Platinum compounds magnetic properties

The first indications of covalency in complexes of two metal oxides appear if one of the metals belongs to the platinum group. The oxide complexes in this group are not well known only very recently a few complexes have been prepared and their magnetic properties measured. The compound Na2Ir03, that is formed when a mixture of the metal and Na2GOs is heated in oxygen... 

It will not be possible, in this paper, to deal with all of the platinum metal chalcogenides. Instead, a number of examples will be chosen and their electrical as well as magnetic properties correlated with the atomic positions in the various structures formed. The first group of compounds to be discussed crystallize with the pyrite structure, which is shown in Figure 1. This structure is similar to the NaCl structure if we replace Na by Fe and each Cl by an S2 group. However, the S-S distance within... 

Metal Complexes.—In an extensive study of the complexing power of thiazoles, numerous zinc(n), cobalt(n), copper(ii), nickel(ii), andplatinum(n) complexes of the parent compound, and of 4-alkyl- or 2,4-dialkyl-thiazoles, usually of the general type MX2L2, have been prepared. A consideration of their spectral and magnetic properties reveals that the zinc and cobalt complexes are tetrahedral, the 4-methyl copper and nickel complexes are octahedral, and the dialkyl complexes of copper and nickel and the platinum complexes are square planar. The four-co-ordinate dialkyl complexes follow the crystal field stabilization energy predictions as to the relative tendency to form tetrahedral or square-planar forms, i.e. Zn > Co > Cu > Ni. The complexes are invariably metal-nitrogen, and not metal-sulphur, co-ordinated. ... 

The only platinum nucleus with magnetic properties is Pt, F=, (33.7% abundance). The resonance frequency in a magnetic field of 2.35 T is approximately 21.4 MHz. Satellite peaks from coupling with Pt were observed in H and P NMR spectra in the 1960s, and much of the early work on Pt detection used INDOR methods. Direct one-dimensional observation of Pt NMR spectra is now routine. Because Pt relaxation times are short for most compounds, there need be only a very short delay between pulses, allowing rapid accumulation. Two-dimensional inverse detection methods are also being increasingly used. 

Tphe application of nuclear magnetic resonance to the study of the compounds of the platinum group metals has been limited by the properties of these nuclei. Data are collected in Table I for all of the isotopes of these elements which have nonzero spins. 

---