First transition series trivalent state

The first study of the solution chemistry of Rf was performed at Berkeley in 1970 and showed that Rf had a stable tetravalent state with properties similar to the gronp-4 elements Zr and Hf and different from Lr and the other trivalent actinides. This established that Rf shonld be placed in the Periodic Table as the heaviest member of group 4 and the first member of a new 6d transition series. It also confirmed the 1945 prediction of Seaborg that the actinide series should end with element 103. The first studies of the solution chemistry of element 105, condncted at the 88-Inch Cyclotron at Berkeley, were reported in 1988 and showed that the element behaved similarly to the group-5 elements Nb and Ta in its sorption properties, bnt differently from the group-4 elements. However, in extractions into certain organic solvents, Db(Ha) and Ta extracted but Nb did not, creating a renaissance of interest in more detailed studies of the behavior of element 105. 

For lanthanide ions, the result is appropriate for transitions from the ground states in the first half of the series where 7= L - 5. In the second half of the series, where J = L + S, the dipole transitions from the ground state correspond to 7 = 7 - 1. The appropriate cross-section is obtained by making the replacement 7 7-1. The forward scattering cross-sections for all the trivalent lanthanides are given in table 1. 

If it is assumed that californium metal does exhibit two metallic valences, then two phases for each valence form can be selected from the crystallographic data in Table 11.3. For the trivalent form, metallic radii of 1.69 and 1.75 A would be obtained, which is in accord with the radii obtained for the first three transplutonium metals, when allowing for a small systematic decrease in radius in going across the series. The divalent form would yield a radius of 2.0 A, which is similar to the radii of divalent europium or ytterbium metals. The trivalent form of californium metal is well-established if a divalent form does exist, it is favored in small quantities (thin films) obtained from higher temperatures (quendted from the vapor or molten states). Only a limited effort has been made to establish transition temperatures for californium metal [72]. 

Manganese can exist in multiple oxidation states from manganese(II) to man-ganese(VII). Of these states, only the lowest three exist in cationic form. Man-ganese(II) hydrolyses at the highest pH of the divalent first series transition metals and, conversely, manganese(III) at the lowest pH of the corresponding trivalent metals. 

The sulfate ion (S04 ), though a simple dianionic ligand, exhibits a rather flexible symmetry and variable mode of binding with metal ions in the crystalline state. Interest in metal sulfate interactions with the hydra-zinium cation arises from the fact that these compounds exhibit one- and three-dimensional magnetic interactions of a linear-chain antiferromag-net. Dihydrazinium sulfate forms a series of double sulfates with divalent and trivalent cation that are well crystallized and, in a few instances, are even less soluble than hydrazinium sulfate itself. The most easily prepared double sulfates are those of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Li, Mg, Al, La, Ce, Pr, Nd, and Sm. These salts are similar to the ammonium alums obtained with some metal sulfates. In contrast to the ammonium double salts, the hydrazinium metal sulfates of first row transition elements and lithium crystallize without water, whereas the lighter lanthanides and aluminum form hydrated salts. 

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