Interaction of tripodal Schiff-base ligands with silver(i): structural and solution studies

Wenzel, M. et al. (2010) Interaction of tripodal Schiff-base ligands with silver(i): structural and solution studies. CrystEngComm, 12(12), pp. 4176-4183. (doi: 10.1039/C0CE00255K)

Abstract

The binding and extraction of Ag(I) by tripodal Schiff-base ligands incorporating different aromatic podand arms are reported. These ligands have been synthesized by condensation of tris(2-aminoethyl)amine with benzaldehyde (1), 4-phenylbenzaldehyde (2), 2- (3) and 4-pyridinecarbaldehyde (4). The structures of 1 and of four Ag(I) complexes [Ag(1)]ClO4, [Ag(2)]ClO4, [Ag3(3)2](ClO4)3 and {[Ag3(4)2](ClO4)3}n have been determined by single crystal X-ray diffraction. The structure of 1 shows intramolecular C–H⋯π (aromatic) interactions between phenyl rings, while bonding of Ag(I) via Ag–N interactions within the ionophore pocket is confirmed. In [Ag(1)]ClO4, and [Ag(2)]ClO4 additional long-range Ag–H interactions are observed, while π–π stacking occurs in the polynuclear species [Ag3(3)2](ClO4)3 and {[Ag3(4)2](ClO4)3}n. Potentiometric titration, liquid–liquid extraction and 1H NMR spectroscopic studies were performed to probe the nature of the silver complexes in solution. Potentiometric studies confirm increasing complex stability with Ag(I) in the order 2 < 4 < 1 < 3, and enhanced Ag(I) extraction efficiency was observed with both increasing lipophilicity of the ionophore and the presence of additional donor groups. 1H NMR spectroscopic studies were employed to probe the solution complexation behaviour of 1–4 towards Ag(I) and these confirm the formation of primarily 1 : 1 Ag : L complexes in solution.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Wilson, Dr Claire
• Authors: Wenzel, M., Wichmann, K., Gloe, K., Gloe, K., Buschmann, H.-J., Otho, K., Schröder, M., Blake, A. J., Wilson, C., Mills, A. M., Lindoy, L. F., and Plieger, P. G.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: CrystEngComm
• Publisher: Royal Society of Chemistry
• ISSN: 1466-8033
• Published Online: 02 August 2010