ISSN:
0894-3230
Keywords:
Organic Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Triplet zero-field splitting parameters were obtained in 2-methyltetrahydrofuran glass at 77 K for phenylene-1,4-dinitrene (1), biphenyl-4,4′-dinitrene (2), (E)-1,2-bis(4′-nitrenophenyl)ethene (3), 1,4-bis(4′-nitrenophenyl)buta-1,3-diene (4) and 1,8-bis(4′-nitrenophenyl)octa-1,3,5,7-tetraene (5). The results were (1) |D/hc| = 0·169 cm-1 |E/hc| = 0·004 cm-1, (2) |D/hc| = 0·189 cm-1, |E/hc| = 0·00 cm-1, (3) |D/hc| = 0·122 cm-1, |E/hc| = 0·00 cm-1, (4) |D/hc| = 0·0865 cm-1, |E/hc| = 0·00 cm-1 and (5) |D/hc| = 0·0442 cm-1, |E/hc| = 0·00 cm-1. All these biradicals are ground-state singlets. Based on the observed decrease in triplet signal intensities as temperature decreases. The substantial magnitudes of |D/hc| for 3-5, despite the large distance between localized nitrene electrons, is much more than can be explained by a simple dipolar interaction between localized electrons, and is attributed at least partly to spin polarization effects on the π-electron clouds of these systems.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/poc.610060807
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