Structure of 4,4-Bisphenylsulfonyl-N,N-dimethylbutylamine: Interplay of Intramolecular C–H···N, C–H···O=S, and ?···? Interactions

2009 ◽  
Vol 62 (9) ◽  
pp. 1062 ◽  
Author(s):  
Jiong Ran ◽  
Ming Wah Wong

Conformations of 4,4-bisphenylsulfonyl-N,N-dimethylbutylamine (BSDBA) were examined by ab initio calculations. Intramolecular C–H···N, C–H···O, and π···π interactions are found to play an important role in governing the conformational properties. This finding is supported by charge density analysis based on the theory of atoms in molecules. The calculated molecular structure and 1H chemical shifts of the methyl derivative (BSTBA) are in excellent agreement with experimental findings. The intramolecular C–H···N hydrogen bond in BSDBA is estimated to have a significant interaction energy of 25 kJ mol–1. The sulfonyl oxygens in BSDBA interact readily with neighbouring methylene, methyl and phenyl hydrogens via C–H···O=S hydrogen bonds. In agreement with experiment, solvent effect calculations indicate that these weaker intramolecular interactions prevail in an aprotic polar medium.

2019 ◽  
Vol 23 (2) ◽  
pp. 205-213
Author(s):  
Dorra Kanzari-Mnallah ◽  
Med L. Efrit ◽  
Jiří Pavlíček ◽  
Frédéric Vellieux ◽  
Habib Boughzala ◽  
...  

Thioxo, Oxo and Seleno diastereomeric cyclophosphamides containing 1,3,2- dioxaphosphorinane are prepared by a one-step chemical reaction. Their structural determination is carried out by means of Nuclear Magnetic Resonance NMR (31P, 1 H, 13C) and High-Resolution Mass Spectroscopy (HRMS). The conformational study of diastereomeric products is described. Density Functional Theory (DFT) calculations allowed the identification of preferred conformations. Experimental and calculated 31P, 13C, 1H NMR chemical shifts are compared. The molecular structure of the 2-Benzylamino-5-methyl-5- propyl-2-oxo-1,3,2-dioxaphosphorinane (3d) has been determined by means of crystal Xray diffraction methods.


2013 ◽  
Vol 1034 ◽  
pp. 43-50 ◽  
Author(s):  
Federico Jiménez-Cruz ◽  
Lubanski Fragoza Mar ◽  
Jose Luis García-Gutierrez

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.


2013 ◽  
Vol 69 (12) ◽  
pp. o1781-o1781 ◽  
Author(s):  
M. Umadevi ◽  
V. Saravanan ◽  
R. Yamuna ◽  
A. K. Mohanakrishnan ◽  
G. Chakkaravarthi

In the title compound, C18H16ClNO2S, the indole ring system forms a dihedral angle of 75.07 (8)° with the phenyl ring. The molecular structure is stabilized by a weak intramolecular C—H...O hydrogen bond. In the crystal, molecules are linked by weak C—H...O hydrogen bonds, forming a chain along [10-1]. C—H...π interactions are also observed, leading to a three-dimensional network.


2014 ◽  
Vol 70 (a1) ◽  
pp. C541-C541
Author(s):  
Dmitry Druzhbin ◽  
Tatiana Drebushchak ◽  
Elena Boldyreva

Paracetamol (p-hydroxyacetanilide, Pbca), acetotoluidine (p-methylacetanilide, P21/c) and methacetin (p-methoxyacetanilide, Pbca) contain acetamide group included in molecular fragments, which play an important role in many drugs and proteins. As all of them are derivatives of acetanilide used in medicine, and due to the presence of the amide bond, their charge density analysis is important for better understanding amide infinite peptide chains. Thus, comparing the data obtained for paracetamol with acetotoluidine and with methacetin charge density data can provide deeper insight into NH···O bonding. Another point of interest is the possibility of methyl group rotation that remains to be ambiguous in these acetanilide molecule based compounds. In the present study we have attempted to elucidate these problems using precise X-ray diffraction at 100K with subsequent charge density topological analysis. All charge density refinements were based on the Hansen and Coppens multipolar atom model. The topologies of the inter- and intramolecular interactions are carefully analyzed for compounds. The atomic charges, bond orders, and the electrostatic energy in molecules are discussed. The topological characteristics in the critical point of the NH···O bond of paracetamol, acetotoluidine and methacetin are shown in the table below. In contrast to similarity in NH···O bonds for all studied compounds, intermolecular interactions between the double bonded oxygen atom and the hydrogen of dimer's methyl group are different. In acetotoluidine and methacetin the (3, –1) critical points with the same topological characteristics were detected between these atoms. In comparison to them, paracetamol with disordered methyl group [1, 2] has no such point. That can be related to the absence of the methyl group disorder in acetotoluidine and methacetin.


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