TY - JOUR
T1 - Beyond n-dopants for organic semiconductors
T2 - use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides
AU - Tang, Kan
AU - Brown, Megan R.
AU - Risko, Chad
AU - Gish, Melissa K.
AU - Rumbles, Garry
AU - Pham, Phuc H.
AU - Luca, Oana R.
AU - Barlow, Stephen
AU - Marder, Seth R.
N1 - Publisher Copyright:
© 2023 Tang et al.; licensee Beilstein-Institut. License and terms: see end of document.
PY - 2023
Y1 - 2023
N2 - 2,2’-Bis(4-dimethylaminophenyl)- and 2,2'-dicyclohexyl-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[d]imidazole ((N-DMBI)2 and (Cyc-DMBI)2) are quite strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced bond-cleavage reactions, specifically dehalogenations. The dimers reduce halides that have reduction potentials less cathodic than ca. −2 V vs ferrocenium/ferrocene, especially under UV photoexcitation (using a 365 nm LED). In the case of benzyl halides, the products are bibenzyl derivatives, whereas aryl halides are reduced to the corresponding arenes. The potentials of the halides that can be reduced in this way, quantum-chemical calculations, and steady-state and transient absorption spectroscopy suggest that UV irradiation accelerates the reactions via cleavage of the dimers to the corresponding radical monomers.
AB - 2,2’-Bis(4-dimethylaminophenyl)- and 2,2'-dicyclohexyl-1,1',3,3'-tetramethyl-2,2',3,3'-tetrahydro-2,2'-bibenzo[d]imidazole ((N-DMBI)2 and (Cyc-DMBI)2) are quite strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced bond-cleavage reactions, specifically dehalogenations. The dimers reduce halides that have reduction potentials less cathodic than ca. −2 V vs ferrocenium/ferrocene, especially under UV photoexcitation (using a 365 nm LED). In the case of benzyl halides, the products are bibenzyl derivatives, whereas aryl halides are reduced to the corresponding arenes. The potentials of the halides that can be reduced in this way, quantum-chemical calculations, and steady-state and transient absorption spectroscopy suggest that UV irradiation accelerates the reactions via cleavage of the dimers to the corresponding radical monomers.
KW - dehalogenation
KW - n-dopant
KW - reduction
KW - reductive dimerization
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U2 - 10.3762/bjoc.19.142
DO - 10.3762/bjoc.19.142
M3 - Article
AN - SCOPUS:85180095687
SN - 1860-5397
VL - 19
SP - 1912
EP - 1922
JO - Beilstein Journal of Organic Chemistry
JF - Beilstein Journal of Organic Chemistry
ER -