Donorfreie und donorhaltige supersilylalkalimetalle tBu3SiM1: Synthesen, charakterisierung, strukturen

The Triphosphide (tBu3Si)2P3Na: Formation, X-ray and Ab initio Structure Analyses, Protonation and Oxidation to Triphosphane (tBu3Si)2P3H and Hexaphosphanes (tBu3Si)4P6⋆

“…6 (the triphosphenide Mes 2 *-P 3 Li was not investigated by means of X-ray diffraction; however according to 31 P-NMR it also has an acyclic structure [6] ). The 31 P{ 1 H}-NMR spectrum of the anion in 1a shows two signals with the splitting pattern of an AX 2 spin system in the range typical for the unsaturated twocoordinate phosphorus atom in diphosphenes [14] , and in a range which is possible for an unsaturated anionic phosphorus atom [9b] ( Figure 2).…”

“…Figure 3. Observed (a) and calculated [20] (b) 31 The 31 P{ 1 H}-NMR spectrum of the 1,1Ј-bicyclotriphosphane 12 shows three multiplets with the classical splitting pattern of an AAЈBBЈMMЈ spectrum. Approximate values for δ P and J PP can be estimated by simple examination of the experimental spectrum [19] ; starting from these values the spectrum can be solved by iterative fitting [20] (Figure 4).…”

“…The structure of the bicyclo[3.1.0]hexaphosphane 13 can be derived from the NMR data after a complete analysis of its 31 P{ 1 H}-NMR spectrum. It shows, as in the case for the analogous hexaphosphanes P 6 tBu 4 [17] and P 6 Cp* 4 [18] the four multiplets of an AAЈBBЈMX spin system ( Figure 5).…”

“…With silyl substituents the allyl preference increases slightly [E rel for cyclic (H 3 Si) 2 P 3 Ϫ is 7.6 kcal/mol]. In contrast, neutral compounds with a P 3 framework like P 3 H 3 (14) [26] , (H 3 Si) 2 ) with respect to 19 is 12.7 kcal/mol)]. Therefore, cyclization of the "protonated anion" 1 to 11 and ring opening of the "reduced halogenide" 9 to 1 is in agreement with our ab initio results for the simple models R 2 P 3 X and R 2 P 3 Ϫ with R ϭ H or SiH 3 and X ϭ H or Cl.…”

“…for R ϭ H, SiH 3 ) and the cyclic isomer could have two 31 P-NMR signals. The question is which R 2 P 3 Na model structure provides computed NMR data which are in agreement with the experiment?…”