This volume encompasses the compounds of boron with Cl, Br, I, S, Se, and Te. The large final chapter treats carboranes and metallocarboranes and gives a listing of carborane-containing polymers. Each chapter continues the corresponding chapter of the preceding supplement series, thus keeping information of the desired topics current. Among the wealth of boron compounds two of these may be especially mentioned: BCl3 and carboranes containing five boron atoms. Boron trichloride has become an important chemical agent, and much is known of its preparation, purification, and application. BCl3 is a preferred boron-supplying compound in chemical vapor deposition to prepare boron carbide or boron nitride. BC13 is also frequently used in dry-etching, boriding, and doping processes, and as a polymerization catalyst. Recent interest in the field of C2B5H7 carboranes and their derivatives stems from detailed investigations on a large number of isomerisation reactions and their mechanisms.