Until recently the low-coordinate compounds of the heavier elementsof group 14 were known only as transient, unstable species whichwere difficult to isolate. However recent developments have led tothe stabilisation of these compounds and today heavier group 14element cations, radicals, anions, carbene analogues, alkene andalkyne analogues and aromatics have all been prepared as highlyreactive, stable, fully characterizable and readily availableorganometallic reagents.Organometallic Compounds of Low-Coordinate Si, Ge, Sn andPb describes the chemistry of this exciting new class oforganometallics, with an emphasis on their major similarities anddifferences with the analogous species in organic chemistry. Topicscovered include include the synthesis, structure, reactions andsynthetic applications of :* Si-, Ge-, Sn and Pb-centered cations, radicals and anions* heavy analogues of carbenes: silylenes, germylenes, stannylenesand plumbylenes* heavy analogues of alkenes: disilenes, digermenes, distannenesdiplumbenes* heavy analogues of alkynes: disilynes, digermynes, distannynesdiplumbynes, and their valence isomers* heteronuclear derivatives: silenes, germenes, stannenessilagermenes, silastannenes, germastannenes* heavy analogues of alkenes of the type:>E14=E13>E14=E15>E14=E16 [where E13E14, E15 and E16 are elements ofthe groups 13, 14, 15 and 16]* cyclic compounds (three-, four-, five-, and six-memberedrings)* heavy analogues of 1,3-dienes, allenes and other cumulenes* heavy analogues of aromatic compounds; including a comparisonbetween organometallic and organic aromaticityOrganometallic Compounds of Low-Coordinate Si, Ge, Sn andPb is an essential guide to this emerging class oforganometallic reagents for researchers and students in main grouporganometallic, synthetic and silicon chemistry

Preface.Abbreviations.1. Heavy Analogs of Carbenium Ions: Si-, Ge-, Sn- andPb-Centered Cations.1.1 Introduction.1.2 Synthesis of RR'R"E¯+Cations (E = Si-Pb).1.3 Reactions and Synthetic Applications of RRRE¯+Cations¯16.1.4 Theoretical Studies.1.5 Early Studies of RR'R"E¯+ Cations: Free orCoordinated?1.6 Stable RR'R"E¯+ Cations.1.7 Summary and Outlook.1.8 References.2. Heavy Analogs of Organic Free Radicals: Si-, Ge-, Sn- andPb-Centered Radicals.2.1 Introduction.2.2 Early Studies: Transient Species RR'R"E.2.3 Persistent Radicals (Generation and Identification).2.4 Stable Radicals.2.5 Summary and Outlook.2.6 References.3. Heavy Analogs of Carbanions: Si-, Ge-, Sn- and Pb-CenteredAnions.3.1 Introduction.3.2 Synthesis.3.3 Structure.3.4 Reactions and Synthetic Applications.3.5 Recent Developments.3.6 Summary and Outlook.3.7 References.4. Heavy Analogs of Carbenes: Silylenes, Germylenes,Stannylenes and Plumbylenes.4.1 Introduction.4.2 Generation.4.3 Spectroscopic Identification.4.4 Structure.4.5 Reactions of Transient Species.4.6 Stable/Persistent Silylenes, Germylenes, Stannylenes andPlumbylenes.4.7 Summary and Outlook.4.8 References.5. Heavy Analogs of Alkenes, 1,3-Dienes, Allenes and Alkynes:Multiply Bonded Derivatives of Si, Ge, Sn and Pb.5.1 Introduction.5.2 Early Studies: Generation and Identification.5.3 Stable Derivatives (Synthesis and Structure).5.4 Summary and Outlook.5.5 References.6. Heavy Analogs of Aromatic Compounds.6.1 Introduction.6.2 Early Studies.6.3 Stable Compounds (Synthesis and Structure).6.4 Summary and Outlook.6.5 References.Index.