Becker, Gerd Brombach, Heike Horner, Stephen T. Niecke, Edgar Schwarz, Wolfgang Streubel, Rainer Würthwein, Ernst-Ulrich Synthesis and Structure of K<sup>+</sup>[<i><sup>i</sup></i><sup></sup>PrNCP]<sup>-</sup>, a 1-Aza-3λ<sup>3</sup>-phospha-3-allenide<sup>†</sup> 2-Isopropyl(trimethylsilyl)amino-1<i>λ</i><sup>3</sup>-phosphaalkyne <b>1</b> reacts with potassium <i>tert</i>-butoxide to form potassium 1-isopropyl-1-aza-3<i>λ</i><sup>3</sup>-phospha-3-allenide (<b>2</b>). This compound was structurally characterized as the corresponding 18-crown-6 ether complex <b>3</b>. The molecular structure of <b>1</b> was also determined in order to compare the bonding situation in the anion and the neutral <i>λ</i><sup>3</sup>-phosphaalkyne. Compound <b>3</b> contains a nitrogen−carbon−phosphorus group for which the parameters were shown by X-ray structural analysis and quantum chemical calculations to lie between the extrema N−C⋮P and NCP, suggesting reactivity typical of an ambident anion. This is indeed the case, as subsequent reaction of <b>2</b> with chlorotrimethylsilane at nitrogen regenerates the <i>λ</i><sup>3</sup>-phosphaalkyne <b>1</b>; with chlorotriphenylsilane the new derivative<b> 4</b> is formed. In contrast, chlorotrimethylstannane reacts at phosphorus, giving the 1-aza-3<i>λ</i><sup>3</sup>-phosphaallene isopropyliminomethylidene(trimethylstannyl)phosphane <b>5</b>. λ 3;quantum chemical calculations;potassium;anion;phosphaalkyne 1 2005-05-02
    https://acs.figshare.com/articles/dataset/Synthesis_and_Structure_of_K_sup_sup_i_sup_i_sup_i_sup_sup_PrN_C_P_sup_sup_a_1_Aza_3_sup_3_sup_phospha_3_allenide_sup_sup_/3373936
10.1021/ic048162+.s001