Supersilyl compounds of phosphorus, V. Preparation, structure, and reactivity of the pentaphosphide (tBu(3)Si)(3)P5Na2 and the pentaphosphane (tBu(3)Si)(3)P-5 [German]

摘要

The orange THF adduct (tBU(3)Si)(3)P5Na2(THF)(4) of the pentaphosphide (tBu(3)Si)(3)P5Na2 (3) has been prepared, (i) by protolysis of the tetraphosphide (tBu(3)Si)(2)P4Na2(THF)(n) (2) with CF3CO2H in THF (molar ratio 2 : 1), (ii) by dissolving crystalline 2 in toluene, and (iii) by the reaction of P-4 with tBu(3)SiNa(THF)(2) in benzene (molar ratio 1 : 4). According to an X-ray structural analysis, the THF adduct of 3 contains a P-3 ring with two PNa(SitBu(3)) substituents in cis position and one SitBu(3) substituent in trans position to the former groups. The protolysis of 3 with CF3CO2H leads to the pentaphosphane P5H2(SitBu(3))(3) (9), the silylation of 3 with Me2SiCl2 to the pentaphosphane P-5(SiMe2)(SitBu(3))(3) (10), and the oxidation of 3 with C-2(CN)(4) to the pentaphosphane P-5(SitBu(3))(3) (5). The structures of 3, 5, 9, and 10 have been assigned from P-31 and Si-29 NMR data. The pentaphosphane 5 contains a hitherto unknown P-5 backbone of a P-3 ring anellated with a P-4 ring. [References: 20]