Salmon, Lionel published the artcileTwo Novel Iron(II) Materials Based on Dianionic N4O2 Schiff Bases: Structural Properties and Spin-Crossover Characteristics in the Series [Fe(3-X,5-NO2-sal-N(1,4,7,10))] (X = H, 3-MeO, 3-EtO), SDS of cas: 38260-01-4, the publication is Inorganic Chemistry (2005), 44(6), 1763-1773, database is CAplus and MEDLINE.
Two spin-crossover (SCO) complexes [FeII(3-MeO,5-NO2-sal-N(1,4,7,10))] (1) and [FeII(3-EtO,5-NO2-sal-N(1,4,7,10))] (2) were prepared and studied (3-MeO,5-NO2-sal-N(1,4,7,10) and 3-EtO,5-NO2-sal-N(1,4,7,10) are deprotonated 2-[12-(hydroxy-3-methoxy-5-nitrophenyl)-2,5,8,11-tetraazadodeca-1,11-dien-1-yl]-2-methoxy-4-nitrophenol and 2-[12-(hydroxy-3-ethoxy-5-nitrophenyl)-2,5,8,11-tetraazadodeca-1,11-dien-1-yl]-2-ethoxy-4-nitrophenol, resp.). The x-ray diffraction anal. of complex 1 evidenced the same Pbnb orthorhombic system at 160 K (high-spin (HS) state) and 100 K (low-spin (LS) state). At 160 K, a 8.4810(9), b 14.7704(14), c 18.769(2) ?, V = 2351.2(4) ?3, and Z = 4. At 100 K, a 8.5317(8), b 14.4674(15), c 18.814(2) ?, and V = 2322.2(4) ?3. Complex 2 crystallizes in the P1? triclinic system. At 160 K (HS state), a 10.265(4), b 10.861(4), c 14.181(5) ?, ¦Á 84.18(4), ¦Â 70.53(5), ¦Ã 88.95(5)¡ã, V = 1482.6(10) ?3, and Z = 2. The Fe(II) coordination sphere is distorted octahedral in 1 and 2 with a cis-¦Á arrangement of the N4O2 donor set of the hexadentate ligand. The mols. are connected into 1-dimensional infinite chains through H contacts involving the secondary amine functions and Onitro atoms of the ligands in adjacent mols. Study of their magnetic properties and Mossbauer spectra revealed very different SCO behaviors: complex 1 exhibits a cooperative SCO without residual LS or HS fraction; complex 2 shows a LS ? HS SCO involving ?5% of the FeII ions in the 30-150 K range. The phenomenol. cooperative interaction parameter J = 138 K evaluated from the area of the hysteresis loop indicates a cooperative effect weaker in 1 than in [FeII(5NO2-sal-N(1,4,7,10))]. The theor. approach to the SCO in 2 indicates a HS ground state and a LS 1st excited level 53 K above: the thermal dependence of the system occurs through population of vibrational states. Comparison of the structural and electronic properties of the ferrous SCO materials with parent N4O2 ligands shows that the properties of SCO are closely related to intermol. interactions and crystal packing.
Inorganic Chemistry published new progress about 38260-01-4. 38260-01-4 belongs to catalysis-chemistry, auxiliary class Chelating Agents, name is N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride, and the molecular formula is C6H20Cl2N4, SDS of cas: 38260-01-4.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia