Rb. Lanjewar et al., MOSSBAUER SPECTROSCOPIC AND THERMAL-DECOMPOSITION STUDIES OF ALKYLAMINE AND NITROGEN HETEROCYCLIC SUBSTITUTED PENTACYANOFERRATE(II) COMPLEXES, Thermochimica acta, 287(1), 1996, pp. 111-129
Substituted pentacyanoferrate(II) complexes Na-3[Fe(CN)(5)L]. xH(2)O h
ave been obtained for di-sec-butylamine, tri-n-amylamine, pyrazole, py
razine, pyrrole, and 2-,3- and 4-cyanopyridine. Microanalysis, UV-visi
ble, infrared, and Mossbauer spectroscopies, TGA-DTG and XRD were used
to characterize the complexes. Each complex has an absorption band in
the visible region that is assigned to a d-d transition. Mossbauer pa
rameters are used to classify the various ligands according to their s
igma- and pi-bonding abilities. The Mossbauer spectra of these complex
es exhibit a quadrupole doublet, Delta E(Q) = 0.71-0.84 mm s(-1) at ro
om temperature. The isomer shift (delta) values fall within 0.00 +/- 0
.02 mm s(-1) which suggests that the iron atom is in a + 2 low-spin st
ate. Thermolysis of the solids leads to water release, ligand release
and/or decomposition, yielding elemental metal, metal carbides, haemat
ite and magnetite.