Vanadyl sulfates: molecular structure, magnetism and electrochemical activity

Ignaszak, Anna; Patterson, Nigel; Radtke, Mariusz; Elsegood, Mark R.J.; Frese, Josef W.A.; Lipman, Joah L.Z.F.; Yamato, Takehiko; Sanz, Sergio; Brechin, Euan K.; Prior, Timothy J.; Redshaw, Carl

Abstract

Reaction of differing amounts of vanadyl sulfate with p-tert-butylthiacalix[4]areneH4 and base allows access to the vanadyl-sulfate species [NEt4]4[(VO)4(3-OH)4(SO4)4]∙1/2H2O (1), [HNEt3]5[(VO)5(3-O)4(SO4)4]∙4MeCN (2∙4MeCN) and [NEt4]2[(VO)6(O)2(SO4)4(OMe)(OH2)]∙MeCN (3∙MeCN). Similar use of p-tert-butylsulfonylcalix[4]areneH4, p-tert-butylcalix[8]areneH8 or p-tert-butylhexahomotrioxacalix[3]areneH3 led to the isolation of [HNEt3]2[H2NEt2]2[VO(OMe)]2p-tert-butylcalix[8-SO2]areneH2] (4), [HNEt3]2[V(O)2p-tert-butylcalix[8]areneH5] (5) and [HNEt3]2[VIV2VV4O11(OMe)8] (6), respectively. Dc magnetic susceptibility measurements were performed on powdered microcrystalline samples of 1-3 in the T = 300 - 2 K temperature range. Preliminary screening for electrochemical water oxidation revealed some activity for 2 with turnover frequency (TOF) and number (TON) of 2.2 × 10-4 s-1 and 6.44 × 10-6 (mmol O2 / mmol cat.), respectively. The compound 3 showed an improved electrochemical activity in the presence of water. This is related to the increased number and the rate of electrons exchanged during oxidation of V4+ species, facilitated by protons generated in the water discharge process.

Citation

Ignaszak, A., Patterson, N., Radtke, M., Elsegood, M. R., Frese, J. W., Lipman, J. L., …Redshaw, C. (2018). Vanadyl sulfates: molecular structure, magnetism and electrochemical activity. Dalton Transactions : an international journal of inorganic chemistry, 47(44), 15983-15993. https://doi.org/10.1039/c8dt03626h

• Journal Article Type: Article
• Acceptance Date: Oct 21, 2018
• Online Publication Date: Oct 22, 2018
• Publication Date: Nov 13, 2018
• Deposit Date: Oct 23, 2018
• Publicly Available Date: Oct 23, 2019
• Journal: Dalton Transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Issue: 44
• Pages: 15983-15993
• DOI: https://doi.org/10.1039/c8dt03626h
• Keywords: Inorganic Chemistry
• Public URL: https://hull-repository.worktribe.com/output/1125676
• Publisher URL: https://pubs.rsc.org/en/Content/ArticleLanding/2018/DT/C8DT03626H