The Spin‐Crossover Phenomenon at the Coherent‐Domains Scale in 1D Polymeric Powders: Evidence for Structural Fatigability

The coherent-domain morphology was determined for a crystalline powder of the 1D polymeric spin-crossover [Fe(Htrz)2(trz)](BF4) {Htrz = 1H-1,2,4-triazole, trz = deprotonated triazolato(–) ligand} compound. This morphology is in adequacy with the crystal packing and proved that the long axis of the domain corresponds to the iron–triazole chains axis, which gives information on the crystal-growth process. Furthermore, thermal cycling clearly demonstrated that the coherent-domain length strongly and continuously decreased as a function of the number of spin-crossover cycles undergone. The degradation in the crystalline quality corresponds to a break in the [Fe(Htrz)2(trz)]+ chains. This structural fatigability was confirmed by similar observations on a close spin-crossover compound, [Fe(NH2trz)3](NO3)2·H2O, showing that a few hundreds of thermal spin-crossover cycles could destroy the crystalline aspect of the sample.

[1]  K. Murray,et al.  Spin-Crossover Complexes , 2018 .

[2]  S. Hayami,et al.  Spin-state switches in molecular materials chemistry , 2015 .

[3]  E. Natividad,et al.  Critical assessment of the nature and properties of Fe(II) triazole-based spin-crossover nanoparticles , 2015 .

[4]  Eugenio Coronado,et al.  Unravelling the chemical design of spin-crossover nanoparticles based on iron(ii)–triazole coordination polymers: towards a control of the spin transition , 2015, Journal of materials chemistry. C.

[5]  M. Shatruk,et al.  Symmetry-breaking structural phase transitions in spin crossover complexes , 2015 .

[6]  P. Guionneau,et al.  Multiscale Experimental and Theoretical Investigations of Spin Crossover FeII Complexes: Examples of [Fe(phen)2(NCS)2] and [Fe(PM-BiA)2(NCS)2] , 2015, International journal of molecular sciences.

[7]  P. Guionneau.  Crystallography and spin-crossover. A view of breathing materials. , 2014, Dalton transactions.

[8]  Jean-François Létard,et al.  Crystal Structures and Spin Crossover in the Polymeric Material [Fe(Htrz)2(trz)](BF4) Including Coherent-Domain Size Reduction Effects , 2013 .

[9]  L. G. Lavrenova,et al.  Spin Crossover and Thermochromism of Iron(II) Coordination Compounds with 1,2,4‐Triazoles and Tris(pyrazol‐1‐yl)methanes , 2013 .

[10]  S. Teat,et al.  An FeII Spin‐Crossover Complex Becomes Increasingly Cooperative with Ageing , 2013 .

[11]  Yann Garcia,et al.  Spin state switching in iron coordination compounds , 2013, Beilstein journal of organic chemistry.

[12]  S. Hébert,et al.  Room temperature bistability with wide thermal hysteresis in a spin crossover silica nanocomposite , 2013 .

[13]  O. Roubeau.  Triazole-based one-dimensional spin-crossover coordination polymers. , 2012, Chemistry.

[14]  P. Rosa,et al.  Mosaicity and structural fatigability of a gradual spin-crossover single crystal , 2012 .

[15]  Fujio Izumi,et al.  VESTA 3 for three-dimensional visualization of crystal, volumetric and morphology data , 2011 .

[16]  A. Kaiba,et al.  The 1-D polymeric structure of the [Fe(NH2trz)3](NO3)2·nH2O (with n = 2) spin crossover compound proven by single crystal investigations. , 2011, Chemical communications.

[17]  J. G. Haasnoot,et al.  Visualization and quantitative analysis of spatiotemporal behavior in a first-order thermal spin transition: A stress-driven multiscale process , 2011 .

[18]  M. Halcrow,et al.  Structure:function relationships in molecular spin-crossover complexes. , 2011, Chemical Society reviews.

[19]  Azzedine Bousseksou,et al.  Molecular spin crossover phenomenon: recent achievements and prospects. , 2011, Chemical Society reviews.

[20]  Sebastian Thallmair,et al.  Complete and incomplete spin transitions in 1D chain iron(II) compounds , 2011 .

[21]  O. Roubeau,et al.  Triazoles and tetrazoles: Prime ligands to generate remarkable coordination materials , 2011 .

[22]  Marinela M. Dîrtu,et al.  Insights into the origin of cooperative effects in the spin transition of [Fe(NH2trz)3](NO3)2: the role of supramolecular interactions evidenced in the crystal structure of [Cu(NH2trz)3](NO3)2.H2O. , 2010, Inorganic chemistry.

[23]  E. Collet,et al.  Structural dynamics of photoinduced molecular switching in the solid state. , 2010, Acta crystallographica. Section A, Foundations of crystallography.

[24]  D. Denux,et al.  Nanoparticles of [Fe(NH2-trz)3]Br2.3H2O (NH2-trz=2-amino-1,2,4-triazole) prepared by the reverse micelle technique: influence of particle and coherent domain sizes on spin-crossover properties. , 2009, Chemistry.

[25]  I. Popov,et al.  Metrological characterization of X-ray diffraction methods for determination of crystallite size in nano-scale materials , 2007 .

[26]  Eugenio Coronado,et al.  Bistable Spin‐Crossover Nanoparticles Showing Magnetic Thermal Hysteresis near Room Temperature , 2007 .

[27]  J. G. Haasnoot,et al.  Spin Transition Regime in New One-Dimensional Polymeric Iron(II) Compounds. Importance of the Water Content for the Thermal and Optical Properties , 2002 .

[28]  Azzedine Bousseksou,et al.  Spin Transitions and Thermal Hysteresis in the Molecular-Based Materials [Fe(Htrz)2(trz)](BF4) and [Fe(Htrz)3](BF4)2.cntdot.H2O (Htrz = 1,2,4-4H-triazole; trz = 1,2,4-triazolato) , 1994 .

[29]  M. Järvinen.  Application of symmetrized harmonics expansion to correction of the preferred orientation effect , 1993 .

[30]  Olivier Kahn,et al.  Spin Transition Molecular Materials for displays and data recording , 1992 .

[31]  Jerome B. Hastings,et al.  Rietveld refinement of Debye–Scherrer synchrotron X‐ray data from Al2O3 , 1987 .

[32]  J. G. Haasnoot,et al.  1,2,4-Triazole Complexes, III Complexes of Transition Metal(II) Nitrates and Fluoroborates , 1977 .

[33]  H. Rietveld.  A profile refinement method for nuclear and magnetic structures , 1969 .

[34]  G. K. Williamson,et al.  X-ray line broadening from filed aluminium and wolfram , 1953 .