Cyanidabbau von (PhP)₅: Bildung, Struktur und Reaktionen des Phenyl‐cyanphosphid‐Ions

Abstract

Phenyl cyanophosphide PhPCN-is formed in the reactions of P(CN); with phenyllithium and of PhP(CN), with C N -, and it may best be prepared by nucleophilic degradation of (PhP), with ammonium or phosphonium cyanides. With sulfur it yields phenyl cyanodithiophosphinates 4, by alkylation alkyl(pheny1)cyanophosphanes 6 and by hydrolysis of the latter alkyl(pheny1)phosphine oxides 7. -The molecular structure of [Ph,PNPPh,]PhPCN (3c) as determined by X-ray analysis shows an almost planar anion with a 102" C P C angle. A long P C and short CN bond in the PCN group make PhPCN-appear as "cyanide complex of phenylphosphinidene".

[3+2] Fragmentation of a Pentaphosphido Ligand by Cyanide

“…The solid‐state molecular structure of [K(18c‐6)] 6‐ t Bu shows an almost linear, phosphanyl‐substituted PCN moiety (P1‐C1‐N1 178.4(1)°) with a P−P distance of 2.1895(4) Å, that is, close to a typical single bond . The structural motif is reminiscent of the anions [P(CN) 2 ] − and [PhPCN] − reported by Schmidpeter et al . The IR spectrum shows the characteristic ν CN stretch at =2049 cm −1 , which is lower than those of known dicyanophosphanides [P(CN) 2 ] − ( =2120, 2113 cm −1 ) and other trivalent monocyanophosphanes ( ≈2160 cm −1 )…”

“…Recently, Borger, Grützmacher, and co‐workers described related cyanodiphosphanides [(NHP)PCN] with bulky N ‐heterocyclic phosphenium (NHP) substituents . These species feature a similar CN stretching frequency ( =2087 to 2046 cm −1 ) and similar bond parameters as [K(18c‐6)] 6‐ t Bu . Analogous to the compounds reported by Grützmacher and co‐workers, the electronic structure of 6‐R may be described as both a cyanophosphanide (R′P − ‐C≡N, I , R′=PR 2 ) and a phosphaketeneimide (R′P=C=N − , II , R′=PR 2 ) resonance structure (c.f.…”

“…[22] Thes olid-state molecular structure of [K(18c-6)]6-tBu shows an almost linear, phosphanyl-substituted PCN moiety (P1-C1-N1 178.4(1)8 8)with aP ÀPdistance of 2.1895(4) ,t hat is,c lose to at ypical single bond. [13] The structural motif is reminiscent of the anions [P(CN) 2 ] À and [PhPCN] À reported by Schmidpeter et al [23][24][25] TheI Rs pectrum shows the characteristic n CN stretch at ñ = 2049 cm À1 , which is lower than those of known dicyanophosphanides [P(CN) 2 ] À (ñ = 2120, 2113 cm À1 ) [23,24] and other trivalent monocyanophosphanes (ñ % 2160 cm À1 ). [26] Recently,B orger, Grützmacher,a nd co-workers described related cyanodiphosphanides [(NHP)PCN] with bulky N-heterocyclic phosphenium (NHP) substituents.…”

Molecules that we made: An essay on phosphorus chemistry

“…Delicate equilibria were found to be derived from the nucleophilic degradation of (PhP) 5 [124,126,132,133]. Such equilibria often allow the transfer of one or more phenylphosphinidene units to another reagent, and there is certainly a lot of unused potential in them.…”

Phosphinocyclopentadienid via Cyclopentadienylphosphid/ Phosphinocyclopentadienide via Cyclopentadienylphosphide

“…Das Gleichgewicht aus 1, 2, 3 und (PhP)5 stellt sich auch ein, wenn man (PhP)5 in Tetrahydrofuran mit B u 4N + zunächst vollständig zu PhPCN-abbaut [9] und daraus das Cyanid mit CpNa wieder verdrängt. Das gelingt, weil sich NaCN aus dem System ab scheidet.…”