Heterocyclic N-oxide ch⋯o hydrogen bonding (part 3). crystal packing of 2,2′-bipyridine-1,1′-dioxide and pyridine N-oxide

Bodige, Satish G.; Zottola, Mark A.; McKay, Scott E.; Blackstock, Silas C.

doi:10.1016/s0025-5408(98)00192-5

Cited by 13 publications

(10 citation statements)

References 23 publications

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“…Despite the approximations involved in the method, there is good evidence to indicate that semi-empirical MO simulations Symmetry-unique torsion-angle distributions for the 258 geometryoptimized potentially unique low-energy conformations of (4) found during an in vacuo random search of the accessible conformational space for the molecule. The torsion angles are de®ned in Table 2. perform well in modelling intermolecular hydrogen bonding (Bodige et al, 1998;Testa, 1999;Santhosh & Mishra, 1998), including weak CÐHÁ Á ÁO interactions (Hajnal et al, 1999;Thaimattam et al, 2001).…”

Section: Mo Theory Calculationsmentioning

confidence: 99%

Conformational analysis: crystallographic, molecular mechanics and quantum chemical studies of C—H...O hydrogen bonding in the flexible bis(nosylate) derivative of catechol

Munro

Mariah

2004

Acta Crystallogr Sect B

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The single-crystal X-ray diffraction analysis of 2-[[(4-nitrophenoxy)sulfonyl]oxy]phenyl 4-nitrophenyl sulfate (4) reveals that an interesting intermolecular or extended structure (a one-dimensional hydrogen-bonded polymer) is formed because of pairs of intermolecular (aryl)C--H...O(nitro) hydrogen bonds between the C(2) symmetry monomer units. The axis of the hydrogen-bonded polymer runs co-linear with the [101] face diagonal of the monoclinic unit cell. Molecular mechanics calculations using a modified version of the MM+ force field and a random conformational search algorithm have been used to locate the important low-energy in vacuo conformations of (4). The MM-calculated conformation of (4) that most closely matches the X-ray structure lies some 26.5 kJ mol(-1) higher in energy than the global minimum-energy conformation, consistent with the notion that the crystallographically observed molecular architecture of (4) is a local energy minimum in the absence of its crystal lattice environment. Since the X-ray conformation of (4) was correctly calculated only when all of the neighbouring molecules in the crystal lattice were included in the simulation, hydrogen bonding and other non-bonded interactions in the crystal lattice clearly dictate the experimentally observed conformation of (4). Quantum chemical calculations (AM1 method) confirm the critical role played by the intermolecular (aryl)C--H...O(nitro) hydrogen bonds in controlling the crystallographically observed conformation of (4) and show that self-recognition in this system by hydrogen bonding is favoured on electrostatic grounds. Collectively, the molecular simulations suggest that because the lowest-energy molecular conformation of (4) does not permit the formation of an extended hydrogen-bonded 'supramolecular' structure, it is not the preferred conformation in the crystalline solid state.

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Section: Mo Theory Calculationsmentioning

confidence: 99%

Conformational analysis: crystallographic, molecular mechanics and quantum chemical studies of C—H...O hydrogen bonding in the flexible bis(nosylate) derivative of catechol

Munro

Mariah

2004

Acta Crystallogr Sect B

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“…Molecular interactions of PNO in benzene solution were characterized by an experimental 'dipolar self-association formation' constant parameter equal to 1.74 M À4 at 298 K (Grunwald et al, 1980). This self-association is believed to be governed by CHÁ Á ÁO contacts, binding the molecules into R 2 2 ð8Þ aggregates (Bodige et al, 1998). The association energy computed for three aggregates with differently oriented PNO molecules suggested that the binding energy in PNO arises from localized CHÁ Á ÁO contacts.…”

Section: Introductionmentioning

confidence: 99%

Isothermal and isochoric crystallization of highly hygroscopic pyridineN-oxide of aqueous solution

Patyk

Marciniak

Tomkowiak

et al. 2014

Acta Crystallogr Sect B

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Highly hygroscopic pyridine N-oxide, C5H5NO, dissolves in water absorbed from atmospheric air, but it crystallizes in the neat form of the aqueous solution under high pressure. The crystals grown at high-pressure isochoric conditions are of the same phase as that obtained from anhydrous crystallization at ambient pressure. This feature can be employed for retrieving compounds highly soluble in water from their aqueous solutions. The crystal structure is strongly stabilized by CH...O contacts. The crystal compression and thermal expansion as well as three shortest H...O distances comply with the inverse-relationship rule of pressure and temperature changes.

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“…However, the first and second dissociation enthalpies of the N-O bonds, hD 1 H m ðN-OÞi and hD 2 H m ðN-OÞi, are not in that interval, exhibiting a considerable difference between them ((282.6 ± 5.6) kJ Á mol À1 and (240.1 ± 4.5) kJ Á mol À1 , respectively). The crystallographic study of 2, 2 0 -dipyridil N,N 0 -dioxide [44] suggests short intermolecular hydrogen-bond type interactions, CHÁ Á ÁO between adjacent molecules. The pattern of 2,2 0 -dipyridil N,N 0 -dioxide associated yields a two dimensional CHÁ Á ÁO hydrogen bonded array in the correspondent crystal.…”

Section: Discussionmentioning

confidence: 99%

“…The pattern of 2,2 0 -dipyridil N,N 0 -dioxide associated yields a two dimensional CHÁ Á ÁO hydrogen bonded array in the correspondent crystal. Each 2,2 0 -dipyridil N,N 0 -dioxide molecule participates in eight CHÁ Á ÁO hydrogen bonds, which occur in two distinct pairs as centric and acentric dimeric linkages whose binding enthalpies are (À28.0 and À9.6) kJ Á mol À1 , by AM1 calculations [44]. One could rotate the two pyridine rings in the molecule (oxygen in opposite sides) and could get a CHÁ Á ÁO type interaction between the hydrogen on carbon atom number 6 with the oxygen atom on the other pyridinic ring.…”

Section: Discussionmentioning

confidence: 99%

Thermochemistry of 2,2′-dipyridil N-oxide and 2,2′-dipyridil N,N′-dioxide. The dissociation enthalpies of the N−O bonds

Santos

Monteiro

Gonçalves

et al. 2011

The Journal of Chemical Thermodynamics

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Heterocyclic N-oxide ch⋯o hydrogen bonding (part 3). crystal packing of 2,2′-bipyridine-1,1′-dioxide and pyridine N-oxide

Cited by 13 publications

References 23 publications

Conformational analysis: crystallographic, molecular mechanics and quantum chemical studies of C—H...O hydrogen bonding in the flexible bis(nosylate) derivative of catechol

Conformational analysis: crystallographic, molecular mechanics and quantum chemical studies of C—H...O hydrogen bonding in the flexible bis(nosylate) derivative of catechol

Isothermal and isochoric crystallization of highly hygroscopic pyridineN-oxide of aqueous solution

Thermochemistry of 2,2′-dipyridil N-oxide and 2,2′-dipyridil N,N′-dioxide. The dissociation enthalpies of the N−O bonds

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