Systematic Study of Pnictogen-Fused Heterofluorenes

Abstract

Heteroatom-fused π-conjugated molecules have attracted considerable attention, and various elements for such fusion have been investigated. Herein, we focused on pnictogen-fused heterofluorenes. The structures, reactivity with O2 and I2, coordination ability to AuCl, and photophysical properties were systematically studied to better understand the effects of pnictogen atoms on the nature of π-conjugated molecules.

Syntheses and Photophysical Properties of Pnictogen‐ and Chalcogen‐Containing Diheteroanthracenes

“…Heavy Pn atoms contain lone pairs with strong s‐characters, which is confirmed by natural bond analysis (NBO). The lone pairs of Pn atoms are sp 1.05 ‐ and sp 1.16 ‐ ( 1 and 4 ), sp 0.66 ‐ ( 2 and 5 ), and sp 0.48 ‐ and sp 0.49 ‐hybridized ( 3 and 6 ) (Table S20) [2b,11] . This is accepted even for ladder‐type compounds because the s‐character of the lone pair is related to the sum of the bond angles around the Pn atom.…”

“…Stibole derivatives may act as anion sensors due to the σ holes around the Sb atoms [5b,c] . Recently, we reported systematic studies regarding the structures, photophysical and electronic properties, and reactivities of Pn‐containing dibenzoheteroles (Pn=N, P, As, Sb, and Bi) [2b] …”

Synthesis and Photophysical Properties of Heavier Pnictogen Complexes

“…The reaction of PhECl 2 (E=Sb, Bi) with 2,2′‐dilithiobiphenyl afforded Sb and Bi‐fused heterofluorenes ( 96 and 97 ) in good yields (Scheme 19). [100] Heterofluorenes ( 93 – 97 ) on bubbling air for 8 h, resulting in only the phosphine analogue being oxidized in 5 % yield, indicating that phosphorus has a stronger affinity for oxygen than other pnictogens. To evaluate the reactivity of C−Pn bonds, heterofluorenes ( 93 – 97 ) were also treated with I 2 .…”

Ultrafast charge transfer of stiboviologens for electrochromism and visible light-induced α-amino C(sp3)–H functionalization

“…This modication signicantly enhances the conjugation and optoelectronic properties of the compound. 43,54,55 Gabbaï and co-workers developed a series of stibole derivatives with enhanced optoelectronic properties and increased Lewis acidity. 56 These derivatives could detect uoride in drinking water at concentrations as low as parts per million (ppm) by utilizing the emission mechanism facilitated by the stibole structure.…”