Halometallates hybrids offer the possibility to obtain (multi)functional materials by combining a functional organic cation with an inorganic anion based on metals of the 14th and 15th groups (typically SnII, PbII, BiIII and SbIII), whose ns2 lone pair has a key role in the collective properties of the material. In the present work, we focused our attention on the synthesis and characterization of viologen halobismuthates and haloantimonates hybrids, the viologen dication (V2+) being well known as a strong electron acceptor. In the first part, we showed that the methylviologen stabilized original 1D halometallates chains of transconnected octahedra, leading to a series of compounds (MV)[MIII(X,X')5]∞ (MV=methylviologen ; MIII=Bi3+, Sb3+, X, X'= Cl-, Br-, I-). The geometry of regular or distorted chains, mainly governed by the stereochemical activity of lone pair of Bi3+ and Sb3+, allowed to obtain a new family of ferroelectric materials, in which, a record value of polarization have been reached in the case of (MV)[BiI3Cl2]∞. In the second part, we tried to understand the photo-induced charge transfer properties in a new family of compounds (V)n+1[MIII 2nX8n+2]∞ (V2+=methylviologen and derivatives, MIII=Bi3+, Sb3+, X=Cl-, Br-, I-, n=1,2,3,∞). We have shown that the color change, resulting from a photo-induced charge transfer reaction, depends on the nature of the metal cation (Bi3+), on the halogen (Cl-), on the viologen (V2+) redox potential, on the size of the inorganic anion and on the nature of weak interactions at the organic-inorganic interface.
