ChemInform Abstract: Hydrogen Bonds with Fluorine. Studies in Solution, in Gas Phase and by Computations, Conflicting Conclusions from Crystallographic Analyses

ChemInform ◽  
2012 ◽  
Vol 43 (37) ◽  
pp. no-no
Author(s):  
Hans-Joerg Schneider
Keyword(s):  
2007 ◽  
Vol 72 (8) ◽  
pp. 1122-1138 ◽  
Author(s):  
Milan Uhlár ◽  
Ivan Černušák

The complex NO+·H2S, which is assumed to be an intermediate in acid rain formation, exhibits thermodynamic stability of ∆Hº300 = -76 kJ mol-1, or ∆Gº300 = -47 kJ mol-1. Its further transformation via H-transfer is associated with rather high barriers. One of the conceivable routes to lower the energy of the transition state is the action of additional solvent molecule(s) that can mediate proton transfer. We have studied several NO+·H2S structures with one or two additional water molecule(s) and have found stable structures (local minima), intermediates and saddle points for the three-body NO+·H2S·H2O and four-body NO+·H2S·(H2O)2 clusters. The hydrogen bonds network in the four-body cluster plays a crucial role in its conversion to thionitrous acid.


2019 ◽  
Vol 75 (12) ◽  
pp. 1919-1924
Author(s):  
Abdelkader Ben Ali ◽  
Youness El Bakri ◽  
Chin-Hung Lai ◽  
Jihad Sebhaoui ◽  
Lhoussaine El Ghayati ◽  
...  

In the title molecule, C13H16N4O3, the mean planes of the phenyl and triazole rings are nearly perpendicular to one another as a result of the intramolecular C—H...O and C—H...π(ring) interactions. In the crystal, layers parallel to (101) are generated by O—H...N, N—H...O and N—H...N hydrogen bonds. The layers are connected by inversion-related pairs of C—H...O hydrogen bonds. The experimental molecular structure is close to the gas-phase geometry-optimized structure calculated by DFT methods. Hirshfeld surface analysis indicates that the most important interaction involving hydrogen in the title compound is the H...H contact. The contribution of the H...O, H...N, and H...H contacts are 13.6, 16.1, and 54.6%, respectively.


2010 ◽  
Vol 133 (12) ◽  
pp. 124312 ◽  
Author(s):  
Diane M. Miller ◽  
Justin W. Young ◽  
Philip J. Morgan ◽  
David W. Pratt

Author(s):  
Akmaljon G. Tojiboev ◽  
Burkhon Zh. Elmuradov ◽  
Halima Mouhib ◽  
Kambarali K. Turgunov ◽  
Askar Sh. Abdurazakov ◽  
...  

The crystal structures of three mackinazolinone derivatives (2-amino-6,7,8,9-tetrahydro-11H-pyrido[2,1-b]quinazolin-11-one at room temperature, and 2-nitro-6,7,8,9-tetrahydro-11H-pyrido[2,1-b]quinazolin-11-one and N-(11-oxo-6,8,9,11-tetrahydro-7H-pyrido[2,1-b]quinazolin-2-yl)benzamide at 100 K) are explored using X-ray crystallography. To delineate the different intermolecular interactions and the respective interaction energies in the crystal architectures, energy framework analyses were carried out using the CE-B3LYP/6-31G(d,p) method implemented in the CrystalExplorer software. In the structures the different molecules are linked by C—H...O, C—H...N and N—H...O hydrogen bonds. Together with these hydrogen bonds, C—H...π and C—O...π interactions are involved in the formation of a three-dimensional crystal network. A Hirshfeld surface analysis allows the visualization of the two-dimensional fingerprint plots and the quantification of the contributions of H...H, H...C/C...H and H...O/O...H contacts throughout the different crystal structures. To obtain additional information on the intrinsic properties of our targets and to compare the experimental crystal structures with their respective conformations in the gas phase, quantum chemical calculations at the B3LYP-D3BJ/6-311++G(d,p) level of theory, including Grimme's D3 correction term and BJ damping functions, were carried out to account for intramolecular dispersion interactions. The identified energy gaps between the highest occupied and the lowest unoccupied molecular orbitals (HOMO–LUMO gap) of our targets in the gas phase and in two implicit solvents (methanol and dimethyl sulfoxide) allow us to quantify the impact of different substituents on the reactivity of mackinazolinone derivatives.


1996 ◽  
Vol 61 (10) ◽  
pp. 1464-1472 ◽  
Author(s):  
Daniel Alexander ◽  
Petr Holý ◽  
Pavel Fiedler ◽  
Zdeněk Havlas ◽  
Jiří Závada

Concise synthesis of the tris(pyrimidones) 1a,b is described. Molecular modeling study demonstrated that both the prepared models 1a,b are capable of self-assembling under formation of spherical dimers locked by 18 hydrogen bonds. Extreme insolubility in all common solvents precluded investigation of the self-assembly in solution. Circumstantial evidence in favor of the self-assembly has been provided in the solid and gas phase.


2017 ◽  
Vol 19 (36) ◽  
pp. 25080-25085 ◽  
Author(s):  
John C. Mullaney ◽  
Chris Medcraft ◽  
David P. Tew ◽  
Luke Lewis-Borrell ◽  
Bernard T. Golding ◽  
...  

The structure and properties of a gas phase complex formed between urea and isocyanic acid are characterised through microwave spectroscopy andab initiocalculations at the CCSD(T)(F12*)/aug-cc-pVTZ level.


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