title: Optical Activity and Dehydration-Driven Switching of Magnetic Properties in Enantiopure Cyanido-Bridged Co(II)3W(V)2 Trigonal Bipyramids.
abstract: The unique enantiopure {[Λ-Co(II)((R)-mpm)2]3[W(V)(CN)8]2}·9H2O [(R)-1] and {[Δ-Co(II)((S)-mpm)2]3[W(V)(CN)8]2}·9H2O [(S)-1], where mpm = α-methylpyridinemethanol, magnetic spongelike materials, crystallizing in the chiral P21 space group, are constructed of cyanido-bridged {Co3W2} trigonal bipyramids with three cis-[Co(II)(mpm)2(μ-NC)2] moieties in equatorial sites and two [W(V)(CN)8](3-) units in apical positions. The arrangement of {Co3W2} clusters in the crystal lattice is controlled by interactions with crystallization H2O molecules, resulting in two independent hydrogen-bonding systems: the first weaving along open channels in the a direction (weakly bonded H2O) and the second closed in the cages formed by the surrounding [W(CN)8](3-) and mpm fragments (strongly bonded H2O). The strong optical activity of (R)- and (S)-1 together with continuous chirality measure (CCM) analysis confirms the chirality transfer from enantiopure (R)- and (S)-mpm to [Co(mpm)2(μ-NC)2] units, a cyanido-bridged skeleton, and to the whole crystal lattice. Magnetic properties confronted with ab initio calculations prove the ferromagnetic couplings within Co(II)-NC-W(V) linkages inside {Co3W2} molecules, accompanied by weak antiferromagnetic intermolecular interactions. The reversible removal of weakly bonded H2O above 50 °C induces the structural phase transition 1 ⇄ 1deh and strongly affects the magnetic characteristics. The observed changes can be interpreted in terms of the combined effects of the decreasing strength of ferromagnetic Co(II)-W(V) coupling and the increasing role of antiferromagnetic intermolecular correlation, both connected with dehydration-induced structural modifications in the clusters' core and supramolecular network of 1.
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Chorazy
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Robert
authors.initials: R
authors.lastname: Podgajny
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Nogaś
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Szymon
authors.initials: S
authors.lastname: Buda
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Nitek
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Mlynarski
authors.affiliation: ‡Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Rams
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kozieł
authors.affiliation: §H. Niewodniczański Institute of Nuclear Physics, Polish Acedemy of Sciences, Radzikowskiego 152, 31-342 Kraków, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Juszyńska Gałązka
authors.affiliation: ⊥Theory of Nanomaterials Group and Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium.
authors.forename: Veacheslav
authors.initials: V
authors.lastname: Vieru
authors.affiliation: ⊥Theory of Nanomaterials Group and Institute of Nanoscale Physics and Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium.
authors.forename: Liviu F
authors.initials: LF
authors.lastname: Chibotaru
authors.affiliation: †Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Sieklucka