Journal of Inclusion Phenomena and Macrocyclic Chemistry 34: 57–68, 1999. © 1999 Kluwer Academic Publishers. Printed in the Netherlands. 57 Synthesis, Characterization and Inclusion Properties of an Iron(II) Polyimine Complex Derived from 2,6-Diacetylpyridine and an Aliphatic Polyamine HENRIQUE E. TOMA ? , TULIO E. CHAVEZ-GIL and REGINALDO C. ROCHA Institutode Quimica, Universidade de São Paulo, CP 26077 CEP 05599-970, São Paulo, SP, Brazil HERCÍLIO R. RECHENBERG Institutode Física, Universidade de São Paulo, CP 66318 CEP 05315-970, São Paulo, SP, Brazil (Received: 6 February 1998; in final form: 10 June 1998) Abstract. A novel multibinding species has been obtained by attaching four aliphatic polyamine chains to an iron(II)-polyimine centre, derived from 2,6-diacetylpyridine. Molecular simulations for the complex corroborate the evidence from 1 H NMR spectroscopy of a symmetric structure, with the four polyamines displaying a tetrahedral arrangement around the metal centre. The protonated polyamine complex interacts with hexacyanoferrate(II) ions, leading to an inclusion compound which has been characterized based on vibrational and Mössbauer spectroscopy, and on cyclic voltammetry. Key words: polyamine complex, iron(II)-polyimines, cyanoiron inclusion compound, Mössbauer spectra 1. Introduction Transition metal polyimine complexes have been used as versatile structural uni- ties for building up supramolecular structures and devices [1–3]. By attaching coordinating groups to the metal-polyimine centre, a novel type of multi-bridging system can be devised for assembling polymetallic species [4] and for molecu- lar recognition purposes. Here, we report on the synthesis and characterization of an iron(II) polyimine complex exhibiting four aliphatic polyamine arms (Fig- ure 1). The basic idea pursued in this work is centred on a new structural unity containing four polyamine chains specially oriented for cooperative binding of the amino/ammonium groups to donor/acceptor substrates. In fact, molecular recognition of hexacyanometallates via outer-sphere association with protonated cyclic polyamine ligands has already been reported in the literature [5–7]. For this reason, a similar approach was attempted in this work by using the multi- ? Author for correspondence.