Synthesis of Oxocarbons

Structures and Properties of the Oxocarbon Acids

Structures of the Oxocarbon Anions: Aromaticity

Reactions of the Oxocarbons

Applications of the Oxocarbons

References

INTRODUCTION

The term ‘oxocarbon’ designatcs compounds in which all, or nearمy all, ofthe carbon atoms bear ketonic oxygen functions or their hydrated equivalents l. The most important oxocarbons are cyclic compounds, and this review will be limited to the chemistry of the monocyclic oxocarbons.

A few years ago we pointcd out that monocyclic oxocarbon anions, C,O:-, are aromatic substances, stabilized by electron delocalization of T electrons in the ring1S2. At present four such species are known, the squarate (l), croconate (2) and rhodizonatc: (3) dianions, and the tetraanion of tetrahydroxy-t-benzoquinone (4).

Much of the current interest in the oxocarbons relates to physical studies of the chemical bonding in these species. However, in this review, in keeping with the purposes of this volume, the chemical reactions of the oxocarbons will be emphasized.