5-Bromo-2-iodo-1,3-dimethyl-benzene
1Department of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China.
Acta Crystallographica. Section E, Structure Reports Online
|January 5, 2011
Summary
This study details the crystal structure of a bromoiodobenzene compound, revealing three independent molecules in its asymmetric unit. Intramolecular hydrogen bonds form planar rings, influencing molecular geometry.
Area of Science:
- Crystallography
- Organic Chemistry
- Chemical Physics
Background:
- Understanding molecular structure and intermolecular interactions is crucial in organic chemistry.
- Bromoiodobenzene (C8H8BrI) is a halogenated aromatic compound with potential applications in materials science.
- The study of crystal structures provides insights into molecular packing and bonding.
Purpose of the Study:
- To elucidate the crystal structure of the title compound, C8H8BrI.
- To investigate the presence and influence of intramolecular hydrogen bonds.
- To analyze the planarity and spatial arrangement of the molecule.
Main Methods:
- Single-crystal X-ray diffraction was employed to determine the crystal structure.
- Analysis of atomic coordinates and bond lengths/angles.
- Identification and characterization of hydrogen bonding interactions.
Main Results:
- The asymmetric unit contains three independent molecules of C8H8BrI.
- In each molecule, bromine, iodine, and methyl carbon atoms are situated in the plane of the benzene ring.
- Intramolecular C-H⋯I hydrogen bonds lead to the formation of three planar five-membered rings.
Conclusions:
- The crystal structure of C8H8BrI exhibits specific molecular arrangements driven by intramolecular hydrogen bonding.
- The planarity of the five-membered rings and their near-coplanarity with adjacent rings dictate the overall molecular conformation.
- These findings contribute to the understanding of halogen bonding and structural diversity in organic compounds.
Related Concept Videos
01:13Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
01:37NMR 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...
01:15Electrophilic Aromatic Substitution: Chlorination and Bromination of Benzene
Chlorination and bromination are important classes of electrophilic aromatic substitutions, where benzene reacts with chlorine or bromine in the presence of a Lewis acid catalyst to give halogenated substitution products. A Lewis acid such as aluminium chloride or ferric chloride catalyzes the chlorination, and ferric bromide catalyzes the bromination reactions. During the bromination of alkenes, bromine polarizes and becomes electrophilic. However, in the bromination of benzene, the bromine...
01:11Reactions at the Benzylic Position: Halogenation
Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.
01:18Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
01:11Nomenclature of Aromatic Compounds with Multiple Substituents
When more than one substituent is present on the benzene ring, the IUPAC nomenclature depends on the number of substituents present.
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...
For disubstituted benzene derivatives, with two groups attached to the benzene ring, three constitutional isomers are possible. For example, consider dimethyl benzene, often called xylene, where the second methyl group can be substituted at the second, third, or fourth carbon. The relative position of the substituents is represented by prefixes ortho, meta, or...