561301-67-5Relevant articles and documents
A digalla[1.1]ferrocenophane and its coordination chemistry: Synthesis and structure of [{Fe(η5-C5H4)2}2 {GaMe}2] and of the adducts [{Fe(η5-C5H4)2}2 {GaMe(D)}2] (D = monodentate donor)
Althoff, Alexander,Jutzi, Peter,Lenze, Norman,Neumann, Beate,Stammler, Anja,Stammler, Hans-Georg
, p. 2766 - 2774 (2003)
Gentle warming of 1,1′-bis(dimethylgally)ferrocene (1) leads to the formation of trimethylgallium and the thermolabile compound [{Fe(η5-C5H4)2}2{GaMe }2] (2), a [1.1]ferrocenophane featuring group 13 elements in bridging positions. While NMR data for 2 prove a dynamic structure in solution, X-ray data reveal an anti conformation of the ferrocenophane framework in the solid state. The anti conformation is maintained in the thermolabile adducts 2a-g, which are obtained from 2 and the donors diethyl ether (2a), pyridine (2b), pyrimidine (2c), quinoxaline (2d), DMSO (2e), pyrazine (2f), and dioxane (2g), by donor-exchange reactions (2b-g) or on gentle warming of the respective donor adducts of 1. Rodlike polymers are formed either by interaction of 2 with bidentate donors (2f,g) or by π-stacking effects of aromatic molecules acting as monodentate donors (2b-d). Steric requirements inhibit the complex formation between 2 and the donor phenazine. A cyclic voltammogram of 2b in pyridine reveals two reversible oxidation steps at -314 and -114 mV, indicating only weak electron delocalization in the cationic species. The formation of 2 from 1 has been shown to be reversible and thus is an example of an application of dynamic covalent chemistry as synthetic strategy.
