Relevance of supramolecular interactions, texture and lattice occupancy in the designer iron(II) spin crossover complexes
Abstract
New Fe{sup II} complexes of formula [Fe(3-Br-phen){sub 2}(NCS){sub 2}].Solvent (Solvent=0.5 CH{sub 3}OH (1), 2 CH{sub 2}Cl{sub 2} (2), desolvation of 2 (3), 0.5 CH{sub 3}COCH{sub 3} (4) and 0 (5)) have been synthesized. {sup 57}Fe Moessbauer and magnetic investigation reveal unique features atypical of classic [Fe(phen){sub 2}(NCS){sub 2}] polymorphs. Complex 1, prepared by precipitation in MeOH, undergoes upon cooling below room temperature an incomplete and gradual thermally induced spin conversion, while 4 prepared by an extraction method remains mostly in the low-spin state. The non solvated compounds 3 and 5, display a more abrupt spin crossover on cooling around T{sub 1/2}=175 K and T{sub 1/2}=198 K, respectively. Defects/soft lattice inclusion due to different methods of material synthesis, extent of aging, reaction medium and associated solvent molecules have enormous influence on the particle size and magnetic properties of these complexes. Scanning electron micrographs helps to establish a logical relationship among methods employed for synthesis, texture of materials and their effect on magnetic properties. The crystal structure of 2 determined in the monoclinic space group P2/c (100 K) reveals a mononuclear complex consisting of a distorted FeN{sub 6} octahedron in the low-spin state, constructed from two 3-bromo-1, 10-phenanthroline and two isothiocyanato anionsmore »
- Authors:
-
- Unite de Chimie des Materiaux Inorganiques et Organiques, Departement de Chimie, Universite Catholique de Louvain, Place L. Pasteur 1, 1348 Louvain-la-Neuve (Belgium)
- Unite de Chimie Structurale et des Mecanismes Reactionnels, Departement de Chimie, Universite Catholique de Louvain, Place L. Pasteur 1, 1348 Louvain-la-Neuve (Belgium)
- Technische Universitaet Kaiserslautern, Fachbereich Physik, Erwin-Schroedinger-Str. 56, 67663 Kaiserslautern (Germany)
- Publication Date:
- OSTI Identifier:
- 21370423
- Resource Type:
- Journal Article
- Journal Name:
- Journal of Solid State Chemistry
- Additional Journal Information:
- Journal Volume: 182; Journal Issue: 6; Other Information: DOI: 10.1016/j.jssc.2009.02.035; PII: S0022-4596(09)00096-6; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Journal ID: ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; AGING; COOLING; CRYSTAL DEFECTS; EXTRACTION; INTERACTIONS; IRON COMPLEXES; MAGNETIC PROPERTIES; METHANOL; METHYLENE CHLORIDE; MOESSBAUER EFFECT; MONOCLINIC LATTICES; PARTICLE SIZE; PHENANTHROLINES; PRECIPITATION; RAMAN SPECTRA; SCANNING ELECTRON MICROSCOPY; SOLVENTS; SPACE GROUPS; SPIN; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; ALCOHOLS; ANGULAR MOMENTUM; AROMATICS; AZAARENES; COMPLEXES; CRYSTAL LATTICES; CRYSTAL STRUCTURE; ELECTRON MICROSCOPY; HETEROCYCLIC COMPOUNDS; HYDROXY COMPOUNDS; MICROSCOPY; ORGANIC CHLORINE COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC HALOGEN COMPOUNDS; ORGANIC NITROGEN COMPOUNDS; PARTICLE PROPERTIES; PHYSICAL PROPERTIES; SEPARATION PROCESSES; SIZE; SPECTRA; SYMMETRY GROUPS; TEMPERATURE RANGE; TRANSITION ELEMENT COMPLEXES
Citation Formats
Naik, Anil D, Tinant, Bernard, Muffler, Kai, Wolny, Juliusz A, Schuenemann, Volker, and Garcia, Yann. Relevance of supramolecular interactions, texture and lattice occupancy in the designer iron(II) spin crossover complexes. United States: N. p., 2009.
Web. doi:10.1016/j.jssc.2009.02.035.
Naik, Anil D, Tinant, Bernard, Muffler, Kai, Wolny, Juliusz A, Schuenemann, Volker, & Garcia, Yann. Relevance of supramolecular interactions, texture and lattice occupancy in the designer iron(II) spin crossover complexes. United States. https://doi.org/10.1016/j.jssc.2009.02.035
Naik, Anil D, Tinant, Bernard, Muffler, Kai, Wolny, Juliusz A, Schuenemann, Volker, and Garcia, Yann. 2009.
"Relevance of supramolecular interactions, texture and lattice occupancy in the designer iron(II) spin crossover complexes". United States. https://doi.org/10.1016/j.jssc.2009.02.035.
@article{osti_21370423,
title = {Relevance of supramolecular interactions, texture and lattice occupancy in the designer iron(II) spin crossover complexes},
author = {Naik, Anil D and Tinant, Bernard and Muffler, Kai and Wolny, Juliusz A and Schuenemann, Volker and Garcia, Yann},
abstractNote = {New Fe{sup II} complexes of formula [Fe(3-Br-phen){sub 2}(NCS){sub 2}].Solvent (Solvent=0.5 CH{sub 3}OH (1), 2 CH{sub 2}Cl{sub 2} (2), desolvation of 2 (3), 0.5 CH{sub 3}COCH{sub 3} (4) and 0 (5)) have been synthesized. {sup 57}Fe Moessbauer and magnetic investigation reveal unique features atypical of classic [Fe(phen){sub 2}(NCS){sub 2}] polymorphs. Complex 1, prepared by precipitation in MeOH, undergoes upon cooling below room temperature an incomplete and gradual thermally induced spin conversion, while 4 prepared by an extraction method remains mostly in the low-spin state. The non solvated compounds 3 and 5, display a more abrupt spin crossover on cooling around T{sub 1/2}=175 K and T{sub 1/2}=198 K, respectively. Defects/soft lattice inclusion due to different methods of material synthesis, extent of aging, reaction medium and associated solvent molecules have enormous influence on the particle size and magnetic properties of these complexes. Scanning electron micrographs helps to establish a logical relationship among methods employed for synthesis, texture of materials and their effect on magnetic properties. The crystal structure of 2 determined in the monoclinic space group P2/c (100 K) reveals a mononuclear complex consisting of a distorted FeN{sub 6} octahedron in the low-spin state, constructed from two 3-bromo-1, 10-phenanthroline and two isothiocyanato anions in cis position. Intermolecular interactions between mononuclear units of the S...Br, S...C(H) and pi-pi type afford a 2D supramolecular network. DFT calculations for the single molecule 2 reveals an energy difference between high-spin and low-spin isomers of 7 kJ/mol suggesting a slight destabilization of the low-spin state compared to [Fe(phen){sub 2}(NCS){sub 2}]. Normal co-ordinate analysis was also carried out for 3 and compared with experimental temperature dependent Raman spectra for 5. - Graphical abstract: New Fe{sup II} complexes of formula [Fe(3-Br-phen){sub 2}(NCS){sub 2}].Solvent have been synthesized by precipitation (1) and extraction (4) methods. {sup 57}Fe Moessbauer and magnetic investigation reveal unique features atypical of classic [Fe(phen){sub 2}(NCS){sub 2}] polymorphs. Complex 1, undergoes upon cooling below room temperature an incomplete and gradual thermally induced spin conversion, while 4 remains mostly in the low-spin state. Role of supramolecular interactions, particles size, lattice solvents have profound influence on magnetic properties.},
doi = {10.1016/j.jssc.2009.02.035},
url = {https://www.osti.gov/biblio/21370423},
journal = {Journal of Solid State Chemistry},
issn = {0022-4596},
number = 6,
volume = 182,
place = {United States},
year = {Mon Jun 15 00:00:00 EDT 2009},
month = {Mon Jun 15 00:00:00 EDT 2009}
}