Platinum complexes INDEX

Thousands of platinum complexes have been synthesized and tested in recent years, and the pace of research remains very fast. The effort has yielded a number of compounds that exhibit higher activity, better selectivity, and/or increased therapeutic index compared to cisplatin. Some of these drugs are discussed herein. 

Finally it should be noted that although one might not find a compound listed uhder an incorrect name, there is no guarantee that it will be listed under its correct name either. In consulting a journal index for information about a compound, one may often save time by selecting what appears to be the most important element in the compound and looking under the section devoted to that element. Thus each of the octahedral cobalt complexes pictured above would be likely to be listed under Cobalt Compounds, whereas the two platinum complexes might very well be listed under Platinum Compounds. ... 

Table 5. Reaction energies for the hydration of platinum complexes subscript denotes a reaction, and a denotes activation energies or Gibbs enthalpies. Index means activation energies corrected on the proper reactant conformer.

In the above equation, v (cm" ) is the wavenumber, vo (cm" ) the wavenumber of the absorption band center, y (cm" ) the damping constant (which gives the band width), B (cm"3 determines the intensity of the band, and e the refractive index far away from resonance. The properties of the adsorbate film are those of CO on platinum. For the middle spectrum, the complex refractive index (n— 5 + 20/) is close to that of platinum at 2000 cm" and k were varied between 2.5 and 10 and between 10 and 40, respectively, in view of the fact that and k vary drastically over the mid-IR region and from metal to metal (55). 

The Fluorination of Platinum in the Presence of Powdered Glass.—Fluorine, diluted with nitrogen, was passed in a slow stream over a heated mixture of powdered glass and platinum at 400° and a mixture of pale brown and black particles was left. J -Ray powder photographs showed these particles were two phases. A simple pattern, characteristic of the black material, was indexed on the basis of a rhombohedral unit-cell, a = 5-39 i 0 02 A, a = 54-7 i 0-2°, / = 97 A. Observed and calculated Ijd" values are in Table 3. The complex pattern of the light brown phase was identical with that of platinum oxide trifluoride. 

The Fluorination of Platinum Dioxide.—Platinum dioxide, in a nickel boat, was fluorinated at 200° until the product appeared to be homogeneous. It was analysed by pyrohydrolysis to 500° (Found F, 21-4 Ft, 73T. PtOFj requires F, 21-3 Pt, 72-8%). The complex X-ray powder photograph was not indexed. The involatile solid hydrolysed slowly in moist air with water its hydrolysis was similar to that of platinum tetrafluoride. 

Bromine trifluoride under reflux, dissolved the tetrafluoride to give a deep red solution. The red-brown solid which remained after vacuum distillation of the bromine trifluoride was the 2 1 bromine trifluoride-platinum tetrafluoride adduct [Found F, 35-1 Pt, 36-7. Calc, for (BrFj)2PtF4 F, 34-9 Pt, 34-9%]. The diamagnetic solid melted with some decomposition at 136°. Its X-ray powder pattern was complex and no attempt was made to index it. Iodine pentafluoride neither dissolved nor reacted with the tetrafluoride even on prolonged refluxing at 100°. Chlorine trifluoride, passed over the tetrafluoride at 300°, converted it into a yellow solid, m. p. 170°, of which the X-ray powder pattern was identical with that of the chlorine trifluoride-platinum pentafluoride adduct. ... 

Properties of the iodine pentafluoride-platinum pentafluoride adduct. The solid, m. p. 140°, begins to decompose at 180° this is complete at 300° and the residue is platinum tetrafluoride. The adduct is paramagnetic, p = 0-65 B.M. (23°). The X-ray powder pattern was complex and no attempt was made to index it. Water reacted vigorously with it to give a solution containing the hexafluoroplatinate(iv) ion. Reaction with most organic solvents was exothermic and complex, but carbon tetrachloride neither reacted with nor dissolved it. 

Refractive index studies allow measurements of the birefringence, but also of the polarisability. The mean polarisability (a) can be determined using an isotropic liquid solution, whereas the polarisability anisotropy (Aa) is measured in the mesophase. Polarisability studies have been made on palladium, platinum, iridium and silver metallomesogens, and show a higher polarisability for the metal complexes than for their parent ligands. ... 

The adsorbed sulfate species on other low-index planes of platinum and gold present a more complex spectroscopic structure [32, 46, 50, 57, 58]. Fig. 16 shows the spectra of adsorbed sulfate at saturation coverage for the three low-index planes of the platinum electrode in a solution of pH = 2.8. Clearly, a second band at 1008 cm can be easily identified for Pt(lOO) (weak) [57] and for Pt(llO) (strong) [58]. These two planes do not match a symmetry for the adsorbed sulfate ions, and therefore we should... 

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