Future prospects in organometallic chemistry of the Main Group metals: small molecules - supramolecular chemistry

Bulky alkyl ligands functionalised with N-donor groups of the type 2-C(SiMe 3)(2)(6-R-2-pyridyl), R = H or Me, stabilise unusual bonding configurations , and lead into geminal bimetallic complexes, including the formation of a tetrametallic zinc cluster. This chemistry is poised for major advances in mixed metal complexes of the Main Group metals and beyond. Magnesium(anthra cene)(THF)(3) and related complexes solve the 'missing link' in Grignard-re agent formation with the ability to routinely prepare Grignard reagents of benzylic halides. Future directions on the use of reactive metals in synthe sis will adopt the principles of green chemistry, for example in the indium (0)-promoted reactions of organic halides with various functional groups in water. Supramolecular chemistry of o-carboranes in association with 'rigid ' container and saddle-shape molecules has led to new classes of inclusion complexes of varying stoichiometry, and extension of this work into materia ls of higher complexity, with other carboranes and larger globular molecule s, and with functionalised container molecules is a realisation. (C) 2000 E lsevier Science S.A. All rights reserved.