Synthese von 6,6,7,7,13,13,14,14‐Octamethyl‐6,7,13,14‐tetrasiladispiro[4.2.4.2]‐ tetradeca‐1,3,9,11‐tetraen und sein Einsatz in der π‐Komplexchemie von p‐ und d‐Block‐Elementen

Synthesis of 6,6,7,7,13,13,14,14‐Octamethyl‐6,7,13,14‐tetrasiladispiro[4.2.4.2] tetradeca‐1,3,9,11‐tetraene and Its Application in the Chemistry of π Complexes of p‐ and d‐Block Elements The title compound 2 can be synthesized either by reaction of ([C 5 H 5 SiMe 2 SiMe 2 C 5 H 5 ] 2‐ 2 Li + ) with XSiMe 2 SiMe 2 X or by an intermolecular nucleophilic substitution reaction between two molecules of ([XSiMe 2 SiMe 2 C 5 H 5 ] ‐ Li + ). Isomers of 2 with allylic hydrogen atoms arise from silatropic rearrangements and therefore show “cyclopentadiene reactivity”. Reaction of the monoanion of 2 with FeCl 2 yields the ferrocene 4 . From the reaction of the dianion of 2 with Me 5 C 5 RuCl, the binuclear ruthenium complex 7 with Si – Si bridges in 1,2‐position can be isolated; reactions with FeCl 2 or Me 5 C 5 Fe(acac), with Me 5 C 5 GeCl, with SnCl 2 , and with PbCl 2 , lead to the metallocenes 6, 7, 8 , and 9 ; in all these complexes the disilane bridges are in 1,2‐position. The binuclear cobalt complex 10 , in which the cyclopentadienyl rings are connected with each other by disilane bridges in 1,3‐position, can be synthesized by the reaction of 2 with CO 2 (CO) 8 . The results of single‐crystal X‐ray structure analyses of 6 and 10 are presented. The possible conformations of the dianion of 2 are discussed.