Related Experiment Video
Updated: May 30, 2026

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
25,26,27,28-Tetra-kis(3-bromo-benzyl-oxy)calix[4]arene
Abstract:
In the title compound, C(56)H(44)Br(4)O(4), the calix[4]arene unit displays the 1,2-alternate conformation with crystallograpically imposed inversion symmetry. The four phen-oxy rings of the calix[4]arene unit are twisted about the mean plane defined by the four methyl-ene C atoms bridging the benzene rings, with dihedral angles of 46.73 (6) and 66.11 (5)°. The dihedral angle between adjacent phen-oxy rings is 74.75 (7)°. The two pendant bromo-phenyl rings on the same side of the calix[4]arene unit are nearly perpendicular to each other, with a dihedral angle of 72.85 (10)° due to an intra-molecular C-H⋯π inter-action. In the crystal, a Br⋯Br contact of 3.6350 (5) Å, an inter-molecular C-H⋯Br hydrogen bond and an inter-molecular C-H⋯π inter-action are observed.
More Related Videos
06:34Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)
Published on: June 20, 2014
11:45Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Related Concept Videos
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Nomenclature of Aromatic Compounds with Multiple Substituents
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...
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Nomenclature of Aromatic Compounds with a Single Substituent