Conformational effect of a spin crossover iron(II) complex: Bis[N-(2-methylimidazol-4-yl)methylidene-2-aminoethyl]propanediamineiron(II) perchlorate

Hiroaki Hagiwara, Akitsugu Kawano, Takeshi Fujinami, Naohide Matsumoto, Yukinari Sunatsuki, Masaaki Kojima, Hiroshi Miyamae

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

A iron(II) complex of the linear hexadentate N6 ligand H 2L2-3-2, [Fe(H2L2-3-2)](ClO 4)2, was synthesized and the spin crossover properties were investigated, where H2L2-3-2 denotes bis[N-(2-methylimidazol-4-yl)methylidene-2-aminoethyl]propanediamine. The complex showed a gradual and reversible one-step spin crossover (SCO) between the high-spin (S = 2) and low-spin (S = 0) states at T1/2 = 208 K without hysteresis. The crystal structures were determined at 296 and 250 K (HS state), 230, 210, and 200 K (intermediate between the HS and LS states) and 150 and 110 K (LS state). The spin transition from 296 to 150 K accompanies with the conformation change of the chelate rings at the triamine moiety and the formation of the hydrogen bond network in the same space group of orthorhombic Pbcn (no. 60). However, in the LS state at 110 K, the space group changed from orthorhombic Pbcn at 150 K (Pcan when the same axial setting to 110 K was used) to monoclinic P21/a (no. 14) at 110 K, although no spin transition and no change of assembly structure between 150 and 110 K were observed. It give us an idea that the space group transformation is mainly related to the conformational thermodynamic stability of the chelate rings at the triamine moiety and is not directly correlated with the spin transition.

Original languageEnglish
Pages (from-to)141-150
Number of pages10
JournalInorganica Chimica Acta
Volume367
Issue number1
DOIs
Publication statusPublished - Feb 28 2011

Keywords

  • Conformation
  • Hexadentate ligand
  • Hydrogen bonds
  • Iron(II) complex
  • Spin crossover

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Conformational effect of a spin crossover iron(II) complex: Bis[N-(2-methylimidazol-4-yl)methylidene-2-aminoethyl]propanediamineiron(II) perchlorate'. Together they form a unique fingerprint.

  • Cite this