Polymorphism, Composition, and Structural Variability in Topology in 1D, 2D, and 3D Copper Phosphonocarboxylate Materials

Abstract

ABSTRACT:The syntheses and structural characterization of 1D, 2D, and 3D materials based on copper phosphonocarboxylate backbones are described. More specifically, the synthesis of materials from diethylphosphonoacetic acid (DEPAA) or the close variant hydroxyphosphonoacetic acid (HPAA) and water-soluble Cu 2+ salts has been studied. The initial synthesis involving copper acetate and DEPAA was carried out at 160°C under hydrothermal conditions and a Cu:P ratio of 1:1 resulted in the formation of a mixture of products with the same composition, Cu 1.5 (O 3 PCH 2 CO 2 ) · H 2 O. Compound 1, which is blue in color and crystallizes in the triclinic space group P1 j , has a layered structure. Compound 2, which is green in color and crystallizes in the monoclinic space group P2 1 /c, has a three-dimensional structure. Reduction of the reaction temperature to 140°C results in the exclusive formation of the R-phase (1), while an increase in the reaction temperature to 180°C yields a pure sample of 2. A Cu:P ratio of 2:3 in a reaction at 180°C yields a third, related phase, Cu(HO 3 PCH 2 CO 2 ) · H 2 O, 3, which is again triclinic but has a chain-like structure. Finally, reaction of copper chloride and HPAA in a Cu:P ratio of 1:1 at room temperature yields one-dimensional Cu(R,S-HO 3 PCH(OH)CO 2 )(H 2 O) 2 ] · H 2 O, 4, that incorporates both R and S HPAA stereoisomers. All materials were studied by single crystal X-ray crystallography, X-ray powder diffraction, TGA, FT-IR, and elemental analyses.

Platonic Relationships in Metal Phosphonate Chemistry: Ionic Metal Phosphonates

“…In contrast, high pH values cause deprotonation, high negative charge on the phosphonate and rapid formation and precipitation of an amorphous metal phosphonate product. Hence, for each metal/phosphonate system there is an optimum pH regime for crystalline product formation [49].…”

Synthesis, Crystal Structure and Characterization of Two Novel One- and Two-Dimensionally Polymeric Copper(II) Phosphonoacetates

“…The phosphonate oxygen atom O(3) is not involved in any hydrogen bond. Lodhia et al [24] reported on a triclinic copper hydrogenphosphonoacetate monohydrate in which each hydrogenphosphonoacetate dianion is coordinated to three Cu 2+ cations.…”

“…The connection between Cu 2+ and phosphonoacetate anions leads to coordination polymers with one-, two and three-dimensional structural features. [19,23,24] The obtained structures depend on the reaction temperature, Cu:P ratio, pH value, and the deprotonation stage of the phosphonoacetate anion. The structures of Cu(II) phosphonoacetates can be modified using additional N-donor ligands.…”

Molecular Copper(II) Complexes Derived from Phosphonoacetic Acid: Crystal Structures and Magnetic Behavior

“…[Cu 4 (O 3 PCH 2 CO 2 ) 2 (5-dmbpy) 4 Table S1 and Figure S4) and involving the terminal aqua ligand, the perchlorate ion, and the phosphonate moieties form a supramolecular 1D system extended along the c axis of the triclinic unit cell in 5 (Supporting information, Table S1 and Figure S5). …”