The hydrothermal synthesis of the new manganese and vanadium oxides, NiMnO3H, MAV(3)O(7) and MA(0.75)V(4)O(10)center dot 0.67H(2)O (MA = CH3NH3)

The hydrothermal reaction of manganese or vanadium oxides in the presence o f organic cations leads to the formation of new layered structures. When ni ckel 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, a nd c = 5.270(1) Angstrom. The magnetic properties of this compound are quit e different from the ilmenite NiMnO3 phase, showing paramagnetism above 390 K and more complex behavior below that temperature. The hydrothermal react ion of vanadium pentoxide with methylamine leads to a series of new layered vanadium oxides, which differ in structure from the corresponding ones pre pared in the presence of the tetramethylammonium ion because of the existen ce of hydrogen bonding. Methylamine is the first organic to form a double s heet 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) Angstro m and beta = 99.865(5)degrees. (CH3NH3)V3O7 shows significant buckling of t he layers compared with N(CH3)(4)V3O7, and has a monoclinic unit cell, spac e group P2(1)/c with a =11.834(8) Angstrom, b = 6.663(4) Angstrom, c = 15.1 93(9) Angstrom and beta = 138.104(1)degrees.