Angew Chem Int Ed Engl
September 2024
Helicene diradical derivatives have attracted widespread attentions because of their unique magnetic and chiroptoelectronic properties, however, crystalline and enantiomerically pure forms of helicene diradicals are extremely rare. Herein, we describe the rational design and synthesis of o-quinone functionalized helicene diradicals with crystalline enantiomerical purity. Diradical dianion salt Rac-3K and its enantiomers P/M-3K were obtained by reduction of corresponding precursors Rac-3 and P/M-3 with two equivalent potassium graphite in THF in the presence of (di)benzo-18-crown-6.
View Article and Find Full Text PDFWe have synthesized a quinone-incorporated bistriarylamine donor-acceptor-donor (D-A-D) semiconductor 1 by B(CF) (BCF) catalyzed C-H/C-H cross coupling via radical ion pair intermediates. Coordination of Lewis acids BCF and Al(OR) (R=C(CF)) to the semiconductor 1 afforded diradical zwitterions 2 and 3 by integer electron transfer. Upon binding to Lewis acids, the LUMO energy of 1 is significantly lowered and the band gap of the semiconductor is significantly narrowed from 1.
View Article and Find Full Text PDFA neutral boron-containing triangular triradical based on a triptycene derivative has been designed and synthesized. Its structure, bonding and physical property have been studied by EPR spectroscopy, SQUID magnetometry and single crystal X-ray diffraction, as well as theoretical calculations. The triradical has a series of isosceles triangle conformations in the solution due to the Jahn-Teller distortion, leading to the splitting of the two low-lying doublet states.
View Article and Find Full Text PDFPolyradicals, i.e., multispin organic molecules, are playing important roles in radical-based material applications for their spin-spin interaction.
View Article and Find Full Text PDFThis work describes a strategy not only to isolate a dynamically stable radical with physical property tunability, but to efficiently regulate the radical dissociation with reversibility and photo controllability. The addition of Lewis acid B(C F ) (BCF) into the solution of a radical σ-dimer (1-1) led to a stable radical (1⋅-2B), which has been characterized by EPR spectroscopy, UV/Vis spectroscopy and single crystal X-ray diffraction, in conjunction with theoretical calculation. The radical species is stabilized mainly by captodative effect, single electron transfer and steric effect.
View Article and Find Full Text PDFA singlet bis(triarylamine) diradical dication and its zigzag 1D magnetic chain catenated by silver cations were isolated and characterized by single-crystal X-ray crystallography, EPR spectroscopy, SQUID measurements, cyclic voltammetry, and UV-Vis-NIR absorption spectroscopy in conjunction with DFT calculations. The Δ has significantly changed due to the coordination of carbonyls (Lewis base) with Ag (Lewis acid), revealing that the diradical character can be modulated by Lewis acid-base coordination and interchain intermolecular coupling interactions.
View Article and Find Full Text PDFCadmium-based coordination polymers, namely, {[Cd(HL)(L)] ⋅ HN(Et) } (1), [Cd (L) (H O) ] (2), [Cd(L)(phen)] (3), [Cd(L)(2,2'-bpy)] (4), [Cd(L)(4,4'-bpy)] (5), [Cd(L)(bpp)] (6), [Cd(L)(dpa)] (7), {[Cd(L)(dpa)] ⋅ H O} (8) (H L=4,4'-((p-tolylazanediyl)bis(methylene))dibenzoic acid, phen=1,10-phenanthroline, 2,2'-bpy=2,2'-bipyridine, 4,4'-bpy=4,4'-bipyridine, bpp=1,3-bis(4-pyridyl)propane, dpa=bis(4-pyridyl)amine) have been synthesized in hydro/solvothermal reactions. 1 is a 4-connect 3D network with an eightfold interpenetrating diamond topology. The 1D ladder chain structure of 2 was composed of the dinuclear [Cd (CO ) ] subunit bridged with two L ligands.
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