Preparation of Rhenium Diamino Dithiolate Complexes. The X-Ray Crystal Structure of Oxo(1,1,8,8-tetraethyl-3,6-diazaoctane-1,8-dithiolato)rhenium

1993 ◽  
Vol 46 (7) ◽  
pp. 1093 ◽  
Author(s):  
TW Jackson ◽  
M Kojima ◽  
RM Lambrecht

The complexes oxo (1,1,8,8-tetraethyl-3,6-diazaoctane-1,8-dithiolato)rhenium[ ReO ( tedadt )], oxo (1,1,8,8-tetraethyl-4,4-dimethyl-3,6-diazaoctane-1,8-dithiolato)rhenium [ ReO ( tedmdadt )] and (1,1,4,4,8,8-hexamethyl-3,6-diazaoctane-1,8-dithiolato) oxorhenium [ ReO ( hmdadt )] were prepared. The crystal structure of the complex ReO ( tedadt ) was determined by X-ray crystallography to be a hydrogen-bonded dimer . This is the first example of intermolecular hydrogen bonding in rhenium diamino dithiolate ( dadt ) complexes.

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch

N,N′,N″,N‴-Tetraisopropylpyrophosphoramide 1 is a pyrophosphoramide with documented butyrylcholinesterase inhibition, a property shared with the more widely studied octamethylphosphoramide (Schradan). Unlike Schradan, 1 is a solid at room temperature making it one of a few known pyrophosphoramide solids. The crystal structure of 1 was determined by single-crystal X-ray diffraction and compared with that of other previously described solid pyrophosphoramides. The pyrophosphoramide discussed in this study was synthesised by reacting iso-propyl amine with pyrophosphoryl tetrachloride under anhydrous conditions. A unique supramolecular motif was observed when compared with previously published pyrophosphoramide structures having two different intermolecular hydrogen bonding synthons. Furthermore, the potential of a wider variety of supramolecular structures in which similar pyrophosphoramides can crystallise was recognised. Proton (1H) and Phosphorus 31 (31P) Nuclear Magnetic Resonance (NMR) spectroscopy, infrared (IR) spectroscopy, mass spectrometry (MS) were carried out to complete the analysis of the compound.


1989 ◽  
Vol 44 (8) ◽  
pp. 942-945 ◽  
Author(s):  
Wolfgang Schnick

Phosphorothionic triamide SP(NH2)3 is obtained by slow addition of SPCl3 dissolved in dry CH2Cl2 to a satured solution of NH3 in CH2Cl2 at —50°C. Ammonium chloride is removed from the resulting precipitate by treatment with HNEt2 followed by extraction with CH2Cl2. Coarse crystalline SP(NH2)3 is obtained after recrystallization from dry methanol. The crystal structure of SP(NH2)3 has been determined by single crystal X-ray methods (Pbca; a = 922.3(1), b = 953.8(1), c = 1058.4(2) pm, Z = 8). In the crystals the molecules show non-crystallographic point symmetry C8. The P—S bond (195.4(1) pm) is slightly longer than in SPCl3. From P—N bond lengths of about 166 pm a significant electrostatic strengthening of the P—N single bonds is assumed. Weak intermolecular hydrogen bonding interactions (N —H · · · N ≥ 329.5 pm; N — H · · · S ≥ 348.3 pm) are observed.Investigation of thermal properties shows a melting temperature of 115°C for SP(NH2)3. According to combined DTA/TG and MS investigations above this temperature the compound decomposes by evolution of H2S and NH3 to yield amorphous phosphorus(V)nitride.


1996 ◽  
Vol 49 (2) ◽  
pp. 239 ◽  
Author(s):  
TW Jackson ◽  
M Kojima ◽  
RM Lambrecht ◽  
DC Craig ◽  
AD Rae

The complex oxo(1,1,8,8-tetramethyl-3-hexyl-3,6-diazaoctane-1,8-dithiolato)rhenium(V) was prepared, and the crystal structure was determined by X-ray crystallography. This compound was more lipophilic than the previously published oxo(1,1,8,8-tetraethyl-3,6-diazaoctane-1,8-dithiolato)rhenium(V) (1c).


1978 ◽  
Vol 56 (7) ◽  
pp. 1020-1025 ◽  
Author(s):  
Farid R. Ahmed ◽  
Angs Ng ◽  
Alex G. Fallis

Methanol extraction of the ground seeds of Uncaria Gambier Roxb. followed by chromatography afforded a crystalline C30H38O10 terpene. This has been shown by X-ray analysis to be 7α-acetoxydihydronomilin. The crystals are orthorhombic, P212121, a = 13.158(2), b = 17.092(2), c = 12.689(2) Å, Z = 4, dx = 1.300, do = 1.300 g cm−3. The structure has been determined by the direct method and Fourier syntheses, and refined by block-diagonal least-squares to R = 0.042 for 2621 observed reflexions. The molecule contains a seven-membered lactone ring A, three six-membered rings B, C, D, a three-membered ring E, a furan ring F, and two acetate groups. A and B are chair, C is twist-boat, D is 1,3-diplanar, while E and F are planar. The A/B, A/C, C/D junctions are trans, D/E is cis, and F is linked to D by an equatorial C—C bond. The two acetate groups are in axial positions on A and B and are cis to each other. The O atom forming the apex of the three-membered ring is wedged between two H atoms and their parent C atoms at short intramolecular distances O … H = 2.28(2) and 2.28(3), and O … C = 2.623(3) and 2.668(4) Å. No intermolecular hydrogen bonding is indicated.


2018 ◽  
Vol 73 (5) ◽  
pp. 281-288
Author(s):  
Qing Zhao ◽  
Ying-Qi Pan ◽  
Xiao-Yan Li ◽  
Han Zhang ◽  
Wen-Kui Dong

AbstractA discrete heterotrinuclear complex [{Ni2LDy(OAc)3(CH3OH)}2] · 2CH3OH · 3CH2Cl2, with a naphthalenediol-based acyclic bis(salamo) ligand H4L, has been synthesized and structurally characterized using elemental analyses, IR, UV/Vis and fluorescence spectra and single crystal X-ray diffraction. The crystal structure shows two crystallographically independent but chemically identical molecules (molecules I and II). All the Ni(II) atoms are hexa-coordinated with slightly distorted octahedral geometries. The central Dy atoms are nona-coordinated with slightly distorted tricapped trigonal prism geometries. An infinite 3D supramolecular structure is formed via intermolecular hydrogen bonding and C–H…π interactions.


2004 ◽  
Vol 82 (2) ◽  
pp. 386-398 ◽  
Author(s):  
Dominic Laliberté ◽  
Thierry Maris ◽  
James D Wuest

Tetraphenylmethane, tetraphenylsilane, and simple derivatives with substituents that do not engage in hydrogen bonding typically crystallize as close-packed structures with essentially no space available for the inclusion of guests. In contrast, derivatives with hydrogen-bonding groups are known to favor the formation of open networks that include significant amounts of guests. To explore this phenomenon, we synthesized six new derivatives 5a–5e and 6a of tetraphenylmethane and tetraphenylsilane with urethane and urea groups at the para positions, crystallized the compounds, and determined their structures by X-ray crystallography. As expected, all six compounds crystallize to form porous three-dimensional hydrogen-bonded networks. In the case of tetraurea 5e, 66% of the volume of the crystals is accessible to guests, and guests can be exchanged in single crystals without loss of crystallinity. Of special note are: (i) the use of tetrakis(4-isocyanatophenyl)methane (1f) as a precursor for making enantiomerically pure tetraurethanes and tetraureas, including compounds 5b, 5c; and (ii) their subsequent crystallization to give porous chiral hydrogen-bonded networks. Such materials promise to include chiral guests enantioselectively and to be useful in the separation of racemates, asymmetric catalysis, and other applications.Key words: crystal engineering, molecular tectonics, hydrogen bonding, networks, porosity, urethanes, ureas, tetraphenylmethane, tetraphenylsilane.


2002 ◽  
Vol 21 (22) ◽  
pp. 4575-4577 ◽  
Author(s):  
Vadapalli Chandrasekhar ◽  
Ramamoorthy Boomishankar ◽  
Sanjay Singh ◽  
Alexander Steiner ◽  
Stefano Zacchini

1996 ◽  
Vol 52 (6) ◽  
pp. 989-998 ◽  
Author(s):  
Q. Li ◽  
T. C. W. Mak

The new inclusion complexes tetraethylammonium nitrate–thiourea (1:3), (C2H5)4N+.NO3 −. 3(NH2)2CS (1), tetra-n-propylammonium nitrate–thiourea–water (1:3:1), (n-C3H7)4N+.NO3 −.3(NH2)2CS.H2O (2), tetramethylammonium nitrate–thiourea (1:1), (CH3)4N+.NO3 −.(NH2)2CS (3), tetra-n-propylammonium nitrate–thiourea (1:1), (n-C3H7)4N+.NO3 −. (NH2)2CS (4), and tetra-n-butylammonium nitrate–thiourea (1:1), (n-C4H9)4N+.NO3 −.(NH2)2CS (5) have been prepared and characterized by X-ray crystallography. Crystal data, Mo Kα: (1), space group P{\bar 1}, a = 10.300 (2), b = 14.704 (3), c = 15.784 (4) Å, α = 75.30 (3), β = 86.98 (3), γ = 72.25 (3)°, Z = 4 and RF = 0.039 for 5034 observed data; (2), space group P21/n, a = 8.433 (2), b = 9.369 (2), c = 34.361 (7) Å, β = 91.01 (3)°, Z = 4 and RF = 0.050 for 2475 observed data; (3), space group Pnma, a = 15.720 (3), b = 8.218 (2), c = 8.709 (2) Å, Z = 4 and RF = 0.073 for 579 observed data; (4), space group P21/n, a = 8.784 (2), b = 14.421 (3), c = 15.078 (3) Å, β = 92.31 (3)°, Z = 4 and RF = 0.046 for 2507 observed data; (5), space group Pna21, a = 19.934 (3), b = 12.680 (2), c = 9.092 (3) Å, Z = 4 and RF = 0.047 for 1646 observed data. In the crystal structure of (1) infinite chains each composed of an alternate arrangement of a twisted thiourea trimer and a nitrate ion are cross-linked to form a puckered layer and further hydrogen bonding between such layers leads to a channel host framework for accommodation of the cationic guests. In the crystal structure of (2) two independent thiourea molecules are used to construct a hydrogen-bonded puckered layer normal to the c axis, whereas the remaining thiourea molecule, together with the nitrate ion and water molecule, generate another puckered layer that is parallel to the first. Hydrogen bonding between these two types of layers gives rise to a channel system running parallel to the [100] direction and the cations are stacked regularly within each column. Compounds (3), (4) and (5) have closely related crystal structures in which the cations are separated by one-dimensional, infinitely extended thiourea–nitrate composite ribbons in a sandwich-like packing arrangement.


2014 ◽  
Vol 70 (11) ◽  
pp. 1007-1010 ◽  
Author(s):  
Cristian Paz Robles ◽  
Viviana Burgos ◽  
Sebastián Suarez ◽  
Ricardo Baggio

The natural compound dendocarbin A, C15H22O3, is a sesquiterpene lactone isolated for the first time fromDrimys winterifor var chilensis. The compound crystallizes in the orthorhombic space groupP212121and its X-ray crystal structure confirmed theS/Rcharacter of the chiral centres at C-5/C-10 and C-9/C-11, respectively. The α-OH group at C-11 was found to be involved in intermolecular hydrogen bonding, defining chains along the <100> 21screw axis.


1976 ◽  
Vol 31 (10) ◽  
pp. 1421-1422 ◽  
Author(s):  
T. Stanley Cameron ◽  
James D. Healy ◽  
Robert A. Shaw ◽  
Michael Woods

The structure of the title compound was determined by X-ray crystallography. The compound is a cyclic dimer with short N···O and N···S contacts.


Sign in / Sign up

Export Citation Format

Share Document