The structure and conformation of cis-2-phenylcyclobutanecarboxylic acid and cis-3-(p-fluorophenyl)cyclobutanecarboxylic acid

1983 ◽  
Vol 61 (7) ◽  
pp. 1422-1427 ◽  
Author(s):  
George M. Reisner ◽  
James D. Korp ◽  
Ivan Bernal ◽  
Richard Fuchs
Keyword(s):  
Unit Cell ◽  
The Other ◽  
Dihedral Angles ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Cyclobutanecarboxylic Acid ◽  
Cyclobutane Ring

The structure of cis-2-phenylcyclobutanecarboxylic acid (1) and cis-3-(p-fluorophenyl)cyclobutanecarboxylic acid (2) have been determined by X-ray diffraction methods. Crystals of 1 are monoclinic, space group C2/c with a = 15.420(8), b = 11.687(6), c = 11.226(5) Å, β = 112.45(4)°, and eight molecules in the unit cell. Crystals of 2 are monoclinic, space group P21/n, a = 8.038(5), b = 5.405(4), c = 22.69(1) Å, and β = 97.30(4)°, with four molecules in the unit cell. In both compounds the cyclobutane ring is puckered, with dihedral angles of 27° and 31°. The bond joining the substituted ring atoms in 1 is significantly longer (1.581(2) Å) than the other three (average 1.535(2) Å), due to crowding of substituents. In 2 both the carboxyl and phenyl substituents are close to the bisecting geometry, whereas in 1 both substituents deviate from this conformation, the carboxyl more than the phenyl.

Die Kristallstrukturen von cis- und trans-Dichlorstilben

1984 ◽  
Vol 39 (4) ◽  
pp. 409-415 ◽  
Author(s):  
Evamarie Hey ◽  
Frank Weller ◽  
Kurt Dehnicke ◽  
Günther Maier
Keyword(s):  
Bond Length ◽  
Point Group ◽  
Unit Cell ◽  
Dihedral Angles ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Phenyl Rings ◽  
Cis And Trans

The crystal structures of cis- and trans-dichlorostilbene were determined from X-ray diffraction data, cw-dichlorostilbene crystallizes in the rhombohedral space group R3̄ with 18 formula units per unit cell (821 observed independent reflexions, R = 0.064) with the dimensions a = b = 3323, c = 601 pm, γ = 120°. The molecule corresponds to the point group C1 with a C = C bond length of 133 pm; the dihedral angles of the phenyl rings with the corresponding C = C-Cl plane are 48° and 72°, respectively. Trans-dichlorostilbene crystallizes in the monoclinic space group P21/n with two formula units per unit cell (1138 independent reflexions, R = 0.056) with the dimensions a = 572, b = 1733, c = 641 pm, β = 111°. The molecule is centrosymmetric (Ci) with a C = C bond length of 133 pm; the dihedral angle of the phenyl rings and the Cl - C = C plane is 71°. The stilbene molecules are disordered about the centre of symmetry in two orientations with the ratio 3:7.

Anionische Komplexe [Mo2(O2CPh)4X2]2⊖ mit X = N3, Cl, Br. Die Kristallstruktur von (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 / Anionic Complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, Cl, Br. The Crystal Structure of (PPh4)2[Mo2(O2C-Ph)4Cl2] · 2CH2Cl2

1985 ◽  
Vol 40 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Kay Jansen ◽  
Kurt Dehnicke ◽  
Dieter Fenske
Keyword(s):  
Crystal Structure ◽  
Ir Spectra ◽  
Diffraction Data ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants ◽  
Anionic Complexes

The syntheses and IR spectra of the complexes [Mo2(O2C-Ph)4X2]2⊖ with X = N3, CI, Br and the counter ion PPh4⊕ are reported. The azido and the bromo complexes are obtained from a solution of [Mo2(O2CPh)4] with PPh4N3 in pyridine or by reaction with PPh4Br in CH2Br2, respectively. When (PPh4)2[Mo2(O2CPh)4(N3)2] is dissolved in CH2Cl2, nitrogen is evolved and the complex with X = CI is obtained. The crystal structure of (PPh4)2[Mo2(O2CPh)4Cl2] · 2CH2Cl2 was determined from X-ray diffraction data (5676 observed independent reflexions, R = 0.042). It crystallizes in the monoclinic space group P21/n with four formula units per unit cell; the lattice constants are a = 1549, b = 1400, c = 1648 pm, β = 94.6°. The centrosymmetric [Mo2(O2CPh)4Cl2]2⊖ ion has a rather short Mo-Mo bond of 213 pm, whereas the MoCl bonds are very long (288 pm)

Notizen: Solid State Structure of N,N-Dibenzylhydroxylamine

1995 ◽  
Vol 50 (4) ◽  
pp. 699-701 ◽  
Author(s):  
Norbert W. Mitzel ◽  
Jürgen Riede ◽  
Klaus Angermaier ◽  
Hubert Schmidbaur
Keyword(s):  
Solid State ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
State Structure ◽  
X Ray Diffraction ◽  
Space Group ◽  
Solid State Structure ◽  
X Ray

The solid-state structure of N,N-dibenzylhydroxylamine (1) has been determined by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 21/n with four formula units in the unit cell. N,N-dibenzylhydroxylamine dimerizes to give N2O2H2 sixmembered rings as a result of the formation of two hydrogen bonds O - H ··· N in the solid state.

scholarly journals Crystallization and preliminary X-ray diffraction studies of guanidinoacetate methyltransferase from rat liver

1999 ◽  
Vol 55 (11) ◽  
pp. 1928-1929 ◽  
Author(s):  
Junichi Komoto ◽  
Yafei Huang ◽  
Yongbo Hu ◽  
Yoshimi Takata ◽  
Kiyoshi Konishi ◽  
...  
Keyword(s):  
Rat Liver ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Guanidinoacetate methyltransferase is the enzyme which catalyzes the last step of creatine biosynthesis. The enzyme is found ubiquitously and in abundance in the livers of all vertebrates. Recombinant rat-liver guanidinoacetate methyltransferase has been crystallized with guanidinoacetate and S-adenosylhomocysteine. The crystals belong to the monoclinic space group P21, with unit-cell parameters a = 54.8, b = 162.5, c = 56.1 Å, β = 96.8 (1)° at 93 K, and typically diffract beyond 2.8 Å.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of the BRPF1 bromodomain in complex with its H2AK5ac and H4K12ac histone-peptide ligands

2014 ◽  
Vol 70 (10) ◽  
pp. 1389-1393 ◽  
Author(s):  
Mulu Y. Lubula ◽  
Amanda Poplawaski ◽  
Karen C. Glass
Keyword(s):  
Diffraction Analysis ◽  
National Laboratory ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Direct Role ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

The bromodomain-PHD finger protein 1 (BRPF1) is an essential subunit of the monocytic leukemia zinc (MOZ) histone acetyltransferase (HAT) complex and is required for complex formation and enzymatic activation. BRPF1 contains a structurally conserved bromodomain, which recognizes specific acetyllysine residues on histone proteins. The MOZ HAT plays a direct role in hematopoiesis, and deregulation of its activity is linked to the development of acute myeloid leukemia. However, the molecular mechanism of histone-ligand recognition by the BRPF1 bromodomain is currently unknown. The 117-amino-acid BRPF1 bromodomain was overexpressed inEscherichia coliand purified to homogeneity. Crystallization experiments of the BRPF1 bromodomain in complex with its H4K12ac and H2AK5ac histone ligands yielded crystals that were suitable for high-resolution X-ray diffraction analysis. The BRPF1 bromodomain–H4K12ac crystals belonged to the tetragonal space groupP43212, with unit-cell parametersa= 75.1,b= 75.1,c= 86.3 Å, and diffracted to a resolution of 1.94 Å. The BRPF1 bromodomain–H2AK5ac crystals grew in the monoclinic space groupP21, with unit-cell parametersa= 60.9,b= 55.6,c= 82.1 Å, β = 93.6°, and diffracted to a resolution of 1.80 Å. Complete data sets were collected from both crystal forms using synchrotron radiation on beamline X29 at Brookhaven National Laboratory (BNL).

Dehydration of microporous vanadosilicates: the case of VSH-13Na

2018 ◽  
Vol 74 (6) ◽  
pp. 483-491 ◽  
Author(s):  
Rosa Micaela Danisi ◽  
Thomas Armbruster
Keyword(s):  
Structural Similarity ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Extraframework Cations

Microporous VSH-13Na of composition Na2(VO)(Si4O10)·3H2O was synthesized under mild hydrothermal conditions and studied by single-crystal X-ray diffraction at room temperature and 398 K. Its vanadosilicate framework, consisting of sheets of silicate tetrahedra connected by vanadyl-type square-based pyramids, closely resembles that of the mineral cavansite, Ca(VO)(Si4O10)·4H2O. Due to the disorder in the orientation of the short apical vanadyl groups, the topological symmetry of VSH-13Na was originally described in space group Imma. However, when analysing the systematic absences in our dataset, only the 21 screw axis along b was strictly fulfilled suggesting monoclinic space group P1211. The resulting structure in P21 with a = 14.364 (4), b = 9.134 (2), c = 10.373 (3) Å, β = 90.056 (7)°, V = 1360.9 (7) Å3 was interpreted as a case of allotwinning of two polytypes with topologically idealized orthorhombic symmetry: A (∼62%) with antiparallel orientation of the vanadyl groups in adjacent (100) layers and B (∼38%) with all vanadyl groups in adjacent layers oriented in the same way. At 398 K, the structure of VSH-13Na became fully dehydrated and adopted the unit-cell parameters a = 12.584 (16), b = 9.525 (13), c = 9.696 (14) Å, β = 90.10 (4)°, V = 1162 (3) Å3 (space group P21). Release of H2O caused severe contraction of T—O—T angles and the unit-cell volume decreased by ∼15%. Despite their structural similarity, the VSH-13Na framework seems to be more flexible upon dehydration compared with cavansite, whose structure collapsed before removal of the last H2O molecule. Thus, the presence of monovalent or divalent extraframework cations plays a key role in the dehydration process of natural and synthetic vanadosilicates.

Crystal and Molecular Structures of the Functional Lithium Cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph, Me

2000 ◽  
Vol 55 (11) ◽  
pp. 1005-1010 ◽  
Author(s):  
Ulrich Jürgen Bildmann ◽  
Martin Winkler ◽  
Gerhard Müller Fachbereich
Keyword(s):  
Solid State ◽  
Functional Group ◽  
Molecular Structures ◽  
The Other ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal and molecular structures of the phosphinomethyl-substituted lithium cyclopentadienides [Li(tmeda)][R2PCMe2C5H4], R = Ph (1), Me (2) (tmeda = N,N,N',N'-tetramethylethylenediamine) were determined as their tmeda adducts on the basis of low temperature single crystal X-ray diffraction. (Crystal data: 1: monoclinic, space group P21/n, a = 8.511(5), b = 11.936(2), c = 24.20(1) Å, β = 90.02(3)°, Z = 4.2: monoclinic, space group P21/n, a = 10.887(2), b = 13.326(2), c = 13.131(2) Å, β= 92.872(6)°, Z = 4). In both compounds lithium has a slightly distorted 17 coordination to the cyclopentadienide (Cp) ring. There are no interactions between lithium and the phosphine donors in the solid state as the phosphinomethyl substituents are oriented to the other side of the Cp ring for steric reasons. The isopropene-substituted lithium cyclopentadienide, which is formed as a by-product in the synthesis of phosphinomethyl cyclopentadienides containing a CMe2 bridge, was also structurally characterized as its tmeda adduct [Li(tmeda)][H2C=CMeC5H4] (3). (Crystal data: monoclinic, P21/c, a = 8.00(2), b = 16.701(2), c = 11.942(6) Å, β= 112.68(7)°, Z = 4). As in 1 and 2, lithium is η5 -coordinated to the Cp ring, and there is no interaction of the functional group (isopropene) with lithium.

A comparison of the molecular structures of Dicyclohexyl(N-phenylthiocarbamoyl)-phosphine and Diphenyl(N-phenylthiocarbamoy1)phosphine as determined by X-ray crystallography

1984 ◽  
Vol 37 (10) ◽  
pp. 1991 ◽  
Author(s):  
SW Cowan ◽  
BF Hoskins ◽  
ERT Tiekink
Keyword(s):  
Three Dimensional ◽  
Unit Cell ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Conformational Effects

The crystal and molecular structures of the title compounds, (C6H11)2PC(S)N(H)C6H5(1) and (C6H5)2PC(S)N(H)C6H5(2) have been determined by single-crystal three-dimensional X-ray diffraction techniques. Crystals of (1) are monoclinic, space group P21/c, with eight molecules in the unit cell of dimensions a 20.541(4), b 17.784(2), c 10.2564(9) � and β 94.54(1)�; (2) crystallizes in the triclinic space group P1 with two molecules in the unit cell which has the dimensions a 9.242(2), b 9.994(3), c 10.373(3) �, α 68.56(2), β 71.21(2) and γ 86.00(2)�. Both structures were refined by a least-squares procedure, applying anisotropic thermal parameters to all non-hydrogen atoms, with the use of 3119 and 2971 statistically significant reflections for (1) and (2) respectively; final R 0.055 for (1) and R 0.061 (Rw 0.062) for (2). The N, C(l), S moieties of both (1) and (2) display features consistent with the delocalization of π-electrons. There are notable differences in some of the bond angles between (I) and (2) which have been attributed to conformational effects arising from variations in steric pressures; this may account for the observed differences in reactivity between the two compounds.

Zur Struktur des Cycloheptatrienid-tricarbonyl-eisen(0)-Anions, [C7H7Fe(CO)3]– / The Structure of the Cyeloheptatrienide Triearbonyl Iron(O) Anion, [C7H7Fe(CO)3]-

1978 ◽  
Vol 33 (3) ◽  
pp. 261-264 ◽  
Author(s):  
Erich Sepp ◽  
Albert Pürzer ◽  
Gerhard Thiele ◽  
Helmut Behrens
Keyword(s):  
Crystal Structure ◽  
Ring System ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Lattice Constants

Abstract The crystal structure of the [C7H7Fe(CO)3]- anion stabilized with the [(C6H5)4As]+ cation has been determinated by X-ray diffraction. The crystals are monoclinic, space group P21/n. The unit cell with lattice constants a = 1607.9 pm, b = 1386.8 pm, c = 1249.1 pm and β - 91.52° includes four formula units. The Fe(CO)3 group is bonded to the allyl anion part of the C7H7 ring system, while the diene part is unco-ordinated.

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