Rhodium bridging

TA 100, and TA 98 consistent with the Pt(II) results. The complexes are extremely lethal for uyrf Salmonella strains TA 1535 and TA 1538 which do not contain the plasmid pKm 101. 

We should note the fact that in the bacterial systems, the substitutionally inert complexes which are mutagenic and active in the repair assay all have effects similar to those of the platinum complexes known to be anti-tumor drugs. Since repair effects are closely correlated with activity of the platinum compounds (17), then the anti-tumor activity could be related to the substitutional inertness of our complexes. We have noted that many of the complexes we have studied are far less bacteriocidal than the platinum compounds, and yet comparable in repair activity. This suggests that further study of substitutionally inert metal complexes may yield anti-tumor drugs which are as effective as the platinum compounds, and yet lack their undesirable toxic side effects. 

Finally, it should be pointed out that our work substantiates the health hazard of substitutionally inert metal ions. Environmental pollution by these ions is potentially a serious problem. 

It should be considered as these metals are widely used in the catalytic converters of automobiles, and because more extensive combustion of coal will introduce more such metal ions into the environment. 

ACS Symposium Series American Chemical Society Washington, DC, 1980. 

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In the following sections, binuclear complexes of rhodium bridged by one or two diphosphine ligands, which are active for the hydrogenation or... 

Similarity with cobalt is also apparent in the affinity of Rh and iH for ammonia and amines. The kinetic inertness of the ammines of Rh has led to the use of several of them in studies of the trans effect (p. 1163) in octahedral complexes, while the ammines of Ir are so stable as to withstand boiling in aqueous alkali. Stable complexes such as [M(C204)3], [M(acac)3] and [M(CN)5] are formed by all three metals. Force constants obtained from the infrared spectra of the hexacyano complexes indicate that the M--C bond strength increases in the order Co < Rh < [r. Like cobalt, rhodium too forms bridged superoxides such as the blue, paramagnetic, fCl(py)4Rh-02-Rh(py)4Cll produced by aerial oxidation of aqueous ethanolic solutions of RhCL and pyridine.In fact it seems likely that many of the species produced by oxidation of aqueous solutions of Rh and presumed to contain the metal in higher oxidation states, are actually superoxides of Rh . ... 

Organometallic chemistry of pyrrole is characterized by a delicate balance of the ti N)- and -coordination modes. Azacymantrene is an illustration of the considerable nucleophilicity of the heteroatom. However, azaferrocene can be alkylated at C2 and C3 sites. Ruthenium and osmium, rhodium, and iridium chemistry revealed the bridging function of pyrroles, including zwitterionic and pyrrolyne complex formation. The ti (CC) coordination of osmium(2- -) allows versatile derivatizations of the heteroring. 

Figure 2.41 A dimeric non-bridged rhodium dimethylglyoxime complex (for clarity the hydrogen atoms in the hydrogen bonds are not shown).

The long Pt-Pt bond (2.694 A) follows the trend observed in rhodium dimers as the number of bridging ligands decreases (Figure 3.98). 

Using the very bulky rhodium porphyrins Rh(TTEPP)- and Rh(TTiPP)- (which contain triethylphenyl and triisopropylphenyl groups), neither of which can dimerize. direct evidence for an alkene adduct and its subsequent dimerization to the four-carbon bridged product has been obtained. Reaction of Rh(TTEPP)- with ethene... 

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