Opening magnetic hysteresis via improving the planarity of equatorial coordination by hydrogen bonding.

Through a mixed-ligand strategy, the structural change from a discrete dinuclear DyIII cluster to a one-dimensional polymeric chain was achieved, maintaining the two magnetic entities with the same {Dy(dppbO2)2(H2O)5} (dppbO2 = 1,4-butylenebis(diphenylphosphine oxide)) core structure. Since the hydrogen bonding between the equatorial coordinated water molecules and the guests/solvents/anions is distinct, the local geometry and the equatorial planarity of the first coordination sphere of the central DyIII ion become slightly different caused by the second coordination sphere. As a result, the dinuclear compound shows typical butterfly-shaped hysteresis loops, while it significantly opens at zero magnetic field up to 11 K for the 1D polymer, which is unprecedented in coordination polymers. Our experimental observations and theoretical analysis indicate that the hydrogen bonding leads to the fine-tuning of certain bond lengths and angles of the coordination environment, as well as the crystal field to a certain extent, revealing that the second coordination sphere affects the first coordination sphere by hydrogen bonding.

Coordination and Supramolecular Assemblies of Fully Substituted Cyclopentanocucurbit[6]uril with Lanthanide Cations in the Presence of Tetrachlorozincate Anions, and Their Potential Applications.

Coordination and supramolecular assemblies of a fully substituted cyclopentanocucurbit[6]uril (CyP6Q[6]) with a series of lanthanide cations (Ln3+) have been investigated in the presence of tetrachlorozincate anion ([ZnCl4]2-). X-ray single-crystal diffraction analysis has revealed that the interaction of CyP6Q[6] and a series of Ln3+cations unexpectedly results in the formation of at least seven different CyP6Q[6]-based coordination complex adduct and supramolecular assemblies groups, including with (1) La3+, Ce3+cations; (2) Pr3+, Nd3+cations; (3) Eu3+, Gd3+, Tb3+, Dy3+ with P1̅ or P1 space group, in which CyP6Q[6] molecules coordinate alternatively with Ln3+cations and form linear coordination polymers; (4) CyP6Q[6] molecules interact alternatively with [Ho(H2O)8]3+ aqueous complexes and form linear supramolecular chains; CyP6Q[6] molecules can assemble two different Ln3+ free porous supramolecular assemblies from CyP6Q[6]-Ln(NO3)3-ZnCl2-HCl systems, Ln = Tm, Yb, and Lu; however, no solid crystals were obtained from system containing Er3+cation. Thus, these differences could lead CyP6Q[6] to be useful in not only the isolation of lighter lanthanides from their heavier lanthanides but also special selectivity for different volatile organic compounds.