Related Experiment Video
Updated: May 20, 2026
08:43
Protocol for the Synthesis of Ortho-trifluoromethoxylated Aniline Derivatives
Published on: January 19, 2016
Methyl 3-[4-(4-nitro-benz-yloxy)phen-yl]propano-ate
Summary
This study reveals subtle yet significant conformational differences between two molecules (A and B) of a title compound. These variations impact the orientation of aryl rings and propanoate groups, influencing crystal packing via C-H⋯O interactions.
Area of Science:
- Crystallography
- Organic Chemistry
- Molecular Structure
Background:
- The asymmetric unit of the title compound (C17H17NO5) contains two distinct molecules, labeled A and B.
- Understanding molecular conformation and crystal packing is crucial in solid-state chemistry.
Purpose of the Study:
- To elucidate the precise three-dimensional structures of the two crystallizing molecules.
- To analyze the conformational variations and their impact on crystal lattice interactions.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the molecular structures.
- Analysis of dihedral angles and torsion angles provided insights into conformational differences.
- Crystal packing was investigated through the identification of intermolecular interactions, specifically C-H⋯O bonds.
Main Results:
- Significant differences in dihedral angles between aryl rings were observed: 18.8(1)° for molecule A and 7.5(1)° for molecule B.
- The propanoate group exhibited distinct orientations relative to the benzene ring: a torsion angle of -44.9(2)° in molecule A versus 8.6(3)° in molecule B.
- Crystal structure is stabilized by characteristic C-H⋯O hydrogen bonding interactions.
Conclusions:
- The title compound exhibits conformational polymorphism in the solid state.
- Subtle structural variations between molecules A and B influence their spatial arrangement and intermolecular interactions.
- C-H⋯O interactions play a key role in the observed crystal packing.
Related Concept Videos
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
01:16IUPAC Nomenclature of Aldehydes
Aldehydes are named based on the systematic nomenclature rules set by the IUPAC. For acyclic aldehydes, the longest carbon chain containing the aldehydic (–CHO) group is considered the parent chain. The aldehyde is named by replacing the last letter “e” in the hydrocarbon name with “al”. For instance, a simple, seven-carbon-membered acyclic aldehyde is called heptanal, derived from heptane. The carbon chain is numbered starting from the aldehydic carbon, although the aldehydic carbon’s locant...
01:07Proton (¹H) NMR: Chemical Shift
Organic molecules primarily contain carbon and hydrogen atoms. While all the hydrogen isotopes are NMR-active, protium or hydrogen-1 is the most abundant. It has a significant energy separation between its nuclear spin states due to its large gyromagnetic ratio. As per Boltzmann's distribution, an increase in the energy separation implies a greater excess population of nuclei available for excitation, resulting in a strong NMR absorption signal.
Absorption signals of all the protium nuclei in a...
Absorption signals of all the protium nuclei in a...
01:33Carboxylic Acids to Methylesters: Alkylation using Diazomethane
Carboxylic acids react with diazomethane in an ether solvent via alkylation at the carboxylate oxygen atom to give methyl esters of the corresponding acid with excellent yields.
03:02Organic Compounds
All living things are formed mostly of carbon compounds called organic compounds. The category of organic compounds includes both natural and synthetic compounds that contain carbon. Although a single, precise definition has yet to be identified by the chemistry community, most agree that a defining trait of organic molecules is the presence of carbon as the principal element, bonded to hydrogen and other carbon atoms. However, some carbon-containing compounds such as carbonates, cyanides, and...
01:13meta-Directing Deactivators: –NO2, –CN, –CHO, –CO2R, –COR, –CO2H
All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for the...