Guest modulation of spin-crossover transition temperature in a porous Iron(II) metal-organic framework: Experimental and periodic DFT studies

Daniel Aravena, Zulema Arcís Castillo, M. Carmen Muñoz, Ana B. Gaspar, Ko Yoneda, Ryo Ohtani, Akio Mishima, Susumu Kitagawa, Masaaki Ohba, José Antonio Real, Eliseo Ruiz

Research output: Contribution to journalArticle

32 Citations (Scopus)

Abstract

The synthesis, structure, and magnetic properties of three clathrate derivatives of the spin-crossover porous coordination polymer {Fe(pyrazine)[Pt(CN)4]} (1) with five-membered aromatic molecules furan, pyrrole, and thiophene is reported. The three derivatives have a cooperative spin-crossover transition with hysteresis loops 14-29?K wide and average critical temperatures Tc=201?K (1fur), 167?K (1pyr), and 114.6?K (1thio) well below that of the parent compound 1 (Tc=295?K), confirming stabilization of the HS state. The transition is complete and takes place in two steps for 1fur, while 1pyr and 1thio show 50?% spin transition. For 1fur the transformation between the HS and IS (middle of the plateau) phases occurs concomitantly with a crystallographic phase transition between the tetragonal space groups P4/mmm and I4/mmm, respectively. The latter space group is retained in the subsequent transformation involving the IS and the LS phases. 1pyr and 1thio display the tetragonal P4/mmm and orthorhombic Fmmm space groups, respectively, in both HS and IM phases. Periodic calculations using density functional methods for 1fur, 1pyr, 1thio, and previously reported derivatives 1CS2, 1I, 1bz(benzene), and 1pz(pyrazine) have been carried out to investigate the electronic structure and nature of the host-guest interactions as well as their relationship with the changes in the LS-HS transition temperatures of 1Guest. Geometry-optimized lattice parameters and bond distances in the empty host 1 and 1Guest clathrates are in general agreement with the X-ray diffraction data. The concordance between the theoretical results and the experimental data also comprises the guest molecule orientation inside the host and intermolecular distances. Furthermore, a general correlation between experimental Tc and calculated LS-HS electronic energy gap was observed. Finally, specific host-guest interactions were studied through interaction energy calculations and crystal orbital displacement (COD) curve analysis.

Original languageEnglish
Pages (from-to)12864-12873
Number of pages10
JournalChemistry - A European Journal
Volume20
Issue number40
DOIs
Publication statusPublished - Sep 26 2014

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Organic Chemistry

Cite this