Complex halides physical properties

The other hydrogen halides add oxidatively to rhodium(I) complexes of ditertiary phosphines or arsines giving rise to numerous monohydrido complexes, whose physical properties are also listed in Table 79. However, it is possible to prepare certain monohydrido complexes from rhodium(III) halides. One interesting reaction, carried out under an atmosphere of CO, gives rise to dicar-bonyldichlororhodate(I) salts (equation 241).226... 

There are two monohydrido complexes which have been prepared by the oxidative addition of hydrogen halides to [Rh P(OMe)3 5][BPli4] (equation 223). Two other monohydrido complexes having hydrogen-bonded anions have been prepared by simultaneous substitution of and oxidative addition to dinuclear rhodium(I) complexes (equation 224). The anions give resonances at very low fields in the H NMR spectra of the complexes. " The physical properties of the monohydrido complexes are listed in Table 77. 

Analytical data on the soluble products isolated from chloroform are in excellent agreement with the composition 1 Ni+2 1 monoalkylated ligand 1 I or Br. The magnetic moment of this methylated complex was found to be 1.89 Bohr magnetons per nickel (II). The molar conductivities of the methylated and benzylated complexes in methanol at 25° C. are 75.4 and 68.4 ohm-1, respectively. These values approximate those expected for uni-univalent electrolytes in this solvent. The formulation of these alkylated compounds as dimeric electrolytes (structure VII) does not appear to be totally consistent with their physical properties. One or both halide ions may be bound to the metal ion. These results lead to the easily understood generalization that terminal sulfur atoms alkylate more readily than bridged mercaptide groups. 

Probably the most numerous bimetallic complexes of rhodium are those containing mercury. The complex //-[RhHCl (AsMePh,)3 ] reacts with mercury(II) halides,1351 phenylmercury(II) halides,1352 or mercury(I) halides 351,1352 to produce/ac-rhodium-mercury complexes (145) (equation 333). The physical properties of the products are shown in Table 94. 

Under elevated pressures, the rocksalt stmcture transforms into the CsCl structure. Changes in lattice constants and measurements of other physical properties have provided much quantitative information for empirical fits to equations of state. Modem theoretical tools are used for obtaining a deeper understanding of charge being transferred back from the anion towards the cation in the aUcah hahdes. However, as can be seen from calculations of their cohesive properties, even nowadays there are problems to be solved for such simple stmctures. The data for the halide ions, in particular, are quite useful and may be transferred to other halide systems, and give good predictive values for more complex systems. 

The cooperative nature of inhibition in this system is ascribed to halide mediated PEG adsorption that may also involve interactions with the Cu+ reaction intermediate. Indeed, the earliest studies of PEG-C1 inhibition discuss the possible formation of various polyether-cuprous chloride compounds ranging from PEG helically wound around a CuCl core to crown-ether like moieties bound to the copper surface via chloride [233, 234], Analogous arguments of complex formation were made based on experimental measurements of the physical properties of solutions containing a high PEG/Cu+/2+ ratio [239, 240]. 

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