Crystal and Molecular Structure of Triaqua-tri-μ-chloro-hexachloro-triangulo-trirhenium(III)-Bis[4,6-dimetylpyrimidine-2(1H)-thione hydrochloride]-Dihydrate

1987 ◽  
Vol 40 (12) ◽  
pp. 2123 ◽  
Author(s):  
LP Battaglia ◽  
AB Corradi ◽  
R Battistuzzi ◽  
T Manfredini
Keyword(s):  
Organic Molecules ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Chloride Ions ◽  
Water Molecules ◽  
Orthorhombic Space Group ◽  
Chlorine Atoms ◽  
Cell Dimensions ◽  
R Value ◽  
Heavy Atom Method

Reaction between rhenium(III) chloride and 4,6-dimethylpyrimidine-2(1H)- thione hydrochloride in concentrated HCl solution results in the formation of [Re3C19(H2O)3].2(C6H7N2S.HCl).-2H2O. The compound crystallizes in the orthorhombic space group Pnma with cell dimensions a 16.797(4), b 21.917(4), c 9.514(1) � and Z 4. The structure was solved by the heavy-atom method and refined by least-squares calculations to a final R value of 0.0517 (R' 0.0602). The structure consists of discrete [Re3Cl9(H2O)3] units, protonated organic molecules, chloride ions, and water molecules. In the cluster three rhenium atoms are linked to form a triangle, with chlorine atoms bridging each pair of rheniums which present short Re-Re bonds [2.440(1), 2.433(1) and 2.444(1) �]. Three water molecules in the equatorial plane and six chlorine atoms perpendicular to it (three above and three below) make the coordination around each rhenium distorted pentagonal bipyramidal.

scholarly journals The crystal and molecular structure of the bis(N,N,N′,N′-tetramethylethanediamine) adduct of I(Br)InInBr2, In2Br3I•2C6H16N2, an indium–indium bonded molecule

1984 ◽  
Vol 62 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Orthorhombic Space Group ◽  
Trigonal Bipyramidal ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Distorted Trigonal Bipyramidal

The crystal structure of the title compound has been determined by the heavy atom method. The crystals are orthorhombic, space group Pbca, with unit cell dimensions a = 22.795(3) Å, b = 17.518(2) Å, c = 12.396(3) Å, Z = 8; R = 0.0409 for 1527 unique "observed" reflections. The structure is disordered, with each halogen site (X) occupied by 75% Br, 25% I. The molecule consists of two X2(tmen)In units (tmen = N,N,N′,N′-tetramethylethanediamine) with distorted trigonal bipyramidal geometry, joined by an In—In bond 2.775(2) Å in length.

Crystal Structure of Adeninium Trichloromercurate(II),

1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares ◽  
Title Compound ◽  
Heavy Atom ◽  
Chloride Ions ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Space Group ◽  
Heavy Atom Method

The title compound belongs to space group P21/c with a = 23.99(1), b = 4.245(2), c = 25.98(1) Å, β = 117.58(7)°, and Z = 8. The structure was solved by the heavy-atom method and refined by block-diagonal least squares on 2589 independent observed reflections. All non-hydrogen atoms were refined anisotropically and some of the hydrogen atoms were located but their parameters were not refined. The final values of R and Rw were 0.042 and 0.047, respectively.The two nonequivalent mercury atoms have very similar environments. Two short Hg—Cl bonds (2.34–2.38 Å) at ∼ 165° define a quasi-molecular HgCl2 unit. Overall octahedral coordination is completed with two chloride ions at 2.76–2.84 Å and two chlorine atoms at 3.19–3.26 Å on neighboring HgCl2 quasi-molecules. HgCl6 octahedra share edges to form twofold ribbons in the b direction. This pattern of octahedra is identical with the onereported for β-NH4HgCl3. The cations are pairs of N(1)-protonated adenine molecules linked by two N(10)—H(10)… N(7) hydrogen bonds and stacked in the b direction. Water molecules act as acceptors in moderately strong hydrogen bonds with acidic protons H(1) and H(9) of adeninium ions. Other generally weaker hydrogen bonds exist between the various parts of the structure.

The crystal and molecular structure of streptomycin oxime selenate tetrahydrate

1978 ◽  
Vol 359 (1698) ◽  
pp. 365-388 ◽  
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Glycosidic Bonds ◽  
Compound C ◽  
Cell Dimensions ◽  
Network Of Hydrogen Bonds

The crystal and molecular structure and absolute configuration of the antibiotic streptomycin have been determined by an X-ray study of the hydrated oxime selenate. The compound (C 21 H 40 N 8 O 12 . 1 1/2 H 2 SeO 4 .4H 2 O) crystallizes in the monoclinic space group C 2, with cell dimensions a = 17.10(1), b = 14.36(1), c = 16.13(1)Å∥, β = 108.0(2)°; Z = 4 The structure was solved by the heavy-atom method, by using 3236 visually-estimated intensities, and refined to a conventional R of 0.086. The analysis has confirmed that streptomycin consists of three fragments, an N -methyl- α-L-glucosamine ring, an α-L-streptose and a streptidine ring, linked together by two glycosidic bonds. The crystal structure contains an elaborate network of hydrogen bonds linking selenate and streptomycin oxime ions and water molecules, analysis of which, though somewhat hampered by inability to observe the hydrogen atoms experimentally, reveals a disordered hydrogen bond occurring between two diad-related water molecules.

Crystal and molecular structure of the m-bromobenzoate derivative of bisnorquassin

1970 ◽  
Vol 48 (2) ◽  
pp. 307-311 ◽  
Author(s):  
H. Lynton
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Unit Cell ◽  
Anisotropic Temperature ◽  
Cell Dimensions ◽  
Final Agreement ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Atomic Parameters

The molecular structure of the m-bromobenzoate derivative of bisnorquassin, C27H27O7Br, has been determined by the heavy atom method. The compound crystallizes in the orthorhombic system, space group P212121, with unit cell dimensions a = 20.09 ± 0.02 Å, b = 14.63 ± 0.02 Å, c = 8.06 + 0.01 Å and 4 molecules in the unit cell. Final atomic parameters have been obtained from a blockdiagonal least-squares refinement using anisotropic temperature parameters. The final agreement residual for 1665 observed reflections is R = 0.107.The structure of bisnorquassin previously proposed by Findlay and Cropp, on the basis of spectroscopic and chemical evidence, is shown to be essentially correct.

Crystal and molecular structure of the tetradecahydrate of cobalt(II) (R,S)-ethylenediamine-N,N'-disuccinato-cobaltate(III)

1980 ◽  
Vol 45 (6) ◽  
pp. 1766-1774 ◽  
Author(s):  
František Pavelčík ◽  
Jiřina Soldánová ◽  
Jaroslav Majer
Keyword(s):  
Molecular Structure ◽  
Oxygen Atom ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Cobalt Atom ◽  
Carboxyl Groups ◽  
Water Molecules ◽  
Crystal Water ◽  
Heavy Atom Method

Crystals of Co3((R,S)-EDDS)2 . 14 H2O are monoclinic with lattice parameters a = 1.1393, b = 1.1856, c = 1.5267 nm, β = 114.6°. The space group is P21/c, Z = 2. The structure was solved by the heavy atom method and refined by the least squares method to R = 0.082. The crystals are composed of binuclear [CO2((R,S-EDDS)2]2- anions, [CO(OH2)6]2+ cations and crystal water molecules. The cobalt atom in [Co2((R,S)-EDDS)2]2- is coordinated octahedrally by two nitrogen atoms and three oxygen atoms from different carboxyl groups in a single [(R,S)-EDDS]4- molecule and one oxygen atom from a neighbouring [(R,S)-EDDS]4- molecule. The [Co(OH2)6]2+ cation is coordinated octahedrally.

Crystal and Molecular Structure of the Synthetic Intermediate, 2-Bromo-3-methoxy-5-hydroxy-5,6,7,8,9,10,13,14-octahydro-8-methyl-10,13-N-acetylaminomethano-phenanthrene, C19H24O3NBr

1973 ◽  
Vol 51 (16) ◽  
pp. 2637-2638 ◽  
Author(s):  
H. Lynton ◽  
P. Y. Siew
Keyword(s):  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
Full Matrix ◽  
Cell Dimensions ◽  
Ring Nitrogen ◽  
Unit Cell Dimensions ◽  
Synthetic Intermediate ◽  
Heavy Atom Method

Crystals of the synthetic intermediate, 2-bromo-3-methoxy-5-hydroxy-5,6,7,8,9,10,13,14-octahydro-8-methyl-10,13-N-acetyl aminomethano-phenanthrene, C19H24O3NBr, are monoclinic, space group P21/n, unit cell dimensions a = 10.62(1), b = 14.47(2), c = 23.88(2) Å, β = 99.4(2)°, z = 8 with two molecules in the asymmetric unit. The structure was solved by the heavy atom method and refined by full matrix least squares to R = 0.096 for 2120 observed reflections. The conformation was found to be cis at the junction between rings A and B making further cyclization to obtain an A ring nitrogen bridge not possible.

The Stereochemistry of Some Organic Derivatives of Group Vb Elements. Part X. The Crystal and Molecular Structure of Triphenylarsenic Difluoride

1975 ◽  
Vol 53 (11) ◽  
pp. 1647-1650 ◽  
Author(s):  
Ann Augustine ◽  
George Ferguson ◽  
Frank C. March
Keyword(s):  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Three Dimensional ◽  
Arsenic Atom ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Phenyl Rings ◽  
Derivatives Of ◽  
Heavy Atom Method

The crystal structure of triphenylarsenic difluoride has been determined from three-dimensional X-ray diffractometer data. Crystals of Ph3AsF2 are orthorhombic, space group Pbcn, with four molecules of C18H15AsF2 in a unit cell of dimensions a = 6.270, b = 16.593, c = 14.519 Å; molecular symmetry C2 is required. The structure was solved by the heavy atom method and refined by full-matrix least-squares calculations to a final residual R of 0.054 for 979 intensities regarded as "observed" (I > 3σ(I)). The crystals contain well separated discrete molecules. The arsenic atom has near regular trigonal bipyramidal geometry with apical fluorine atoms (As—F 1.834(7) Å) and equatorial phenyl rings (mean As—C 1.925(5) Å). Idealized D3 symmetry is not achieved because of unequal rotations of the phenyl rings about the As—C bonds.

scholarly journals Crystal and Molecular Structure of the 1:1 Complex of Chloral Hydrate and 7-Bromo-2,3-dihydro-1-methyl-5-phenyl-1,4-benzodiazepin-2-one

1971 ◽  
Vol 49 (20) ◽  
pp. 3401-3404 ◽  
Author(s):  
R. F. Dunphy ◽  
H. Lynton
Keyword(s):  
Chloral Hydrate ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Unit Cell ◽  
Orthorhombic System ◽  
Cell Dimensions ◽  
Final Agreement ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Atomic Parameters

The structure of a 1:1 complex of chloral hydrate and 7-bromo-2,3-dihydro-1-methyl-5-phenyl-1,4-benzodiazepin-2-one has been determined by the heavy atom method. The complex crystallizes in the orthorhombic system, space group Pbca, with unit cell dimensions a = 13.45(1), b = 26.74(2), c = 11.23(1) Å and 8 molecules in the unit cell. The 1:1 complex of chloral hydrate and diazepam, 7-chloro-2,3-dihydro-1-methyl-5-phenyl-1,4-benzodiazepin-2-one, is isomorphous with the above compound and has unit cell dimensions a = 13.43(1), b = 26.60(2), c = 11.20(1) Å. The final atomic parameters have been obtained from a block-diagonal least squares refinement using anisotropic thermal parameters. The final agreement residual for 575 observed reflections is R = 0.079.The structure consists of chains of chloral hydrate and Br-diazepam molecules linked by hydrogen bonds.

Crystal and Molecular Structure of 2-Bromo-11-ethyl-5,9-dimethoxytetracyclo[5.4.1.14,12•18,11]tetradecan-3-one, C18H27BrO3

1971 ◽  
Vol 49 (15) ◽  
pp. 2497-2500 ◽  
Author(s):  
R. F. Dunphy ◽  
H. Lynton
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Unit Cell ◽  
Monoclinic System ◽  
Cell Dimensions ◽  
Final Agreement ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Atomic Parameters

The molecular structure of 2-bromo-11-ethyl-5,9-dimethoxytetracyclo[5.4.1.14,12•18,11]tetradecan-3-one, C18H27BrO3, synthesized in an attempt to develop a method of conversion from an advanced relay compound to the alkaloid delphinine, has been determined by the heavy atom method. The compound crystallizes in the monoclinic system, space group P21/c, with unit cell dimensions a = 9.684(9), b = 13.481(15), c = 12.988(14) Å, β = 99.47(7)°, and four molecules in the unit cell. The atomic parameters were refined by block-diagonal least squares using anisotropic thermal parameters. The hydrogen atom positions were established but the parameters were not refined. The final agreement residual for 816 observed reflections is R = 0.044.The stereochemistry of the compound was found to be unsuitable for the delphinine synthesis.

The Crystal and Molecular Structure of sym-fac-(1,4,7-Triazaheptane)-(S)-aspartatocobalt(III) Diperchlorate Dihydrate

1994 ◽  
Vol 59 (5) ◽  
pp. 1052-1058 ◽  
Author(s):  
Jan Ondráček ◽  
Jana Ondráčková ◽  
Jaroslav Maixner ◽  
František Jursík
Keyword(s):  
Molecular Structure ◽  
Aspartic Acid ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Membered Ring ◽  
Boat Conformation ◽  
Hydrogen Atoms ◽  
Orthorhombic System ◽  
Anisotropic Temperature ◽  
Heavy Atom Method

The crystal and molecular structure of s-fac-[Co((S)-Asp)(dien)]ClO4 . HClO4 .2 H2O (dien = 1,4,7-triazaheptane) was solved by the heavy atom method. The position parameters of the non-hydrogen atoms and their anisotropic temperature parameters were refined based on 1 726 observed reflections with a final value of R = 0.073. The substance crystallizes in the orthorhombic system in the space group P212121, Z = 4, a = 8.506(1), b = 17.171(2), c = 13.277(1) Å. The structure involves hydrogen bonds between the O2, O4 and HN2 atoms of aspartic acid and the two molecules of water. The five-membered dien chelate rings take the asymmetric envelope conformations. The five-membered ring of (S)-aspartic acid possesses the symmetric envelope conformation whereas the six-membered ring exhibits the skew boat conformation.

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