Structural and spectroscopic studies of dipotassium 3,3,3′,3′-tetramethylcystinate trihydrate, K2[C10H18N2O4S2]3H2O

1984 ◽  
Vol 62 (6) ◽  
pp. 1127-1133 ◽  
Author(s):  
Romolo Faggiani ◽  
Helen Elaine Howard-Lock ◽  
Colin James Lyne Lock ◽  
Maria Lurdes Martins ◽  
Philip Stuart Smalley
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Spectroscopic Studies ◽  
The Other ◽  
Ionic Interactions ◽  
Water Molecules ◽  
Torsional Angle ◽  
X Ray Diffraction ◽  
Standard Methods ◽  
X Ray

The compound dipotassium 3,3,3′,3′-tetramethylcystinate trihydrate, K2[C10H18O4N2S2]3H2O, has been prepared and characterized by single crystal X-ray diffraction. Crystals were monoclinic, P21a = 6.160(1), b = 26.473(8), c = 6.193(1) Å, β = 113.94(1)°, with two formula units in the unit cell. Intensities were measured on a Syntex P21, diffractometer with use of MoKα radiation. The structure was solved by standard methods and refined to R1 = 0.0469, R2 = 0.0472 based on 2303 independent observed reflections. The C—S bonds (1.877(6), 1.891(6) Å) are longer than in many similar compounds although the S—S bond (2.040(2) Å) is not. The C—S—S—C torsional angle (108.7(3)°) is larger than normal in dithiol compounds. Other distances and angles are normal. Two types of potassium coordination are present, one a distorted octahedron, the other a distorted trigonal prism. In addition to the ionic interactions, hydrogen bonds involving the water molecules are important in stabilizing the structure.

Crystal Structure of Calcium Picrate Pentahydrate: A New Eight-Coordinate Stereochemistry for [M(bidentate)2(unidentate)4]

1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Water Molecule ◽  
Single Crystal ◽  
Title Compound ◽  
Lattice Site ◽  
The Other ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Triangular Face ◽  
X Ray

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.

Molekülstrukturen, Schwingungsspektren und Konformation der Thiooxalsäurederivate CH3S-CO-CONH2, CH3S-CS-CONH2, C2H5O-CO-CSNH2 und K[OSC-CONH2] / Molecular Structure, Vibrational Spectra and Conformation of the Thiooxalic Acid Derivatives CH3S-CO-CONH2, CH3S-CS-CONH2, C2H5O-CO-CSNH2 and K[OSC-CONH2]

1983 ◽  
Vol 38 (3) ◽  
pp. 335-340 ◽  
Author(s):  
Rainer Mattes ◽  
Franz Waldmann
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Structures ◽  
Sulfur Atom ◽  
Vibrational Spectra ◽  
Torsional Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Centrosymmetric Dimers

Abstract The crystal structures of CH3S-CO-CONH2 (1), CH3S-CS-CONH2 (2), C2H5O-CO-CSNH2 (3) and K[OSC-CONH2] (4) have been determined by single crystal X-ray diffraction. The molecules 1, 2 and 3 are nearly planar and form centrosymmetric dimers by N H···O or N-H···S hydrogen bonds with the amidic oxygen or sulfur atom as acceptor atoms. The anion of 4 is not quite planar. The torsional angle around the C-C bond is 18.4°. The conformations of the title compounds are E, Z' (1 and 2), Z, Z' (3) and Z (4). According to the vibrational spectra, which are discussed briefly, 1 and 3 retain their conformation also in solution.

Säure-Base-Eigenschaften des zyklischen Triamins N,N′,N″-Trimethyl-1,4,7-triazacyclononan: Die Kristallstruktur seiner monoprotonierten Form [C9H22N3]ClO4) / Acid-Base Properties of the Cyclic Triamine N,N′,N″-Trimethyl-1,4,7-triazacyclononane and Crystal Structure of its Monoprotonated Form [C9H22N3](ClO4)

1987 ◽  
Vol 42 (3) ◽  
pp. 279-281 ◽  
Author(s):  
K. Wieghardt ◽  
S. Brodka ◽  
K. Peters ◽  
E. M. Peters ◽  
A. Simon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
The Other ◽  
X Ray Diffraction ◽  
Acid Base ◽  
Amine Nitrogen ◽  
X Ray ◽  
Acidic Proton ◽  
Proposed Model

The crystal structure of the monohydroperchlorate of N,N',N"-trimethyl-1,4,7-triazacyclo-nonane, [C9H22N3](ClO4), has been determined by single crystal X-ray diffraction. The acidic proton of the cation is bonded to one amine nitrogen and it forms hydrogen bonds to the other two N-atoms in agreement with a proposed model, which has been invoked to interpret successive protonation constants of cyclic triamines. The salt [Me6[9]aneN3](BF4)3 has also been prepared

A new hydrated ammonium hydroxyborate, (NH4)2[B10O14(OH)4]·H2O

2003 ◽  
Vol 59 (11) ◽  
pp. i115-i116 ◽  
Author(s):  
Lin-Yan Li ◽  
Guo-Bao Li ◽  
Ming Xiong ◽  
Ying-Xia Wang ◽  
Jian-Hua Lin
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Title Compound ◽  
Building Blocks ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Ammonium Ions ◽  
Synthetic Compound ◽  
Triclinic Space Group ◽  
X Ray

The structure of a new synthetic compound, diammonium tetrahydroxydecaborate monohydrate, has been determined by single-crystal X-ray diffraction. It crystallizes in triclinic space group P\overline 1 and all atoms occupy general sites. The title compound is composed of [B10O15(OH)4]4− ions as the fundamental building blocks, and these are linked end-to-end by sharing two common O atoms, thus producing infinite chains of composition [B10O14(OH)4] n 2n–. These chains are linked by hydrogen bonds, thus forming borate sheets. Water molecules and ammonium ions between these sheets connect adjacent sheets via hydrogen bonds.

(Hydroxymethyl)diphenyl(piperidinoalkyl)silane des Typs (HOCH2)(C6H5)2Si(CH2)nNC5H10(n=2,3) und deren Methoiodide: Synthese, Struktur und antimuscarinische Eigenschaften / (Hydroxymethyl)diphenyl(piperidinoalkyl)silanes of the Type (HOCH2)(C6H5)2Si(CH2)nNC5H10(n = 2,3) and their Methiodides: Synthesis, Structure and Antimuscarinic Properties

1994 ◽  
Vol 49 (7) ◽  
pp. 898-910 ◽  
Author(s):  
Reinhold Tacke ◽  
Martin Kropfgans ◽  
Andrea Tafel ◽  
Frank Wiesenberger ◽  
William S. Sheldrick ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Related Compound ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Independent Molecules ◽  
Ir Spectroscopic ◽  
Centrosymmetric Dimers

Abstract Starting from (MeO)3SiCH2Cl (10) and Ph2(H)SiCH2OH (16), respectively, the (hydroxymethyl)diphenyl(piperidinoalkyl)silanes (HOCH2)Ph2Si(CH2)2NC5H10 (6) and (HOCH2)Ph2Si(CH2)3NC5H10 (8) have been synthesized [10→Ph2(MeO)SiCH2Cl (11)→Ph2(CH2=CH)SiCH2Cl (12)→Ph2(CH2=CH)SiCH2OAc (13)→Ph2(CH2=CH)SiCH2OH (14)→Ph2(CH2=CH)SiCH2OSiMe3 (15)→6; 16→Ph2(H)SiCH2OSiMe3 (17)→8; NC5H10 = piperidino]. N-Quaternization of 6 and 8 with MeI gave the corresponding methiodides 7 and 9, respectively. As shown by IR-spectroscopic studies, compounds 6 and 8 form intramolecular O-H···N hydrogen bonds in solution (CCl4). In the crystal, 6 (space group Pna21; two crystallographically independent molecules) also forms intramolecular O-H···N hydrogen bonds whereas 8 (space group P1̅) forms intermolecular O-H···N hydrogen bonds leading to the formation of centrosymmetric dimers (single-crystal X-ray diffraction studies). The (hydroxymethyl) silanes 6-9 and the related silanols (HO)Ph2Si(CH2)2NC5H 10 (sila-pridinol; 1), sila-pridinol methiodide (2), (HO)Ph2Si(CH2)3NC5H10 (sila-difenidol; 3) and sila-difenidol methiodide (4) were investigated for their antimuscarinic properties. In functional pharmacological experiments as well as in radioligand competition studies, all compounds behaved as simple competitive antagonists at muscarinic M1-, M2-, M3- and M4-receptors. In general, the silanols 1-4 displayed higher receptor affinities (up to 100-fold) than the corresponding (hydroxymethyl) silanes 6-9 . In the (hydroxymethyl)silane series, compound 7 was found to be the most potent muscarinic antagonist [pA2/pKi= 8,71/8,6 (M1), 8,23/7,8 (M2), 8,19/7,8 (M3); pKi = 8,2 (M4)]. In the silanol series, the related compound 2 showed the most interesting antimuscarinic properties [pA2/pKi = 10,37/9,6 (M1), 8,97/8,8 (M2), 9,08/8,8 (M3); pKi = 9,4 (M4)].

scholarly journals X-ray crystal structure of trans-bis(pyridin-3-yl)ethylene: comparing the supramolecular structural features among the symmetrical bis(n-pyridyl)ethylenes (n = 2, 3, or 4) constitutional isomers

2020 ◽  
Vol 76 (12) ◽  
pp. 1859-1862
Author(s):  
Jay Quentin ◽  
Eric W. Reinheimer ◽  
Leonard R. MacGillivray
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Structural Features ◽  
The Other ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Packing Assembly

The molecular structure of trans-bis(pyridin-3-yl)ethylene (3,3′-bpe), C12H10N2, as determined by single-crystal X-ray diffraction is reported. The molecule self-assembles into two dimensional arrays by a combination of C—H...N hydrogen bonds and edge-to-face C—H...π interactions that stack in a herringbone arrangement perpendicular to the crystallographic c-axis. The supramolecular forces that direct the packing of 3,3′-bpe as well as its packing assembly within the crystal are also compared to those observed within the structures of the other symmetrical isomers trans-1,2-bis(n-pyridyl)ethylene ( n , n ′-bpe, where n = n′ = 2 or 4).

Structural Study of an Unusual Diels-Alder Adduct

1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Diffraction Study ◽  
Structural Study ◽  
Spectroscopic Studies ◽  
Diels Alder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Chemical Evidence ◽  
Alder Adduct

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.

Molecular tapes in the structure of isoguaninium chloride

2017 ◽  
Vol 74 (1) ◽  
pp. 108-112 ◽  
Author(s):  
Urszula Anna Budniak ◽  
Paulina Maria Dominiak
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Charge Density ◽  
Interaction Energy ◽  
Electrostatic Interaction ◽  
Electrostatic Interactions ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Structure

Isoguanine, an analogue of guanine, is of intrinsic interest as a noncanonical nucleobase. The crystal structure of isoguaninium chloride (systematic name: 6-amino-2-oxo-1H,7H-purin-3-ium chloride), C5H6N5O+·Cl−, has been determined by single-crystal X-ray diffraction. Structure analysis was supported by electrostatic interaction energy (E es) calculations based on charge density reconstructed with the UBDB databank. In the structure, two kinds of molecular tapes are observed, one parallel to (010) and the other parallel to (50\overline{4}). The tapes are formed by dimers of isoguaninium cations interacting with chloride anions. E es analysis indicates that cations in one kind of tape are oriented so as to minimize repulsive electrostatic interactions.

Salts of purine alkaloids caffeine and theobromine with 2,6-dihydroxybenzoic acid as coformer: structural, theoretical, thermal and spectroscopic studies

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Mateusz Gołdyn ◽  
Anna Komasa ◽  
Mateusz Pawlaczyk ◽  
Aneta Lewandowska ◽  
Elżbieta Bartoszak-Adamska
Keyword(s):  
Hydrogen Bonds ◽  
Water Solubility ◽  
Theoretical Calculations ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Purine Alkaloids ◽  
Vis Spectroscopy

The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.

Thermal-induced transformation of glutamic acid to pyroglutamic acid and self-cocrystallization: a charge–density analysis

2022 ◽  
Vol 78 (2) ◽  
Author(s):  
Sehrish Akram ◽  
Arshad Mehmood ◽  
Sajida Noureen ◽  
Maqsood Ahmed
Keyword(s):  
Hydrogen Bonds ◽  
Glutamic Acid ◽  
Single Crystal ◽  
Diffraction Data ◽  
Density Functional ◽  
Quantitative Estimation ◽  
Topological Analysis ◽  
Pyroglutamic Acid ◽  
X Ray Diffraction ◽  
X Ray

Thermal-induced transformation of glutamic acid to pyroglutamic acid is well known. However, confusion remains over the exact temperature at which this happens. Moreover, no diffraction data are available to support the transition. In this article, we make a systematic investigation involving thermal analysis, hot-stage microscopy and single-crystal X-ray diffraction to study a one-pot thermal transition of glutamic acid to pyroglutamic acid and subsequent self-cocrystallization between the product (hydrated pyroglutamic acid) and the unreacted precursor (glutamic acid). The melt upon cooling gave a robust cocrystal, namely, glutamic acid–pyroglutamic acid–water (1/1/1), C5H7NO3·C5H9NO4·H2O, whose structure has been elucidated from single-crystal X-ray diffraction data collected at room temperature. A three-dimensional network of strong hydrogen bonds has been found. A Hirshfeld surface analysis was carried out to make a quantitative estimation of the intermolecular interactions. In order to gain insight into the strength and stability of the cocrystal, the transferability principle was utilized to make a topological analysis and to study the electron-density-derived properties. The transferred model has been found to be superior to the classical independent atom model (IAM). The experimental results have been compared with results from a multipolar refinement carried out using theoretical structure factors generated from density functional theory (DFT) calculations. Very strong classical hydrogen bonds drive the cocrystallization and lend stability to the resulting cocrystal. Important conclusions have been drawn about this transition.

Sign in / Sign up

Export Citation Format

Share Document