TRIPOD LIGANDS WITH 3 DIFFERENT DONOR GRO UPS - SYNTHESIS AND COORDINATION OF CH3C(CH2PR2)(CH2PR'2)(CH2PR''2)

Tripod ligands CH3C(CH2PR2)(CH2PR'2)(CH2PR''2), 6(a-e), with three dif ferent donor groups are obtained from CHC(CH2Cl)(CH2Br)(CH2OSO2CF3), 3 , by successive replacement of the three different leaving groups. 3 i tself is easily accessible from CHC(CH2OH)3 in a few simple steps. The general applicability of this strategy is demonstrated by the prepara tion of five different ligands 6(a - e). For one specific example (6 a ) the coordination behaviour is examplified by the synthesis of its Mo (CO)3 derivative: H3C(CH2P)Ph)2)(CH2P(3-Tol)2)(CH2P(4-Tol)2).Mo(CO)3 ( 7). All compounds, including their intermediates CH3C(CH2Cl)(CH2Br)(CH 2PR2), 4(a-c), and CH3C(CH2PR2)(CH2PR'2)(CH2Cl), 5(a-c), have been obt ained in an analytically pure state and fully characterized by their s pectroscopic data. The methods developed lend themselves to the almost deliberate shaping of tripod metal templates.