The structure of Dimethylaminomethanediphosphonic Acid,C3H11NO6P2

M_r = 218.9, monoclinic, P 2₁/c, a = 6.870(1), b = 10.824(2), c = 11.337(2) Å, β = = 94.59(2)⁰, Z = 4, V = 840.5(3) ų, D_x = 1.73 Mgm⁻³. Final R = 0.033 for 2648 independent reflections, excluding those with |F₀| < 3σ(F₀). Intensities were measured with an automatic diffractometer. This organophosphorous compound is characterized by two P C bonds. Four symmetrically independent intermolecular hydrogen bonds determine the threedimensional packing of the molecules and the unique chemical properties of the campound.     

Crystal structure of a spirophosphonium compound,C24H18ClN2P,CH3OH

10,10-(5H,5H)-spirobiphenophosphazinium chloride is one of the few examples of a spirophosphonium salt reported in the literature. This compound crystallized in space groupP2₁/c witha = 12·293(7),b = 13·279(8),c = 17·56(1) Å, = 130·43(3) ° andZ = 4. The finalR index was 0·057. The results of the X-ray analysis indicated that this phosphorus heterocycle may indeed possess aromatic character. This contention was supported in solution by a³¹ P nmr study.Taken in part from the thesis submitted by R. N. Jenkins for the Ph.D. degree, August 1972.     

The structure of N-Pyrid-2-yl-iminotriphenylphosphorane,C23H19N2P

M_r = 353.9, monoclinic, P 2₁/c, a = 11.371(4), b = 11.391(5), c = 14.699(11) Å, β = = 97.78(2)⁰, Z = 4, V = 1888.6(6) ų, D_x = 1.28 Mgm⁻³, final R = 0.052 for 2360 independent reflections excluding those with |F₀| < 5 σ(F₀). Intensities were measured with an automatic diffractometer. The PN C- part of the molecule is nearly coplanar with the pyridinring (torsion angle 6.4°). The P atom and the N(2) atom of the pyridinring overlap with their van der Waals spheres and have nearly the position with the maximum of steric hindrance. This conformation of the molecule is the consequence of a conjugation between the Ph₃P=N-group and the N-standing pyridine ring as well as of an attraction between the P atom and the N(2) atom.     

The crystal and molecular structure of 1,12-dibromododecane,C12H24Br2

The α,ω-dihaloalcanes could serve as model compounds for polyethylenes in further studies of infrared and Raman-spectra. The 1,12-dibromododecane, belonging to this class of compounds, has the monoclinic space group P 2₁/a with the cell parameters a = 24.8 Å, b = 5.40 Å, c = 5.50 Å, β = 99°, Z = 2. The preparation of crystals was very difficult. The crystal finally used gives only few and bad X-ray data measured by film method (equiinclination Weissenberg). Therefore the accuracy of the structure determination is not high, but the result is reliable and has model character for related compounds. All molecules are ordered with their long molecular axes parallel to the (401) planes of the unit cell. There are alternating plane layers of bromine atoms on the one hand and aliphatic parts of the molecules on the other hand, both parallel to the (100)-planes. This molecular arrangement explains well the spectroscopic and crystal optical properties of the structure and also of related compounds like 1,10-dibromodecane and 1,18-dibromooctadecane.     

The structure of N-Pyrid-4-yl-iminotriphenylphosphorane,C23H19N2P

M_r = 353.9, monoclinic, P 2₁/c, a = 11.248(2), b = 11.323(2), c = 14.845(4) Å, β = = 95.87(2)⁰, Z = 4, V = 1880.8(3) ų, D_x = 1.28 Mgm⁻³, final R = 0.049 for 1995 independent reflections excluding those with |F₀| < 5 σ(F₀). Intensities were measured with an automatic diffractometer. The PN C-group of the molecule is nearly coplanar with the pyridine ring (dihedral angle 4.1°). The P atom and the C(2) atom of the pyridine ring overlap with their van der Waals spheres and have nearly the position with the maximum of steric hindrance. This conformation is the consequence of a conjugation between the Ph₃PN group and the N-standing pyridine ring as well as of an attraction between the P atom and the C(2) atom. A similar conformation has been observed in the molecule of N-pyrid-2-yliminotriphenylphosphorane.     

Crystal structure of 2-N,N-diethylamino-1-carbomethoxy-2a,8a-dihydro-2a-methoxycyclobuta [b]naphthalene-3,8-dione,C19H21NO5

Crystals of the title compound, C₁₉H₂₁NO₅, are monoclinic, space groupP2₁/c,a = 7·706,b = 14·470,c = 16·836 Å, = 106·45°,Z = 4. The structure was determined with CuK diffractometer data by symbolic addition procedures and Fourier syntheses, and was refined by full-matrix least-squares methods toR = 0·079 for 2192 observed reflexions. All non-methyl hydrogen atom positions were determined. The non-aromatic six-membered ring has aboat conformation. The four-membered ring, which iscis-fused to the six-membered ring, is slightly folded, and the planar amino and carboxyl groups lie almost in the four-membered ring plane. This geometry, and the detailed bond distances suggest electron delocalization, which may make the compound a useful intermediate in the synthesis of a stable cyclobutadiene system.We thank Dr M. E. Kuehne for suggesting the problem and for crystals, the National Research Council of Canada for financial support, and the University of British Columbia Computing Centre for assistance.     

Crystal structure of Zn[Cl2Ti(C5H5)2]2·2C6H6

The structure of crystals of the composition Zn[Cl₂Ti(C₅H₅)₂]₂·2C₆H₆ has been determined from Patterson and Fourier syntheses of two projections, and refined toR = 0·117 by full-matrix three-dimensional least-squares methods. The crystals are orthorhombic:Pbcn,a = 18·45(5),b = 15·40(6),c = 11·35(3) Å,Z= 4. The complex consists of a central distorted ZnCl ₄ ^2– tetrahedron linked along the Cl—Cl edges to two distorted TiCl₂(C₅H₅)₂ ⁺ tetrahedra in such a way that their centres are nearly collinear The two C₆H₆ molecules in the formulae unit may be regarded as benzene of crystallization.     

The crystal and molecular structure of [K·DB-18-C-6][AlMe3NO3]·0.5C6H6

The use of dibenzo-18-crown-6 in the synthesis of trimethylaluminum adducts of KNO₃ results in the formation of a 1/1 adduct, [K·DB-18-C-6]-[AIMe₃NO₃]. The crystal structure of [K·DB-18-C-6][AlMe₃NO₃]-has been determined from single-crystal X-ray diffraction data collected by counter methods. The title compound crystallizes in the monoclinic space groupP2₁/c (No. 14) with unit cell parametersa=11.804(3),b=28.828(4),c=9.118(3) Å, =96.61(3)°, andD _calc=1.23 forZ=4. Least-squares refinement gave a final conventionalR value of 0.045 for 983 independent observed reflactions. The potassium atom is centered among the six oxygen atoms of the crown at an average KO contact of 2.74(2) Å. Its environment is completed by an oxygen atom of a nitrate anion (2.88 Å) and a benzo group (>3.44 Å) of a neighboring crown ether. The trimethylaluminum moeity is coordinated to the nitrate anion by an oxygen atom at an Al-O bond distance of 1.92(1) Å.     

Crystal structure of protogenkwanin,C16H14O6

The crystal structure of protogenkwanin, C₁₆H₁₄O₆, has been determined by single-crystal diffraction methods. The compound crystallizes in the monoclinic space groupP2₁/c witha=6.804(4),b=7.457(3),c=26.234(3)Å,=95.66(2)° andZ=4. A total of 3275 unique reflection intensities were recorded on a Rigaku AFC6R diffractometer (MoK radiation) at room temperature. The structure was solved by direct methods and electron density calculations. Full-matrix least-squares refinement gaveR=0.058 for 1257 observed [I>3(I)] reflections. Thecrystal structure confirms results from earlier studies on protogenkwanin and elucidates the steric orientation of the hydroxyl substituents of the cyclohexadiene ring: the hydroxyl groups aretrans orientated.     

Crystal structure and absolute configuration of yohimbine hydrochloride,C21H27ClN2O3

Yohimbine (C₂₁H₂₆N₂O₃) is an important indole alkaloid found in the Indian snake rootrauwolfia serpentina, and is very closely related to reserpine. Yohimbine hydrochloride (C₂₁H₂₇ClN₂O₃) is orthorhombic:P2₁2₁2₁,a = 11·54,b = 24·88,c = 7·00 Å,Z = 4. X-ray diffraction data to a Bragg angle of 80 ° were collected on a G.E. diffractometer using CuK radiation. The structure was solved by direct methods, and refined to a reliability index of 9·9 % by the block-diagonal least-squares method. Yohimbine has a ring system very similar to that of reserpine, though the conformations of the ringsC andD about the C—N bond are different in the two molecules. The absolute configuration of the molecule, determined by X-ray anomalous scattering, confirms the 3, 15, 20 configuration assigned earlier by conformational analysis.     

Crystal structure of 1-phenylamino-2-phenyl-4-p-chlorophenylimidazole, C21H16N3Cl

The condensation of amidrazones with -bromoketones through ring closure affords two isomeric products. The minor product was subjected to X-ray diffractometric analysis and turned-out to be a substituted imidazole. The title compound crystallizes in space group P2₁/c, with a = 11.838(2), b = 13.249(1), c = 11.226(2) Å, = 91.01(1)°. The packing of molecules is determined by a hydrogen bond N–HN (2.908(5)).     

Crystal and molecular structure of 3a,6a-dihydro-3-phenylthiolan [2,3-d]isoxazole-4-oxide,C11H11NO2S

The crystal and molecular structure of the title compound, C₁₁H₁₁NO₂S, has been determined by X-ray analysis from diffractometric data. The crystals are monoclinic:P2₁/n, a=17.186(4),b=10.848(2),c=5.588(1) Å,=91.96(1)°,Z=4. The structure was solved by direct methods, and refined by full-matrix least-squares toR=0.043 for 1551 observed reflections. Bond lengths and angles have normal values. The isoxazoline and the thiolane rings are in an intermediate envelope/twist conformation, with a dihedral angle of 109.7(1)° between their best planes, whereas the phenyl ring is rotated 4.1(1)° from the isoxazoline ring, thus allowing extensive conjugation within this moiety.     

Crystal structure of the orange isomer of [(C6H5)3P]2[C2S2(CF3)2]RuCO

The structure of the title compound has been determined by X-ray analysis. It is monoclinic:a = 10.147,b = 10.081,c = 38.627 Å, β = 102.27 °,Z = 4,P2₁/c. The structure was solved by standard methods and refined by least squares to a (conventional)R-factor of 4.7%. The Ru atom is in square-pyramidal configuration: the Ru-S distances (2.286, 2.336Å) are significantly different, but the Ru-P distances average to 2.389 Å. Comparisons are made with the violet isomer.     

Crystal structure of the diacetate of (+)-epipinoresinol,C24H26O8

The crystal structure of the diacetate of (+)-epipinoresinol, C₂₄H₂₆O₈, has been determined by single-crystal diffraction methods. The compound crystallizes in the monoclinic space groupP2₁ witha=7.506(3),b=8.526(4),c=17.746(8) Å,=97.12(4)° andZ=2. A total of 3504 reflexion intensities were recorded on a Syntex P2₁ diffractometer (MoK radiation) at room temperature. The structure was solved by direct methods and electron density calculations. Full-matrix least-squares refinement gaveR=0.056 for 2297 observed [I>3(I] reflexions. The individual central tetrahydrofuran rings have envelope conformations with coplanar carbon atoms and the oxygen atoms as flaps; the carbon atom planes form an angle of 119.9(3)°. Bond distances are C-C (aromatic) 1.386(12) Å, C(sp ³)-O 1.421(12) Å, C(sp ²)-O 1.372(20) Å, and C(sp ²)=O 1.186(9) Å. The influence of molecular structure on the positions of signals in the¹H nmr spectrum of the diacetate of (+)-epipinoresinol is discussed.     

Crystal structure of bis-(rhodanine)copper(I) iodide,C6H6CuIN2O2S4

The structure of the polymeric rhodanine compound, C₆H₆CuIN₂O₂S₄, was determined by X-rays.M _r =456.8, monoclinic, space groupP2₁/c,a=4.1947(7),b=17.6999(12),c=17.1048(8) Å,=96.15(1)°,V _c =1262.6 ų,Z=4,D _c =2.40Mg m^–3, CuK radiation (graphite crystal monochromator, =1.54056 Å),(CuK)=278.9 cm^s-1,F(000)=872,T=290 K. Final conventionalR-factor=0.029, andR _w =0.044 for 2384 unique reflections and 153 variables. The structure was solved using Patterson methods andDirdif, and refined by full-matrix least-squares methods. The compound forms zigzag chains alonga. The copper atom is in trigonal pyramidal coordination, with two sulfur atoms of the thiocarbonyl group and two bridging iodine atoms. The copper-sulfur distances are 2.278(1) and 2.299(1) Å, and the copper-iodine distances are 2.657(1) and 2.814(1) Å.     

Crystal structure and hydrogen bonding of propargylammonium hexafluorosilicate, 2(C3H6N)+ (SiF6)2−

The X-ray crystal structure of propargylammonium hexafluorosilicate, 2(C₃H₆N)⁺ (SiF₆)^2?, is determined. The SiF₆ anion is involved in N?H...F and C?H...F interactions with eight surrounding cations. This involves two-three-and four-center N?H...F hydrogen bonds, and additional C?H...F interactions with C...F distances down to 2.963(6) Å. The alkynyl C?H donors form only C?H...F interactions of unfavorable geometries.     

Crystal and molecular structure of tetrakisthiourea cobalt (II) nitrate monohydrate,C4H16CoN8S4 2+,2NO 3 − ,H2O

The crystal structure of tetrakisthiourea cobalt(II) nitrate monohydrate has been solved and refined by full-matrix least squares, including anisotropic temperature factors, to a finalR of 0.066. The structure is made up of discrete tetrakisthiourea Co(II) molecular ions and NO ₃ ^– ions bound together by hydrogen bonds with water molecules as well as ionic and van der Waals interactions. The local configuration of the cobalt(II) and its four bonded nearest sulfur neighbors is that of a distorted tetrahedron with an average Co-S distance of 2.30 Å. Three of the Co-S bonds appear to be made with sulfur sp² orbitals and lone pairs whereas the remaining Co-S bond involves the S-C molecular orbital as the electron donor. The thiourea groups appear to be normal. Tetrakisthiourea cobalt(II) nitrate monohydrate: orthorhombic,Pbca,a = 33.704(8),b = 11.734(2),c = 10.253(2) Å,Z = 8,D _m = 1.68(2),D _e = 1.66 g cm^–3.     

Crystal and molecular structure of tetrakis-(phenylenethiourea)tellurium(II) perchlorate hexahydrate,C28H24N8O8S4Cl2Te·6H2O

The synthesis and structural characterization of the title compound, C₂₈H₂₄N₈O₈S₄Cl₂Te·6H₂O are reported. The crystals are triclinic, space group P¯1 (No. 2), withZ=1 in a unit cell of dimensionsa=10.312(7),b=7.144(6),c=14.256(7) Å,=83.04(5),=92.15(5), and=101.25(6)°,V _c =1022 ų. The structure was solved by Fourier methods, and refined by full-matrix least squares toR=0.073 andR _w =0.077 for 1305 unique reflections. The tellurium atom in the molecule lies at a crystallographic center of symmetry, and is bonded to four phenylenethiourea sulfur atoms in a near square-planar arrangement with Te-S(1)=2.666(5), Te-S(2)=2.675(6) Å, and S(1)-Te-S(2)=88.7(3)°. The ligands behave as thiones. The crystal packing is stabilized by the extensive hydrogen bonding involving oxygen and nitrogen atoms. The Cl-O bond lengths are 1.29-1.36 Å and the O-Cl-O angles are 90–130° in the ClO₄ ^– moiety, and differ considerably from the normal values of 1.44 Å and 109°, respectively.