Conductivity derived from electronic structure

There have been no reports of complexes of " JV-substituted thiosemicarbazones derived from 2-formylpyridine, but 2-acetylpyridine JV-methyl-thiosemicarbazone, 3a, formed [Fe(3a-H)2]C104 and [Fe(3a-H)2]FeCl4 [117]. The nature of these two species was established by partial elemental analyses, molar conductivities, magnetic moments, electronic, infrared, mass and electron spin resonance spectra. A crystal structure of a related selenosemicarbazone complex confirmed the presence of a distorted octahedral iron(III) cation coordinated by two deprotonated anions so that each ligand is essentially planar and the azomethine nitrogens are trans to each other the pyridyl nitrogen and selenium donors are both cis. 

The metallic structure essentially consists of atomic nuclei and associated core electrons, surrounded by a sea of free electrons. The high electrical conductivity of metals is derived from the presence of these free electrons. In addition to high electrical conductivity, the free electrons provide the metals with good thermal conductivity as well. The electrical resistivity of a metal increases with temperature. 

The remarkable variety of redox systems which can already be derived from the Weitz type underline the wide scope of the general structure A and C as a basic principle for two step redox systems. The empirical material as well as general rules regarding structural influences on potentials and Ksem have been developed to such an extent, that redox systems can be taylored to meet special purposes. Catalysts for electron transfer, light positive systems and compounds of high electrical conductivity are some fields in which these redox systems could occupy key positions. Some applications have already been discussed in a previous review of wider scope h)... 

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