Germanium, Tin, and Lead

E = Ge 37, E = Sn) (see Fig. 13), and formally contain Ge(IV) and Sn(IV), respectively. Moreover, a formal double bond exists between the main-group element and the symmetry-unique tungsten atom, which factor is reflected in the X-ray-derived bond lengths (Table II). Reactions involving 37 with THF 

Transition Metal Bond Lengths to Germanium, Tin and Lead 

1 Bond lengths are to the central tin atom. 9 See Fig. 22 for numbering scheme. 

A number of interesting complexes are known to involve multiple bonding to manganese. These fall into two classes, the first comprising two manganese 

The first example of the former was described by Weiss and Gade (49) from the reaction of K.[Mn(GeH3)(CO)2(C5H4Me)] with acetic acid, which affords [Ge Mn(CO)2(C5H4Me) 2], 39, the structure of which is shown in 

McAloon, Fh.D. Thesis, University of Manchester Institute of Science and Technology, 1970. 

Germanium was predicted as the missing element of a triad between silicon and tin by J. A. R. Newlands in 1864, and in 1871 

Mendeleev specified the properties that ekasilicon would have (p. 29). The new element was discovered by C. A. Winkler in 1886 during the analysis of a new and rare mineral argyrodite, AggGeSg he named it in honour of his country, Germany. By contrast, tin and lead are two of the oldest metals known 

Germanium and Sn are non-toxic (like C and Si). Lead is now recognized as a heavy-metal poison it acts by complexing with oxo-groups 

Harrison and D. P. H. Laxen, Lead Pollution, Chapman and Hall, London, 1981, 175 pp T. C. Hutchinson and K. N. Meema (eds.). Lead, Mercury, Cadmium and (ctd.) 

The following hexahalo ions have been characterized for the first four elements of Group IV  

What reasons can you think of to explain these differences  

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The concept of oxidation states is best applied only to germanium, tin and lead, for the chemistry of carbon and silicon is almost wholly defined in terms of covalency with the carbon and silicon atoms sharing all their four outer quantum level electrons. These are often tetrahedrally arranged around the central atom. There are compounds of carbon in which the valency appears to be less than... 

Silicon, germanium, tin and lead can make use of unfilled d orbitals to expand their covalency beyond four and each of these elements is able (but only with a few ligands) to increase its covalency to six. Hence silicon in oxidation state -f-4 forms the octahedral hexafluorosilicate complex ion [SiFg] (but not [SiCl] ). Tin and lead in oxidation state -1-4 form the hexahydroxo complex ions, hexahydroxostannate(IV). [Sn(OH) ] and hexahydroxoplum-bate(IV) respectively when excess alkali is added to an aqueous solution containing hydrated tin(IV) and lead(IV) ions. 

Lead has only one form, a cubic metallic lattice. Thus we can see the change from non-metal to metal in the physical structure of these elements, occurring with increasing atomic weight of the elements carbon, silicon, germanium, tin and lead. 

All Group IV elements form tetrachlorides, MX4, which are predominantly tetrahedral and covalent. Germanium, tin and lead also form dichlorides, these becoming increasingly ionic in character as the atomic weight of the Group IV element increases and the element becomes more metallic. Carbon and silicon form catenated halides which have properties similar to their tetrahalides. 

Compare and contrast the chemistry of silicon, germanium, tin and lead by referring to the properties and bond types of their oxides and chlorides. 

Not applicable to silicon, germanium, tin, and lead perhydro- is prefixed to the name of the corresponding unsaturated compound. 

Silicon (3), which resembles metals in its chemical behavior, generally has a valence of +4. In a few compounds it exhibits a +2 valence, and in silicides it exists as a negative ion and largely violates the normal valency rules. Silicon, carbon, germanium, tin, and lead comprise the Group 14 (IVA) elements. Silicon and carbon form the carbide, SiC (see Carbides). Silicon and germanium are isomorphous and thus mutually soluble in all proportions. Neither tin nor lead reacts with silicon. Molten silicon is immiscible in both molten tin and molten lead. 

Germanium, Tin and Lead Table 10.1 Atomic properties of Group 14 elements... 

Martinho Simoes JA, Liebman JF, Slayden SW (1995) In Chemistry of Organic Germanium Tin and Lead Compounds. Wiley, Chichester, p 245... 

Organometallic Nitrogen Compounds of Germanium, Tin, and Lead, 3, 397 Organometallic Pseudohalides, S, 169 Organometallic Reaction Mechanisms, 4, 267 Organopolysilanes, 6, 19... 

Khabashesku, V. N., Boganov, S. E., Kerzina, Z. A., Nefedov, O. M., Tamas, J., Gomory, A. and Besenyei, I. (1989). 36th International Conference on Or-ganometallic and Coordination Chemistry of Germanium, Tin and Lead Compounds, Brussels. Abstr. P.37... 

Galus Z. 1985. Carbon, sihcon, germanium, tin, and lead. In Bard AJ, Parsons R, Jordan J, editors. Standard Potentials in Aqueous Solution. New York Marcel Dekker. 

I. Zharov and J. Michl, in The Chemistry of Organic Germanium, Tin and Lead Compounds,... 

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