Two novel flexible multidentate ligands for crystal engineering: Syntheses, structures, and properties of CuII, MnII complexes with N-[(3-carboxyphenyl)-sulfonyl]glycine and N,N′-(1,3-phenylenedisulfonyl) bis(glycine)

Article abstract of DOI:10.1002/ejic.200700847

One novel N-[(3-carboxyphenyl)sulfonyl]glycine (H₃L¹) ligand (1) was prepared in high yield, and its structure was determined by single-crystal X-ray diffraction. Reaction of H₃L¹ with Mn(ClO₄)₂·6H₂O at different pH values gave two new dinuclear complexes: [Mn₂(HL¹) ₂(phen)₄]·16H₂O (2) and [Mn ₂L¹(phen)₄(H₂O)]ClO ₄·3H₂O (3) (phen = 1,10-phenanthroline). Additionally, two copper(II) complexes, [K₂Cu(L²) ₂-(H₂O)₂]_n (4) and [CuL ²(H₂O)]₂·2H₂O (5), involving another novel ligand, N,N′-(1,3-phenylenedisulfonyl)bis(glycine) (H ₂L²), were prepared by a one-pot reaction of 1,3-phenylenebis(sulfonyl chloride), glycine, and KOH or triethylamine in the presence of Cu^II ions. A self-assembled (H₂O)₃₀ cluster containing a puckered (H₂O)₁₂ ring core was found in 2, which presents a new mode of association of water molecules not predicted theoretically or previously observed experimentally. Furthermore, 2 forms a 2-D supramolecular structure through hydrogen bonding and unique π-π stacking interactions. In 3, there also exist discrete trimeric water clusters. The identity of the base determines the specific structural characteristics of 4 and 5. When potassium hydroxide was used for the synthesis of 4, it led to a 3-D copper(II)-potassium(I) coordination polymer; when triethylamine was used, paddle-wheel dinuclear units of copper(II) carboxylate were produced. Magnetic measurements show that there are weak antiferromagnetic interactions in 2-4. In 5 the χ_MT vs. T curve shows a minimum at 110 K and a climb from 110 K to 5 K, then a long-range antiferromagnetic ordering occurs, as revealed by a decrease in χ_MT with T. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.