| Abstract |
A water-soluble iron(III) complex [Fe(H2O)(3)(L)]center dot 5H(2)O (1) was prepared by reaction of iron(III) chloride with 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydro xy-benzenesulfonic acid (H3L). The complex was characterized by IR, H-1 NMR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. The coordination environment of the central iron(III) is a distorted octahedron, three sites being occupied by L3- ligand, which chelates in O,N,O fashion, while three other sites are filled with the water molecules. The uncoordinated water molecules are held in the channels of the overall 3D supramolecular structure by the carbonyl and sulfonyl groups of L3- and the ligated waters. Apart from the multiple hydrogen bonds, an intermolecular charge-assisted O center dot center dot center dot Cl halogen bonding with 3.044 angstrom distance was described. 1 acts as an effective catalyst in the Henry reaction producing nitroaldols from nitroethane and various aldehydes with yields up to 90\% and threo/erythro diastereoselectivity ranging from 3:1 to 1:1. Crown Copyright (c) 2013 Published by Elsevier B.V. All rights reserved. |
