European Journal of Inorganic Chemistry
European Journal of Inorganic Chemistry
4 years ago

Supramolecular Maleate Adducts of Copper(II) 12-Metallacrown-4: Magnetism, EPR and Alcohol Sorption Properties

Mikhail A. Kiskin, Vadim V. Minin, Elena A. Ugolkova, Anna V. Pavlishchuk, Matthias Zeller, Anthony W. Addison, Vladimir M. Novotortsev, Samuel E. Lofland, Sergey V. Kolotilov, Nikolay N. Efimov
With maleate, [Cu5(ahpha)4]2+ gives two complexes, [Cu5(ahpha)4(DMF)2](MalH)2·2DMF (1) and [Cu5(ahpha)4(MalH)2] (2) (ahpha2- is 3-amino-3-hydroximinopropane hydroxamate; MalH2 is maleic acid). Both 1 and 2 contain non-oligomerised [Cu5(ahpha)4]2+ metallacrown blocks; in 1, two MalH- are bound to [Cu5(ahpha)4]2+ only via H-bonds, while in 2, they coordinate to Cu2+. X-Band EPR of 1 was observed at 20 K, 100 K and 295 K. The EPR at 20 K was of an S = 1/2 ground state, while at room temperature anisotropic |ΔMs| = 1 and |ΔMs| = 2 resonances around 3200 G (g ≈ 2.19) and 1600 G (g ≈ 4.25) were observed for the Cu5 system, due to partial occupation of an S =3/2 state. The room temperature EPR of 1 was simulated as the weighted sum of the spectra of its various S = 1/2, 3/2 and 5/2 states. Its magnetic behaviour was fitted with a χMT vs. T model using a spin Hamiltonian accounting for central-peripheral (J1), peripheral-peripheral (J2) Cu2+-Cu2+ and intercrown (zJ') spin interactions, yielding J1= -156(4) cm-1, J2= -63(1) cm-1 and zJ'= -4.5(3) cm-1. For sorption of methanol and ethanol vapours at 293 K by a desolvated polycrystalline sample of 1, the shape of the absorption and desorption isotherms indicated a "gates opening" phenomenon.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/ejic.201700976

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.