ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Reactions of [2N]cyclophanes (N = 2,⃛6) with solvated electrons in 1,2-di-methoxyethane at 193 K have been studied by ESR. and ENDOR. spectroscopy. All but the two most highly bridged cyclophanes (N = 5 and 6) are reduced to paramagnetic species under these conditions. Whereas the radical anions of [2.2]-paracyclophane and [23](1,2,4)- and [24](l,2,4,5)cyclophanes are sufficiently persistent to be characterized by their hyperfine data, those of the remaining five cyclophanes undergo a rapid cyclization to the radical anions of 4,5,9,10-tetrahydropyrenes. These have been identified as the unsubstituted tetrahydropyrene (from [2.2]-metacyclophane and [23](l,2,3)cyclophane), the 2,7-dimethyl-derivative (from [23](1,3,5)- and [24](l,2,3,5)cyclophanes) and the 1,8-dimethyl-derivative (from (24l,2,3,4)cyclophane). The persistence of the cyclophane radical anions seems to depend on the numbers, nmeta and npara, of the meta-and para-positions of the bridging ethano groups in the two benzene rings. The prerequisite for the radical anion to be persistent is nmeta≤npara.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19820650510
