Beryllium oxygen ligands

Few inorganic ligands form stable complexes with the beryllium ion in aqueous solution. This is a reflection of the fact that on the one hand Be2+ shows a strong preference for oxygen donor ligands such as water and the hydroxide ion, and on the other hand reacts with the more basic ligands such as ammonia to give the insoluble hydroxide. Reported equilibrium constants are in Table V. 

Published equilibrium constants for monocarboxylato complexes are summarized in Table VII. All that can be deduced with certainty from these data is that the anions derived from monocarboxylic acids form rather weak complexes with beryllium. In all probability they act as monodentate ligands. The possibility of bidentate chelation using both carboxylate oxygen atoms can be ruled out on the grounds... 

Because of its toxicity, the number of well-characterized beryllium compounds of all types is much lower than that of the other alkaline earth metals. The largest number of the pubhshed berylhum structures involve oxygen donor ligands, " and beryllium amides have been reviewed, at least in part, under the aegis of wider-ranging surveys - of group 2... 

Where the valency of a metal is not indicated, the normal valency of the metal is assumed. Beryllium probably is placed in the 0=N group because of the stability of its phthalocyanine chelate. Most often Be forms very stable bonds with oxygen as the donor element. Vanadium, nickel, and copper from the N > O group and iron from the ON group are the elements most frequently found in petroleum, chelated with porphyrin ligands. The porphyrin chelate contains four nitrogens as donor elements. 

All the cations form complexes with oxygen, nitrogen donor ligands (see Chapter 15), and also with the lighter halides. Beryllium (Be) is limited to a maximum coordination number of four due to its small size (more than four atoms just can t fit around it ). Magnesium and calcium can be six coordinate, and strontium and barium can have even higher coordination numbers. 

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