Interplay of Non-covalent Bonds: Effect of Crystal Structure on Molecular Structure

2006 ◽  
pp. 67-90 ◽  
Author(s):  
Jonathan W. Steed
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Covalent Bonds

A three-dimensional metal–organic polymer: poly[bis(μ2-pyrimidine-2-thiolato-κ4N1,S:S,N3)lead(II)]

2015 ◽  
Vol 71 (7) ◽  
pp. 517-520 ◽  
Author(s):  
Vania Denise Schwade ◽  
Ernesto Schulz Lang ◽  
Luana Floriano
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Metal Ion ◽  
Three Dimensional ◽  
Organic Polymer ◽  
Covalent Bonds ◽  
Coordination Environment ◽  
Dimensional Network ◽  
Thiolate Anion ◽  
Metal Organic

The title compound, [Pb(C4H3N2S)2]n, was prepared by the reaction of [Pb(OAc)2]·3H2O (OAc is acetate) with pyrimidine-2-thione in the presence of triethylamine in methanol. In the crystal structure, the PbIIatom has an N4S4coordination environment with four ligands coordinated by N- and S-donor atoms. This compound shows that the pyrimidine-2-thiolate anion can lead to a three-dimensional network when the coordination number of the metal ion can be higher than 6, as is the case with the PbIIion. This compound presents only covalent bonds, showing that despite the possibility of the hemidirected geometries of PbII, the eight-coordinated ion does not allow the formation of an isolated molecular structure with pyrimidine-2-thiolate as the ligand.

Synthesis, Conformational Analysis and Crystal Structure of New Thioxo, Oxo, Seleno Diastereomeric Cyclophosphamides Containing 1,3,2-dioxaphosphorinane

2019 ◽  
Vol 23 (2) ◽  
pp. 205-213
Author(s):  
Dorra Kanzari-Mnallah ◽  
Med L. Efrit ◽  
Jiří Pavlíček ◽  
Frédéric Vellieux ◽  
Habib Boughzala ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Density Functional ◽  
Chemical Shifts ◽  
Structural Determination ◽  
Conformational Study ◽  
Functional Theory ◽  
One Step ◽  
High Resolution Mass Spectroscopy ◽  
Resolution Mass

Thioxo, Oxo and Seleno diastereomeric cyclophosphamides containing 1,3,2- dioxaphosphorinane are prepared by a one-step chemical reaction. Their structural determination is carried out by means of Nuclear Magnetic Resonance NMR (31P, 1 H, 13C) and High-Resolution Mass Spectroscopy (HRMS). The conformational study of diastereomeric products is described. Density Functional Theory (DFT) calculations allowed the identification of preferred conformations. Experimental and calculated 31P, 13C, 1H NMR chemical shifts are compared. The molecular structure of the 2-Benzylamino-5-methyl-5- propyl-2-oxo-1,3,2-dioxaphosphorinane (3d) has been determined by means of crystal Xray diffraction methods.

scholarly journals Molekül- und Kristallstruktur von 1.1-Dimethylsilylentitanocendichlorid, (CH3)2Si(C5H4)2TiCl2 / Molecular and Crystal Structure of l,r-Dimethylsilylene Titanocene Dichloride, (CH3)2Si(C5H4)2TiCl2

1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Structure Determination ◽  
Titanocene Dichloride ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Structural Dimensions

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2

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.

The Meisenheimer rearrangement in heterocyclic synthesis. II. Synthesis and X-ray crystal structure of a tetrahydro-1H-2,3-benzoxazocine and preparation of a hexahydro-2,3-benzoxazonine

1980 ◽  
Vol 33 (6) ◽  
pp. 1323 ◽  
Author(s):  
JB Bremner ◽  
EJ Browne ◽  
PE Davies ◽  
CLWAH Raston
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Acetic Acid ◽  
Crystal And Molecular Structure ◽  
Phosphorus Oxychloride ◽  
Crystallographic Analysis ◽  
Heterocyclic Synthesis ◽  
Reaction Conditions ◽  
X Ray ◽  
Heterocyclic Derivatives

The heterocyclic derivatives, 8,9-dimethoxy-3-methyl-1-phenyl-3,4,5,6- tetrahydro-1H-2,3-benzoxazocine(3a) and 9,10-dimethoxy-3-methyl-1- phenyl-1,3,4,5,6,7-hexahydro-2,3-benzoxazonine (3b),examples of two new ring systems, have been prepared by Meisenheimer rearrangement of the corresponding 2-benzazepine and 2-benzazocine N-oxide derivatives (2a) and (2b). The Bischler-Napieralski-type cyclization reaction was used in the preparation of the tertiary amine precursors of these N-oxides reaction conditions for the cyclization were critical and phosphorus oxychloride in refluxing butanenitrile was found to give the best yields of the seven- or eight-membered cyclic imine intermediates. Reductive cleavage of the benzoxazocine derivative (3a) with zinc in acetic acid followed by N-methylation gave the expected product, [2-{3- (dimethylamino)propyl}-4,5-di-methoxyphenyl]phenylmethanol (12). The crystal and molecular structure of (3a) has been determined by X-ray crystallographic analysis.

scholarly journals X-Ray Single Crystal Structural Analysis of Magnetically Oriented Microcrystals

2014 ◽  
Vol 70 (a1) ◽  
pp. C1138-C1138
Author(s):  
Chiaki Tsuboi ◽  
Kazuki Aburaya ◽  
Shingo Higuchi ◽  
Fumiko Kimura ◽  
Masataka Maeyama ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Single Crystal ◽  
Three Dimensional ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Data Set ◽  
Uv Curable ◽  
X Ray

We have developed magnetically oriented microcrystal array (MOMA) technique that enables single crystal X-ray diffraction analyses from microcrystalline powder. In this method, microcrystals suspended in a UV-curable monomer matrix are there-dimensionally aligned by special rotating magnetic field, followed by consolidation of the matrix by photopolymerization. From thus achieved MOMAs, we have been succeeded in crystal structure analysis for some substances [1, 2]. Though MOMA method is an effective technique, it has some problems as follows: in a MOMA, the alignment is deteriorated during the consolidation process. In addition, the sample microcrystals cannot be recovered from a MOMA. To overcome these problems, we performed an in-situ X-ray diffraction measurement using a three-dimensional magnetically oriented microcrystal suspension (3D MOMS) of L-alanine. An experimental setting of the in-situ X-ray measurement of MOMS is schematically shown in the figure. L-alanine microcrystal suspension was poured into a glass capillary and placed on the rotating unit equipped with a pair of neodymium magnets. Rotating X-ray chopper with 10°-slits was placed between the collimator and the suspension. By using this chopper, it was possible to expose the X-ray only when the rotating MOMS makes a specific direction with respect to the impinging X-ray. This has the same effect as the omega oscillation in conventional single crystal measurement. A total of 22 XRD images of 10° increments from 0° to 220° were obtained. The data set was processed by using conventional software to obtain three-dimensional molecular structure of L-alanine. The structure is in good agreement with that reported for the single crystal. R1 and wR2 were 6.53 and 17.4 %, respectively. RMSD value between the determined molecular structure and the reported one was 0.0045 Å. From this result, we conclude that this method can be effective and practical to be used widely for crystal structure analyses.

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