The long‐sought carbene–bismuthinidene, (CAAC)Bi(Ph), has been synthesized. Notably, this represents both the first example of a carbene‐stabilized subvalent bismuth complex and the extension of the carbene‐pnictinidene concept to a non‐toxic metallic element (Bi). The bonding has been investigated by single‐crystal X‐ray diffraction studies and DFT calculations. This report also highlights the hitherto unknown reducing and ligand transfer capability of a beryllium(0) complex.

To study pnictogen bonding involving bismuth, flexible accordion‐like molecular complexes of the composition [P(C 6 H 4 ‐ o ‐CH 2 SCH 3 ) 3 BiX 3 ], (X=Cl, Br, I) have been synthesised and characterised. The strength of the weak and mainly electrostatic interaction between the Bi and P centres strongly depends on the character of the halogen substituent on bismuth, which is confirmed by single‐crystal X‐ray diffraction analyses, DFT and ab initio computations. Significantly, 209 Bi– 31 P through‐space coupling ( J =2560 Hz) is observed in solid‐state 31 P NMR spectra, which is so far unprecedented in the literature, delivering direct information on the magnitude of this pnictogen interaction.

Cyclic(alkyl)(amino) carbene (CAAC)-stabilized complexes of phosphorus, one of the lightest group 15 elements, are well-established and can often be obtained in high yields. In contrast, analogous CAAC compounds of bismuth, the heaviest nonradioactive member of group 15, are unknown. Indeed, reactivity increases as you descend the group, and as a result there are only a few examples of N-heterocyclic carbene (NHC)-bismuth complexes. Moreover, activated bismuth compounds often readily extrude bismuth metal, making isolation of stable complexes highly challenging. We report that CAACs react with phenylbismuth dichloride (PhBiCl) to afford CAAC-Bi(Ph)Cl and CAAC-Bi(Ph)Cl. Significantly, these complexes represent the first structurally characterized examples of CAAC-coordination to bismuth. The CAAC-stabilized bismuth compounds can also be obtained from air-stable salts, [CAAC-H] [Cl(Ph)Bi(μ-Cl)Bi(Ph)Cl] and [CAAC-H] [Cl(Ph)Bi(μ-Cl)Bi(Ph)Cl], by deprotonation with potassium bis(trimethylsilyl)amide, K[N(SiMe)]. The electronic effects of the ligand on the bismuth center were investigated by comparing the CAAC-Bi(Ph)Cl complexes to the NHC analogues, SIPr-Bi(Ph)Cl(THF) and IPr-Bi(Ph)Cl (SIPr = 1,3-bis(2,6-diisopropylphenyl)-4,5-dihydroimidazole-2-ylidene; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene). Interestingly, the "normal" IPr-Bi(Ph)Cl slowly isomerizes to the "abnormal" carbene complex, Cl(Ph)Bi-IPr-H, at -37 °C. In the solid-state, the CAAC-, NHC-, and abnormal NHC-bismuth compounds exhibit Bi atomic centers in unique coordination environments. The complexes were fully characterized by NMR, elemental analysis, and single crystal X-ray diffraction studies. In addition, the bonding was probed by natural bond orbital (NBO) calculations.

This article presents the synthesis of a new family of naphthyl‐fused phosphepines through Ni‐mediated C−C coupling. Interestingly, the chlorophosphine oxide intermediate shows strong resistance toward oxidation/hydrolysis owing to a combination of steric hindrance and pnictogen interactions. However, it can undergo substitution reactions under specific conditions. The optical/redox properties and the electronic structure of these new π‐systems were studied experimentally (UV/Vis absorption, emission, cyclic voltammetry) and computationally (TD‐DFT calculations, NICS investigation). Taking advantage of the luminescence of these derivatives, a blue‐emitting OLED has been prepared, highlighting that these novel π‐conjugated P‐heterocycles appear to be promising building blocks for solid‐state lighting applications.