| Abstract: | Alternative Ligands. XXX Novel Tripod Ligands XM' (OCH2PMe2)n(CH2CH2PMe2)3?n (M' = Si, Ge; n = 0–3) for Cage Structures Attempts to prepare new tripod ligands XSi(OCH2PMe2)3 X = CF3 ( 15 ), C6F5 ( 16 ), NMe2 ( 17 ), Cl ( 18 ), F ( 19 ), H ( 20 ), OEt ( 21 ), OMe ( 22 )] prove to be unsuccessful in spite of using different pathways, because the groups X undergo following reactions giving insoluble solids (polyadducts) or form inseparable mixtures, e. g. (RO)nSi(OCH2PMe2)4?n (R = Me, Et). In many cases Si(OCH2PMe2)4 ( 13 ) can be isolated from the reaction mixture. The syntheses of the ligands XSi(CH2CH2PMe2)3 X = NMe2 ( 6 ), Cl ( 7 ), F ( 8 ), OMe ( 9 ), Vi ( 12 )], Si(OCH2PMe2)4 ( 13 ) und Me3GeOCH2PMe2 ( 14 ) are successful. The compounds MeSi(OCH2PMe2)2CH2CH2NMe2 ( 10 ) and MeSi(OCH2PMe2)2CH2CH2P(CF3)2 ( 11 ) with different donor groups are obtained in good yields. The preparative program includes the synthesis of the known representatives MeSi(OCH2PMe3)3 ( 1 ), MeSi(OCH2PMe2)2CH2CH2PMe2 ( 2 ), MeSi(OCH2PMe2)(CH2CH2PMe2)2 ( 3 ), MeSi(CH2CH2PMe2)3 ( 4 ) and MeGe(OCH2PMe2)3 ( 5 ). Important preparative steps are the substitution of M'Cl (M' = Si, Ge) by Me2PCH2O groups and the photochemically induced or base catalyzed addition of HNMe2, HPMe2 or HP(CF3)2 to SiVi functions. The novel compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations. |
