Intramolecular hydrogen bonds in crystals of thiophosphorylbenzopyrane derivatives – X-ray and FT-IR studies

2006 ◽  
Vol 320 (2-3) ◽  
pp. 247-258 ◽  
Author(s):  
Agnieszka J. Rybarczyk-Pirek ◽  
Alina T. Dubis ◽  
Sławomir J. Grabowski ◽  
Jolanta Nawrot-Modranka
Keyword(s):  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Ir Studies ◽  
Ft Ir ◽  
Intramolecular Hydrogen

3,3′-N,N′-Bis(amino)-2,2′-bipyridine — An unusually methylation-resistant amine

2011 ◽  
Vol 89 (8) ◽  
pp. 971-977
Author(s):  
Danielle M. Chisholm ◽  
Robert McDonald ◽  
J. Scott McIndoe
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Complex Mixtures ◽  
Amino Groups ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Intramolecular Hydrogen

Methylation of aromatic amino groups is usually straightforward, but the formation of two intramolecular hydrogen bonds in 3,3′-N,N′-bis(amino)-2,2′-bipyridine and (or) the potential for ring methylation prevents the clean tetramethylation of this molecule. Numerous attempts to make 3,3′-N,N′-bis(dimethylamino)-2,2′-bipyridine produced only complex mixtures of variously methylated products, and the only isolated molecule was 3,3′-N,N′-bis(methylamino)-2,2′-bipyridine, for which an X-ray crystal structure was obtained.

Intramolecular hydrogen bonds in the sulfonamide derivatives of oxamide, dithiooxamide, and biuret. FT-IR and DFT study, AIM and NBO analysis

Tetrahedron ◽  
2010 ◽  
Vol 66 (44) ◽  
pp. 8551-8556 ◽  
Author(s):  
B.A. Shainyan ◽  
N.N. Chipanina ◽  
T.N. Aksamentova ◽  
L.P. Oznobikhina ◽  
G.N. Rosentsveig ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Nbo Analysis ◽  
Dft Study ◽  
Intramolecular Hydrogen Bonds ◽  
Ft Ir ◽  
Intramolecular Hydrogen ◽  
Derivatives Of ◽  
Aim And Nbo

Heterocyclic Tautomerism. II. 4-Acylpyrazolones. X-Ray Crystal Structures of 4-Benzoyl-5-methyl-2-phenylpyrazol-3(2H)-one and 4-Acetoacetyl-3-methyl-1-phenylpyrazol-5-ol

1985 ◽  
Vol 38 (3) ◽  
pp. 401 ◽  
Author(s):  
MJ O'Connell ◽  
CG Ramsay ◽  
PJ Steel
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Room Temperature ◽  
Crystalline Form ◽  
Intermolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Intramolecular Hydrogen

The colourless crystalline form of the benzoylpyrazolone (2) has molecules with the NH structure (2c) stabilized by intermolecular hydrogen bonds. At room temperature crystals are monoclinic: P21/c, a 13.508(5), b 9.124(4), c 11.451(3)Ǻ, β 90.80(3)°, Z4; the structure was refined to R 0.059, Rw 0.048. The acetoacetylpyrazolone (3) has the OH structure (3c) with two intramolecular hydrogen bonds. At 193 K crystals are triclinic: Pī , a 7.142(2), b 13.704(8), c 14.699(7)Ǻ, α 117.36(3), β 96.87(3), γ 93.73(3)°, Z 4; the structure was refined to R 0.049, Rw 0.054.

scholarly journals A novel сalcium trifluoroacetate structure

2021 ◽  
Vol 16 (4) ◽  
pp. 352-362
Author(s):  
A. A. Vasilyeva ◽  
T. Yu. Glazunova ◽  
D. S. Tereshchenko ◽  
E. Kh. Lermontova
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Bonds ◽  
Trifluoroacetic Acid ◽  
Calcium Fluoride ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Cell Parameters ◽  
Intramolecular Hydrogen

Objectives. The study was devoted to considering the features of the synthesis and crystal structure of calcium trifluoroacetate Ca2(CF3COO)4·8CF3COOH and investigating the products of its thermal behavior.Methods. The compositions of the proposed structural form were characterized by various physicochemical methods (X-ray diffraction, IR spectroscopy), and the products of thermal decomposition were determined under dynamic vacuum conditions.Results. The reaction between calcium carbonate and 99% trifluoroacetic acid yielded a new structural type of calcium trifluoroacetate Ca2(CF3COO)4·8CF3COOH (I) in the form of colorless prismatic crystals unstable air. X-ray diffraction results confirmed the composition I: space group P21, with unit cell parameters: a = 10.0193(5) Å, b = 15.2612(7) Å, c = 16.3342(8) Å, β = 106.106(2)°, V = 2399.6(2) Å3, Z = 2. The structure is molecular, constructed from Ca2(CF3COO)4·8CF3COOH dimers. The end molecules of the trifluoroacetic acid were involved in the formation of intramolecular hydrogen bonds with oxygen atoms of the bidentate bridging anions CF3COO−. There were strongly pronouncedsymmetric and asymmetric absorption bands of COO and CF3-groups in the IR spectrum of the resulting compound in the range of 1200–1800 cm−1. The definite peak of the oscillation of the OH-group at 3683 cm−1 corresponds to the trifluoroacetic acid molecules present in the structure. The broadpeak of the valence oscillations in the range of 3300–3500 cm−1 is caused by the presence of intramolecular hydrogen bonds. Decomposition began at 250°C and 10−2 mm Hg with calcium fluoride CaF2 as the final decomposition product.Conclusions. We obtained a previously undescribed calcium–trifluoroacetic acid complex whose composition can be represented by Ca2(CF3COO)4·8CF3COOH. The crystal island structure is a dimeric molecule where the calcium atoms are bound into dimers by four trifluoroacetate groups. The complex was deposited in the Cambridge Structural Data Bank with a deposit number CCDC 2081186. Although the compound has a molecular structure, thermal decomposition leads to the formation of calcium fluoride characterized by a small particle size, which may further determine its applications.

scholarly journals Unusual Effects of Intramolecular Hydrogen Bonds and Dipole Interaction on FTIR and NMR of Some Imines

2019 ◽  
pp. 1-6 ◽  
Author(s):  
Elham Abdalrahem Bin Selim ◽  
Mohammed Hadi Al–Douh
Keyword(s):  
Hydrogen Bonds ◽  
Chemical Shifts ◽  
Dipole Interaction ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
X Ray Crystallography ◽  
Dipole Interactions ◽  
Intramolecular Hydrogen

Unusual effects of intramolecular hydrogen bonds and dipole interactions are investigated using FTIR, NMR and X-Ray crystallography analyses of some imines. These phenomena affect both FTIR absorptions and chemical shifts.

Unusual crystal structure ofN-substituted maleamic acid – very strong effect of intramolecular hydrogen bonds

2014 ◽  
Vol 70 (6) ◽  
pp. 942-947 ◽  
Author(s):  
Raju Francis ◽  
Pallepogu Raghavaiah ◽  
Kuruvilla Pius
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Amide Group ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Planar Molecule ◽  
C And N ◽  
Maleamic Acid ◽  
Intramolecular Hydrogen

N-Carbamylmaleamic acid (malur) undergoes cyclodehydration under favourable conditions, as expected, to giveN-carbamyl maleimide.N-(Carboxymethyl) maleamic acid (malgly), however, does not undergo a similar cyclization reaction. Strong π bonding between the C and N of the amide group as well as two intramolecular hydrogen bonds makesmalglya planar molecule, as revealed by single-crystal X-ray studies.

scholarly journals X-ray evidence for metal–N-7 bonding in a hydrated manganese derivative of guanosine 5′-monophosphate

1974 ◽  
Vol 139 (3) ◽  
pp. 791-792 ◽  
Author(s):  
Patrice de Meester ◽  
David M. L. Goodgame ◽  
T. Jeffrey Jones ◽  
Andrzej C. Skapski
Keyword(s):  
Hydrogen Bonds ◽  
Single Crystal ◽  
Manganese Atom ◽  
Metal Phosphate ◽  
Water Molecules ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
Nucleotide Base ◽  
Phosphate Bonding ◽  
Intramolecular Hydrogen

Single-crystal X-ray studies of a manganese(II) derivative of guanosine 5′-monophosphate, [Mn(5′-GMP)(H2O)5],3H2O, have shown that it is isostructural with its nickel analogue. The manganese atom therefore is bonded to five water molecules with the remaining octahedral co-ordination site being occupied by N-7 of the nucleotide base. No direct metal–phosphate bonding is involved, but there are structure-stabilizing intramolecular hydrogen bonds between two phosphate oxygen atoms and co-ordinated water molecules.

Dissolution of Cellulose and Synthesis of Cellulose-Graft-Poly (L-Lactide) via Ring-Opening Polymerization in an Ionic Liquid

2012 ◽  
Vol 476-478 ◽  
pp. 1897-1900 ◽  
Author(s):  
Shu Xiao ◽  
Lin Dai ◽  
Jing He
Keyword(s):  
Ionic Liquid ◽  
Hydrogen Bonds ◽  
1H Nmr ◽  
Ring Opening ◽  
Graft Copolymerization ◽  
Ring Opening Polymerization ◽  
Intramolecular Hydrogen Bonds ◽  
Ft Ir ◽  
Intramolecular Hydrogen ◽  
Organic Catalyst

Dissolution and homogeneous graft copolymerization of cellulose were performed in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) with L-lactide. The best synthetic condition of the cellulose-graft-poly (L-) (cellulose-g-PLLA) was that cellulose 0.6g, L-lactide 5.34g and 4-dimethylaminopyri lactide dine (DMAP) as an organic catalyst 0.69g reacted for 12 hours at 80°C. The synthesized AmimCl and cellulose graft copolymers were characterized by FT-IR, 1H-NMR, GPC, TG and WAXD. The results indicated that AmimCl dissolved cellulose directly by destroying intermolecular and intramolecular hydrogen bonds in cellulose and the grafting rate of the polymer reached 4.44, which was higher than that reported in AmimCl with Sn(oct)2 as a catalyst.

scholarly journals A hemicryptophane with a triple-stranded helical structure

2018 ◽  
Vol 14 ◽  
pp. 1885-1889 ◽  
Author(s):  
Augustin Long ◽  
Olivier Perraud ◽  
Erwann Jeanneau ◽  
Christophe Aronica ◽  
Jean-Pierre Dutasta ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Helical Structure ◽  
Aromatic Rings ◽  
Nmr Studies ◽  
Intramolecular Hydrogen Bonds ◽  
X Ray ◽  
H Nmr ◽  
Amine Groups ◽  
Intramolecular Hydrogen

A hemicryptophane cage bearing amine and amide functions in its three linkers was synthesized in five steps. The X-ray molecular structure of the cage shows a triple-stranded helical arrangement of the linkers stabilized by intramolecular hydrogen bonds between amide and amine groups. The chirality of the cyclotriveratrylene unit controls the propeller arrangement of the three aromatic rings in the opposite part of the cage. 1H NMR studies suggest that this structure is retained in solution.

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