Solvent-Induced Polymorphism of Iron(II) Spin Crossover Complexes.

ABSTRACT: Two new mononuclear iron(II) compounds (1) and (2) of the general formula [Fe(L)₂](BF₄)₂·nCH₃CN (L = 4-(2-bromoethyn-1-yl)-2,6-bis(pyrazol-1-yl)pyridine, n = 1 for (1) and n = 2 for compound (2)), were synthesized. The room temperature crystallization afforded concomitant formation of two different solvent analogues: compound (1) exhibiting triclinic P-1 and compound (2) monoclinic C2/c symmetry. Single-crystal X-ray studies confirmed the presence of the LS (low-spin) state for both compounds at 180 K and of the HS (high-spin) state for compound (2) at 293 K, in full agreement with the magnetic investigations for both solvent polymorphs. Compound (1) exhibits spin transition above 293 K followed by subsequent solvent liberation, while the spin transition of (2) takes already place at 237 K

SUBMITTER: Salitros I 

PROVIDER: S-EPMC5456902 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature