Thiophene-based twisted bistricyclic aromatic ene with tricoordinate boron: a new n-type semiconductor

Abstract

A new boron-embedded bistricyclic aromatic ene (BAE) exhibits a low-energy absorption and obvious n-type semiconducting character with moderate electron field-effect mobilities in OFETs.

Tunable Solid‐State Thermochromism: Alkyl Chain Length‐Dependent Conformational Isomerization of Bianthrones

“…Melting points were determined on a Yanaco MP-500D micro melting point apparatus. 1 H and 13 C NMR spectra were obtained using a JEOL RESONANCE ECA-400 (400 MHz), and a JEOL RESONANCE ECAMX-500SP (500 MHz) spectrometers. The chemical shift was recorded by using tetramethylsilane (0.00 ppm) as an internal standard for 1 H and 13 C NMR spectra.…”

“…1 H and 13 C NMR spectra were obtained using a JEOL RESONANCE ECA-400 (400 MHz), and a JEOL RESONANCE ECAMX-500SP (500 MHz) spectrometers. The chemical shift was recorded by using tetramethylsilane (0.00 ppm) as an internal standard for 1 H and 13 C NMR spectra. Positive ESI mass spectra were taken by a Thermo Fisher Scientific Orbitrap XL.…”

“…After filtration and concentration, the residue was fractionated by column chromatography on silica gel using DCM. Then, the products were washed with acetonitrile to afford the title compound as a black solid (37 mg, 17%): mp 185-186 °C; 1 H NMR of 3 (folded) (500 MHz, CDCl 3 ) δ (ppm) 7.53 (d, J = 3.0 Hz, 4H), 7.02 (d, J = 8.5 Hz, 4H), 6.71 (dd, J = 2.5, 8.5 Hz, 4H), 4.01-4.10 (m, 8H), 1.77-1.85 (m, 8H), 1.47-1.56 (m, 8H), 0.99 (t, J = 7.5 Hz, 12H); 13…”

“…Overcrowded ethylene, given a distorted C=C bonds by sterically bulky substituents, is a typical example of an external stimuli‐responsive molecule whose structural and physical properties can be significantly altered by releasing the strain energy upon stimulation [1–14] . Bianthrone 1 , one of the overcrowded ethylenes, has two conformational isomers, a major folded form and a minor twisted form, to avoid steric repulsion (Figure 1).…”

Future prospects in boron chemistry: new boron compounds and Lewis acids for catalysis and materials science

“…These unprecedented boron compounds with new structures and reactivities will enable the observation of new coordination modes at boron, in the isolation of long sought after reaction intermediates and new classes of boron-mediated reactions in the near future. 1E] [26] , π-conjugated boron compounds embedded in polyaromatic antiaromatic architectures [Figure 1F] [27] , redox-active tetraanionic diborafluorenes [Figure 1G] [28] , boron-nitrogen embedded polycyclic aromatic hydrocarbons [Figure 1H] [29] , BN-doped cycloparaphenylenes [Figure 1I] [30] , highly emissive donor-acceptor arylamino-9-borafluorene [Figure 1J] [31] , bora subporphyrins [Figure 1K] [32] and thiophene-based polycyclic aromatic tricoordinate boron semiconductor [Figure 1L] [33] are all receiving increasing recognition for their outstanding optical, photophysical, electrochemical and photoresponsive properties.…”