Interactions between Metal Ions and Carbohydrates. Coordination Behavior of Neutral Erythritol to Ca(II) and Lanthanide Ions

Abstract

The study of the sugar-metal ion interactions remains one of the main objectives of carbohydrate coordination chemistry because the interactions between metal ions and carbohydrates are involved in many biochemical processes. This paper presents a comparison of coordination structures of erythritol with alkaline-earth-metal and lanthanide chloride and nitrate in the solid state using FT-IR and X-ray diffraction. Neutral, nondeprotonated erythritol (E) reacts with CaCl(2) to give three CaCl(2)(-)erythritol (CaE(I), CaE(II), CaE(III)) complexes, showing that three of the five general features of calcium-carbohydrate complexes deduced in the reference encounter contrary examples. Different coordination structures have been observed for calcium and lanthanide chloride and nitrates. The coordination of carbohydrates to metal ions is complicated, and erythritol, chloride ions, nitrates, water molecules, and ethanol (crystallization medium and reaction solvents) have the chance to coordinate to metal ions. IR spectral results show that different lanthanide ions, from LaCl(3) to TbCl(3), have similar coordination structures with erythritol. The results show that erythritol can act as two bidentate neutral ligands (CaE(I), CaE(II), CaE(III), CaEN, PrE, NdE) or as a three-hydroxyl donor (NdEN). The IR results are consistent with the crystal structures.

[(2R,3S)-Butane-1,2,3,4-tetraol-κ3O1,O2,O3](ethanol-κO)tris(nitrato-κ2O,O′)samarium(III)

“…In the title compound the Sm III cation is 10-fold coordinated by three hydroxyl groups (O1, O2 and O3) from one erythritol molecule, by one hydroxyl group from ethanol (O5), and by three bidentate nitrate ions through O6, O7; O9, O10; O12, O13. The structure of SmEN is isotypic with its Nd, Eu, Y, Gd, Tb (Yang et al, 2003(Yang et al, , 2004(Yang et al, , 2012 and Ho (Hua et al, 2013) analogues. The Sm-O distances range from 2.416 (2) to 2.611 (2) Å, the average Sm-O distance being 2.499 Å.…”

“…For the crystal structure of free erythritol, see: Bekoe & Powell (1959). For isotypic structures of the title compound, see : Yang et al (2003: Yang et al ( , 2004: Yang et al ( , 2012; Hua et al (2013).…”

Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to neodymium ion

“…The structure of another neodymium chloride-erythritol complex, NdE(I), NdCl 3 AE C 4 H 10 O 4 AE 6H 2 O was determined in our laboratory [14]. The crystal of NdE(I) is triclinic system with P 1 space group.…”

“…For natural neutral erythritol, three calcium chloride complexes, two kinds of lanthanide chloride-erythritol complexes, including one neodymium ion-erythritol complex, NdE(I) (NdCl 3 AE C 4 H 10 O 4 AE 6H 2 O) have been reported [14,15]. For the two kinds of lanthanide chloride-erythritol complexes, one coordination mode is that Ln 3+ ion coordinates with four hydroxyl groups from two erythritol molecules, four water molecules and one chloride ion, the formula is LnCl 3 AE C 4 H 10 O 4 AE 6H 2 O, including LaCl 3 , PrCl 3 , NdCl 3 , EuCl 3 , TbCl 3 -erythritol complexes [14]; another coordination mode was observed in the europium chloride-erythritol complex (2EuCl 3 AE 2C 4 H 10 O 4 AE 7H 2 O), its characteristic is the presence of binuclear europium ions with different coordination structures: one Eu 3+ ion is nine-coordinated with five Eu-O bonds from water molecules and four from hydroxyl groups of two erythritol molecules and another Eu 3+ is 8-coordinated with two water molecules, two chloride ions and four hydroxyl groups from two erythritol molecules [15].…”

“…For the two kinds of lanthanide chloride-erythritol complexes, one coordination mode is that Ln 3+ ion coordinates with four hydroxyl groups from two erythritol molecules, four water molecules and one chloride ion, the formula is LnCl 3 AE C 4 H 10 O 4 AE 6H 2 O, including LaCl 3 , PrCl 3 , NdCl 3 , EuCl 3 , TbCl 3 -erythritol complexes [14]; another coordination mode was observed in the europium chloride-erythritol complex (2EuCl 3 AE 2C 4 H 10 O 4 AE 7H 2 O), its characteristic is the presence of binuclear europium ions with different coordination structures: one Eu 3+ ion is nine-coordinated with five Eu-O bonds from water molecules and four from hydroxyl groups of two erythritol molecules and another Eu 3+ is 8-coordinated with two water molecules, two chloride ions and four hydroxyl groups from two erythritol molecules [15]. The results indicate that lanthanide ions also form several types of complexes with erythritol, the coordination structures are complicated and different from calcium chloride-erythritol complexes.…”