| Abstract: | Reactions of Silylated Cyclotetraphosphanes with Lithium Alkyles While the cyclotetraphosphanes P4(CMe3)3SiMe3 1 and trans-P4(CMe3)2(SiMe3)2 2 in reaction with LiR (R = Me, n-Bu) in THF yield the cyclic phosphides LiP4(CMe3)3 3 and trans-LiP4(CMe3)2SiMe3 4 , respectively, the compounds P4(SiMe3)4 5 , P4(SiMe3)3 CMe3 6 and cis-P4(CMe3)2(SiMe3)2 7 by cleavage of a P? P bond produce primary n-tetraphosphides, which rearrange (1,3-shift of Li/SiMe3) in THF even at low temperature to form the corresponding secondary n-tetraphosphides. Warming these solutions to room temperature initiates consecutive reactions including elimination of LiP(SiMe3)2, (Me3Si)3P, RP(SiMe3)2 and producing P-rich compounds. In this way Li3P7 is obtained as main-product from compound 5 , and LiP5(CMe3)4, LiP3(CMe3)2, P4(CMe3)4 from compound 7 . However, the reaction of 6 and LiR gives raise only to traces of Li3P7 and Li2P7CMe3. The above mentioned primary as well as the secondary n-tetraphosphides generate stable n-tetraphosphane derivatives by reaction with Me3SiCl, or MeCl, respectively. |
