Abstract
We review here new advances in the synthesis and investigation of iron(II) coordination compounds with tris(pyrazol-1-yl)methane and its derivatives as ligands. The complexes demonstrate thermally induced spin crossover accompanied by thermochromism. Factors that influence the nature and temperature of the spin crossover are discussed.
Highlights
Spin crossover (SCO) is the change in spin multiplicity under the influence of external conditions, representing one of the most interesting phenomena in the field of coordination chemistry of Cr2+, Mn2+/3+, Fe2+/3+, and Co2+/3+ [1,2,3]
Most of the synthesized iron(II) complexes with HC(pz)3 are stable on storing in the air at room temperature for a long time and non-hygroscopic. These compounds were studied by static magnetic susceptibility, diffuse reflectance, IR spectroscopy, and powder and single-crystal X-ray diffraction (XRD)
A comparison of the properties of the [Fe(HC(pz)3 )2 ][Eu(dipic)2 (Hdipic)] complex [62] with data for compounds of this class shows that the introduction of a complex anion of “gigantic” size into the crystal lattice did not lead to a significant change in the Tc and thermal stability of the compound, and there were no noticeable changes in the nature of the μeff (T) dependence curve in the SCO region (Figure 4c)
Summary
Spin crossover (SCO) is the change in spin multiplicity under the influence of external conditions, representing one of the most interesting phenomena in the field of coordination chemistry of Cr2+ , Mn2+/3+ , Fe2+/3+ , and Co2+/3+ [1,2,3]. FeN6 [9,10,11,12] In many of these complexes, the six donor nitrogen atoms surrounding the iron ion belong to different heterocycles, imines, and/or amines. SCO is by provided byinathe change in the magnetic color (oftentimes, but(oftentimes, not always)but [14].not These properties whethercan these used as materials information recording recording and storage systems, displays compounds can be usedfor as materials for information and storage systems, displays[15,16],. Steric bulk at thebulk periphery of the ligand sphere can promote promote the LS state if it inhibits the expansion of the metal coordination sphere, or the HS state it the LS state if it inhibits the expansion of the metal coordination sphere, or the HS state if it leadsif to leads to distortion of the ligand–metal dative interaction.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
