Related Experiment Video
Updated: Jun 1, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
A second polymorph of (2E)-1-(4-fluoro-phen-yl)-3-(3,4,5-trimethoxy-phen-yl)prop-2-en-1-one
Abstract:
The crystal structure of the title compound, C(18)H(17)FO(4), reported here is a polymorph of the structure first reported by Patil et al. [Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. A (2007), 461, 123-130]. It is a chalcone analog and consists of substituted phenyl rings bonded at the opposite ends of a propenone group, the biologically active region. The dihedral angle between the mean planes of the aromatic rings within the 4-fluoro-phenyl and trimethoxy-phenyl groups is 28.7 (1)° compared to 20.8 (6)° in the published structure. The angles between the mean plane of the prop-2-ene-1-one group and the mean plane of aromatic rings within the 4-fluoro-phenyl and trimethoxy-phenyl groups are 30.3 (4) and 7.4 (7)°, respectively, in contast to 10.7 (3) and 12.36° for the polymorph. While the two 3-meth-oxy groups are in the plane of the trimeth-oxy-substituted ring, the 4-meth-oxy group is in a synclinical [-sc = -78.1 (2)°] or anti-clinical [+ac = 104.0 (4)°] position, compared to a +sc [53.0 (4)°] or -ac [-132.4 (7)°] position. While no classical hydrogen bonds are present, weak inter-molecular C-H⋯π-ring inter-actions are observed which contribute to the stability of the crystal packing. The two polymorphs crystallize in the same space group, P2(1)/c, but have different cell parameters for the a, b and c axes and the β angle. A comparison of the mol-ecular geometries of both polymorphs to a geometry optimized density functional theory (DFT) calculation at the B3-LYP/6-311+G(d,p) level for each structure provides additional support to these observations.
More Related Videos
Related Concept Videos
Structure and Nomenclature of Alcohols and Phenols
Alcohols are one of the most important functional groups in organic chemistry. The name of alcohol comes from the hydrocarbon from which it is derived. Alcohols are organic molecules containing the functional hydroxyl or –OH group directly bonded to carbon. Phenols have an OH group directly attached to a benzene ring. While alcohols are colorless, phenol is a white crystalline compound with a characteristic "hospital smell" odor.
As with other organic compounds, alcohols and phenols...
Characteristics and Nomenclature of Homopolymers
Structure and Nomenclature of Epoxides
Prochirality
Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene

