Lactone Hydrobromide

Abstract The absolute configuration of bromoanhydrotetrodoic lactone, C11H14O7N3Br, has been determined on the basis of an X-ray study of its hydrobromide. The crystals are orthorhombic, with four chemical units in a unit cell of these dimensions: a=10.88±0.04, b=15.95±0.05, and c=8.55±0.03 Å; the space group is P212121. The observations for Bijvoet inequalities were made on equi-inclination integrating Weissenberg photographs taken with CuKα radiation around the a axis. On the other hand, the calculations were carried out with the parameters at the stage of the R factor of 11.9% and with anomalous dispersion correction of −0.9 for Δf′Br and 1.5 forΔf″Br . The observed and calculated inequalities for ten pairs of reflections were all in agreement with each other, so the absolute configuration was determined without any uncertainty. In addition to the X-ray determination of the absolute configuration mentioned above, the present paper will describe the details of the crystal and molecular structure.

The Crystal and Molecular Structure of Demycarosyl Leucomycin A3 Hydrobromide

Abstract The stereochemically-complete molecular structure of demycarosyl leucomycin A3, C30H49-NO11, has been determined by means of an X-ray crystal analysis of its hydrobromide. The crystals of the hydrobromide are orthorhombic with four chemical units in a unit cell with the dimensions of a=19.52±0.03, b=20.63±0.03, and c=9.28±0.03 Å. The space group is P212121. As a result of the present study, it has been found that the crystals contain about 0.6 mole of ethanol per mole of the hydrobromide as alcohol of crystallization. The intensity data were obtained from equi-inclination integrating Weissenberg photographs taken with CuKα radiation around the b and c axes. The structure was elucidated by means of the minimum function, least-squares, and Fourier methods. The atomic coordinates obtained were refined by the block-diagonal least-squares method, anisotropic thermal motion being assumed for only the bromine atom. The final R factor is 14.6%. The molecular structure thus obtained corresponds exactly to that proposed in 1967 by Hata et al. on the chemical evidence, considering the allylic rearrangement in the hydrolysis of leucomycin A3 with dilute hydrochloric acid. The conjugated diene system in the macro ring has the trans-trans configuration. The sugar component, mycaminose, forms a β-glycosidic linkage with the lactone ring.

The Crystal Structure of Copper Yunainate Trihydrate, Cu(C5H8O3NS)2·3H2O

Abstract The crystal structure of copper yunainate trihydrate, Cu(C5H8O3NS)2·3H2O, has been studied by means of three-dimensional X-ray analysis. The crystal is monoclinic, with two formula units in a unit cell of the dimensions: a=15.94, b=6.33, c=8.60 Å, and β=95.6°; the space group is P21. The intensities were measured visually from equi-inclination integrating Weissenberg photographs taken with CuKα radiation around the b and c axes. The structure was elucidated by Sim’s method, and refined by the block-diagonal-matrix least-squares method, assuming anisotropic thermal motions for all the atoms. The final R factor is 9.2%. The copper atom is coordinated by imino nitrogen and carboxyl oxygen atoms of two yunainate groups, and a water oxygen atom. The first four atoms lie almost on a plane and make a square configuration of the trans type. The last one is bonded to the copper atom nearly in the direction of the normal of the plane. Thus, the coordination number of copper is five in the present crystal. Of the three sorts of water of crystallization, one is connected with the copper atom, as has already been mentioned, and the remaining two are lattice water, forming a hydrogen-bonded spiral chain around the screw axis. Further, these water molecules connect complex molecules to one another by their hydrogen bonds, forming a threedimensional hydrogen-bonded structure.

X-ray photography as a means of accurate intensity measurement

The methods normally used for photographic intensity measurement are briefly reviewed and the evidence given for the accuracy claimed (~ 1% error) for the method of choice – photometry of integrating Weissenberg photographs taken with Cu Kα radiation. Examples are given of the use of the method in critical cases and the advantages and requirements of the photographic method are stated.

Measurement of X-ray intensities on integrated Weissenberg photographs

A simple photometer for the measurement of X-ray intensities on integrated Weissenberg photographs is described. Conditions are given for sufficiently homogeneous development of the film.