Zirconium electron configuration

Question. From the ground electron configuration of zirconium derive the ground state (i.e. the values of L, S and J) explaining which rules enable you to do this. Then derive the states arising from the excited configuration... 

Assume that the Russell-Saunders coupling approximation applies to both configurations. Answer. The ground electron configuration of zirconium (Z = 40) is (see Table 7.1)... 

We may expect that the future will see many additional uses of cationic zirconocenes in organic synthesis, in which their Lewis acidic character, coupled with the special properties of zirconium (oxophilic, fluorophilic) and its d°-electron configuration (leading, for example, to weak back-bonding) will come into play. 

Indicate the position of titanium, zirconium, and hafnium in Mendeleev s periodic table of the elements, the electron configurations and size of their atoms, and their oxidation states. 

Due to its 5t/-6.v- electron configuration, hafnium forms tctravalent compounds readily, although the Ilf1 ion docs not exist as such In aqueous solution except at very low pH values, Ihe common cation being HfO lor Hf OH)i ) and many of the tctravalent compounds are partly covalent. There are also less stable Hf(lll) compounds, There is close similarity in chemical properties to those of zirconium due to the similar outer electron configuration (4identical ionic radii (ZrJ is 0.80 A) the relatively low value for Hf being due lo the Lanthanide contraction. 

Ferrocene is only one of a large number of compounds of transition metals with the cyclopentadienyl anion. Other metals that form sandwich-type structures similar to ferrocene include nickel, titanium, cobalt, ruthenium, zirconium, and osmium. The stability of metallocenes varies greatly with the metal and its oxidation state ferrocene, ruthenocene, and osmocene are particularly stable because in each the metal achieves the electronic configuration of an inert gas. Almost the ultimate in resistance to oxidative attack is reached in (C5H5)2Co , cobalticinium ion, which can be recovered from boiling aqua regia (a mixture of concentrated nitric and hydrochloric acids named for its ability to dissolve platinum and gold). In cobalticinium ion, the metal has the 18 outer-shell electrons characteristic of krypton. 

The Gp. IVA transition elements, titanium, zirconium and hafnium all have the [n — l)d2ws electron configuration. They differ from the transition elements of the later groups in their tendency to form compounds to the exclusion of those in which lower charge numbers occur especially is this true of Zr and Hf. 

Write the ground-state electron configuration for zirconium. 

The completion of the fourth shell represents the end of the rare earth series, and the next, as yet undiscovered, element is expected to be a transition metal and a homologue of zirconium, showing a valence of 4. The general approach used by Bohr in his assignment of electron shells is to ensure an overall agreement with the known periodic table. The form of the periodic table in fact guided Bohr to electronic configurations, as he sometimes admitted. 

Titanium and zirconium chemistry is conveniently divided between simple complexes and those based on the metallocene imit Cp2M (Cp = CsHs = cyclopentadienyl). Most simple complexes are oligomeric, insoluble, and difficult to characterise, although alkyl titanium complexes such as X3TiR have found some use as non-basic Grignard equivalents. The dicyclopenta-dienyl metal moiety, Cp2M, renders complexes monomeric, soluble, and easily characterised by NMR spectroscopy, and thus many applications based on these systems have been devised. The most stable electronic configuration of titanocene and zirconocene complexes has only 16 electrons in the valence shell, not the 18 electrons common in most of the rest of the transition metal series. The empty orbital this leaves on the metal is crucial for reactivity. 

Zirconium see also Elements electrical resistivity, 12-39 to 40 electron configuration, 1-18 to 19 heat capacity, 4-135 history, occurrence, uses, 4-1 to 42 ionization energy, 10-203 to 205 isotopes and their properties, 11-56 to 253 magnetic susceptibility, 4-142 to 147 molten, density, 4-139 to 141 physical properties, 4-133 to 134 thermal properties, 12-201 to 202 vapor pressure, 6-61 to 90 vapor pressure, high temperature, 4-136 to 137... 

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