scholarly journals Hydrogen-bonding catalysis of sulfonium salts

2017 ◽  
Vol 53 (1) ◽  
pp. 119-122 ◽  
Author(s):  
Shiho Kaneko ◽  
Yusuke Kumatabara ◽  
Shoichi Shimizu ◽  
Keiji Maruoka ◽  
Seiji Shirakawa
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Atoms ◽  
Sulfonium Salts

The catalytic ability of trialkylsulfonium salts as hydrogen-bonding catalysts on the basis of the characteristic properties of the acidic α hydrogen atoms on alkylsulfonium salts was demonstrated.

Effects of Dodecanoic Acid Modified SIO2 on Filler Dispersion and Ionic Conductivity of PMMA/ENR 50/LIBF4 Electrolytes

2016 ◽  
Vol 846 ◽  
pp. 528-533 ◽  
Author(s):  
Siti Izzati Husna Mohd Azuan ◽  
Famiza Abdul Latif ◽  
Sharil Fadli Mohamad Zamri
Keyword(s):  
Hydrogen Bonding ◽  
Surface Modification ◽  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Dodecanoic Acid ◽  
Hydrogen Atoms ◽  
Casting Technique ◽  
Bonding Interaction ◽  
Filler Dispersion ◽  
Overall Performance

Previously, the addition of silicon dioxide (SiO2) improved the homogeneity of polymethyl methacrylate/50 % epoxidised natural rubber (PMMA/ENR 50) blend. However, the presence of SiO2 agglomerates limits its overall performance. The formation of these agglomerates was due to the hydrogen bonding interaction that form between the oxygen atoms in silanol groups (Si-OH) and hydrogen atoms from the surrounding moisture. Therefore, in this study, SiO2 were modified with dodecanoic acid (DOA) to reduce the number of Si-OH on the SiO2 surface using esterification technique. Interestingly, it was found that the addition of DOA modified SiO2 (D-SiO2) improves the homogeneity of PMMA/ENR 50 blend. However, the amount of DOA used in the modification affect the capability of forming hydrogen bonding with the neighbouring of polymer chain. Different amounts of DOA were used upon the surface modification of SiO2 filler and then were added into PMMA/ENR 50 blends doped with lithium tetrafluoroborate (LiBF4). The films were prepared by solvent casting technique. CHNS analysis proven the increases of percentage of carbon atoms in D-SiO2. The attachment of DOA on SiO2 surface was confirmed using Fourier transform infrared spectroscopy (FTIR) and ionic conductivity of PMMA/ENR 50/LiBF4 filled D-SiO2 films was measured by electrochemical impedance spectroscopy (EIS). The result shows the blend properties and ionic conductivity of PMMA/ENR 50 filled D-SiO2 films was improved due to surface modification of SiO2 filler.

scholarly journals Notizen: Hydrogen Bonding in MoO2Cl2 · H2O Determined by Electrostatic Energy Calculations

1977 ◽  
Vol 32 (11) ◽  
pp. 1358-1359 ◽  
Author(s):  
Werner H. Baur
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Systematic Variation ◽  
Electrostatic Energy ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Energy Calculations ◽  
Internal Geometry

The configuration of least electrostatic energy for the hydrogen atoms in both polytypes of MoO2Cl2 · H2O was obtained by systematic variation of the orientations of the water molecules. The internal geometry of the H2O group was kept constant throughout the variation. The hydrogen bonds are of the bifurcated type: [xxx]

Lateral, Chiral Tin(IV) Porphyrin Assemblies

1998 ◽  
Vol 02 (03) ◽  
pp. 273-284 ◽  
Author(s):  
BIANCA ROSENGARTEN ◽  
CHRISTOPH BÖTTCHER ◽  
ANDREA SCHULZ ◽  
J.-H. FUHRHOP ◽  
ULRICH SIGGEL
Keyword(s):  
Hydrogen Bonding ◽  
Lactic Acid ◽  
Circular Dichroism ◽  
Hydrochloric Acid ◽  
Protoporphyrin Ix ◽  
Mirror Image ◽  
Chloride Ions ◽  
Hydrogen Atoms ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

The μ-Oxo stacks of tin(IV) porphyrins rearrange to staircase-type and lateral aggregates upon replacement of the oxygen ligands by chloride ions. The lateral aggregation of tin(IV) 2,18-dipropionate porphyrins in hydrochloric acid at pH 0–0.5 is favoured by 8,13-ethyl groups instead of the natural 8,13-vinyl groups of protoporphyrin IX and is impeded by hydrogen atoms at these positions. Replacement of axial chloride counterions to the tin(IV) central ions by cyanate counterions at pH 4.5 leads to similar aggregates if the cyanate ions are connected by hydrogen bonding to acetic or lactic acid. In this case, aggregation is not necessarily impeded by hydrogen atoms at positions 8 and 13. D- and L-lactic acid enforce chiral assemblies of the tin(IV) deuteroporphyrin 1a with mirror image CD (circular dichroism) spectra (θ ≈ 8 × 105 deg cm 2 dmol −1), whereas the gluconoyl hydrazide-substituted tin(IV) deuteroporphyrin 1d does not form aggregates at all.

scholarly journals The crystal structure of cyanotrichite

2015 ◽  
Vol 79 (2) ◽  
pp. 321-335 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy ◽  
Fernando Colombo ◽  
Jason R. Price
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Local Structure ◽  
Unit Cell ◽  
Group Symmetry ◽  
Hydrogen Atoms ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Bonding Scheme

AbstractWe report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].

Structure, Stereochemistry and Novel 'Hydrogen Bonding' in Two Bipyridinium Salts of the B10H102- Anion

1987 ◽  
Vol 40 (12) ◽  
pp. 2097 ◽  
Author(s):  
DJ Fuller ◽  
DL Kepert ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Charge Transfer ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Structure Determinations ◽  
Positively Charged

Crystal structure determinations of (LH)2(B10H10), (1), and (LH2)(B10H10), (2), L = 2,2'- bipyridine , have been carried out by single-crystal X-ray diffraction methods at 295 K, being refined by full-matrix least squares to residuals of 0.041, 0.047 for 1758, 1771 'observed' independent reflections respectively. Crystals of (1) are monoclinic, P21/n, a 12.040(7), b 17.71(1), c 11.142(4) �, β 101.78(4)�, Z 4. Crystals of (2) are monoclinic, P21/c, a 9.937(4), b 10.837(3), c 14.856(5) �, β 109 2l(3)�, Z 4. The colour of the compounds is accounted for by charge-transfer interactions of a novel type, namely between the positively charged cationic acid hydrogen atoms and the negatively charged non-apical hydrogen atoms of the anion. In yellow (1), these distances are 2.26(5) �, while in red (2), they are much shorter, being 1.89(4), 1.97(3) �.

Bonding and Release of Hydrogen in a-Si:C:H Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
W. Beyer ◽  
H. Wagner ◽  
H. Mell
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Content ◽  
Thermal Instability ◽  
Amorphous Material ◽  
Discharge Process ◽  
Hydrogen Atoms ◽  
Hydrogen Density ◽  
Optical Gap ◽  
Absorption Studies

AbstractHydrogen evolution and infrared absorption studies of a-Si:C:H films prepared from mixtures of hydrocarbon (CH4' C2H6' C2H4) and silane gases (SiH4 'Si2H6)by the glow-discharge process show that both the absolute hydrogen content and the hydrogen bonding is uniquely determined by the carbon content. Up to a carbon concentration of ∼45 % the widening of the optical gap is mainly due to an increase of the hydrogen content. For a hydrogen density NH > 1- 2x1022cm-3 the incorporated hydrogen atoms lead to the formation of voids, resulting in thermal instability of the bonded hydrogen and in a deterioration of the electronic quality of the amorphous material.

scholarly journals Quinine dihydrochloride hemihydrate

IUCrData ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Grace I. Anderson ◽  
Sophia Bellia ◽  
Matthias Zeller ◽  
Patrick C. Hillesheim ◽  
Arsalan Mirjafari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Double Bond ◽  
Long Range ◽  
Title Compound ◽  
Asymmetric Unit ◽  
Hydrogen Atoms ◽  
Non Covalent Interactions ◽  
Long Range Ordering ◽  
Covalent Interactions

Numerous non-covalent interactions link together discrete molecules in the crystal structure of the title compound, 2C20H26N2O2 2+·4Cl−·H2O {systematic name: 4-[(5-ethenyl-1-azoniabicyclo[2.2.2]octan-2-yl)(hydroxy)methyl]-6-methoxyquinolin-1-ium dichloride hemihydrate}. A combination of hydrogen bonding between acidic H atoms and the anions in the asymmetric unit forms a portion of the observed hydrogen-bonded network. π–π interactions between the aromatic portions of the cation appear to play a role in the formation of the long-range ordering. One ethylene double bond was found to be disordered. The disorder extends to the neighboring carbon and hydrogen atoms.

The Structure Directing Effect of Hydrogen Bonding in the Novel Polymeric Thioantimonate Mn2(H2N(CH2)2NH2)2Sb2S5

2002 ◽  
Vol 57 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Michael Schur ◽  
Wolfgang Bensch
Keyword(s):  
Hydrogen Bonding ◽  
Transition Metal ◽  
Title Compound ◽  
The Novel ◽  
Hydrogen Atoms ◽  
Structure Pattern ◽  
Secondary Building Units ◽  
Covalently Linked ◽  
Directing Effect ◽  
Solvothermal Conditions

A new transition metal thioantimonate(III) with composition Mn2(H2N(CH2)2NH2)Sb2S5 has been synthesised under solvothermal conditions. Two trigonal SbSb3 pyramids and two octahedrally coordinated Mn atoms are interconnected to form Mn2SbS4 heterocubanes as secondary building units (SBU’s). The SBU’s are covalently linked into linear infinite onedimensional rods. Long Sb-S bonds connect the rods to form layers. The two N atoms of the ethylenediamine molecule (en) are chelating one Mn(II) ion. The amino hydrogen atoms of the en ligand are engaged in hydrogen bonding which is responsible for the different structure pattern of the title compound compared to a previously reported series of Mn-amino-thioantimonates(III) with analogous stoichiometry built up from different amino ligands.

scholarly journals Site Dependent Hydrogenation in Graphynes: A Fully Atomistic Molecular Dynamics Investigation

2015 ◽  
Vol 1726 ◽  
Author(s):  
Pedro A. S. Autreto ◽  
Douglas S. Galvao
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonding ◽  
Structural Changes ◽  
Hydrogen Atoms ◽  
Carbon Allotrope ◽  
Reactive Molecular Dynamics ◽  
Triple Bonds ◽  
Covalently Bonded ◽  
Hydrogenation Reactions ◽  
Dynamics Simulations

ABSTRACTGraphyne is a generic name for a carbon allotrope family of 2D structures, where acetylenic groups connect benzenoid rings, with the coexistence of sp and sp2 hybridized carbon atoms. In this work we have investigated, through fully atomistic reactive molecular dynamics simulations, the dynamics and structural changes of the hydrogenation of α, β, and γ graphyne forms. Our results showed that the existence of different sites for hydrogen bonding, related to single and triple bonds, makes the process of incorporating hydrogen atoms into graphyne membranes much more complex than the graphene ones. Our results also show that hydrogenation reactions are strongly site dependent and that the sp-hybridized carbon atoms are the preferential sites to chemical attacks. In our cases, the effectiveness of the hydrogenation (estimated from the number of hydrogen atoms covalently bonded to carbon atoms) follows the α, β, γ-graphyne structure ordering.

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