TY - JOUR
T1 - ESR and magnetic studies of octahedral [Fe(III)(Cl)(pcd)(H 2O)(DMSO)] (pcd = pyridine-2,6-dicarboxylato) compound showing Fe(III) species with different spin states in solution
AU - Hernández-Anzaldo, Samuel
AU - Sánchez-Morales, Nailea
AU - Zamorano-Ulloa, Rafael
AU - Escudero, Roberto
AU - De Jesús Rosales Hoz, María
AU - Reyes-Ortega, Yasmi
N1 - Funding Information:
The present work has been supported by Vicerrectoría de Investigación y Estudios de Posgrado from BUAP, Divulgation of Science, 2009–2010.
PY - 2013/5/22
Y1 - 2013/5/22
N2 - By direct synthesis has been obtained the octahedral complex [Fe(III)(Cl)(pdc)(H2O)(DMSO)] 1 (pdc = pyridyn-2,6-dicarboxylato), which shows a supramolecular structure and a clear and large molecular distortion. UV-Vis spectrum of 1 shows at 741 nm, 836 nm (= 100 M-1 cm-1) and 970 nm (= 1600 M-1 cm-1) typical iron d-d transitions. FIR spectrum of 1 shows vibrations υFeO, υFeN and υFeCl. NMR 1H spectroscopy is typical of paramagnetic compounds. The susceptibility data fit to a Hamiltonian, Hex = -2J S1 · S2, using two models, give close exchange interaction constant values of: J = -1.803 cm-1, g = 1.810 and J = -1.102 cm-1, g = 1.832. X-band ESR spectra of powder sample of 1 at 300 K/77 K show broad signals at H ≈ 56.70 mT/64.53 mT, characteristic of ferromagnetic absorptions. X-band spectra of 1 at 77 K in methanol solution at different concentrations show typical signals of Fe(III) species with high spin, S = 5/2, quantum mixed spin state (qms), 5/2, 3/2, which are present in ESR spectra of peroxidase enzymes, and a low spin S = 1/2. 1 has been used as catalyst in the guaiacol test, characteristic of peroxidase enzymes, giving positive by visual observation and by UV-Vis spectroscopy. By ERS spectroscopy has been observed the characteristic π-cationic-radical ferryl, enzyme covalently modified, when the peroxidase enzyme is active. The presence of Fe(III) species with qms observed by ESR spectra of 1, and its catalytic activity, both characteristic of peroxidase enzymes, are a significant conclusion of the work.
AB - By direct synthesis has been obtained the octahedral complex [Fe(III)(Cl)(pdc)(H2O)(DMSO)] 1 (pdc = pyridyn-2,6-dicarboxylato), which shows a supramolecular structure and a clear and large molecular distortion. UV-Vis spectrum of 1 shows at 741 nm, 836 nm (= 100 M-1 cm-1) and 970 nm (= 1600 M-1 cm-1) typical iron d-d transitions. FIR spectrum of 1 shows vibrations υFeO, υFeN and υFeCl. NMR 1H spectroscopy is typical of paramagnetic compounds. The susceptibility data fit to a Hamiltonian, Hex = -2J S1 · S2, using two models, give close exchange interaction constant values of: J = -1.803 cm-1, g = 1.810 and J = -1.102 cm-1, g = 1.832. X-band ESR spectra of powder sample of 1 at 300 K/77 K show broad signals at H ≈ 56.70 mT/64.53 mT, characteristic of ferromagnetic absorptions. X-band spectra of 1 at 77 K in methanol solution at different concentrations show typical signals of Fe(III) species with high spin, S = 5/2, quantum mixed spin state (qms), 5/2, 3/2, which are present in ESR spectra of peroxidase enzymes, and a low spin S = 1/2. 1 has been used as catalyst in the guaiacol test, characteristic of peroxidase enzymes, giving positive by visual observation and by UV-Vis spectroscopy. By ERS spectroscopy has been observed the characteristic π-cationic-radical ferryl, enzyme covalently modified, when the peroxidase enzyme is active. The presence of Fe(III) species with qms observed by ESR spectra of 1, and its catalytic activity, both characteristic of peroxidase enzymes, are a significant conclusion of the work.
KW - Catalytic activity
KW - Fe(III) upramolecular structure
KW - High spin /
KW - Low spin
KW - Magnetic studies
KW - Quantum mixed spin state / /
UR - http://www.scopus.com/inward/record.url?scp=84875063129&partnerID=8YFLogxK
U2 - 10.1016/j.molstruc.2013.02.021
DO - 10.1016/j.molstruc.2013.02.021
M3 - Artículo
SN - 0022-2860
VL - 1040
SP - 39
EP - 46
JO - Journal of Molecular Structure
JF - Journal of Molecular Structure
ER -