Acid-induced formation of hydrogen-bonded double helix based on chiral polyphenyl-bridged bis(2,2′-bipyridine) ligands

RSC Advances ◽  
2014 ◽  
Vol 4 (28) ◽  
pp. 14513-14526 ◽  
Author(s):  
Kiu-Chor Sham ◽  
Chi-Chung Yee ◽  
Yi Pan ◽  
Kai-Chung Lau ◽  
Shek-Man Yiu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Perchloric Acid ◽  
Double Helix ◽  
X Ray ◽  
Hydrogen Bonded

Chiral polyphenyl-bridged bis(2,2′-bipyridine) ligands L2–4 give intense CD signals when protonated with tetrachloroferric acid or perchloric acid. X-ray crystal structure of [(L2)2H2](FeCl4)2 shows that a double-stranded helix stabilized by both interior and exterior hydrogen bonding is formed. Theoretical DFT calculations show that such stabilization exists in solution.

scholarly journals Synthesis, Crystal Structure, and DFT Calculations of 1,3-Diisobutyl Thiourea

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Ataf A. Altaf ◽  
Adnan Shahzad ◽  
Zarif Gul ◽  
Sher A. Khan ◽  
Amin Badshah ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Single Crystal ◽  
Crystal Packing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Model Support

1,3-Diisobutyl thiourea was synthesized and characterized by single crystal X-ray diffraction. It gives a monoclinic (α=γ= 90 andβ  ≠90) structure with the space group P21/c. The unit cell dimensions area= 11.5131 (4) Å,b= 9.2355 (3) Å,c= 11.3093 (5) Å,α= 90°,β= 99.569° (2),γ= 90°,V= 1185.78 (8) Å3, andZ= 4. The crystal packing is stabilized by intermolecular (N–H⋯S) hydrogen bonding in the molecules. The optimized geometry and Mullikan's charges of the said molecule calculated with the help of DFT using B3LYP-6-311G model support the crystal structure.

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
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dithiolate Complexes ◽  
Hydrogen Bonded

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.

Heterocyclic Tautomerism. IV. The Solution and Crystal Structures of 1-Aryl-3-phenyl-1,2,4-triazol-5-ones

1988 ◽  
Vol 41 (4) ◽  
pp. 419 ◽  
Author(s):  
AD Rae ◽  
CG Ramsay ◽  
PJ Steel
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Solid State ◽  
Crystal Structures ◽  
Complex Network ◽  
Water Molecules ◽  
X Ray ◽  
Structure Determinations ◽  
Hydrogen Bonded

The title compounds are shown to exist in solution and in the solid state as 4H-tautomers. X-Ray crystal structure determinations show that 1,3-diphenyl-1,2,4-triazol-5-one exists as a dimeric pair of strongly hydrogen-bonded molecules and that 3-phenyl-1-(2-pyridyl)-1,2,4- triazol-5-one exists as the 4H-tautomer stabilized by a complex network of hydrogen bonding to water molecules.

Solid-state and gas-phase structures of two conformers of N-(4-methylphenyl)-N′,N′′-bis(morpholinyl) phosphoric triamide; insights from X-ray crystallography and DFT calculations

2011 ◽  
Vol 67 (3) ◽  
pp. 238-243 ◽  
Author(s):  
Khodayar Gholivand ◽  
Hamid Reza Mahzouni
Keyword(s):  
Hydrogen Bonding ◽  
Solid State ◽  
Dft Calculations ◽  
Gas Phase ◽  
Bond Critical Point ◽  
X Ray ◽  
X Ray Crystallography ◽  
Equal Chance ◽  
Phosphoric Triamide ◽  
Hydrogen Bonded

A phosphoric triamide with the formula (4-CH3—C6H4NH)P(O)(NC4H8O)2 has been synthesized and characterized. X-ray crystallography at 120 K reveals that the title compound is composed of two symmetrically independent molecules in the solid state. Density functional theory (DFT) calculations reveal that two conformers A and B are very close to each other from an energy point of view. Thus there is equal chance that the presence of two conformers in the lattice may lead to hydrogen-bonded chains with an ABABAB arrangement. Hydrogen bonds of the type OP...H—N (OP being the phosphoryl O atom) are established between the two conformers with binding energies of −18.8 and −20.3 kJ mol−1 (at B3LYP/6–31+G*). The electronic delocalization LP(OP) → σ*(N—H), LP(OP) being the lone pair of OP, leads to a decrease in the strength of the N—H bond during hydrogen bonding between the conformers. The charge density (ρ) at the bond critical point (b.c.p.) of N—H decreases by ∼ 0.012–0.014 e Å–3 when the molecule participates in hydrogen bonding. This may explain the red shift of the ν(N—H) stretching frequency from a single molecule in the gas phase to a hydrogen-bonded one in the solid state.

scholarly journals Exploring the Structural Chemistry of Pyrophosphoramides: N,N′,N″,N‴-Tetraisopropylpyrophosphoramide

Chemistry ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 149-163
Author(s):  
Duncan Micallef ◽  
Liana Vella-Zarb ◽  
Ulrich Baisch
Keyword(s):  
Crystal Structure ◽  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Intermolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
X Ray

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.

The molecular and crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

The crystal structure of gatehouseite

2011 ◽  
Vol 75 (6) ◽  
pp. 2823-2832
Author(s):  
P. Elliott ◽  
A. Pring
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Direct Methods ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manganese Phosphate ◽  
Phosphate Mineral ◽  
Unit Formula

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space group P212121, a = 17.9733(18), b = 5.6916(11), c = 9.130(4) Å, V= 933.9(4) Å3, Z = 4, has been solved by direct methods and refined from single-crystal X-ray diffraction data (T = 293 K) to an R index of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6 octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6 octahedra coupled by PO4 tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.

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