A general frustrated Lewis pair chelation approach was used to access the parent iminoborane isomers HBNH and NBH2.

We report phosphinidenes (PR) stabilized by an intramolecular frustrated Lewis pair (FLP) chelate. These adducts include the parent phosphinidene, PH, which is accessed via thermolysis of coordinated HPCO. The reported FLP-PH species acts as a springboard to other phosphorus-containing compounds, such as FLPadducts of diphosphorus (P 2 ) and InP 3 . Our new adducts participate in thermal-or light-induced phosphinidene elimination (of both PH and PR, R = organic group), transfer P 2 units to an organic substrate, and yield the useful semiconductor InP at only 110 °C from solution.

The reactivity of [PB{SiX2}] (X = Cl, Br; PB = 1,2-iPr2C6H4BCy2; E = Si, Ge) adducts is described, with an initial focus on reduction attempts to access [PB{E}]x species; however,...

Optimized synthetic procedures for pyridinium ions featuring iminophosphorano (−N=PR3; R=Ph, Cy) π‐donor substituents in the 2‐ and 4‐ positions are described. Crystallographic and theoretical studies reveal that the strongly donating substituents severely polarize the π‐electrons of the pyridyl ring at the expense of aromaticity. Moreover, the pyridinium ions are readily deprotonated to generate powerful bispyridinylidene (BPY) organic electron donors. Electrochemical studies show exceptionally low redox potentials for the two‐electron BPY/BPY2+ couples, ranging from −1.71 V vs the saturated calomel electrode for 3PhPh (with four Ph3P=N− groups) to −1.85 V for 3CyCy (with four Cy3P=N− groups). These new compounds represent the most reducing neutral organic electron donors (OEDs) currently known. Some preliminary reductions involving 3CyCy showed enhanced capability owing to its low redox potential, such as the thermally activated reduction of an aryl chloride, but purification challenges were often encountered.

The Front Cover shows a drawing of the Rocky Mountains in Alberta, Canada. The new frustrated Lewis pair (FLP) [iPr2P(C13H8)BCy2] is depicted at the center of the drawing. This molecule contains an unusually reactive B−C bond which behaves as a “masked” FLP. The molecules to its left and right depict the FLP's reaction products with Cl2PPh and H3N•BH3, respectively; these demonstrate its ability to activate P−Cl and N−H bonds. The raccoon in the right corner symbolizes the “masked” behavior of the FLP, in a nod to the table of contents image. More information can be found in the Research Article by E. Rivard and co‐workers.

We report the synthesis and reactivity of the geminal‐linked fluorene‐derived P/B frustrated Lewis pair (FLP) iPr2P(C13H8)BCy2 (1). Compound 1 displays anomalous behavior towards small molecules, acting as a “masked” FLP. This behavior stems from significant polarization of the B−C(fluorene) bond in 1, as identified by density functional theory (DFT) computations. We exploit this B−C bond polarity through reactions with PhPCl2, H3N ⋅ BH3, and iPrNH2, demonstrating P−Cl and N−H bond activation, respectively.

We report phosphinidenes (PR) stabilized by an intramolecular frustrated Lewis pair (FLP) chelate. These adducts include the parent phosphinidene, PH, which is accessed via thermolysis of coordinated HPCO. The reported FLP‐PH species acts as a springboard to other phosphorus‐containing compounds, such as FLP‐adducts of diphosphorus (P2) and InP3. Our new adducts participate in thermal‐ or light‐induced phosphinidene elimination (of both PH and PR, R=organic group), transfer P2 units to an organic substrate, and yield the useful semiconductor InP at only 110 °C from solution.