Coordination polymers from a highly flexible alkyldiamine-derived ligand: structure, magnetism and gas adsorption studies

Hawes, Chris S.; Chilton, Nicholas F.; Moubaraki, Boujemaa; Knowles, Gregory P.; Chaffee, Alan L.; Murray, Keith S.; Batten, Stuart R.; Turner, David R.

Abstract

The synthesis and structural, magnetic and gas adsorption properties of a series of coordination polymer materials prepared from a new, highly flexible and internally functional tetrakis-carboxybenzyl ligand H4L derived from 1,2-diaminoethane have been examined. The compound poly-[Ni3(HL)2(OH2)4]·2DMF·2H2O 1, a two-dimensional coordination polymer, contains aqua- and carboxylato-bridged trinuclear NiII clusters, the magnetic behaviour of which can be well described through experimental fitting and ab initio modelling to a ferromagnetically coupled trimer with a positive axial zero-field splitting parameter D. Compound poly-[Zn2L]·2DMF·3H2O 2, a three-dimensional coordination polymer displaying frl topology, contains large and well-defined solvent channels, which are shown to collapse on solvent exchange or drying. Compound poly-[Zn2(L)(DMSO)4]·3DMSO·3H2O 3, a highly solvated two-dimensional coordination polymer, displayed poor stability characteristics, however a structurally related material poly-[Zn2(L)(bpe)(DMSO)2]·DMSO·3H2O 4 was prepared under similar synthetic conditions by including the 1,2-bis(4-pyridyl)ethylene bpe co-ligand. Compound 4, containing small one-dimensional solvent channels, shows excellent structural resilience to solvent exchange and evacuation, and the evacuated material displays selective adsorption of CO2 over N2 at 273 K in the pressure range 0–1 atm. Each of the coordination polymers displays subtle differences in the conformation and binding mode of the ligand species, with switching between two distinct conformers (X-shaped and H-shaped), as well as a variable protonation state of the central core, with significant effects on the resulting network structures and physical properties of the materials.

• Journal Article Type: Article
• Acceptance Date: Jul 16, 2015
• Online Publication Date: Jun 17, 2023
• Deposit Date: Jun 15, 2023
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 40
• Pages: 17494-17507
• DOI: https://doi.org/10.1039/c5dt02323h
• Keywords: Inorganic Chemistry
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Crystal Structure Data; : Nicholas F. Chilton (ORCID); : David R. Turner (ORCID); : David R. Turner (ResearcherID); : The Royal Society of Chemistry has an exclusive publication licence for this journal; : Single-blind; : Received 18 June 2015; Accepted 16 July 2015; Accepted Manuscript published 17 July 2015; Advance Article published 30 July 2015; Version of Record published 6 October 2015