Germanium complexes tetravalent

Now a series of tetravalent germanium complexes of this ligand has been synthesized and at the same time the series of germanium phthalocyanines (3,4) has been extended. Accordingly comparisons between the two series have been made possible and these enable the chemistry of octahedral germanium to be more clearly delineated. 

In contrast to the sulfide of silicon (p. 187). the sulfides of tetravalent germanium (white) and tetravalent tin (yellow) are stable in water, but form complexes in the presence of excess sulfide ion. The sulfides of divalent tin and lead (both black) dissolve neither in strong base, in excess sulfide, nor in dilute acids. Note that PbS has the same structure as sodium chloride and is probably the most nearly covalent salt known having this structure, its color and metallic lustre setting it apart from the structurally similar ionic halides and oxides. 

Porphycenes have also been shown to form stable complexes with tetravalent metal cations. Examples of tetravalent systems include the tin(IV) and germanium(IV) complexes 3.82-3.84 (Figure 3.1.16). In each of these complexes, two axial chloride anions were found to be coordinated to the metal atom. While it is... 

---