Spin transition with a very large thermal hysteresis in a molecular crystal: an EPR study of Fe(PM-PEA)2(NCS)2

Effect of Metal Dilution on the Thermal Spin Transition of [FexZn1–x(bapbpy)(NCS)2]

“…All the vials were closed with a plastic cap and the nine solutions were stirred at room temperature for 16 h. The suspension in each vial was filtered through Micropore Whatman filter paper (RC 55, pore diameter 0.45 μm), washed with MeOH (3 ϫ 2 mL), and dried under vacuum (P ≈ 10 -2 Torr) for 3 h to yield the nine samples (a) to (i). Yields: 22,21,21,20,18,19,18,17,19 mg, respectively. Characterization was performed with elemental analysis, IR spectroscopy, X-ray powder diffraction, and magnetic susceptibility measurements.…”

“…[5] The preparation method consisted of the impregnation of a suspension of the bapbpy ligand in methanol by a solution of the precursor [Zn(NCS) 2 ] in methanol. The solution of [Zn(NCS) 2 ] in methanol was prepared in situ by the Kahn method, [18] which consisted of precipitating K 2 SO 4 from a stoichiometric mixture of KSCN and ZnSO 4 ·7H 2 O in methanol. Compound 3 is more soluble than 1 in methanol, and it was obtained as a yellowish powder in slightly lower yields than 1 (80 versus 88 %).…”

Spin-crossover Compounds with Wide Thermal Hysteresis

“…30 The transition hysteresis in 3 varies strongly depending on how it is measured, from ¦T = 19 K by single crystal unit cell measurements, 31 to ¦T = 6065 K by magnetic susceptibility and EPR data from powder samples. 16,32 This discrepancy has not been explained in detail but may relate to the different patterns of structural defects and domain sizes in these types of sample. 31 Comparison with related compounds implies that a short intermolecular CH£S contact is the structural origin of the transition cooperativity ( Figure 2).…”

Crystal structure of bis[(2,4-dimethylphenyl)iminomethylpyridine-k2N,N′]-dinitratomercury(II), Hg(C14H14N2)2(NO3)2

“…The metal centers play akey role in enhancing fluorescent emission of the ligands [8]. More classic complexes with functionalized iminopyridines have been reported to exhibit very interesting properties such as spin crossover [9], second order non-linear optical properties [10], or mesogenic behavior [11]. The crystal structure of the title compound …”