Protonated Aminophosphines

Site of Protonation of Carboxylic and Non-Carboxylic Amides in the Gas Phase and in Water

“…P-Protonation of P(NEt 2 ) 3 and related compounds has in fact been demonstrated. [49,50] No evidence for N-protonation is found, which somewhat contrasts with the small DE (aq) of 3.7 kcal mol À1 ; again, this is probably due to an overestimation of the solvation of the non-alkylated model. Phosphoric acid triamides: PO(NH 2 ) 3 is an oxygen base in the gas phase, [11] but for PO(NMe 2 ) 3 the preference is much less marked (DE(MP2) 11.0 and 3.7 kcal mol À1 , respectively).…”

“…Experimentally, the 14 N T 1 remains constant and the 31 P signal is shielded by 127 ppm, as predicted for P-protonation (but Dd is much larger). For this strong base [49,50] slow proton exchange conditions are attained, and the 31 P signal appears as a doublet, which unambiguously indicates P-protonation. As a further proof, we note that its T 1 decreases and the NOE increases from 0.0 to its maximum value of 1.2, as expected.…”

“…We could not obtain satisfactory 14 N spectra of either cyanamide in triflic acid, since its addition (even at low temperature) caused a vigorous reaction, particularly with NH 2 CN. The Phosphorous acid triamides: P(NH 2 ) 3 and P(NMe 2 ) 3 : [49,50] Comparing experimental and theoretical results is somewhat complicated by the nitrogen atoms, which lie in different environments in the rigid calculated structure but become equivalent if free rotation is allowed. N-Protonation leads (as usual) to a large efg decrease at the quaternized nitrogen; when this is averaged with the others (unaffected), a c R eff of 0.8 results.…”

Mono‐Phosphazenyl Phosphines (R2N)3P=N–P(NR2)2 – Strong P‐Bases, P‐Donors, and P‐Nucleophiles for the Construction of Chelates

“…The P–H proton exhibits a proton resonance at δ = 6.94 ppm in [D 3 ]MeCN and a strong 1 J P,H coupling constant of 587.4 Hz. Even stronger 1 J P,H coupling constants were reported for [(Et 2 N) 3 P‐H] + [BF 4 ] – (630 Hz), [((CH 2 ) 5 N) 3 P‐H] + [BF 4 ] – (632 Hz) or the unstable [(Me 2 N) 3 P‐H] + [OSO 2 CF 3 ] – (680 Hz) …”

“…The preparation of thermally highly stable protic ionic liquids containing protonated superbases like phosphazenes or ARTICLE guanidines as cations and a bis(triflyl)imide anion was reported by Luo et al [39] In this context, we obtain a room temperature ionic liquid of low viscosity by direct protonation of (Me 2 N) 3 P=N-P(NMe 2 ) 2 (1) with bis(triflyl)imide (HTFSI) in ethyl ether (Scheme 6). The reaction is accompanied by a high field shift of the P III signal and a shift of the 2 [40] or the unstable [(Me 2 N) 3 P-H] + [OSO 2 CF 3 ] -(680 Hz). [41] Scheme 6.…”