Halochromic coordination polymers based on a triarylmethane dye for reversible detection of acids

Abstract

Chromeazurol B (Na2HL) is a pH-sensitive (halochromic) dye based on a hydroxytriarylmethane core and two carboxylate functional groups, which makes it suitable for the synthesis of coordination polymers. Two new coordination polymers [NaZn4(H2O)3(L)3]·3THF·3H2O (1) and [Zn3(H2O)3(μ2- OH2)(μ3-OH)(HL)2(H2L)]·2THF·3H2O (2) incorporating Chromeazurol B linkers have been prepared and characterised. The structure of 1 comprises pentanuclear heterometallic {Zn4Na} nodes linked by six L3– anions to give a layered structure with a honeycomb topology. 2 crystallizes as a double-chain ribbon (ladder) structure with two types of metal node: a mononuclear Zn(II) cation and tetranuclear {Zn(II)}4 cluster. Chromeazurol B anions link each tetranuclear cluster to four individual Zn(II) cations and each Zn(II) cation with four tetranuclear clusters. Both compounds show pH-sensitivity in water solution which can be observed visually, giving the first example of a halochromic coordination polymer. The halochromic properties of 1 towards HCl vapors were systematically investigated. As-synthesized violet-grey 1 reversibly changes color from orange to pink in the presence of vapors of 2M and 7M HCl, respectively. The coordination of the Chromeazurol B anion at each color stage was examined by diffuse reflectance spectroscopy and FT-IR measurements. The remarkable stability of 1 to acid and the observed reversible and reproducible color changes provide a new design for multifunctional sensor materials.

Citation

Zavakhina, M. S., Yushina, I. V., Samsonenko, D. G., Dybtsev, D., Fedin, V. P., Argent, S. P., …Schröder, M. (2017). Halochromic coordination polymers based on a triarylmethane dye for reversible detection of acids. Dalton Transactions, 46(2), 465-470. https://doi.org/10.1039/C6DT03969C

• Journal Article Type: Article
• Acceptance Date: Dec 5, 2016
• Online Publication Date: Dec 5, 2016
• Publication Date: Jan 3, 2017
• Deposit Date: Dec 6, 2016
• Publicly Available Date: Dec 6, 2016
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 46
• Issue: 2
• Pages: 465-470
• DOI: https://doi.org/10.1039/C6DT03969C
• Keywords: Coordination polymers, Zinc, Chromeazurol B, pH sensing, halochromic
• Public URL: https://nottingham-repository.worktribe.com/output/842275
• Publisher URL: http://pubs.rsc.org/en/Content/ArticleLanding/2016/DT/C6DT03969C#!divAbstract
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Crystal Structure Data; : Stephen P. Argent (ResearcherID); : Alexander J. Blake (ORCID); : Alexander J. Blake (ResearcherID); : Martin Schröder (ORCID); : The Royal Society of Chemistry has an exclusive publication licence for this journal; OPEN ACCESS: This article is freely available. This article is licensed under a Creative Commons Attribution 3.0 Unported Licence (CC BY 3.0); : Single-blind; : Received 16 October 2016; Accepted 5 December 2016; Accepted Manuscript published 5 December 2016; Advance Article published 13 December 2016; Version of Record published 3 January 2017