tensive compilations on [Cp2ML2] complexes containing ligands whose donor atoms are elements of main Groups V, VI and VI 1. Particular attention is given to the corresponding compounds containing metal-carbon o bonds. Three Registered names, trademarks, err. used in this journal, men when not marked as such. are not to be considered unprotected by law. 0 VCH Verlagsgesellschaft mbH. D.6940 Weinheim. 1987. -Printed in the Federal Republic of Germany by Zechnersche Buchdntckerei, Speyer/Rhetn. At1 rights reserved (including those of translation into foreign languages). No part Of this issue may be he reproduced rn any formby photoprint, microfilm. or any othcr meansnor tranrmitted or translated into a machine language without written permission from the publishers. Only single copies of contributions, or parts thereof, may be made lor personal use. Valid lor users in the USA: The appearance of the wde at the bottom of the first Page Of an article in this journal (serial) indicates the copyright owner's wnsent that wpics of the article may be made for personal or internal use. or for the personal or internal use of specrfic clients. This consent is given on the condition, however, that the copier pay the slated per-copy fee through the Copyright Clearana Center. Inc., for copying beyond that permitted hy Sections 107 or 108 of the US. Copyright Law This mnxnt docs not extend to other kinds of copying, such as mpying for general distribution. for advertising or promotional purpoys for crating new follcnive works, or for resale. For copying from back volumes of this journal see 'Permissions to PhotoCopy. Puhlisher's Fce List' of the CCC. Editofid affiec: Pappelallce 3. M940 Weinheim, Federal Rrpublic of Germany, Telephone (06201) 602315, Telex 465516 vchwh d, Telefax (06201) 602328. mitor: P, C6hlZ.