6533b85bfe1ef96bd12bb44a

RESEARCH PRODUCT

Control of the spin state by charge and ligand substitution: two-step spin crossover behaviour in a novel neutral iron(II) complex

José Antonio RealKateryna ZnovjyakM. Carmen MuñozJoachim KuszMaria NowakMaksym SeredukMaksym Seredyuk

subject

Ligand field theorySteric effectsSpin statesChemistryStereochemistryLigandHydrostatic pressureCrystal structureInorganic ChemistrySpin crossoversCrystallographyDeprotonationSpin crossoverFISICA APLICADALigand substitutionSpin stateIron complex

description

The influence of the charge and steric hindrance on the spin state of a series of four monomeric Fe-II complexes derived from the tridentate tigands 2-(1H-benzoimidazol-2-yl)-1,10-phenanthroline (Hphenbi) and 2-(1H-benzoimidazol-2-yl-9-methyl-1,10-phenanthroline (Hmphenbi) and their deprotonated forms (phenbi(-), mphenbi(-)) are investigated. The crystal structure and magnetic properties show that [Fe(Hphenbi)(2)](BF4)(2)center dot 1.5C(6)H(5)NO(2)center dot H2O (1) and its neutral form [Fe(phenbi)(2)]center dot 2CHCl(3)center dot H2O (2) are low-spin complexes at 400 K due to the strong ligand field imparted by the terpyridine-like tigand. In contrast, the steric hindrance induced by the methyl group in [Fe(Hmphenbi)21(BF4)2 (3) stabilizes the high-spin state of the Fe-II ion at all temperatures. Application of a hydrostatic pressure of 0.43 GPa shows that 3 displays incomplete thermal-induced spin crossover behaviour. However, upon deprotonation of the ligand the resulting neutral complex [Fe(mphenbi)(2)]center dot 2CHCl(3) (4) shows a complete two-step spin crossover behaviour at ambient pressure.

yearjournalcountryeditionlanguage
2014-08-20
10.1039/c4dt01885khttps://doi.org/10.1039/c4dt01885k