Alkylammonium hexachlorostannates(IV), (RnNH4−n)2SnCl6: crystal structure, infrared spectrum, and hydrogen bonding

1983 ◽  
Vol 61 (7) ◽  
pp. 1620-1646 ◽  
Author(s):  
Osvald Knop ◽  
T. Stanley Cameron ◽  
Margaret Ann James ◽  
Michael Falk
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Fermi Resonance ◽  
Molecular Volume ◽  
Site Symmetry ◽  
Dilution Technique ◽  
Orientational Disorder ◽  
Anomalous Temperature ◽  
Ammonium Compounds ◽  
Anion Packing

In an effort to advance our understanding of the principles governing the structures of and the hydrogen bonding in alkylammonium hexachlorostannates(IV), (RnNH4−n)2SnCl6, we have determined the room-temperature crystal structures of (Me2NH2)2SnCl6 and (Me3NH)2SnCl6 (variants of the antifluorite structure); (EtNH3)2SnCl6 and (n-PrNH3)2SnCl6 (anti-Cdl2 type, with orientational disorder in the Et compound); and (n-Pr3NH)2SnCl6. We have also studied the infrared spectra in the regions of the NH and ND stretching fundamentals, between 10 and 293 K, of these five compounds and of (MeNH3)2SnCl6, (Me3NH)2SnBr6, (Et2NH2)2SnCl6, (n-Bu3NH)2SnCl6 and, in less detail, the mixed-anion salt (n-Pr2NH2)3(SnCl6)Cl. The spectra are often complicated by Ferim resonance involving absorptions diagnostically critical for the strength and type of [Formula: see text] bonding and for the site symmetry at the N atom. In this respect they are less useful than the corresponding spectra of the unsubstituted ammonium compounds reported previously. Several of the spectra provide striking examples of temperature-tuned Fermi resonance of NH and ND vibrations. The [Formula: see text] bonds are invariably trifurcated, bifurcated, or at least highly bent; these characteristics give rise to anomalous temperature dependence of the frequencies of the NH and ND stretching fundamentals. Temperature-induced transitions were detected in (Me2NH2)2SnCl6 (Ttr ~ 100 K), Et NH3)2SnCl6 (Ttr ~ 125 K), and (Et2NH2)2SnCl6 (Ttr ~ 330 K). The specific results for the ten compounds studied arc discussed in detail. The discussion also includes the limits of usefulness of the isotopisc dilution technique; symmetry aspects of the cation–anion packing in alkylammonium hexahalometallates(IV); symmetries of the arrangements of the SnCl6 octahedra; the geometry of hydrogen bonding in (RnNH4−n)2SnCl6; and the possibility of detection of the presence of hydrogen bonding from molecular volume trends.

Triethylammonium halides, Et3NHX (X = Cl, Br, I): simple structure, complex spectrum

1985 ◽  
Vol 63 (7) ◽  
pp. 1750-1758 ◽  
Author(s):  
Margaret Ann James ◽  
T. Stanley Cameron ◽  
Osvald Knop ◽  
Murray Neuman ◽  
Michael Falk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Ir Spectra ◽  
Structure Determination ◽  
Room Temperature ◽  
Simple Structure ◽  
Fermi Resonance ◽  
Crystal Structure Determination ◽  
Complex Spectrum ◽  
Resonance Interactions

A crystal structure determination has shown that the ethyl groups in the three isostructural (P63mc, Z = 2) triethylammonium halides, Et3NHX (X = Cl, Br, I), at room temperature are orientationally disordered and the [Formula: see text] groups are linear by symmetry. The unusual extent and complexity of the NH and ND stretching absorptions in the ir spectra of all three compounds between 10 and 293 K are discussed in terms of Fermi resonance interactions. The centroid ν(NH) and ν(ND) frequencies extracted from the spectra correlate with the [Formula: see text] distances. It is shown that if Fermi resonance is the sole cause of the complexity of the stretching absorptions, then these centroids represent the ν(NH) and ν(ND) frequencies unperturbed by Fermi resonance. The centroid frequencies in the three halides are unusually low, pointing to strong [Formula: see text] hydrogen bonding.

Bis(triethylammonium) hexachlorostannate (IV): crystal structure and hydrogen bonding

1981 ◽  
Vol 59 (16) ◽  
pp. 2550-2555 ◽  
Author(s):  
Osvald Knop ◽  
T. Stanley Cameron ◽  
Margaret Ann James ◽  
Michael Falk
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Room Temperature ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Fermi Resonance ◽  
Ammonium Compound ◽  
Compound A ◽  
Stretching Vibration ◽  
Cl Atoms

The crystal structure of (Et3NH)2SnCl6 at room temperature consists of a monoclinically distorted antifluorite packing of Et3NH+ and SnCl62− ions. Each anion has two cations centrosymmetrically associated with it through bifurcated hydrogen bonds to four of the Cl atoms, leaving two of the six chlorines unengaged. The bifurcation is nearly symmetric and the [Formula: see text] group is nearly planar. Infrared spectra of undeuterated and partially deuterated polycrystalline (Et3NH)2SnCl6 show that the NH stretching vibration is essentially uncoupled while the corresponding ND vibration undergoes a complex Fermi resonance resulting in a multiplet in the spectrum of even weakly deuterated material. The hydrogen bonding in (Et3NH)2SnCl6 is stronger than in the corresponding ammonium compound. A negative temperature coefficient of the NH and ND stretching frequencies is consistent with the bifurcation of the hydrogen bond. If a low-temperature transition exists, it was not evident in the NH and ND stretching absorptions.

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 hydrogen-bonding properties of a room temperature phosphorescence cellulose substrate

1986 ◽  
Vol 90 (21) ◽  
pp. 4941-4945 ◽  
Author(s):  
Georg W. Suter ◽  
Alan J. Kallir ◽  
Urs P. Wild ◽  
Tuan Vo-Dinh
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Room Temperature Phosphorescence ◽  
Cellulose Substrate ◽  
Bonding Properties

scholarly journals Crystal structure of the new hybrid material bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate

2015 ◽  
Vol 71 (11) ◽  
pp. 1384-1387
Author(s):  
Marwen Chouri ◽  
Habib Boughzala
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Room Temperature ◽  
Molar Ratio ◽  
Water Molecules ◽  
Site Symmetry ◽  
Two Dimensional ◽  
Slow Evaporation ◽  
Solution Ph

The title compound bis(1,4-diazoniabicyclo[2.2.2]octane) di-μ-chlorido-bis[tetrachloridobismuthate(III)] dihydrate, (C6H14N2)2[Bi2Cl10]·2H2O, was obtained by slow evaporation at room temperature of a hydrochloric aqueous solution (pH = 1) containing bismuth(III) nitrate and 1,4-diazabicyclo[2.2.2]octane (DABCO) in a 1:2 molar ratio. The structure displays a two-dimensional arrangement parallel to (100) of isolated [Bi2Cl10]4−bioctahedra (site symmetry -1) separated by layers of organic 1,4-diazoniabicyclo[2.2.2]octane dications [(DABCOH2)2+] and water molecules. O—H...Cl, N—H...O and N—H...Cl hydrogen bonds lead to additional cohesion of the structure.

Sodium perchlorate in the space group Pnma

2006 ◽  
Vol 62 (7) ◽  
pp. i150-i151 ◽  
Author(s):  
Gui-Ling Zhang ◽  
Yan-Tuan Li ◽  
Zhi-Yong Wu ◽  
Yu-Lan Song
Keyword(s):  
Room Temperature ◽  
Sodium Perchlorate ◽  
Site Symmetry ◽  
Orthorhombic System ◽  
Space Group

The first example of Na+ClO4 − in the orthorhombic system in space group Pnma at room temperature is reported. The Na, Cl and two O atoms are located on positions of site symmetry m.

scholarly journals (S)-2-[(4-Fluorophenyl)formamido]-3-phenylpropanoic acid

IUCrData ◽  
2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Kathleen S. Lee ◽  
Luke Turner ◽  
Cynthia B. Powell ◽  
Eric W. Reinheimer
Keyword(s):  
Hydrogen Bonding ◽  
Title Compound ◽  
Phenyl Ring ◽  
Room Temperature ◽  
Solid Phase ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Torsion Angles ◽  
Compound C ◽  
Independent Molecules

The title compound, C16H14FNO3, was synthesized via solid phase methods; it exhibits monoclinic (P21) symmetry at room temperature. The two independent molecules that comprise the asymmetric unit display distinct torsion angles of 173.2 (2) and 72.6 (2)° along the central sp 3 C—N bond. In the crystal, hydrogen bonding through N—H...O contacts couples the asymmetric unit molecules into pairs that align in layers extending parallel to (100) via additional O—H...O interactions. The phenyl ring of one independent molecule was found to be disordered over two sets of sites in a 0.55 (3):0.45 (3) ratio.

A room-temperature self-healing elastomer with ultra-high strength and toughness fabricated via optimized hierarchical hydrogen-bonding interactions

2022 ◽  
Author(s):  
Liangliang Xia ◽  
Ming Zhou ◽  
Hongjun Tu ◽  
wen Zeng ◽  
xiaoling Yang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Mechanical Strength ◽  
Room Temperature ◽  
Polymeric Materials ◽  
High Strength ◽  
Self Healing ◽  
High Mechanical Strength ◽  
Hydrogen Bonding Interactions ◽  
Healing Efficiency ◽  
Good Healing

The preparation of room-temperature self-healing polymeric materials with good healing efficiency and high mechanical strength is challenging. Two processes are essential to realise the room-temperature self-healing of materials: (a) a...

Hydrogen bonding-catalysed alcoholysis of propylene oxide at room temperature

2021 ◽  
Author(s):  
Yueting Xu ◽  
Yanfei Zhao ◽  
Fengtao Zhang ◽  
Yuepeng Wang ◽  
Ruipeng Li ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Ionic Liquids ◽  
Propylene Oxide ◽  
Room Temperature ◽  
Glycol Ethers ◽  
High Yields

Alcoholysis of propylene oxide is achieved over azolate ionic liquids at room temperature by hydrogen-bonding catalysis, accessing glycol ethers in moderate to high yields with selectivity of >99%.

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