TY - JOUR
T1 - Supramolecular Maleate Adducts of Copper(II) 12-Metallacrown-4
T2 - Magnetism, EPR, and Alcohol Sorption Properties
AU - Pavlishchuk, Anna V.
AU - Kolotilov, Sergey V.
AU - Zeller, Matthias
AU - Lofland, Samuel E.
AU - Kiskin, Mikhail A.
AU - Efimov, Nikolay N.
AU - Ugolkova, Elena A.
AU - Minin, Vadim V.
AU - Novotortsev, Vladimir M.
AU - Addison, Anthony W.
N1 - Funding Information:
A. V. P. thanks the Russian Foundation of Basic Research (grant no. 12-03-90913) and the European Community's Seventh Framework Programme (FP7/2007-2013, grant agreement no. 611488). M. A. K., N. N. E., E. A. U., V. V. M., and V. M. N. acknowledge the Federal Agency of Scientific Organizations of Russia (project 0088-2014-0001) for financial support. A. W. A. thanks the College of Arts & Sciences of Drexel University for support. We thank Mr. T. Wade for skilled support for the ESI-MS analyses. The X-ray diffractometers were funded by National Science Foundation (NSF) grant 0087210, Ohio Board of Regents Grant CAP-491, Youngstown State University, and National Science Foundation Major Research Instrumentation (NSF-MRI) grant CHE 1625543.
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2017/11/9
Y1 - 2017/11/9
N2 - 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-oligomerized [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+. The 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 behavior 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 vapors at 293 K by a desolvated polycrystalline sample of 1, the shape of the adsorption and desorption isotherms indicated a “gates opening” phenomenon.
AB - 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-oligomerized [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+. The 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 behavior 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 vapors at 293 K by a desolvated polycrystalline sample of 1, the shape of the adsorption and desorption isotherms indicated a “gates opening” phenomenon.
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U2 - 10.1002/ejic.201700976
DO - 10.1002/ejic.201700976
M3 - Article
AN - SCOPUS:85033384874
VL - 2017
SP - 4866
EP - 4878
JO - Chemische Berichte
JF - Chemische Berichte
SN - 0009-2940
IS - 41
ER -