Structures and Magnetic Properties of a Series of Metal Phosphonoacetates Synthesized from in Situ Hydrolysis of Triethyl Phosphonoacetate

Abstract

Seven new metal phosphonoacetates, namely, [Zn7(OH)2(ppat)4(H2O)2] (1), H3O[Zn(ppat)] (2), [Zn3(4,4‘-bpy)(ppat)2] (3), H2dmpz0.5[Zn(ppat)]·H2O (4), (H3O)2[Co3(OH)2(ppat)2] (5), H24,4‘-bpy[VIV2O2(ppat)2] (6), and [FeIII(ppat)(H2O)] (7) (H3ppat = phosphonoacetic acid, 4,4‘-bpy = 4,4‘-bipyridine, dmpz = N,N‘-dimethylpiperazine) were hydrothermally synthesized by the in situ hydrolysis of triethyl phosphonoacetate route. X-ray crystallography reveals that 1 shows a two-dimensional layered structure containing octahedral, tetrahedral, and trigonal bipyramidal Zn sites and an unprecedented inorganic Zn−O ribbon; 2 has a three-dimensional framework with one-dimensional dumbbell-shaped channels encapsulating protonated water molecules; 3 is a neutral three-dimensional framework constructed by [Zn(4,4‘-bpy)]n2n+ chains and [Zn(ppat)]nn- layers, two types of structural motifs; 4 shows a three-dimensional hydrogen bond network constructed by [Zn(ppat)]- anionic layers and N,N‘-dimethylpiperazinium cations; 5 is a layered structure containing inorganic Co−O chains consisting of edge-shared CoO6 octahedra; 6 has a 3D hydrogen bond array constructed from [V2O2(ppat)]n2n- layers and doubly protonated 4,4‘-bpy cations; 7 crystallizes in a chiral space group and has a 3D four-connected framework with diamond topology. Magnetic measurements reveal antiferromagnetic behavior for 5, paramagnetic behavior for 6, and canted antiferromagnetic behavior for 7.