(Z)-Perchlorostilbene

Abstract

Steric repulsion of the bulky C1 atoms causes the perchlorophenyl rings to rotate out of the plane of the central double bond eliminating the conjugation between the three 7r systems. Molecules pack as interlocking dimers and the dimeric pairs adhere by face-to-face 7r stacking.

Effects of Steric Congestion on Stilbene Radical Anions and Dianions: DFT Calculations in the Interpretation of Stilbene Radical Anion ESR Spectra

“…Stilbenes are an important class of compounds with a broad range of applications in basic and applied research. − Sterically congested stilbenes such as 2,2,5,5-tetramethyl-3,4-diphenylhex-3-ene, 3 and 4 , have recently received growing attention. − The unusual geometries of 3 and 4 are expected to impart unique properties to these materials. The preparation and characteristic properties of the radical anions and dianion of 3 and 4 are investigated and compared to stilbenes 1 and 2 .…”

Double Stereochemical Labeling in Stilbene Photochemistry: Tracing Phenyl Rotation Reveals Stereochemically Distinct Reaction Pathways for Formation of the E Photoproducts

“…Studies in our laboratories have focused on the sterically congested stilbenes 3 and 4 (2,2,4,4-tetramethyl-3,4-diphenylhex-3-enes). − Their geometries are distinctly different from planar 1 and slightly twisted 2 , Due to steric congestion, rotation about the C e −Ph bond in 3 and 4 is sufficiently slow to study the stereochemistry of the phenyl rotation during the Z / E photoisomerization.…”

“…Studies in our laboratories have focused on the sterically congested stilbenes 3 and 4 (2,2,4,4-tetramethyl-3,4-diphenylhex-3-enes). [16][17][18][19][20][21][22] Their geometries are distinctly different from planar 1 and slightly twisted 2. 3 Both 3 and 4 are planar about the C e dC e bond; however, steric repulsion rotates the phenyl groups 90°out of the molecular plane so their planes are perpendicular to the plane of the central C e dC e bond.…”