ISSN:
0009-2940
Keywords:
Bis[2.2]metacyclophanes
;
Stilbenes
;
π-π Interaction
;
Tricarbonylchromium complexes
;
Charge-transfer
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
(E)-8,8′-(Ethene-1,2-diyl)bis(5-tert-butyl[2.2]metacyclo-phane) (2) was obtained from a McMurry reaction of 5-tert-butyl-8-formyl[2.2]metacyclophane (1). Irradiation of 2 with a high-pressure mercury lamp gave the corresponding (Z) isomer 3. X-ray crystallographic analyses of 2 and 3 show a certain degree of twisting of the bond connecting the meta-cyclophane unit and the central π system due to steric crowding. UV spectra of 2 and 3 and of the charge-transfer complexes [2/TCNE] and [3/TCNE] allow for a discussion of π-π interaction between the central stilbene subunit and the outer benzene rings of the metacyclophane units. Bis[2.2]meta-cyclophanes 2 and 3 reacted regioselectively with hexacar-bonylchromium on the outer benzene rings giving 1:1 and 1:2 complexes 9-14 with tricarbonylchromium. No 1:3 and 1:4 complexes formed due to steric restrictions. Analysis of UV spectral data of the complexed [2.2]metacyclophanes was performed for an indication of π-π interactions in the complexes.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19961290308
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