Mixed metalII–metalIV hybrid fluorides

Six MII–MIV type II hybrid fluorides (MII = Cu, Ni; MIV = Si, Ti, Mo) are compared: (Ni(en)3)·(TiF6), [Hpy]2·(Cu(py)4(MF6)2) (MIV = Ti, Mo), [H3O]2·(SiF6(CuF(py)4)2)·(F)2 and Cu(en)2MF6 (MIV = Ti, Si). They are obtained at 160 °C under microwave heating and the structures are determined either from single crystal or powder X-ray diffraction data. All phases involve neutral amines that are linked to MII cations, a feature of type II hybrids. In (Ni(en)3)·(TiF6), the cationic (Ni(en)3)2+ and anionic (TiF6)2− entities are isolated. In [Hpy]2·(Cu(py)4(TiF6)2) and [Hpy]2·(Cu(py)4(MoF6)2), extra non metal bonded amines are protonated to give [Hpy]+ cations that exchange hydrogen bonds with fluoride anions, a feature of type I hybrids. All phases exhibit a fully fluorinated octahedral environment of MIV cations, at the opposite from previously reported [H3O]2·(NbOF5(CuF(py)4)2)·(F)2 or [Hpy]2·(Cu(py)4)(MoO2F4)2. In [Hpy]2·(Cu(py)4(MF6)2) (MIV = Ti, Mo) or [H3O]2·(SiF6(CuF(py)4)2)·(F)2, CuII and MIV entities are associated by fluoride anions to give anionic or neutral trimetallic clusters, respectively; the results of thermal analysis suggest that the oxidation state is +IV for molybdenum and it is proposed that H3O+ and “free” F− ion pairs can be replaced locally by H2O and HF couples. In Cu(en)2MF6, the CuII and MIV entities alternate and build infinite chains

Graphical abstractSix type II mixed metal hybrid fluorides are obtained under solvothermal conditions assisted by microwave heating. The structures are determined either from single crystal or powder X-ray diffraction data.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Six type II mixed metal hybrid fluorides prepared by solvothermal synthesis assisted by microwave heating. ► Phases based on MII and MIV elements and on pyridine or ethylene diamine. ► Structures with 0D and 1D dimensionalities determined either from single crystal or powder X-ray diffraction data.