Organostannoxanes and cyclophosphazenes as scaffolds for multi-ferrocene assemblies

The reactions of n-butylstannonic acid and di n-butyltinoxide with ferrocen e monocarboxylic acid have been studied. In the former reaction a hexameric compound, [n-BuSn(O)OC(O)C5H4FeC5H5](6) has been isolated in a quantitativ e yield. In the latter reaction a tetrameric compound [{n-Bu2SnO2C(C5H4FeC5 H5)}(2)O](2) has been isolated. In contrast to the drum like structure of t he former compound, the latter has a ladder like arrangement. Both [n-BuSn( O)OC(O)C5H4FeC5H5](6) and [{n-Bu2SnO2C(C5H4FeC5H5)}(2)O](2) are electrochem ically robust and show a single oxidation peak in the cyclic voltammetric e xperiment corresponding to the simultaneous oxidation of six and four ferro cene substituents respectively. The hydrazine substituted cyclophosphazenes , N3P3[N(Me)NH2](6), gem-N3P3Ph2[N(Me)NH2](4), and gem-N3P3(O2C12H8)(2)[N(M e)NH2](2), are readily condensed with ferrocene carboxaldehyde, C5H5FeC5H4C HO, to afford the corresponding cyclophosphazenes linked to the ferrocenyl moiety through the hydrazone linkage, N3P3[N(Me)N=CHC5H4FeC5H5](6), gem-N3P 3Ph2[N(Me)N=CHC5H4FeC5H5](4), and gem-N3P3(O2C12H8)(2)[N(Me)N=CHC5H4FeC5H5] (2). These cyclophosphazene linked multi-ferrocene derivatives are also thermall y as well as electrochemically robust similar to the stannoxane linked deri vatives. All of these compounds have been characterized by multinuclear NMR (H-1, C-13, P-31, Sn-119), mass spectroscopy, and X-ray crystallography.