Intercalation of thiazole in layered solids. A 3D framework supported in dipolar and quadrupolar intermolecular interactions

Thiazole molecule was intercalated between layers of T[Ni(CN)₄] with T = Mn, Fe, Co, Ni. The formed hybrid inorganic-organic 3D solid crystallizes with an orthorhombic unit cell, in the Pmna space group, and it remains stable on heating up to 185 °C. From this temperature, the intercalated molecules evolve. Their crystal structure was solved and refined from powder X-ray diffraction data, complemented with structural information from IR and UV-Vis spectroscopies. Intercalates molecules were found coordinated through their N atom to the available axial positions of the metal T while the Ni atom preserves the planar coordination geometry. In the interlayer region, molecules coordinated to neighboring layers remain interacting through dipolar and quadrupolar interactions. In the resulting 3D solids, the layer adopt a rippled sheets configuration determined by the dipole-dipole intermolecular interactions. For Fe and Co a pronounced temperature dependent spin-orbit coupling was observed from the derived values for the effective magnetic moment. The magnetic behavior of this series of intercalated solids is determined by the co-existence of two types of interactions, between T metals centers within the layer, which has antiferromagnetic character, and the one observed for metals from neighboring layers through the π-π cloud overlapping between ring planes, which is ferromagnetic. For the solids obtained by intercalation of thiazole, the antiferromagnetic interaction dominates.