HYDROTHERMAL SYNTHESIS AND CRYSTAL-STRUCTURES OF 2 NOVEL VANADIUM-OXIDES CONTAINING INTERLAMELLAR TRANSITION-METAL COMPLEXES

Two new vanadium oxide compounds, which contain interlamellar transiti on metal complexes bound to vanadium oxide sheets, were synthesized hy drothermally. The crystal structure of each reveals unusual coordinati on geometries and interlayer bonding. [Ni(2,2'-bipyridine)](2)[V12O32] (1) was prepared from the reaction of V2O5, NiO, H2O and 2,2'-bipyrid yl in the molar ratio 4:8:3312:0.5. The isomorphous compounds [M(2,2'- bipy)](2)[V12O32] (where M is Co (1a) and Cu (1b)) were prepared in a similar fashion. The Ni coordination compound 1 crystallizes as amber needles, and the structure was solved in the space group C2/m (#12) wi th unit cell parameters (a) under bar = 24.344(3) Angstrom, (b) under bar = 6.897(3) Angstrom, (c) under bar = 12.028(2) Angstrom, beta = 93 .60(2)degrees (R(Rw) = 0.039(0.038)). This compound is composed of van adium(V) oxide layers with nickel atoms coordinated within a single la yer via four Ni-O-V linkages. Bidentate bipyridine (bpy) ligands compl ete the coordination sphere of the nickel atoms and interdigitate via pi-pi stacking with bpy ligands from the adjacent layer. Cu(en)2[V6O14 ] (2) crystallizes as black plates in the space group P2(1)/n (#14) wi th unit cell parameters (a) under bar = 8.934(2) Angstrom, (b) under b ar = 6.558(1) Angstrom, (c) under bar = 15.694(2) Angstrom, beta = 99. 93(2)degrees (R(Rw) = 0.039(0.035)). from the reaction of CuCl2. 2H(2) O, V2O5, H2O and ethylenediamine in the ratio 1:1:447:4. This structur e consists of mixed-valent vanadium(IV,V) oxide sheets forming weak O- Cu bonds to intercalated copper bis(ethylenediamine) complexes. (C) 19 98 Elsevier Science B.V. All rights reserved.