Cobalt abundance data

When the data for vanadium, nickel, cobalt, copper, and iron in petroleum of the Western Interior Region (15) shown below are divided by the average crustal abundance of these elements, the relation, V>Ni>Co>Cu>Fe is... 

Conformational analysis of perhydroazocine (3) was accomplished using a novel cobalt(III) porphyrin shift reagent (see Structures (3a) and (3b)) <90MRC343>. The structure of the AT-benzyl derivative of perhydroazocine was elucidated by C NMR <8lAJC2307>. Natural abundance of 0 NMR data for 30 lactones and 36 lactams in acetonitrile at 75°C was reported <89H(29)30i, 89H(29)307>. 

Data on the abundance of the REE in igneous rocks are presented in table 2 (Moeller 1963). The most plentiful rare earths are cerium (Ce) and yttrium (Y) occurring at an abundance similar to tin (Sn) and cobalt (Co). Neodymium (Nd) and lanthanum (La) occur in similar quantities to lead (Pb) and all the other REE occur at a level of abundance somewhat above silver (Ag) and cadmium (Cd). 

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