abstract
Using crystal engineering concepts, the first three-dimensional (3D) mixed-metal-centre inorganic-organic hybrid frameworks incorporating N-(phosphonomethyl)iminodiacetate (pmida(4-)) were synthesised under mild hydrothermal conditions (100 degreesC) and characterised structurally. The crystal structures, obtained by the displacement of the coordinated water molecules in [Co2V2O2(pmida)(2)(H2O)(10)](.)2(H2O) (1) [P2(1)/c monoclinic space group, Z = 2, a = 9.996(2) Angstrom, b = 14.854(3) Angstrom, c = 10.781(2) Angstrom, beta = 110.90(3)degrees and V = 1495.5(5) Angstrom(3)] by the rod-like bridging 4,4'-bipyridine (4,4'-bpy) ligand - [CdVO(pmida)(4,4'-bpy)(H2O)(2)](.)(4,4'-bpy)(0.5)(H2O)-H-. (2) and [CoVO(pmida)(4,4'-bpy)(H2O)(2)](.)(4,4'-bpy)(0.5) (3) - are isostructural and were also determined in the P2(1)/c monoclinic space group (Z = 4) by single-crystal X-ray diffraction studies at low temperature (180 K): for 2, a = 9.1267(18) Angstrom, b = 17.610(4) Angstrom, c = 15.361(3) Angstrom, beta = 93.06(3)degrees and V = 2465.3(9) Angstrom(3); for 3, a = 8.7734(18) Angstrom, b = 17.264(4) Angstrom, c = 15.507(3) Angstrom, beta = 93.94(3)degrees and V = 2343.2(8) Angstrom(3). All the crystal structures contain centrosymmetric dimeric [V2O2(pmida)(2)](4-) units connected to neighbouring M2+ cations (Cd2+ for 2, and Co2+ for 1 and 3) through the phosphonate group. In 2 and 3, extended two-dimensional [MVO(pmida)(H2O)(2)](n) layers are formed, with the 4,4'-bpy molecules acting as pillars between adjacent layers, leading to porous 3D supramolecular structures, [MVO(pmida)(4,4'-bpy)(H2O)(2)](infinity), with a topology resembling that of the NbO net.
keywords
COORDINATION-POLYMER; CRYSTAL-STRUCTURE; MAGNETIC-PROPERTIES; X-RAY; SUPRAMOLECULAR ISOMERISM; VANADIUM HALOPEROXIDASE; CLATHRATION ABILITY; LAYERED COMPOUNDS; DIFFRACTION DATA; POROUS SOLIDS
subject category
Chemistry
authors
Paz, FAA; Shi, FN; Klinowski, J; Rocha, J; Trindade, T
our authors
Fa-Nian Shi
Researcher
Filipe Alexandre Almeida Paz
Principal Researcher
João Rocha
Full Professor