The Effect of Localized Magnetic Fields on the Spatially Controlled Crystallization of Transition Metal Complexes

A series of nickel (II) bis-phosphine organometallic complexes along with two pseudo [M7] (M = Ni(II), Zn(II)) metallocalix[6]arene complexes and a dysprosium acetate coordination polymer have each been crystallised in the presence of localized magnetic fields set up using neodymium magnets, using custom made Magnetic Crystallization Towers (MCTs). In all cases, whether the product complex is diamagnetic or paramagnetic, a complex spatial patterning of the crystals occurs based on the orientation of the magnetic field lines. When using magnetic block towers, the crystallization generally occurs adjacent to the magnet face. The effects of nucleation and solution concentration gradients on the crystallization process are also explored. These observations show how the crystallization process is affected by magnetic fields and thus these results have far-reaching effects which most certainly will include crystallization and ion migrations in biology.