1IntroductionThis chapter follows the usual pattern with emphasis on the organometallic and coordination chemistry of Groups 1 and 2 published in 2001.Reviews which contain material relevant to s-block chemistry have appeared on the chemistry of compounds containing the tris(trimethylsilyl)methyl or related groups,11-azaallyl complexes,2imido analogues of oxo anions,3tetraorganodichalcogenoimidodiphosphorus acids and their derivatives,4metal inverse crowns, based on combinations of alkali metal and magnesium (or zinc) amides,5the oxygen-scavenging properties of alkali metal-containing organometallic compounds,6the use of macrocyclic polyethers with aromatic side-chains to study alkali metal cation–π interactions,7the emerging use of magnesium bis(amides) as reagents in organic synthesis,8Ziegler–Natta heterogeneous catalysts, especially those basedon alkoxymagnesium species,9and the aqueous coordination chemistry of beryllium with a focus on aqua, fluoro, hydroxo, oxo and peroxo complexes as well as various carboxylates, carbonates, phenolates, enolates and polyolates in a bioinorganic context.10Group 1 metallation of 2-trimethylsilylaminopyridine (LH) in the presence of 12-crown-4 ether affords [LiL(12-crown-4)], the unusual ate complex [Na(12-crown-4)2][NaL2(thf)](thf) and [ML(12-crown-4)]2·nC6H5Me, (M = K,n= 2; M = Rb,n= 0; M = Cs,n= 1). X-Ray crystallography showed that the pyridine ligand bonds through both nitrogen atoms and bridges through both nitrogen atoms in the dimers. The structure of [Cs(NH-2-py)(12-crown-4)]∞was also reported.11The structure and reactivity of MCH2OMe (M = Li, Na, K) have been investigated usingab initiomethods. The MCO angle was found to be acute due to strong M–O interactions and the intermolecularmethylene transfer reaction to give MOCH2CH2OMe was found to occur more readily than methylene transfer to MMe or α-elimination of CH2. The important interaction takes place between σ(M–C) in the nucleophile and σ*(C–O) in the electrophile; electrophilic character decreases from Li to K.12The conformations of α-alanine and those of the eight most stable adducts that it forms with M+(M = Li, Na or K) have been studied using density functional theory. The lowest energy structures are either N,O-bicoordinate systems (M = Li or Na) or O-monocoordinate species (M = K).13The structural, electronic and vibrational properties of MCp (M = Li, Na or K) and MCp* (M = Li or Na) have been studied, using both spectroscopic and density functional techniques, with a view to investigatethe influence of methyl groups on spectral features, M–C force constants and change in ionic character of the M–C bond for different metals.14The enthalpies of formation of MCp (M = Li, Na, K or Tl) have been determined and those for M = Rb or Cs estimated.15Several cyclic and acyclic oligo(dimethylsilylene)phenylene species have been found to form cation–π complexes with alkali metal cations using electrospray mass spectrometry. The ability of the trimethylsilyl group to enhance the interaction was demonstrated usingab initiocalculations.16Reactivity studies and two crystal structures have been reported for [MSiX(SiBut3)2] (M = Li, Na or K; X = H, Me, Ph, F, Cl or Br).17The lithium and sodium salts of (dimethylfluorenylsilyl)cyclopentadieneform polymeric chains.18A crystallographic study of a series of alkali metal complexes of [(2-py)(SiMe3)CH2] (R1H) and [(6-Me-2-py)(SiMe3)CH2] (R2H), [MR1(pmdien)]2(M = Na or K), [NaR1(tmen)]2, [LiR2(pmdien)] and the magnesium complex [MgR12(hmpa)2] revealed that all are metal enamides in the solid state. The preference for the enamide, rather than the carbanion or azaallyl formulation was addressed byab initiocalculations.19The crystal structures of some organometallic compounds of lithium and magnesium containing the bulky ligands C(SiMe3)2(SiMe2X) (X= Me, Ph, NMe2or 2-py) have been reported.20The solid state structures of sodium and calcium complexes of sulfonated azo dyes [O3SC6H4NNC6H3R1R2]−(R1= H, R2= OH or NH2; R1= R2= OH) form a series of supramolecular arrays with one-, two- and three-dimensional frameworks. Sodium forms close linked sheets, chains and cages similar to many inorganic minerals whilst calcium adopts ring-ladder structures resembling those found in s-block amide chemistry.21The preparations of [M(μ-Cl)(η5-C4Et4E)(thf)n]2(M = Mg,n= 1; M = Ca,n= 2; E = P, As or Sb) and [M(η5-C4Et4E)2(thf)n] (M= Sr,n= 1; M = Ba,n= 0) have appeared. The structure of the barium compound shows molecules linked into chainsviaBa⋯P interactions.22A series of new alkaline earth metallocenes and their adducts with the carbene 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene have been described.23A simple, cheap and safe method of disposal for sodium and potassium has been published. A ceramic flower pot is half-filled with fine-ground sand, the residues are added and the pot is filled with sand and then placed in a tray of water. Capillary action then draws water into the sand and destroys the metal. The sand can be washed and used again.24