N-alkyl pyrrolidone ether podands as versatile alkali metal ion chelants

Perrin, Andrea; Myers, Dominic; Fucke, K.; Musa, Osama M.; Steed, Jonathan W.

Abstract

This work explores the coordination chemistry of a bis(pyrrolidone) ether ligand. Pyrrolidones are commercially important functional groups because of the high polarity and hence high hydrophilicity and surface affinity. An array of alkali metal ion complexes of a podand bearing two pendant pyrrolidone functionalities, namely 1-{2-[2-(2-oxo-pyrrolid-1-yl)-ethoxy]-ethyl}-pyrrolid-2-one (1) are reported. Reaction of this ligand with sodium hexafluorophosphate gives two discrete species of formulae [Na(1)2]PF6 (3) and [Na3(H2O)2(μ-1)2](PF6)3 (4), and a coordination polymer {[Na3(μ3-1)3(μ2-1)](PF6)3}n (5). The same reaction in methanol gives a 1 : 1 complex, namely [Na2(μ-1)2(MeOH)2](PF6)2 (6). Use of tetraphenyl borate as a less coordinating counter ion gives [Na2(1)2(H2O)4](BPh4)2 (7) and [Na2(1)4](BPh4)2 (8). Two potassium complexes have also been isolated, a monomer [K(1)2]PF6 (9) and a cyclic tetramer [K4(μ4-H2O)2(μ-1)4](PF6)4 (10). The structures illustrate the highly polar nature of the amide carbonyl moiety within bis(pyrrolidone) ethers with longer interactions to the ether oxygen atom. The zinc complex is also reported and {[ZnCl2(μ-1)]}n (11) exhibits bonding only to the carbonyl moieties. The ether oxygen atom is not necessary for Na+ complexation as exemplified by the structure of the sodium complex of the analogue 1,3-bis(pyrrolid-2-on-1-yl)- butane (2). Reaction of compound 1 with lithium salts results in isolation of the protonated ligand.

Citation

Perrin, A., Myers, D., Fucke, K., Musa, O. M., & Steed, J. W. (2014). N-alkyl pyrrolidone ether podands as versatile alkali metal ion chelants. Dalton Transactions, 43(8), 3153-3161. https://doi.org/10.1039/c3dt53001a

• Journal Article Type: Article
• Publication Date: Feb 28, 2014
• Deposit Date: Jan 16, 2014
• Publicly Available Date: Feb 6, 2014
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 43
• Issue: 8
• Pages: 3153-3161
• DOI: https://doi.org/10.1039/c3dt53001a
• Public URL: https://durham-repository.worktribe.com/output/1445364