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Barium(II)–Chromium(III) Coordination Polymers Based on Dimethylmalonate Anions: Synthesis, Crystal Structure, Magnetic Properties, and EPR Spectra
Author(s) -
Bazhina Evgeniya S.,
Kiskin Mikhail A.,
Korlyukov Alexander A.,
Babeshkin Konstantin A.,
Efimov Nikolay N.,
Shmelev Maxim A.,
Kottsov Sergey Yu.,
Khoroshilov Andrey V.,
Ugolkova Elena A.,
Starikova Alyona A.,
Korchagin Denis V.,
Minin Vadim V.,
Eremenko Igor L.
Publication year - 2020
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.202000630
Subject(s) - chemistry , electron paramagnetic resonance , chromium , crystallography , crystal structure , counterion , polymer , magnetization , inorganic chemistry , stereochemistry , ion , nuclear magnetic resonance , organic chemistry , physics , quantum mechanics , magnetic field
A new 1D coordination polymer {[Ba 2 Cr 2 (OH) 2 (Me 2 mal) 4 (H 2 O) 6 ] · 2H 2 O} n ( 1 ) containing binuclear structural units [Cr 2 (OH) 2 (Me 2 mal) 4 ] 4– was synthesized by the reaction of an inorganic chromium(III) salt with a barium salt of dimethylmalonic acid (H 2 Me 2 mal). Depending on the nature of the counterion of the starting chromium salt, the addition of an excess of H 2 Me 2 mal to the reaction mixture resulted in the formation of a new 2D polymer {[Ba 2 Cr(Me 2 mal) 2 (HMe 2 mal) 2 (NO 3 )(H 2 O) 5 ] · 3.55H 2 O} n ( 2 ) containing mononuclear units [Cr(Me 2 mal) 2 (HMe 2 mal) 2 ] 3– or a new 3D polymer {[BaCr(Me 2 mal) 2 (HMe 2 mal)(H 2 O) 2 ] · H 2 O} n ( 3 ) composed of two types of mononuclear units, [Cr(Me 2 mal) 2 (HMe 2 mal) 2 ] 3– and [Cr(Me 2 mal) 2 (H 2 O) 2 ] – . Magnetic measurements, EPR spectroscopy studies, and quantum chemical calculations demonstrated that compound 1 exhibits ferromagnetic exchange interactions between Cr III ions in the binuclear unit (2 J = 6.77 cm –1 ) and displays slow relaxation of the magnetization in external dc ‐magnetic field. Compound 3 has porous structure, with channels occupied by solvent water molecules. However, the dehydration of 3 is accompanied by a structural rearrangement and the collapse of the porous structure.