NEUTRAL AND CATIONIC RHODIUM COMPLEXES WITH POTENTIALLY BIDENTATE PHOSPHANE LIGANDS, IPR2PCH2CH2OME, IPR2PCH2CH2NME2 AND IPR2PCH2CH2CH2NME2

The complex [Rh(eta-2-iPr2PCH2CH2OMe)2]PF6 (3), which is prepared from [RhCl(eta-1-iPr2PCH2CH2OMe)(eta-2-iPr2PCH2CH2OMe)] (2) and KPF6 or AgPF6, reacts with CO and H-2 to give the monocarbonyl [Rh(CO)(eta-1-iPr2PCH2CH2OMe)(eta-2-iPr2PCH2CH2OMe)]PF6 (4) and the rather unstable dihydride [RhH2(eta-2-iPr2PCH2CH2OMe)2]PF6 (5). From [(C2H4)2RhCl]2 and [(C8H14)2-RhCl]2 and two equivalents of iPr2PCH2CH2OMe the compounds [RhCl(olefin)(eta-1-iPr2PCH2-CH2OMe)]2 (olefin = C2H4 (6), C8H14 (7)) have been obtained. Reaction of [(C8H14)2RhCl]2 with an excess of R2PCH2CH2OMe leads to the formation of the dimers [RhCl(eta-1-R2PCH2-CH2OMe)2]2 (R = Ph (9), Me (10)). The monomeric compound [RhCl(eta-1-Ph2PCH2CH2OMe)(eta-2-Ph2PCH2CH2OMe)] (11) has been prepared from RhCl3.aq and Ph2PCH2CH2OMe. Treatment of [(C2H4)2RhCl]2 and[(C8H14)2RhCl]2 with two equivalents of the aminophosphine iPr2PCH2CH2NMe2 gives [RhCl(olefin)(eta-2-iPr2PCH2CH2NMe2)] (olefin = C2H4 (13), C8H14 (14)). In contrast, the reaction of [(C8H14)2RhCl]2 with iPr2PCH2CH2CH2NMe2 affords the bis(phosphine)rhodium compound [RhCl(eta-1-iPr2PCH2CH2CH2NMe2)(eta-2-iPr2PCH2CH2CH2NMe2)] (16) which like 2 is fluctional at room temperature in solution. Treatment of 16 with CO, C2H4 and H-2 leads to opening of the chelate ring and formation of the complexes [RhCl(L)(eta-1-iPr2PCH2CH2CH2NMe2)2] (L = CO (17), C2H4 (18)) and [RhH2Cl(eta-1-iPr2PCH2CH2CH2NMe2)2] (19).