Synthesis, structure and bonding nature of heavy dipnictene radical anions

Abstract

Cyclic voltammetry studies of two L(X)Ga-substituted dipnictenes [L(R2N)GaE]2 (E = Sb, R = Me 1; E =Bi; R = Et 2; L = HC[C(Me)NDipp]2; Dipp= 2,6-i-Pr2C6H3) showed reversible reduction events....

Synthesis, Structure and Electronic Properties of a Stable π‐Type 3‐Electron‐2‐Center‐Bonded Species: A Silicon Analogue of a Bicyclo[1.1.0]butane Radical Anion

“…A natural bond orbital (NBO) analysis of 1 opt and 1 .− opt indicated that the total electron occupancy between the bridgehead silicon atoms decreased by approximately half upon reduction ( 1 opt : 1.57 e − ; 1 .− opt : 0.72 e − ) (see below) which follows the same trend as the WBIs calculated for 1 .− opt and 1 opt ( 1 opt : 0.54; 1 .− opt : 0.26). Such half reduction in electron occupancy of π‐orbitals has also been observed in previously reported radical anions of heavier main‐group elements such as the distibene (1.91 e − →0.93 e − ) and dibismuthene (1.90 e − →0.92 e − ) radical anion recently reported by Shultz and co‐workers [7a, 12] . Although the NBO analysis of 1 .− opt did not provide a bond between the bridgehead silicon atoms, it indicated the existence of two p‐orbitals with an electron occupancy of ≈0.4 for each bridgehead silicon atom (occ.…”

Recent advances in stable main group element radicals: preparation and characterization

“…130 Two heavy dipnictene radical anions Sb-A2 and Bi-A1 were isolated in 2021. 143 Reducing Sb-PA2 and Bi-PA1 with KC 8 in the presence of B-18-c-6 led to the formation of Sb-A2 and Bi-A1, respectively (Scheme 97). Both products exhibit broad resonances in their 1 H NMR spectra, implying their paramagnetic nature.…”

A diarsene radical anion

“…The observed g-anisotropy (g 11 = 2.17, g 12 = 2.01, and g 13 = 1.85) is due to increased spin-orbit contributions that further support an As-centred radical. 26 The signal could be satisfactorily modelled by coupling of the electron spin to two, yet slightly inequivalent 75 Comparable radical anions of heavier pnictenes (Sb, Bi) [14][15][16] and radical diarsenic cations 6,18,19 show only coupling to twoequivalent pnictogen atoms, which exhibit exclusively symmetric radical anions or cations in the solid state. UV/Vis spectroscopic examination of 1 (Fig.…”

“…1, bottom). 14 Due to the scarcity of dipnictene radical anions [REQER] À , their reactivity is virtually unexplored. 16 Remarkably, isolable diarsene radical anions have not been reported to date, with a related singular phosphaarsene radical anion only being characterized by EPR spectroscopy.…”