A very large number of organo derivatives is formed by the Group IV ele- ments silicon, germanium, tin, and lead. In comparing the general properties of these elements, Table 1. 1 shows that the first ionization energies decrease (though not in a regular way) with increase in size and atomic number, con- sistent with the general increase in metallic character of the elements. Electro- negativity values (which have been the subject of considerable controversy) show no clear trend. Although purely inorganic compounds of tin(n) and leaden) are well known, almost all organo Group IV derivatives show an oxidation state of IV. Bonds to carbon become weaker on passing from silicon to lead, as do the element-element bonds themselves. With any particular element M (M = Si, Ge, Sn, or Pb), there is a small decrease in bond energy in the order: M-Ph > M - Me > M - Et. Although accurate data for organo derivatives are lacking, strengths of bonds to other elements probably decrease in the order: M-F> M-O > M-CI > M-H ~ M-N ~ M-S ~ M-Br > M-I, while for a particular element X, the order is: Si-X > Ge-X > Sn-X > Pb-X. It is therefore understandable that reactions leading to Si-F, Si-O, or Si-CI bonds are especially favoured in a thermodynamic sense.

Table of Contents:
Group IV Silicon, Germanium, Tin, and Lead.- 1 Introduction.- 2 Silicon.- Tetra-alkyls and tetra-aryls of silicon.- Unsaturated organosilicon compounds.- Heterocyclic compounds of silicon and carbon.- Cyclic saturated organosilanes.- Cyclic unsaturated organosilanes.- Organosilicon(II) compounds and organosilicon radicals.- Organosilicon halogen compounds.- Monohalides, R3SiX.- Dihalides, R2SiX2.- Trihalides, RSiX3.- Organosilicon pseudohalides.- Organosilicon oxygen compounds.- Silanols.- Silanolates or siloxy-metal derivatives.- Alkoxides and aryloxides.- Siloxanes.- Silicones.- Short-lived R2Si=O intermediates.- Peroxides.- Ketones.- Organosilicon sulphur, selenium, and tellurium compounds.- Organosilicon nitrogen compounds.- Aminosilanes.- Disilazanes.- Cyclic silicon-nitrogen compounds.- Hydrazine derivatives.- Organosilylazenes.- Derivatives of hydroxylamine and amides.- Silatranes.- Organosilicon phosphorus, arsenic, antimony, and bismuth compounds.- Organosilicon hydrides.- Compounds containing silicon-silicon bonds.- Acyclic derivatives.- Cyclic derivatives.- Organosilicon-metal compounds.- Groups I and II.- Groups III and IV.- Transition-metal derivatives.- Silylmethyl-transition-metal derivatives.- 3 Germanium.- Tetra-alkyls and tetra-aryls of germanium.- Unsaturated organogermanium compounds.- Heterocyclic compounds of germanium and carbon.- Organogermanium(II) compounds and organogermanium radicals.- Organogermanium halogen compounds.- Monohalides, R3GeX.- Dihalides, R2GeX2.- Trihalides, RGeX3.- Alkylgermanes with halogenated side-chains.- Organogermanium pseudohalides.- Organogermanium oxygen compounds.- Oxides and hydroxides.- Alkoxides.- Peroxides.- Esters.- Ketones.- Organogermanium sulphur, selenium, and tellurium compounds.- Organogermanium nitrogen compounds.- Organogermanium phosphorus, arsenic, antimony, and bismuth compounds.- Organogermanium hydrides.- Compounds containing germanium-germanium bonds.- Organogermanium-metal compounds.- Alkali-metal and magnesium derivatives.- Derivatives of other main-group metals.- Transition-metal derivatives.- 4 Tin.- Tetra-alkyls and tetra-aryls of tin.- Unsaturated organotin compounds.- Heterocyclic compounds of tin and carbon.- Organotin(II) compounds and organotin radicals.- Organotin halogen compounds.- Monohalides, R3SnX.- Dihalides, R2SnX2.- Trihalides, RSnX3.- Complexes of organotin halides.- Organotin(II) halides.- Organotin pseudohalides.- Organotin oxygen compounds.- Monohydroxides and derivatives.- Alkoxy and aryloxy derivatives, R3SnOR1.- Dihydroxides and derivatives.- Tetra-alkyl distannoxanes, (XR2Sn)2O, and related derivatives.- Stannonic acids.- Peroxides.- Sn-O compounds in organic synthesis.- Organotin sulphur, selenium, and tellurium compounds.- Organotin nitrogen compounds.- Organotin phosphorus, arsenic, antimony, and bismuth compounds.- Organotin hydrides.- Hydrostannation.- Hydrostannolysis.- Use of organotin hydrides in synthesis.- Compounds containing tin-tin bonds.- Derivatives of distannane.- Derivatives of hexa-alkyl or -aryl-ditin compounds.- Derivatives of higher stannanes.- Derivatives of the type (R2Sn)n.- Organotin-metal compounds.- Alkali-metal derivatives.- Derivatives of other main-group elements.- Transition-metal derivatives.- 5 Lead.- Tetra-alkyls and tetra-aryls of lead.- Unsaturated organolead compounds.- Organolead(II) compounds and organolead radicals.- Organolead halogen compounds.- Monohalides, R3PbX.- Dihalides, R2PbX2.- Trihalides, RPbX3.- Organolead oxygen compounds.- Organolead sulphur, selenium, and tellurium compounds.- Organolead Group V compounds.- Organolead hydrides.- Compounds containing lead-lead bonds.- Dilead derivatives.- (R2Pb)x derivatives.- Organolead-metal compounds.- Alkali-metal derivatives.- Transition-metal derivatives.- References: Group IV.- V Arsenic, Antimony, and Bismuth.- 6 Introduction.- 7 Arsenic.- Tri-alkyls and tri-aryls of arsenic.- Unsaturated organoarsenic compounds.- Penta-alkyls and penta-aryls of arsenic.- Ylides of arsenic.- Organoarsenic halogen compounds.- Derivatives of arsenic(V).- Arsonium salts.- Dihalides, R3AsX2.- Trihalides, R2AsX3.- Tetrahalides, RAsX4.- Complexes of Arsenic(V) halides.- Derivatives or arsenic(III).- Monohalides, R2AsX.- Dihalides, RAsX2.- Organoarsenic oxygen, sulphur, and selenium compounds.- Oxygen derivatives of arsenic(V).- Tetraorgano hydroxides, R4AsOH.- Triorgano oxides, R3AsO.- Triorgano hydroxy-halides, R3As(OH)X.- Arsinic acids, R2AsO(OH).- Arsonic acids, RAsO(OH)2.- Sulphur and selenium derivatives of arsenic(V).- Derivatives of arsenic(III).- Arsonous acids, RAs(OH)2 and related derivatives.- Organoarsenic nitrogen compounds.- Derivatives of arsenic(V).- Derivatives of arsenic(III).- Organoarsenic hydrides.- Compounds containing arsenic-arsenic bonds.- Diarsines, R2AsAsR2.- Polyorganoarsines and related compounds.- Organoarsenic-metal compounds.- Alkali-metal derivatives.- Transition-metal derivatives.- 8 Antimony.- Tri-alkyls and tri-aryls of antimony.- Unsaturated organoantimony compounds.- Penta-alkyls and penta-aryls of antimony.- Ylides of antimony.- Organoantimony halogen compounds.- Derivatives of antimony(V).- Stibonium salts, R4SbX.- Dihalides, R3SbX2.- Trihalides, R2SbX3.- Tetrahalides, RSbX4.- Complexes of antimony(V) halides.- Derivatives of antimony(III).- Monohalides, R2SbX.- Dihalides, RSbX2.- Organoantimony oxygen, sulphur and selenium compounds.- Oxygen derivatives of antimony(V).- Tetraorgano hydroxides, R4SbOH, and alkoxy compounds, R5-xSb(OR)x.- Triorgano oxides, R3SbO.- Stibinic acids, R2SbO(OH).- Stibonic acids, RSbO(OH)2.- Sulphur and selenium derivatives of antimony(V).- Derivatives of antimony(III).- Organoantimony hydrides.- Compounds containing antimony-antimony bonds.- Organoantimony-metal compounds.- 9 Bismuth.- Tri-alkyls and tri-aryls of bismuth.- Unsaturated organobismuth compounds.- Penta-aryls of bismuth.- Organobismuth halogen derivatives.- Derivatives of bismuth(V).- Derivatives of bismuth(III).- Organobismuth-metal compounds.- References: Group V.