"Organoiron Compounds" A, Ferrocene 10 systematicalty covers the literature through the end of 1986 and includes so me references published more recently. A formula index provides ready access to the compounds covered. This volume ends the description of mononuclear unbridged disubstituted ferrocenes, 1 2 FeC HRR . The description of the unbridged disubstituted ferrocenes was initiated with lO a 1 2 "Organoiron Compounds" A, Ferrocene 7 (starting with R and R containing C and Hand 1 containing halogen at least in R\ and continuing with compounds containing 0 at least in R to form alcohols and phenols, their esters, ethers, acetals, and aldehydes), and was foltowed 1 by "Organoiron Compounds" A, Ferrocene 8 (with at least R containing 0). "Organoiron 1 Compounds" A, Ferrocene 9 treated compounds in wh ich at least R contains N, S, Se, B, or Si. This volume now comprises the rest of the disubstituted ferrocenes containing P, As, or a 1 metal at least in R . Beyond that it includes the description of alt the mononuclear unbridged trisubstituted ferrocenes, FeClOH7R1R2R3. Series A so far comprises volumes A 1 to A 10 and has been surveyed in the preface to A 7 (1980). The data in tables are given in abbreviated form without dimensions; for dimensions, explanations, and further abbreviations used, see p. X (next page). Additional remarks are given in the headings of the tables where necessary.

This volume 8 is the fourth in a series dealing with organomolybdenum compounds. An Empirical Formula Index and a Ligand Formula Index provide ready access to the compounds covered. Volume 5 describes mononuclear organomolybdenum compounds with isocyanide, 3 4 carbene, carbyne, alkynyl, alkene, alkyne, L, and L ligands with and without additional CO groups. Volume 6 starts the description of mononuclear organomolybdenum compounds with 5 one L Ligand, a Ligand bonded to molybdenum by five carbon atoms. The compounds contain either zero or one CO group bonded to the molybdenum atom. Volume 7 continues the 5 description of L-molybdenum compounds containing two CO groups, but no additional nl 5 ligands. This volume describes L-molybdenum compounds with two CO groups and additional 1 4 L to L ligands. Following the nomenclature used in this series of organomolybdenum com pounds, nl is an organic Ligand bonded by n C atoms to molybdenum, and mo is an electron 2 donor Ligand with m donor electrons. Thus 0 denotes a Ligand such as PR . 3 Many of the data, particular those in tables, are given in an abbreviated form without units; for explanations see p. X. Additional information, if necessary, is given before the individual table. Frankfurt am Main Manfred Winter November 1992 Wolfgang Petz X Remarks on Abbreviations and Dimensions Many compounds in this volume are presented in tables in which numerous abbreviations are used, the dimensions are omitted for the sake of conciseness. This necessitates the following clarifications.

PF3, (CH3)3SiCl -> (CH3)3SiF, and RC(O)Cl -> RC(O)F. Others include the conversion of (C6H5)3P into (C6H5)3PF2 and of (R3NC(S)S)2 into R2NCF3, R=alkyl. In organic chemistry, fluorides are easily accessible from alcohols, geminal fluorides RR'CF2 from the respective aldehydes or ketones, and acyl fluorides RC(O)F from carboxylic acides by using DAST. Because DAST is easy to handle and gives clean reactions in syntheses, this Gmelin volume devotes much space to the description of the chemical and physical properties od DAST.