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.

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 Very Short Intramolecular Hydrogen Bonds in the Crystal Structure of 1-[Bis(4-Fluorophenyl)Methyl]Piperazinediium Dimaleate

2012 ◽  
Vol 42 (10) ◽  
pp. 1046-1051 ◽  
Author(s):  
A. S. Dayananda ◽  
Grzegorz Dutkiewicz ◽  
H. S. Yathirajan ◽  
B. Narayana ◽  
Maciej Kubicki
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen

Intramolecular hydrogen bonds and the orientation of amino groupsin o-phenylenediamines

1967 ◽  
Vol 45 (19) ◽  
pp. 2135-2141 ◽  
Author(s):  
P. J. Krueger
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Infrared Absorption ◽  
Substituent Effect ◽  
Proton Donor ◽  
Proton Acceptor ◽  
Amino Groups ◽  
Intramolecular Hydrogen Bonds ◽  
Infrared Absorption Spectra ◽  
Intramolecular Hydrogen

The infrared absorption spectra of partially deuterated o-phenylenediamine and 4,5-di-methyl-, 4-methyl-, and 4-chloro-o-phenylenediamine in dilute CCl4 solution show double intramolecular [Formula: see text] hydrogen bonds in which the two NHD groups are equivalent and each group acts as both a proton donor and a proton acceptor. The ring substituent effect on this interaction in these compounds is small. In 4-methoxy-o-phenylenediamine, the amino groups are not equivalent, but double intramolecular hydrogen bonds are still present. In 4-nitro-o-phenylenediamine, only one intramolecular [Formula: see text] hydrogen bond appears to exist. The effect of N-substitution on some of these observations is discussed.

2-(Dibenzoylamino)pyridine

2006 ◽  
Vol 62 (5) ◽  
pp. o1868-o1869 ◽  
Author(s):  
Yan-Bo Weng ◽  
Jing-Kang Wang ◽  
Yan-Fei Wang
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Intramolecular Hydrogen Bonds ◽  
Compound C ◽  
Highly Effective ◽  
Intramolecular Hydrogen

The title compound, C19H14N2O2, is a highly effective nematicide. No inter- or intramolecular hydrogen bonds are observed in the crystal structure.

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.

The molecular and crystal structure of benzamidinium bromoacetate

1988 ◽  
Vol 53 (2) ◽  
pp. 294-300 ◽  
Author(s):  
Bohumil Kratochvíl ◽  
Jan Ondráček ◽  
Karel Malý ◽  
László Csordás
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Least Squares Method ◽  
Ion Pairs ◽  
Molecular And Crystal Structure ◽  
Monoclinic Space Group ◽  
Fourier Synthesis ◽  
Intramolecular Hydrogen Bonds ◽  
Intramolecular Hydrogen ◽  
Oxygen Atoms

The molecular and crystal structure of benzamidinium bromoacetate was solved on the basis of Patterson and Fourier synthesis. The position of all the atoms were localized and the least squares method was employed to refine the coordinates of all the atoms together with their thermal vibration parameters. A final R factor value of 0.067 was obtained for 1 349 observed reflections (I 1.96 σ(I)). The substance crystallizes in the P21/n monoclinic space group with lattice parameters of a = 1 145.7(2), b = 1 571.3(3), c = 578.3(1) pm, γ = 90.65(1)°, Z = 4. Intramolecular hydrogen bonds form ion pairs in the structure between the nitrogen atoms of the amidinium group and the oxygen atoms of the bromoacetate. Intramolecular hydrogen bonds, also between nitrogen and oxygen atoms, connect the molecules in an infinite chain. The molecular chains are joined together by van der Waals forces. The N···O distance in the hydrogen bonds varies between 280.3(8) and 284.5(8) pm.

The crystal structure of C.I. Pigment Red 2, 1′-(2,5-dichlorophenyl)azo-2′hydroxy-3′-phenylamidonaphthalene

1977 ◽  
Vol 146 (4-6) ◽  
Author(s):  
A. Whitaker
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Intramolecular Hydrogen

AbstractThe crystal and molecular structure of C.I. Pigment Red 2, l′-(2,5-dichlorophenyl)azo-2′-hydroxy-3′-phenylamidonaphthalene has been determined by x-ray diffraction techniques. It crystallizes in the monoclinic system with cell parametersThe hydrogen atoms have been found and included but not refined. The final residual is 15.3%. The molecule is probably in the form of the hydrazone tautomer. The intramolecular hydrogen bonds keep most of the molecule approximately planar while it appears that the remainder is held in the same plane due to steric hinderence between the molecules. The molecules are packed in columns with alternate molecules antiparallel and are linked by van der Waals forces.

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