The correlation between magnetism and structures for new solvent free iron(III) and chromium(III) homoleptic 8-quinolinato complexes

Two new solvent free complexes α-Feq3 (1) and α-Crq3 (2) have been synthesised under the hydrothermal reaction. Complex 1 with one dimensional void channels only consists of fac-Feq3 and crystallizes in the trigonal P 3 ¯ space group. Complex 2 possessing the phase transition ability is composed of mer-Crq3, which crystallizes in the triclinic P 1 ¯ space group. The detail magnetic studies accompanying with DFT investigations for the first time demonstrate the correlation between supramolecular assembly and magnetism among the Mq3 complexes that the larger the overlaps with the same signs of spin densities on stacking ligands, the more negative the value of the Weiss constant. Our investigations highlight that the spin density should be the dominant factor in analyzing the intermolecular magnetic interactions, which was rather difficult to figure out.