Rhodium pentaammine

Rhodium, iodotetrakis(difluoro(diethylamino)-phosphine)-, 4, 924 Rhodium, pentaamminethiocyanato-base hydrolysis, 1, 504 Rhodium, pentaammincurea-linkage isomerism, 4, 961 Rhodium, pentaammine(urea)-decomposition, 1,186... 

Y. Harel, A. W. Adamson. Photocalorimetry. 4. Enthalpies of Substitution Reactions of Rhodium(III) and Iridium(lll) Pentaammine Halides and of Ruthenium(II) Hexaammine. J. Phys. Chem. 1986, 90, 6690-6693. 

COBALT(III), RHODIUM(III), AND IRIDIUM(III) CARBONATO COMPLEXES OF THE PENTAAMMINE TYPE... 

The procedure described here is based on the observation that amine monohydroxo complexes of cobalt(III), rhodium(IIl), and iridium(III) react directly with carbon dioxide to form the corresponding carbonato complexes,2 3 without effect on the configuration of the amine ligands.4 The amine monoaqua complex is allowed to react with lithium carbonate or carbon dioxide gas at room temperature at pH 8.0 for a few minutes, and the carbonato complex is isolated by adding alcohol. The procedure has been used to prepare salts of the following cations pentaammine(carbonato)-cobalt(III),2 ds-ammine(carbonato)bis(ethylenediamine)cobalt(III),5 trans-... 

The spontaneous isomerization from the nitrito (—ONO) to the nitro (—N02) pentaammine-rhodium(III) complex has been well studied, and compared to the isomerizations of the analogous Co, Ir and Cr complexes. Isomerization was shown to occur in both the solid state and, about an order of magnitude more rapidly, in aqueous solution.517 The volume of activation (AF ) in aqueous solution is comparable for [M(NH3)5ONO]2+ (M = Co, Ir and Rh, AF = —6.7, —5.9 and — 7.4 + 4 cm3 mol-1 respectively), which is consistent with the anticipated intramolecular isomerization.584 The linkage isomerization is catalyzed by OH-,585 and by Hg2+, 5B6 In alkaline solution, the linkage isomerization of nitritopentaamminerhodium(III) obeys the rate expression rate =... 

FgNtOgOsSaCsHu, Osmium(III), (acetoni-trile)pentaammine-, tris(trifluoro-methanesulfonate), 24 275 F9N609RhS3C3H,8, Rhodium(III), hexaam-mine-, tris(trifluoromethanesulfonate), 24 255... 

Z>) Reactions of [Rh(NH ),X. The aquation and anation of [Rh(NH3X]" in acidic aqueous solution (equation 105 was first studied by Lamb who used conductance changes to monitor the interconversion of acido and aqua rhodium complexes , for the chloro and bromopentaanimine-rhodium(III) cations. He found that both aquation and anation are first-order in [Rh ], and that the hydrolysis is accelerated by the presence of OH . The forward form of equation (105) (aquation) has since been studied for X = Cl-, Br , l-, >.=56 oHj, SO, NO3" and Nj . Representative results for the aquation of various pentaammine salts are given in Table 25. For aquations of halides or nitrate ions, rate expressions which are first-order in [Rh] and zero-order in [H+] are found. Poe gives a detailed discussion of the thermodynamic, kinetic and intrinsic-kinetic trans effects, and compares the aquation and anation of [Rh(NH3)5X]-" (X = Cl, Br and I) with the [RhfenjjXY]" system. When X = S04, a two-term rate expression was observed... 

PENTAAMMINE(TRIFLUOROMETHANESULFONATO-O)RHODIUM(in) TRIFLUOROMETHANESULFONATE, PENTAAMMINEAQUARHODIUM(III) PERCHLORATE, AND HEXAAMMINERHODIUM(III) TRIFLUOROMETHANESULFONATE OR PERCHLORATE... 

Complexes of trifluoromethanesulfonate anion with cobalt(III) are labile oward substitution under mild conditions, and they have proved to be useful synthetic precursors to a variety of aminecobalt(III) complexes. The pentaammine-(trifluoromethanesulfonato-O)rhodium(III) ion, which is readily prepared from [Rh(NH3)5Cl]Cl2 in hot CF3SO3H, is also versatile as a synthetic precursor. " Its synthesis and solvolysis to give essentially quantitative yields of the penta-ammineaqua- and hexaamminerhodium(III) ions are described below. The aqua complex has previously been prepared by the base hydrolysis or Ag -induced aquation of [Rh(NH3)5Cl]Cl2 in water, but the present method presents a cleaner and more rapid alternative. The methods for preparation of the [RhCNHj) ] ion have evolved from the procedure of J0rgensen. They involve prolonged reaction of [Rh(NH3)5Cl]Cl2 with ammonia in a pressure vessel at elevated temperature. The solvolysis of [Rh(NH3)5(0S02CF3)](CF3S0j)2 in liquid ammonia is a simple, high-yield, and rapid alternative. 

Pentaammine(trifluoromethanesulfonato-0)rhodium(lII)trifluoromethanesul-fonate (2 g) is dissolved in liquid ammonia (-33 , —50 mL) in a 250-mL rotary evaporator flask. 

Syntheses reported for the pentaammine(trifluoromethanesulfonato-O) complexes can be readily adapted for other amine or multidentate amine analogs. Syntheses of coIbalt(III) complexes with 1,2-ethanediamine or A -ethyl-l,2-eth-anediamine ligands have been reported earlier in this series. To exemplify the procedures further, trifluoromethanesulfonato-O complexes of cobalt(III), chro-mium(III), and rhodium(III) with unidentate methylamine ligands based on the readily prepared [M(NH3)5Cl]Cl2 precursors are reported here. The following sections report syntheses of 1,2-ethanediamine complexes of Rh(III) and Irflll) and of Ru(II) and Os(II) diimines with trifluoromethanesulfonato ligands. Such syntheses indicate the diversity of the synthesis technique, and the complexes described are excellent precursors for other compounds. 

Further reactions of the first product with various reagents in sequence are cited here in order to illustrate efficiently and briefly the wide range of applicable procedures and products for rhodium(III) ammines. The NH3 in the pentaammines is... 

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