In:
Chemistry – A European Journal, Wiley, Vol. 23, No. 21 ( 2017-04-11), p. 5104-5116
Abstract:
Optimized syntheses of 6,13‐dimesityl‐6,13‐dihydro‐6,13‐diborapentacene ( DBP ) and a related compound ( DBI ) featuring two biphenylene‐2,3‐diyl units in place of naphthalene‐2,3‐diyl moieties are reported. Striking differences between the optoelectronic properties of DBP and DBI have been experimentally observed, and explained by quantum chemical calculations. DBP is a member of the oligoacene family, DBI is a linear [ N ]phenylene derivative. The yellow DBP shows blue photoluminescence, the deep red DBI is nonfluorescent. Both compounds give rise to two reversible redox transitions at E =−2.03 V, −2.75 V ( DBP ) and −1.52 V, −2.30 V ( DBI ; THF, vs. FcH/FcH + ). The higher electron affinity of DBI agrees with a lower calculated LUMO energy level [−0.57 eV for DBI with respect to DBP @HF//SCS‐MP2/def2‐TZVP] and a higher Lewis acidity of its boron centers, which is reflected in the trend of adduct formation with small Lewis bases (MeCN, F − ). The thermochemistry underlying this trend, as well as the mechanism of fluorescence quenching in DBI , are revealed by state‐of‐the‐art quantum chemical calculations. It is suggested that the nonradiative deactivation occurs via a low‐lying, doubly excited state.
Type of Medium:
Online Resource
ISSN:
0947-6539
,
1521-3765
DOI:
10.1002/chem.201700056
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
1478547-X
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