One- and two-dimensional polymers from proline and calcium bromide

Abstract

Reactions of calcium bromide with enantiopure and racemic proline in aqueous solution lead to two solids in which the zwitterionic amino acid acts as a bridging ligand between neighbouring cations. Depending on the chirality of the amino acid, topologically very different products are obtained. With racemic proline, bromide acts as a simple uncoordinated counter-anion for the cationic heterochiral chains in catena-poly[[aquacalcium(II)]-μ-aqua-μ3-DL-proline-μ2-DL-proline], {[Ca(C5H9NO2)2(H2O)2]Br2}n. In agreement with chemical intuition, only carboxylate and aqua O atoms coordinate the alkaline earth cation in a low-symmetry arrangement. In contrast, L-proline affords the two-dimensional network poly[dibromidobis(μ2-L-proline)calcium(II)], [CaBr2(C5H9NO2)2]n, with an unexpected CaBr2 unit in a more regular coordination sphere.

Discriminative ionic capabilities on hydrogen-bond transition from the mode of ordinary water to (Mg, Ca, Sr)(Cl, Br)2 hydration

“…Salt solvation is ubiquitously important to our living quality and research fields such as environmental engineering 1-2 , medicine industry 3 , food science and technology [4][5] , metallurgical engineering [6][7][8] and construction materials 9 . The solvation of a divalent salt has striking impact on the biochemistry, organic chemistry, food and medicine, and health care of human beings [10][11] , which modulate not only the surface stress and viscosity of the solutions but also changes the solution ability of biological molecules such as denature of DNA and dissolving proteins. The interaction between salt ions and water molecules play a critical role in mediating the structure and property of solvent water.…”

Capabilities of Anion and Cation on Hydrogen-bond Transition from the Mode of Ordinary Water to (Mg, Ca, Sr)(Cl, Br)2 Hydration

“…Salt solvation is ubiquitously important to our living quality and research fields such as environmental engineering [1][2] , medicine industry 3 , food science and technology [4][5] , metallurgical engineering [6][7][8] and construction materials 9 . The solvation of a divalent salt has striking impact on the biochemistry, organic chemistry, food and medicine, and health care of human beings [10][11] , which modulate not only the surface stress and viscosity of the solutions but also changes the solution ability of biological molecules such as denature of DNA and dissolving proteins. The interaction between salt ions and water molecules play a critical role in mediating the structure and property of solvent water.…”

Capabilities of Anion and Cation on Hydrogen-bond Transition from the Mode of Ordinary Water to (Mg, Ca, Sr)(Cl, Br)2 Hydration

“…Salt solvation is ubiquitously important to our living quality and research fields such as environmental engineering [1][2] , medicine industry 3 , food science and technology [4][5] , metallurgical engineering [6][7][8] and construction materials 9 . The solvation of a divalent salt has striking impact on the biochemistry, organic chemistry, food and medicine, and health care of human beings [10][11] , which modulate not only the surface stress and viscosity of the solutions but also changes the solution ability of biological molecules such as denature of DNA and dissolving proteins. The interaction between salt ions and water molecules play a critical role in mediating the structure and property of solvent water.…”