Stable Organic Neutral Diradical via Reversible Coordination

Abstract

We report the formation of a stable neutral diboron diradical simply by coordination of an aromatic dinitrogen compound to an ortho-phenyldiborane. This process is reversible upon addition of pyridine. The diradical species is stable above 200 °C. Computations are consistent with an open-shell triplet diradical with a very small open-shell singlet-triplet energy gap that is indicative of the electronic disjointness of the two radical sites. This opens a new way of generating stable radicals with fascinating electronic properties useful for a large variety of applications.

One tool to bring them all: Au-catalyzed synthesis of B,O- and B,N-doped PAHs from boronic and borinic acids

“…This promotes a coplanar conformation between the respective B,O heterocycle and, e.g., B-bonded phenyl substituents and can thus contribute to the increase of conjugation lengths and the extension of the frontier orbitals from the oxaborin moiety to the phenyl ring. 38,47,52,[58][59][60] If one proceeds further from B,E-PAHs to (B,E)n-PAHs with E = N or O and n > 1, the available information again becomes dramatically less, 9,11,13,30,32,39,54,55,[61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] which is unfortunate, because some evidence has already been gathered that the number n of embedded -B=E + units significantly influences the chemical and physical properties of corresponding compounds. 30,54,68,72,79 Thus, new atom-economic strategies for the construction of (B,E)n-PAHs, which ideally avoid the use of sensitive boron halides, sophisticated organometallic reagents, or forcing reaction conditions, are still in demand.…”

Selective CO2 Splitting by Doubly Reduced Aryl Boranes to Give CO and [CO3]2−

“…We next treated M 2 [1]( M= Li, Na) with only 1equiv of CO 2 .T he bicyclo[2.2.2] adducts M 2 [2]f ormed quantitatively (Scheme 3a). [27] Na 2 [2]g ives rise to two 11 BNMR signals: ab road one at d = 2.0 ppm, similar to the [CO 3 ] 2À adduct Na 2 [4], is assignable to the BOa tom. As harp one at d = À14.6 ppm corresponds to the boron center attached to the carbonyl carbon atom.…”

Control of Excited‐State Conformations in B,N‐Acenes

“…Piers and co‐workers installed a pattern with two B−N moieties in the synthesis of triphenylene analogues with B 2 N 2 C 2 cores, which show photophysical properties for potential applications in organic‐based devices, such as OLEDs and OFETs . In our group, the B 2 N 2 C 2 core was observed spectroscopically during investigations of a stable neutral diradical . One reason for neglecting the (B 2 N 2 )‐substitution pattern in current studies is their difficult synthesis.…”