Publication detail

Spin-crossover in iron(II)-phenylene ethynylene-2,6-di(pyrazol-1-yl) pyridine hybrids: toward switchable molecular wire-like architectures

SENTHIL KUMAR, K. ŠALITROŠ, I. HEINRICH, B. MOLDOVAN, S. MAURO, M. RUBEN, M.

Original Title

Spin-crossover in iron(II)-phenylene ethynylene-2,6-di(pyrazol-1-yl) pyridine hybrids: toward switchable molecular wire-like architectures

Type

journal article in Web of Science

Language

English

Original Abstract

Luminescent oligo(p-phenylene ethynylene) (OPE) and spin-crossover (SCO) active Fe(II)-2,6-di(pyrazol-1-yl) pyridine (BPP) systems are prominent examples proposed to develop functional materials such as molecular wires/memories. A marriage between OPE and Fe(II)-BPP systems is a strategy to obtain supramolecular luminescent ligands capable of metal coordination useful to produce novel spin-switchable hybrids with synergistic coupling between spin-state of Fe(II) and a physical property associated with the OPE skeleton, for example, electronic conductivity or luminescence. To begin in this direction, two novel ditopic ligands, namely L1 and L2, featuring OPE-type backbone end-capped with metal coordinating BPP were designed and synthetized. The ligand L2 tailored with 2-ethylhexyloxy chains at the 2 and 5 positions of the OPE skeleton shows modulated optical properties and improved solubility in common organic solvents relative to the parent ligand L1. Solution phase complexation of L1 and L2 with Fe(BF4)2•6H2O resulted in the formation of insoluble materials of the composition [Fe(L1)]n(BF4)2n and [Fe(L2)]n(BF4)2n as inferred from elemental analyses. Complex [Fe(L1)]n(BF4)2n underwent thermal SCO centred at T 1/2 = 275 K as well as photoinduced low-spin to high-spin transition with the existence of the metastable high-spin state up to 52 K. On the other hand, complex [Fe(L2)]n(BF4)2n, tethered with 2-ethylhexyloxy groups, showed gradual and half-complete SCO with 50% of the Fe(II)-centres permanently blocked in the high-spin state due to intermolecular steric interactions. The small angle x-ray scattering (SAXS) pattern of the as-prepared solid complex [Fe(L1)]n(BF4)2n revealed the presence of nm-sized crystallites implying a possible methodology towards the template-free synthesis of functional-SCO nanostructures. © 2020 IOP Publishing Ltd.

Keywords

molecular magnetism, spin-crossover, functional materials

Authors

SENTHIL KUMAR, K.; ŠALITROŠ, I.; HEINRICH, B.; MOLDOVAN, S.; MAURO, M.; RUBEN, M.

Released

13. 5. 2020

ISBN

1361-648X

Periodical

Journal of Physics Condensed Matter

Year of study

32

Number

20

State

United Kingdom of Great Britain and Northern Ireland

Pages from

1

Pages to

9

Pages count

9

URL

https://iopscience.iop.org/article/10.1088/1361-648X/ab6cc2

BibTex

@article{BUT163840,
  author="Kuppusamy {Senthil Kumar} and Ivan {Šalitroš} and Benoît {Heinrich} and Simona {Moldovan} and Matteo {Mauro} and Mario {Ruben}",
  title="Spin-crossover in iron(II)-phenylene ethynylene-2,6-di(pyrazol-1-yl) pyridine hybrids: toward switchable molecular wire-like architectures",
  journal="Journal of Physics Condensed Matter",
  year="2020",
  volume="32",
  number="20",
  pages="1--9",
  doi="10.1088/1361-648X/ab6cc2",
  issn="1361-648X",
  url="https://iopscience.iop.org/article/10.1088/1361-648X/ab6cc2"
}