Diindeno‐Fused Dibenzo[a, h]anthracene and Dibenzo[c, l]chrysene: Syntheses, Structural Analyses, and Properties. Issue 30 (2nd May 2019)

• Record Type: Journal Article
• Authors: Boominathan, Siva Senthil Kumar; Chang, Kai‐Hsin; Liu, Yu‐Chiao; Wang, Chi‐Shin; Wu, Cheng‐Feng; Chiang, Ming‐Hsi; Chou, Pi‐Tai; Wu, Yao‐Ting
• Is Part Of: Chemistry. Volume 25:Issue 30(2019)
• Page Start: 7280
• Page End: 7284
• Publication Date: 2019-05-02
• Subjects: aromaticity -- biradicals -- naphthoquinodipropene -- polyarenes -- quinodipropene; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201901021
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Diindeno‐fused dibenzo[ a, h ]anthracene 6 and diindeno‐fused dibenzo[ c, l ]chrysene 9 contain the key moieties 1, 4‐quinodipropene (1, 4‐QDP) and 2, 6‐naphthoquinodipropene (2, 6‐NQDP), respectively, and they both have an open‐shell singlet ground state. The latter compound exhibits a strong biradical character and interesting properties, including a low Δ E T−S (2.44 kcal mol −1 ), a small HOMO–LUMO gap (1.06 eV), a wide photoabsorption range (250–1172 nm), and a large two‐photon absorption cross‐section ( σ =1342±56 GM). This work verifies that 6 has a slightly larger HOMO–LUMO gap and Δ E T−S than its helical isomer diindeno[2, 1‐ f :1′, 2′ ‐j ]picene (DIP), but is a much stronger two‐photon absorber, verifying the important effect of geometry on the photophysical properties. Abstract : Radical chemistry ! Diindeno‐fused dibenzo[ a, h ]anthracene and dibenzo[ c, l ]chrysene, which contain the key moieties of 1, 4‐quinodipropene (1, 4‐QDP) and 2, 6‐naphthoquinodipropene (2, 6‐NQDP), respectively, both have singlet biradical character and many interesting properties. Compound 6 with the quasi‐planar structure is suitable for verifying the through‐space interactions of the singlet biradical helicene DIP (see scheme).