Premium
Magnesium Versus Zinc Coordination to Multidentate Schiff Base Ligands
Author(s) -
Erxleben Andrea,
Schumacher Dinah
Publication year - 2001
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/1099-0682(200112)2001:12<3039::aid-ejic3039>3.0.co;2-2
Subject(s) - chemistry , schiff base , salicylaldehyde , deprotonation , denticity , carboxylate , zinc , coordination complex , stereochemistry , hydrogen bond , medicinal chemistry , crystal structure , polymer chemistry , molecule , crystallography , metal , organic chemistry , ion
The reactions of two mononuclear zinc complexes, [Zn(HL 1 )(H 2 O) 2 ], 1 , and [ZnL 4 (H 2 O)], 7 , (H 3 L 1 = Schiff base derived from 3‐formylsalicylic acid and glycine, H 2 L 4 = Schiff base derived from 2,6‐diformyl‐4‐methylphenol and 1,2‐diaminoethane), with Mg 2+ has been studied. These complexes contain binucleating Schiff base ligands and have vacant coordination sites. For both compounds, substitution of zinc by magnesium has been observed in DMSO. Likewise, the Zn complex of H 2 L 2 (Schiff base derived from salicylaldehyde and glycine) can be converted into the corresponding Mg compound. The following complexes were characterized by single‐crystal X‐ray analysis: [MgL 3 (H 2 O) 3 ], 4 , [MgL 2 (H 2 O) 2 ] n , 5 , [Mg(sal) 2 (H 2 O) 2 ], 6 , and [MgL 4 (H 2 O)(CH 3 OH)], 8 (H 2 L 3 = Schiff base derived from 5‐bromosalicylaldehyde and glycine, Hsal = salicylaldehyde). The tri‐ and tetradentate N,O ligands H 2 L 3 and H 2 L 4 form discrete complex molecules in the solid state, while a carboxylate‐bridged polymeric structure is formed by H 2 L 2 . In 4 and 8 the aqua ligands hydrogen bond with the deprotonated phenolate and carboxylate oxygen atoms, resulting in the formation of dimers. In 6 two aqua ligands, two phenolate oxygens and two aldehyde oxygens give rise to an O 6 coordination sphere.