The hydrothermal synthesis of the new manganese and vanadium oxides, NiMnO3H, MAV3O7 and MA0.75V4O10•0.67H2O (MA = CH3NH3)

The hydrothermal reaction of manganese or vanadium oxides in the presence of organic cations leads to the formation of new layered structures. When nickel salts are hydrothermally reacted with tetramethylammonium permanganate a new orthorhombic form of nickel manganese oxide, NiMnO3Hx (where x less than or equal to 1) is formed. It readily chemically intercalates lithium; it has space group Cmc2(1), a = 2.861(1) Angstrom, b = 14.650(1)Angstrom, and c = 5.270(1) Angstrom. The magnetic properties of this compound are quite different from the ilmenite NiMnO3 phase, showing paramagnetism above 390 K and more complex behavior below that temperature. The hydrothermal reaction of vanadium pentoxide with methylamine leads to a series of new layered vanadium oxides, which differ in structure from the corresponding ones prepared in the presence of the tetramethylammonium ion because of the existence of hydrogen bonding. Methylamine is the first organic to form a double sheet vanadium oxide, (CH3NH3)(0.75)V4O10. 0.67H(2)O, with the delta-AgxV2O5 structure. (CH3NH3)(0.75)V4O10. 0.67H(2)O is monoclinic, space group C2/m with a = 11.673( 1) Angstrom, b = 3.668( 1) Angstrom, c = 11.095(1) Angstrom and beta = 99.865(5)degrees. (CH3NH3)V3O7 shows significant buckling of the layers compared with N(CH3)(4)V3O7, and has a monoclinic unit cell, space group P2(1)/c with a =11.834(8) Angstrom, b = 6.663(4) Angstrom, c = 15.193(9) Angstrom and beta = 138.104(1)degrees.