Structural Studies of Some o- and p-Nitrophenylcarbamates by IR Spectroscopy and X-Ray Diffraction

2008 ◽  
Vol 63 (12) ◽  
pp. 1402-1406
Author(s):  
Monika Simon ◽  
Carol Csunderlik ◽  
G. Jones
Keyword(s):  
Ir Spectroscopy ◽  
Crystal Structures ◽  
Ir Spectrum ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray

N-Alkyl-o-nitrophenylcarbamates as solids present two carbonyl stretching bands in the region 1700 - 1800 cm−1 but similar N-alkyl-p-nitrophenylcarbamates have only one such band in the IR spectrum. In solution both kinds of carbamate present one carbonyl stretching band, but for the former, the splittings occur when the carbamates crystallize. Four crystal structures were analyzed by X-ray diffraction. The two ortho derivatives have more than one molecule in the asymmetric unit, which is consistent with the IR observations.

Influence of 3-{5-[4-(diethylamino)benzylidene]rhodanine}propionic acid on the conformation of 5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-4(5H)-one

2018 ◽  
Vol 74 (11) ◽  
pp. 1427-1433 ◽  
Author(s):  
Ewa Żesławska ◽  
Wojciech Nitek ◽  
Waldemar Tejchman ◽  
Jadwiga Handzlik
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Protonated Form ◽  
Acid Form ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Basic Form ◽  
Piperazine Ring ◽  
X Ray ◽  
Intermolecular Contacts

The arylidene–imidazolone derivatives are a group of compounds of great interest in medicinal chemistry due to their various pharmacological actions. In order to study the possible conformations of an arylidene–imidazolone derivative, two new crystal structures were determined by X-ray diffraction, namely (Z)-5-(4-chlorobenzylidene)-2-(4-methylpiperazin-1-yl)-3H-imidazol-5(4H)-one, C15H17ClN4O, (6), and its salt 4-[5-(4-chlorobenzylidene)-5-oxo-4,5-dihydro-3H-imidazol-2-yl]-1-methylpiperazin-1-ium 3-{5-[4-(diethylamino)benzylidene]-4-oxo-2-thioxothiazolidin-3-yl}propionate, C15H18ClN4O+·C17H19N2O3S2 −, (7). Both compounds crystallize in the space group P\overline{1}. The basic form (6) crystallizes with two molecules in the asymmetric unit. In the acid form of (6), the N atom of the piperazine ring is protonated by proton transfer from the carboxyl group of the rhodanine acid derivative. The greatest difference in the conformations of (6) and its protonated form, (6c), is observed in the location of the arylidene–imidazolone substituent at the N atom. In the case of (6c), the position of this substituent is close to axial, while for (6), the corresponding position is intermediate between equatorial and axial. The crystal packing is dominated by a network of N—H...O hydrogen bonds. Furthermore, the crystal structures are stabilized by numerous intermolecular contacts of types C—H...N and C—H...Cl in (6), and C—H...O and C—H...S in (7). The geometry with respect to the location of the substituents at the N atoms of the piperazine ring was compared with other crystal structures possessing an N-methylpiperazine moiety.

Structural studies of technetium complexes. V. The preparation and crystal structure of Dichlorobis(diethyldithiocarbamato)thionitrosyltechnetium(III)

1984 ◽  
Vol 37 (4) ◽  
pp. 751 ◽  
Author(s):  
J Baldas ◽  
J Bonnyman ◽  
MF Mackay ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Positive Charge ◽  
Mirror Plane ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Data Set ◽  
Coordination Environment ◽  
X Ray

Dichlorobis(diethyldithiocarbamato)thionitrosyltechnetium(III), [Tc(S2CNEt2)2Cl2(NS)], has been prepared by the reaction of [Tc(S2CNEt2)2N] with either disulfur dichloride or thionyl chloride. The crystal structure of [TC(S2CNEt2)2Cl2(NS)] has been determined by single-crystal X-ray diffraction methods at 15�C. Crystals are orthorhombic, space group Pcmn, with a 8.936(1), b 15.681(1), c 28.445(7) �, and Z 8. Automatic diffractometry has provided significant Bragg intensities for 2078 independent reflections, and the structure has been refined by full-matrix least-squares methods to R 0.078. The crystal lattice is disordered across a non-crystallographic mirror plane, the degree of disorder being 4.0(2)% for the crystal described above, and 21.9(7)% for another crystal initially used to obtain an intensity data set. There are two independent molecules of [Tc(S2CNEt2)2Cl2(NS)] in the asymmetric unit, and in each the technetium atom is seven-coordinate with a pentagonal-bipyramidal coordination environment. The Tc=N=S bonding is linear with Tc=N c. 1.75 and N=S c. 1.52 �, which indicates that the thionitrosyl group is a three-electron donor with a formal positive charge. This is only the third crystal structure of a complex containing the thionitrosyl group to be determined, and the first for technetium.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of human DNA primase

2014 ◽  
Vol 70 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Andrey G. Baranovskiy ◽  
Jianyou Gu ◽  
Nigar D. Babayeva ◽  
Vinod B. Agarkar ◽  
Yoshiaki Suwa ◽  
...  
Keyword(s):  
Active Site ◽  
Large Subunit ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Human Dna ◽  
Structural Details

Human primase synthesizes RNA primers and transfers them to the active site of Pol α with subsequent extension with dNTPs. Human primase is a heterodimer of two subunits: a small catalytic subunit (p49) and a large subunit (p58). The structural details of the initiation and elongation steps of primer synthesis, as well as primer length counting, are not known. To address these questions, structural studies of human primase were initiated. Two types of crystals were obtained. The best diffracting crystals belonged to space groupP1, with unit-cell parametersa= 86.2,b= 88.9,c= 94.68 Å, α = 93.82, β = 96.57, γ = 111.72°, and contained two heterodimers of full-length p49 and p59 subunits in the asymmetric unit.

Conformational study of the 3,6-dihydro-2H-1,4-oxazin-2-one fragment in 8-tert-butyl-7-methoxy-8-methyl-9-oxa-6-azaspiro[4.5]decane-2,10-dione stereoisomers

2017 ◽  
Vol 73 (7) ◽  
pp. 556-562
Author(s):  
Ewa Żesławska ◽  
Anna Jakubowska ◽  
Wojciech Nitek
Keyword(s):  
Amino Acids ◽  
Crystal Structures ◽  
Stereoselective Synthesis ◽  
Biologically Active ◽  
Asymmetric Unit ◽  
Conformational Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Natural Amino Acids ◽  
Heterocyclic Moiety

Unnatural cyclic α-amino acids play an important role in the search for biologically active compounds and macromolecules. Enantiomers of natural amino acids with a D configuration are not naturally encoded, but can be chemically synthesized. The crystal structures of two enantiomers obtained by a method of stereoselective synthesis, namely (5R,8S)-8-tert-butyl-7-methoxy-8-methyl-9-oxa-6-azaspiro[4.5]decane-2,10-dione, (1), and (5S,8R)-8-tert-butyl-7-methoxy-8-methyl-9-oxa-6-azaspiro[4.5]decane-2,10-dione, (2), both C14H21NO4, were determined by X-ray diffraction. Both enantiomers crystallize isostructurally in the space group P21, with one molecule in the asymmetric unit and with the same packing motif. The crystal structures are stabilized by C—H...O hydrogen bonds, resulting in the formation of chains along the [100] and [010] directions. The conformation of the 3,6-dihydro-2H-1,4-oxazin-2-one fragment was compared with other crystal structures possessing this heterocyclic moiety. The comparison showed that the title compounds are not exceptional among structures containing the 3,6-dihydro-2H-1,4-oxazin-2-one fragment. The planar moiety was more frequently observed in derivatives in which this fragment was not condensed with other rings.

scholarly journals Crystal structures of 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane cobalt(III) mono-phenylacetylide and bis-phenylacetylide

2018 ◽  
Vol 74 (4) ◽  
pp. 522-529 ◽  
Author(s):  
Benjamin M. Oxley ◽  
Brandon Mash ◽  
Matthias Zeller ◽  
Susannah Banziger ◽  
Tong Ren
Keyword(s):  
Crystal Structures ◽  
Symmetry Operator ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Weak Base ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Independent Molecules ◽  
Solvent Molecules ◽  
Occupancy Rates

Reported in this contribution are the synthesis and crystal structures of new mono- and bis-phenylacetylides based on CoIII(DMC) (DMC is 5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane). Chlorido(5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)(phenylethynyl)cobalt(III) chloride–acetonitrile–methanol (1/1/1), [Co(C8H5)Cl(C12H28N4)]Cl·CH3CN·CH3OH, 1, and (5,12-dimethyl-1,4,8,11-tetraazacyclotetradecane)bis(phenylethynyl)cobalt(III) trifluoromethanesulfonate–dichloromethane (2/1), [Co(C8H5)2(C12H28N4)]2(CF3SO3)2·CH2Cl2, 2, were prepared under weak-base conditions in satisfactory yields. Single-crystal X-ray diffraction studies revealed that both 1 and 2 adopt a pseudo-octahedral symmetry in which the Cl—Co—C angles of 1 and C—Co—C of 2 range from 177.7 (2) to 178.0 (2)° and from 177.67 (9) to 179.67 (9)°, respectively. In both structures, the CoIII metal center is coordinated in the equatorial plane by four N atoms, in which the N—Co—N angles range from 85.6 (3) to 94.4 (3)°. The structure of 1 features two crystallographically independent molecules in its triclinic cell (Z′ = 2), which are related to each other by pseudo-monoclinic symmetry. The crystal investigated was twinned by a symmetry operator of the approximate double-volume C-centered cell (180° rotation around [201] of the actual triclinic cell), with a refined twin ratio of 0.798 (3) to 0.202 (3). Both methanol solvent molecules in 1 are disordered, the major occupancy rates refined to 0.643 (16) and 0.357 (16). Compound 2 also contains two molecules in the asymmetric unit, together with two trifluoromethanesulfonate anions [of which one is disordered; occupancy values of 0.503 (16) and 0.497 (16)] and a disordered dichloromethane [occupancy values of 0.545 (12) and 0.455 (12)].

scholarly journals Crystal structures of cristobalite-type and coesite-type PON redetermined on the basis of single-crystal X-ray diffraction data

2015 ◽  
Vol 71 (11) ◽  
pp. 1325-1327 ◽  
Author(s):  
Maxim Bykov ◽  
Elena Bykova ◽  
Vadim Dyadkin ◽  
Dominik Baumann ◽  
Wolfgang Schnick ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Crystal Structures ◽  
Rotation Axis ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations ◽  
Anisotropic Displacement Parameters

Hitherto, phosphorus oxonitride (PON) could not be obtained in the form of single crystals and only powder diffraction experiments were feasible for structure studies. In the present work we have synthesized two polymorphs of phosphorus oxonitride, cristobalite-type (cri-PON) and coesite-type (coe-PON), in the form of single crystals and reinvestigated their crystal structures by means of in house and synchrotron single-crystal X-ray diffraction. The crystal structures ofcri-PON andcoe-PON are built from PO2N2tetrahedral units, each with a statistical distribution of oxygen and nitrogen atoms. The crystal structure of thecoe-PON phase has the space groupC2/cwith seven atomic sites in the asymmetric unit [two P and three (N,O) sites on general positions, one (N,O) site on an inversion centre and one (N,O) site on a twofold rotation axis], while thecri-PON phase possesses tetragonalI-42dsymmetry with two independent atoms in the asymmetric unit [the P atom on a fourfold inversion axis and the (N,O) site on a twofold rotation axis]. In comparison with previous structure determinations from powder data, all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles.

A twofold interpenetrating three-dimensional CdIIcoordination framework: poly[[μ2-1,3-bis(2-methyl-1H-imidazol-1-yl)benzene](μ3-5-nitrobenzene-1,3-dicarboxylato)cadmium(II)]

2014 ◽  
Vol 70 (12) ◽  
pp. 1138-1142 ◽  
Author(s):  
Le Li ◽  
Jian-Qing Tao
Keyword(s):  
Thermal Analysis ◽  
Solid State ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Three Dimensional ◽  
Pentagonal Bipyramid ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coordination Framework

A twofold interpenetrating three-dimensional CdIIcoordination framework, [Cd(C8H3NO6)(C14H14N4)]n, has been prepared and characterized by IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. The asymmetric unit consists of a divalent CdIIatom, one 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) ligand and one fully deprotonated 5-nitrobenzene-1,3-dicarboxylate (NO2-BDC2−) ligand. The coordination sphere of the CdIIatom consists of five O-donor atoms from three different NO2-BDC2−ligands and two imidazole N-donor atoms from two different 1,3-BMIB ligands, forming a distorted {CdN2O5} pentagonal bipyramid. The NO2-BDC ligand links three CdIIatomsviaa μ1-η1:η1chelating mode and a μ2-η2:η1bridging mode. The title compound is a twofold interpenetrating 3,5-connected network with the {42.65.83}{42.6} topology. In addition, the compound exhibits fluorescence emissions in the solid state at room temperature.

scholarly journals Al5B12O25(OH) and Ga4InB12O25(OH) – two additional triel borates with the structure type M5B12O25(OH) (M = Ga, In)

2020 ◽  
Vol 75 (6-7) ◽  
pp. 605-613
Author(s):  
Daniela Vitzthum ◽  
Daniel S. Wimmer ◽  
Ingo Widmann ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Ir Spectroscopy ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature

AbstractThe isotypic triel borates Al5B12O25(OH) and Ga4InB12O25(OH) were synthesized in a Walker-type multianvil apparatus under high-pressure/high-temperature conditions of 12.0 GPa/1400 °C and 12.3 GPa/1200 °C, respectively. The crystal structures of both compounds, determined by single-crystal X-ray diffraction, constitute new representatives of the structure type M5B12O25(OH) (M = Ga, In) crystallizing in the space group I41/acd. The presence of the hydroxyl groups was confirmed via single-crystal IR spectroscopy.

Azide und Cyanamide – ähnlich und doch anders/Azides and Cyanamides – Similar and Yet Different

2003 ◽  
Vol 58 (11) ◽  
pp. 1097-1104 ◽  
Author(s):  
Olaf Reckeweg ◽  
Arndt Simon
Keyword(s):  
Ir Spectroscopy ◽  
Single Crystals ◽  
Crystal Structures ◽  
Spectroscopic Data ◽  
Structural Features ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Time ◽  
Raman And Ir Spectroscopy

Abstract The crystal structures of LiN3*H2O (P63/mcm (No. 193), Z = 6; 924.01(13); 560.06(7) pm); NH4N3 (Pmna (No. 53), Z =4; a=889.78(18), b=380,67(8), c=867.35(17) pm); Ca(N3)2 (Fddd (No. 70), Z = 8; a=595.4(2), b=1103.6(5), c=1133.1(6) pm), Sr(N3)2 (Fddd (No. 70), Z =8; a= 612.02(9), b = 1154.60(18), c = 1182.62(15) pm); Ba(N3)2 (P21/m (No. 11), Z = 2; a = 544.8(1), b = 439.9(1), c = 961.3(2) pm, β = 99.64(3)°) and TlN3 (I4/mcm (No. 140), Z = 2; 618.96(9); 732.71(15) pm) have been either determined for the first time or redetermined by X-ray diffraction on single crystals. The afore mentioned compounds, AN3 (A = Na, K, Rb, Cs), M(N3)2 · 2.5 H2O (M = Mg, Zn) and the cyanamides Li2CN2, CdCN2 and CuCN2 were investigated by Raman and IR spectroscopy (KBr technique). Structural features and spectroscopic data of azides and cyanamides from this work and from literature are listed and compared.

The conformational analyses of 2-amino-N-[2-(dimethylphenoxy)ethyl]propan-1-ol derivatives in different environments

2020 ◽  
Vol 76 (7) ◽  
pp. 681-689
Author(s):  
Wojciech Nitek ◽  
Agnieszka Kania ◽  
Henryk Marona ◽  
Anna M. Waszkielewicz ◽  
Ewa Żesławska
Keyword(s):  
Crystal Packing ◽  
Picolinic Acid ◽  
Structural Studies ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Ether Group ◽  
Space Group ◽  
X Ray ◽  
Hirshfeld Surfaces ◽  
Hydrogen Bonded

Four crystal structures of 2-amino-N-(dimethylphenoxyethyl)propan-1-ol derivatives, characterized by X-ray diffraction analysis, are reported. The free base (R,S)-2-amino-N-[2-(2,3-dimethylphenoxy)ethyl]propan-1-ol, C13H21NO2, 1, crystallizes in the space group P21/n, with two independent molecules in the asymmetric unit. The hydrochloride, (S)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium chloride, C13H22NO2 +·Cl−, 2c, crystallizes in the space group P21, with one cation and one chloride anion in the asymmetric unit. The asymmetric unit of two salts of 2-picolinic acid, namely, (R,S)-N-[2-(2,3-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium pyridine-2-carboxylate, C13H22NO2 +·C6H4NO2 −, 1p, and (R)-N-[2-(2,6-dimethylphenoxy)ethyl]-1-hydroxypropan-2-aminium pyridine-2-carboxylate, C13H22NO2 +·C6H4NO2 −, 2p, consists of one cation and one 2-picolinate anion. Salt 1p crystallizes in the triclinic centrosymmetric space group P\overline 1, while salt 2p crystallizes in the space group P41212. The conformations of the amine fragments are contrasted and that of 2p is found to have an unusual antiperiplanar arrangement about the ether group. The crystal packing of 1 and 2c is dominated by hydrogen-bonded chains, while the structures of the 2-picolinate salts have hydrogen-bonded rings as the major features. In both salts with 2-picolinic acid, the specific R 1 2(5) hydrogen-bonding motif is observed. Structural studies have been enriched by the generation of fingerprint plots derived from Hirshfeld surfaces.

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