X-ray structure of a sterically protected 1-aza-3-phospha-allene

Insertion of tBuNC into thorium–phosphorus and thorium–arsenic bonds: phosphaazaallene and arsaazaallene moieties in f element chemistry

“…As with transition metals, such complexes are very rare as only two phosphaazaallene compounds have been isolated: 42 There is a substantial elongation of the N-C bond (N2-C11) to 1.348(8) and 1.347(7) Å in 4 and 5, respectively, compared to a metal free heterocumulene such as PhNvCvPMes*, with a N-C bond distance of 1.210 Å. 43 The N-C bonds in 4 and 5 are also longer than those found in products of isocyanide insertion into actinide-alkyl bonds. For example, 1.276 7 46 The formation of 4 and 5 is expected to occur through a 1,1 insertion of the alkyl isocyanide in the Th-P bond.…”

On 1,3-phosphaazaallenes and their diverse reactivity

“…1,2 Although known for almost 40 years, 1,3-phosphaazaallenes have been scarcely investigated, especially when compared to the "lighter" carbodiimides and other heteroallene analogues. Another synthetic route was disclosed by Yoshifuji, 3,4 and Appel, 5 who reacted Mes*P(Li)SiMe 2 tBu (Mes* ¼ 2,4,6-tBu 3 C 6 H 2 ) with isocyanates in a Peterson-type reaction to give Mes*PCNR (R ¼ Ph, nPr, tBu). In 2000, Zhou and co-workers expanded this series to include Mes*PCN(4-ClC 6 H 4 ).…”

“…In 2000, Zhou and co-workers expanded this series to include Mes*PCN(4-ClC 6 H 4 ). 6 Mes*PCN(4-ClC 6 H 4 ) and Mes*PCNPh 4 are the only structurally characterized 1,3-phosphaazaallenes bearing classic organic substituents. Sterically demanding groups on the P atom suppress dimerization to the corresponding 1,3-diphosphetanes, which can only be reconverted to the 1,3-phosphaazallenes by flash vacuum pyrolysis.…”

Theoretical Investigation on the PCP(O) Linear Moiety: How to Stabilize Diphosphaallenic Derivatives

“…Ab initio calculations have previously been reported for the parent 1,3-diphosphaallene HP C PH, for several XP C PX (X = H, F, Cl) models, 5,6 for azaphosphaallene HP C NH, 5,7 and for phosphaketene HP C O. 8 Owing to our interest in diphosphaallenes containing the P C P( E) unit (E = O, S), 4 we have recently theoretically investigated all the possible isomers with the formula H 2 CP 2 O, including the 1,3-diphosphaallene model compound HP C P( O)H. 9 This study suggested that although the isomers containing the P C P O moiety do not have the lowest relative energy, their stabilization might be achieved by varying the substituents at the phosphorus atoms.…”