Packing Modes in Nitrobenzene Derivatives. II. The `Pseudo-Herringbone' Mode

André, Ingemar; Foces‐Foces, C.; Cano, F. H.; Martı́nez-Ripoll, M.

doi:10.1107/s0108768197010835

Cited by 7 publications

(3 citation statements)

References 15 publications

(23 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The whole hydrogen-bonding scheme, makes up tapes propagating along the direction of the c axis. All C-HÁ Á ÁON and CÁ Á ÁON distances are shorter than the mean values of 2.7 (2) and 3.5 (2) Å , respectively, found in a study of nitrobenzenes (André et al, 1997), although the C-HÁ Á ÁON angles are within the accepted range [C-HÁ Á ÁO = 133 (20) ]. Even when C-HÁ Á ÁO interactions involving an NO 2 group as acceptor are half as strong as C-HÁ Á ÁO interactions (Allen et al, 1997) involving a CO group as the acceptor, they play a significant role in packing owing to their co-operative action.…”

Section: Figurecontrasting

confidence: 51%

The zwitterion of 4-nitro-2-{(E)-[2-(piperidin-1-yl)ethyl]iminomethyl}phenol

Santos-Contreras¹,

Ramos-Organillo²,

Garcı́a-Báez³

et al. 2008

Acta Crystallogr C

View full text Add to dashboard Cite

The title Schiff base compound, 4-nitro-1-oxo-2-{(E)-[2-(piperidin-1-yl)ethyl]iminiomethyl}cyclohexadienide, C(14)H(19)N(3)O(3), exists as a zwitterion, with the H atom of the phenol group being transferred to the imine N atom. The C=O, C(Ar)-C(Ar) and C-N bond lengths are in agreement with the oxocyclohexadienide-iminium zwitterionic form. The iminium H atom is engaged in a strong intramolecular hydrogen bond with the O atom of the keto group (N(+)-H...O) to form an S(6) motif. Soft C-H...O interactions in the ac plane lead to the development of hydrogen-bonded tapes, which are pi-stacked through the oxocyclohexadienide ring and iminium group. The significance of this study is in providing crystallographic evidence, supported by NMR and IR data, of the predominance of the oxocyclohexadienide-iminium zwitterion form over the noncharged canonical form in the title Schiff base.

show abstract

Section: Figurecontrasting

confidence: 51%

The zwitterion of 4-nitro-2-{(E)-[2-(piperidin-1-yl)ethyl]iminomethyl}phenol

Santos-Contreras¹,

Ramos-Organillo²,

Garcı́a-Báez³

et al. 2008

Acta Crystallogr C

View full text Add to dashboard Cite

show abstract

“…The implicit modeling of the nitro group flexibility is clearly necessary: the phenyl-nitro dihedral angle can be readily deformed by packing forces, varying by around as much as 30° for the same adjacent substituents (further exemplified by 2,4 DCNB), and a significant proportion of aromatic nitro groups in short Cl···O contacts have torsion angles in the range of 70–90°, well above the range shown in Table . Taking account of the nitro group rotation in crystal structure prediction has been deemed “a very problematic task” as it appears to have a significant influence on the packing mode of nitrobenzene derivatives, both in CSD surveys and in the observed and hypothetical structures. Computational methods taking into account the packing forces on the conformation are being developed, but they are very sensitive to the accurate balance of inter and intramolecular energies which proved, for 2,4-DCNB, to require very computationally demanding ab initio methods.…”

Section: Discussionmentioning

confidence: 99%

A Systematic Experimental and Theoretical Study of the Crystalline State of Six Chloronitrobenzenes

Barnett

Johnston

Florence

et al. 2008

Crystal Growth & Design

View full text Add to dashboard Cite

Experimental and computational searches for the crystal structures of the five commercially available isomers of dichloronitrobenzene and 3,4-dinitrochlorobenzene were performed to assess the relationship between functional group interactions and steric requirements in determining the solid forms. Experimentally, this resulted in the first crystal structure determination of 2,4-dichloronitrobenzene, two solvates of 3,4-dichloronitrobenzene and one of 3,4-dinitrochlorobenzene. Additionally, low temperature redeterminations of the crystal structures were obtained for 2,5-dichloronitrobenzene, 3,4-dichloronitrobenzene, and both the βand γ-forms of 3,4-dinitrochlorobenzene. The searches for energetically feasible structures of each of these compounds showed a wide variety of distributions leading to varying degrees of clarity of prediction of the solid state behavior. These range from 2,3-dichloronitrobenzene, which only adopts the crystal structure that was clearly the most thermodynamically stable of all five isomers, through complex systems, which show a range of low energy minima indicating possible polymorphism and solvate formation, to 2,4-dichloronitrobenzene, which can conformationally distort and adopts a complicated Z′ ) 2 crystal structure.

show abstract

“…The 6-NO 2 group is involved in HB in a monocoordinative motif, 21 whose CH/ON and C/ON distances are shorter than the mean values of 2.7(2) and 3.5(2) A ˚found in a CSDB study on nitrobenzenes. 22 The amide and lactone carbonyls act as donors of electronic density, the former to the pyrone [C11-O11/Cg(1), (T3, E4)] and benzenoid [C11-O11/Cg(2) (T3, E5)] rings of two neighboring molecules, and the latter to a benzenoid ring [C2-O2/ Cg(2) (T3, E6)], (Fig. 2e).…”

Section: Intermolecular Arrangement and Crystal Packingmentioning

confidence: 99%