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Crystal Structures of Z and E ortho ‐Tetrafluoroazobenzene
Author(s) -
Hermann Daniela,
Schwartz Heidi A.,
Ruschewitz Uwe
Publication year - 2017
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201702185
Subject(s) - crystallography , crystal structure , supramolecular chemistry , diffraction , crystal (programming language) , chemistry , x ray crystallography , stereochemistry , physics , optics , programming language , computer science
The crystal structures of Z ‐ ( Pna 2 1 , Z =4; single‐crystal X‐ray diffraction data) and E ‐ ortho ‐tetrafluoroazobenzene ( Pna 2 1 , Z =4; synchrotron powder diffraction data) were solved and refined. These structural analyses reveal that the phenyl rings are almost coplanar in the E isomer, whereas a tilting by 67.8(5)° was found in the Z isomer. This leads to significantly different molecular shapes (longest elongations 13.2 Å x 8.1 Å x 4.0 Å for the E isomer vs. 9.6 Å x 7.0 Å x 6.9 Å for the Z isomer). A comparison of the supramolecular structures of Z ‐ and E ‐ ortho ‐tetrafluoroazobenzene with other known fluorinated azobenzenes shows that mainly H … F interactions occur in both isomers of ortho ‐tetrafluoroazobenzene, whereas H … F and F … F interactions exist in E ‐4H,4H’‐octafluoroazobenzene, only F … F interactions in E ‐perfluoroazobenzene, and N … C, F … C as well as F … F interactions in Z ‐perfluoroazobenzene.