Rhodium complexes bidentate anions

Rhodium(—I) complexes, 4,904,905 Rhodium(Q) complexes, 4,905,906 triphenylphosphine, 4,905 Rhodium(I) complexes, 4,906-929 anionic, 4,906 bidentate anions... 

The complexes which contain a bidentate anion are listed in Table 67. Two preparative routes exist to these complexes. One involves oxidative addition of two monoanions to a rhodium(I) complex containing a bidentate anion. These are usually complexes containing a disulfur anion (equation 195).65 Dibenzoylmethane, in contrast to pentane-2,4-dione (see Section 48.6.3.2 above) adds in a similar fashion (equation 196).920... 

Besides those complexes which contain bidentate anionic ligands there are also complexes which contain one bidentate neutral ligand. Very frequently this type of complex contains two identical neutral ligands one of which is monodentate and the second bidentate by virtue of complexing to rhodium through a second functional group on the ligand. 

Rhodium)-1) complexes, 904, 905 Rhodium(O) complexes, 905, 906 triphenylphosphine, 905 Rhodium(l) complexes, 906-929 anionic, 906 bidentate anions At-methylsalicylaldiminato, 908 pentane-2,4-dionato, 908 trifluoroacetato. 908 bridged, 908-911 dinitrogen, 919 binuclear, 920 four-coordinate anions, 925 hydrido, 921 hydrido dinitrogen, 920 pen tacoordin ate anions, 929... 

The structures of a series of rhodium complexes, [Rh(L)(CO)2H], of various bisphosphine and bisphosphite ligands, which are equipped with an integral anion binding site, have been studied by Dydio et al Small values of ca. 10 Hz or less found for the phosphorus-hydride coupling at rt have indicated that all bidentate ligands in the complexes under study are coordinated predominantly in the ee fashion (the expected averaged values of /hp fof the ee and ea are around 2 and 100 Hz, respectively). 

J. Am. Chem. Soc., 126. 4494. (i) Takacs, J.M., Chaiseeda, K. and Moteki, S.A. (2006) Rhodium-catalyzed asymmetric hydrogenation using self-assembled chiral bidentate ligands. Pure Appl. Chem., 78, 501. (j) Duckmanton, P.A., Blake, A.J. and Love, f.B. (2005) Palladium and rhodium ureaphosphine complexes Exploring structural and catalytic consequences of anion binding. Inorg. Chem., 44, 7708-7710. 

Apart from anion exchange reactions the complexes are inert. One of the few reagents to bring about a change in the coordination sphere is sulfur dioxide which coordinates to rhodium without displacement of a bidentate ligand. However, the product is not well characterized and the crystals contain clathrated sulfur dioxide.250... 

The complexes are usually prepared by displacing ligands from other rhodium(I) complexes. Complexes containing two bidentate ligands may be prepared similarly. Additionally, simultaneous anion metathesis and ligand displacement may... 

Balzani et al. have reported the electrochemical, photochemical, and photophysical properties of many dpp-bridged complexes. The Ru(II)/Os(II)-Rh(III) complexes, [Ru (dpp)Rh(ppy)2 3](PFe)5 and [Os dpp)Rh(ppy)2 3](PF6)5 (Fig. 17) (ppy = phenylpyridine anion), reported by Balzani et al. incorporate the dpp BL and a C-N type cyclometallating terminal ligand (TL) in the construction of complex molecular architectures. The dpp BL provides electronic coupling of the bridged metals. The tris(bidentate) coordination environments of rhodium inhibit reactivity at this site. 

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