This fourth volume on organoantimony compounds describes pentavalent antimony com- pounds of the type R and R . The R denotes an organic group bonded by carbon 3SbX2 3Sb=X to the antimony atom. X represents a group, inorganic or organic, which is bonded to the antimony by an atom other than carbon. The X atoms in R may be part of a 3SbX2 ring system. In the case of bidentate X ligands like 02- , S2-, SO~-, CO~-, and others, the compounds are placed with the mononuclear RssbX compounds. 2 I once again thank Dr. Margot Becke and Dr. Ekkehard Fluck for the stimulus that led to this book. To the editor of the former volumes, Dr. Hubert Bitterert gratitude and memory are due. I especially thank Drs. Ulrich Kruerke and Marlies Mirbach for editing this volume, Mrs. Ursula Hettwer for systematically arranging the compounds, and Mr. Edgar Rudolph for preparing the index. Last but not least I thank my wife Sigrid for putting my handwritten manuscript into legible form. Gramschatz, Altes Forsthaus, June 1986 Markus Wieber x Explanations, Abbreviations, and Units Many eompounds in this voLume are presented in tabLes in whieh abbreviations are used and the units are omitted for the sake of eoneiseness. This neeessitates the foLLowing ctarifieation.