Abstract
The complexes Fe[CH3PO3]·H2O, Fe2[O3P(CH2)2PO3]·2H2O and Fe2[O3P(CH2)2PO3] were synthesized and characterized by thermogravimetric analysis and UV-visible and infrared spectroscopy and their magnetic properties studied using a superconducting quantum interference device magnetometer. Preliminary X-ray single-crystal data suggest for Fe[CH3PO3]·H2O a lamellar structure similar to that observed in Cd[CH3PO3]·H2O. The structure of cadmium phosphonate consists of alternating inorganic and organic layers, with the metal ion octahedrally co-ordinated by five oxygens from phosphonate and one from a water molecule. The inorganic layers are then separated by bilayers of methyl groups, and van der Waals contacts are established between them. In Fe2[O3P(CH2)2PO3]·2H2O a pillared structure similar to that found in the corresponding zinc(II) ethylenebis(phosphonates) is suggested. All the compounds reported contain FeII in the d6 (S = 2) high-spin electronic configuration, as determined from magnetic measurements in the high temperature region. Below 100 K the effective magnetic moment of Fe[CH3PO3]·H2O decreases down to 30 K, then rises rapidly to a maximum at 24 K, and decreases again. The 3-D long-range antiferromagnetic order, defined as the temperature of the onset of the magnetization, has been located at TN = 25 K. Similar behavior has been observed in Fe2[O3P(CH2)2PO3]·2H2O. Below the critical temperature, TN, both compounds behave as a “weak ferromagnet”. After dehydration Fe2[O3P(CH2)2PO3]·2H2O loses the water molecules, and its magnetic behavior changes drastically in the low temperature region. The magnetic data at low temperatures of anhydrous Fe2[O3P(CH2)2PO3] are consistent with a magnetically disordered ground state, possibly a spin-glass like state.
Sign-in/Register to access full text options 
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 callMore From: Journal of the Chemical Society, Dalton Transactions
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
