scholarly journals Hydrogen Bonds between Acidic Protons from Alkynes (C–H···O) and Amides (N–H···O) and Carbonyl Oxygen Atoms as Acceptor Partners

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Pierre Baillargeon ◽  
Tommy Lussier ◽  
Yves L. Dory

Crystals of tert-butyl (2S)-2-(prop-2-yn-1-ylcarbamoyl)pyrrolidine-1-carboxylate (Boc-L-Pro-NHCH2CCH) have been obtained. The title compound crystallizes easily as sharp needles in orthorhombic system, space group P 21 21 21 with a = 9.2890(2), b = 9.7292(2), c = 15.7918(4) Å, V = 1427.18(6) Å3, and Z = 4. The main feature of the structure is the orientation of the carbamate and amide. Their dipoles add up and the molecule displays an electric dipole moment of 5.61 D from B3LYP/6-31G(d) calculations. The antiparallel H bonding of amides and the alignment of dipoles induce columnar stacking (the dipole moment along the columnar a axis is 4.46 D for each molecule). The other components across the other axes are, therefore weaker, (3.17 D and 1.23 D along the b and c axes, resp.). The resulting anisotropic columns pack side by side, in an antiparallel fashion mostly by (alkyne) CH···O=C (carbamate) interactions.

1992 ◽  
Vol 57 (11) ◽  
pp. 2309-2314 ◽  
Author(s):  
Josef Loub ◽  
Zdeněk Mička ◽  
Jana Podlahová ◽  
Karel Malý ◽  
Jürgen Kopf

Structure of sodium hydrogen selenite-selenious acid (1:3) was solved by heavy-atom method and refined anisotropically to R = 0.098 for 1223 unique observed reflections. The title compound crystallizes in the Pc space group with a = 5.756(2), b = 4.911(2), c = 20.010(5) Å, β = 100.48(3)°, V = 556(1) Å3, T = 293 K, (a = 5.763(2), b = 4.878(1), c = 20.03(1) Å, β = 100.48(3)°, V = 554(1) Å3, T = 173 K), Z = 2. The structure consist of HSeO3- anions, molecules of selenious acid and Na+ cations which are octahedrally coordinated with oxygen atoms. The structure is stabilized by a system of hydrogen bonds.


1995 ◽  
Vol 50 (7) ◽  
pp. 1137-1140 ◽  
Author(s):  
Karl Peters ◽  
Eva-Maria Peters ◽  
Gerhard Bringmann ◽  
Paul Anthony Keller ◽  
Manuela Schäffer

The title compound was prepared by hydrogenolytic deprotection of the corresponding Nbenzyl derivative, which had previously been synthesized by a Picted-Spengler condensation of the corresponding arylethylamine. It crystallizes from dichloromethane/methanol in the orthorhombic system, space group P212121 ; a = 1305.7(2), b = 1400.3(3), c = 727.4(1) pm. Hydrogen bonds between Cl and OH and NH2 groups cause a threedimensional arrangement.


IUCrData ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Jae Myoung Lee ◽  
Sung Baek Kim ◽  
Wonbo Sim ◽  
Jai Young Lee

The title compound, C51H48N2O7, was synthesized by the reaction of 25,27-(3,6,9-trioxaundecane-1,11-dioxy)-26,28-(3-phenyl)-3-azapentane-1,5-dioxy)calix[4]arene with tetracyanoethylene in dry DMF. The compound has a 1,3-alternate conformation with an oxo-crown-5 unit and an aza-crown-3 unit with a nitrogen atom connecting tricyanoethylenephenyl group as a chromophore. Pairs of benzene rings of the calixarene are facing one another. Three of the four oxygen atoms connected to a benzene have endo-conformations while the other is exo. The oxo-crown-5 system has a t–g–g–t conformation. The dichloromethane solvent molecule is linked to the main molecule by a C—H...Cl hydrogen bond. In the crystal, C—H...O, C—H...Cl hydrogen bonds and C—H...π(ring) interactions are observed.


2020 ◽  
Vol 76 (8) ◽  
pp. 1307-1310 ◽  
Author(s):  
Erika Samolová ◽  
Jan Fábry

Caesium propanoate monohydrate, Cs+·C3H5O2 −·H2O, is composed of two symmetry-independent Cs+ cations, which are situated on the special position 4e of space group P\overline421 m, one symmetry-independent propanoate molecule in a general position and a pair of water molecules also situated on special position 4e. Two pairs of these symmetry-independent cations, four propanoate molecules and two pairs of symmetry-independent water molecules form a repeat unit. These units form columns that are directed along the c axis and possess symmetry mm2. There are four such columns passing through each unit cell. Each column is interconnected to its neighbours by four bifurcated three-centred Ow—H...Op (w = water, p = propanoate) hydrogen bonds of moderate strength. There are also four intramolecular Ow—H...Op hydrogen bonds of moderate strength within each column. One Cs+ cation is coordinated by six oxygen atoms (two water and four carboxylate) in a trigonal–prismatic geometry, while the other Cs+ cation is coordinated by four water and four carboxylate O atoms in a tetragonal–prismatic arrangement.


2006 ◽  
Vol 61 (8) ◽  
pp. 979-982 ◽  
Author(s):  
Murat Taş ◽  
Hanife Saraçoğlu ◽  
Hümeyra Bati ◽  
Nezihe Çalışkan ◽  
Orhan Büyükgüngör

The molecules of the title compound, [Cu(C11H13N2O2)2], lie across centres of inversion in space group P21/c and are linked by intermolecular N-H···O and C-H···O hydrogen bonds. The central Cu atom has a slightly distorted square-planar coordination comprised of four N atoms. Cu-N bond distances are 1.975(2) and 2.020(2) Å . The interplanar angle between the phenyl and succinimidato ring is 87.34(10)°


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