Thermodynamic/Kinetic Control in the Isomerization of the [{tBuNP(μ‐NtBu)}₂]²⁻ Ion

Abstract

The unique structure of [(tBuN)(2)PK]( infinity ) (2) (containing [(tBuN)(2)P](-) monoanions) is in stark contrast to the previously reported Li(+) analogue [[[tBuNP(mu-NtBu)](2)](2)]Li(4) (1) (containing the dimeric [[tBuNP(mu-NtBu)](2)](2-) ion). DFT and (31)P NMR spectroscopic studies reveal that the formation of the monoanion arrangements are most thermodyamically favored for Li, Na, and K, 1 being the product of kinetic control and 2 being the product of thermodynamic control.

Germylenes and stannylenes stabilized within N2PE rings (E = Ge or Sn): combined experimental and theoretical study

“…Nevertheless changing of the synthetic strategy, using the treatment of 2 with potassium gave smoothly in 48h (or in 2h with potassium graphite) potassium bis(t-butylimino)phosphide 18 after a crystallization from toluene (Scheme 5). The 31 P NMR spectrum showed signal at δ = 351.6 ppm, which is consistent with the value reported for analogous tmeda free potassium bis(t-butylimino)phosphide 26 [δ( 31 P) = 356.7 ppm]. The 1 H and 13 C NMR spectra also revealed expected set of signals for t-Bu groups and tmeda (see ESI).…”

“…Finally, the structure of 18 was determined and is shown in Figure 11. In contrast to its non-solvated analogue reported by Wright et al, 26 Figure 1G). 7 The 119 Sn NMR spectrum of 20 showed signal at δ = 430.9 ppm, which is also consistent with the proposed structure.…”

Synthesis of a Silylated Phosphorus Biradicaloid and Its Utilization in the Activation of Small Molecules

“…As early as 1984, Paine reported the reduction of tert ‐butyl‐substituted species (Scheme ), which led to the formation of the dimeric cage compound α‐ 2 t Bu. Wright and co‐workers discovered that upon irradiation α‐ 2 t Bu isomerizes, affording β‐ 2 t Bu . Clearly, in 1 t Bu steric congestion is too small, which raised the idea to successively increase the steric hindrance.…”

Chromium Catalysts Supported by a Nonspectator NPN Ligand: Isolation of Single‐Component Chromium Polymerization Catalysts

“…In spite of our expectations for facial, octahedral d 3 trivalent complexes, the reaction of the dianion, in the form of the dilithium salt, with either [CrCl 2 (thf) 2 ] or [CrCl 3 (thf) 3 ] produced the same divalent, distorted square‐planar complex [( t BuNPN t Bu) 2 Cr] ( 1 ; Scheme ). In this species the dianion was cleaved into two ( t BuNPN t Bu) − monoanions, a transformation occasionally observed but only with main‐group elements 8h,j. 9…”