Three‐Dimensionally Ordered CDW State in Quasi‐One‐Dimensional Iodo‐Bridged Dinuclear Platinum Mixed‐Valence Compounds, A4[Pt2I(pop)4]·nH2O (A = Aromatic Ammonium Cations)

Linear-chain iodo-bridged dinuclear Pt mixed-valence compounds with aromatic ammonium countercations, A4[Pt2I(pop)4]·nH2O [pop = P2O5H22–, A = benzyl ammonium (n = 2; 1), anilinium (n = 2; 2), and p-methoxy anilinium (n = 2; 3)], that have three-dimensionally ordered structures were synthesized. In the case of 1–3 the aromatic ammonium countercations were located between neighboring Pt chains and stacked in 1D columns. π–π Interactions between the phenyl rings and hydrogen bonds between the –NH3+ moieties and the oxygen atoms of the pop ligand link the Pt chains together, thus giving rise to a three-dimensionally ordered CDW state. This is the first observation of this phenomenon in compounds of this type.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)