4-Anilino-3-nitro-N-phenyl-benzamide
Summary
This study details the crystal structure of a C(19)H(15)N(3)O(3) compound, revealing specific molecular orientations and hydrogen bonding. These interactions, including pi-pi stacking, influence the compound's crystal packing and stability.
Area of Science:
- Crystallography
- Organic Chemistry
- Molecular Structure
Background:
- Understanding the three-dimensional arrangement of atoms in organic molecules is crucial for predicting their properties.
- Crystal structure analysis provides detailed insights into molecular conformation and intermolecular interactions.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, C(19)H(15)N(3)O(3).
- To analyze the molecular geometry, including dihedral angles and nitro group orientation.
- To investigate the intermolecular interactions governing crystal packing.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular and crystal structure.
- Analysis of bond lengths, bond angles, and dihedral angles provided geometric information.
- Identification and analysis of intra- and intermolecular hydrogen bonds and pi-pi interactions.
Main Results:
- The anilino and benzamide rings exhibit distinct dihedral angles relative to the nitro-substituted benzene ring.
- The nitro group shows a slight twist relative to its attached benzene ring.
- Intra-molecular N-H⋯O hydrogen bonding forms an S(6) ring, while inter-molecular hydrogen bonds and slipped pi-pi interactions stabilize the crystal lattice.
Conclusions:
- The crystal structure of C(19)H(15)N(3)O(3) is characterized by specific dihedral angles and a twisted nitro group.
- Intra- and intermolecular hydrogen bonding, along with pi-pi interactions, play significant roles in stabilizing the molecular arrangement in the crystal.
- The findings contribute to the understanding of structure-property relationships in organic crystalline materials.
Related Concept Videos
Nomenclature of Aryl and Heterocyclic Amines
The simplest aromatic amine is phenylamine, which contains an –NH2 functionality directly attached to an aromatic ring. The name aniline is designated for this skeleton. As shown in Figure 1, the common names of the functionalized anilines involve prefixes ortho-, meta-, and para- to indicate the substitution position. Different functionalized aniline derivatives also have notable trivial names.
Electrophilic Aromatic Substitution: Nitration of Benzene
The nitration of benzene is an example of an electrophilic aromatic substitution reaction. It involves the formation of a very powerful electrophile, the nitronium ion, which is linear in shape. The reaction occurs through the interaction of two strong acids, sulfuric and nitric acid.
Physical Properties of Amines
Amines with low molecular weight are usually gaseous at room temperature, while those with high molecular weight are liquid or solids in nature. Usually, low molecular weight amines have a rotten fish-like smell. Diamines typically have a pungent smell. For instance, cadaverine and putrescine, depicted in Figure 1, are two molecules responsible for decaying tissue.
Diazonium Group Substitution: –OH and –H
Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
NMR Spectroscopy of Benzene Derivatives
Simple unsubstituted benzene has six aromatic protons, all chemically equivalent. Therefore, benzene exhibits only a singlet peak at δ 7.3 ppm in the 1H NMR spectrum. The observed shift is far downfield because the aromatic ring current strongly deshields the protons. Any substitution on the benzene ring makes the aromatic protons nonequivalent, and the protons split each other. The peak is, therefore, no longer a singlet and the splitting pattern and their associated coupling constants depend...
2° Amines to N-Nitrosamines: Reaction with NaNO2
Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.


