Di-2-pyridylamine complexes of iron(II)

Mössbauer and Infrared Spectra of Octahedral Complexes of Iron(II) Halides with Amides and Related Ligands

“…For example a decrease in isomer shift on lowering the coordination number has been observed by several workers for iron(I1) (12,13). The effect is also evident in comparing isomer shifts of a number of tetrahedral (14)(15)(16) and octahedral iron(I1) complexes (6,(17)(18)(19)(20). These data show that shifts of 1.3 mmls, or less, are usually characteristic of tetrahedral iron(II), while shifts greater than 1.3 mm/s are characteristic of octahedral iron(I1).…”

High-spin Iron Complexes

“…is anomalous in that it contains two iron sites, [80] although it does not show the 'crossover' found for the 1,10-phenanthroline and 2,2'-bipyridyl isothiocyanates. Relevant Mossbauer parameters are listed in Table 6.6.…”

“…If a rotated coordinate system is used, based approximately on the distorted fluorine octahedron, then the electronic ground state is 0·99 I x 2 -y2) + O· 10 I Z2). A more recent analysis of data between 97 and 692 K gives values of 800 cml and 900 cml [7], while study of the second-order Doppler shift, recoil-free fraction and quadrupole splitting between 80 and 300 K has led to values of 740 and 930 cml [8]. Ingalls [5] proposed that the very weak temperature dependence of the quadrupole interaction was compatible with excited-state levels at 750 cml and 2900 em-I, whereas Okiji and Kanamori [6] deduced values of 1028 cml and 1484 em-I.…”

“…Parameters have been measured [80,84] for a number of 4-coordinate iron(II) complexes which can be thought of as derived from the corresponding FeX 4 2 -ions (see Table 6.7). The Fe(dipyam)X2 and Fe(quinhX2 complexes show a larger quadrupole splitting than the [Fe(quin)X3]-anions implying a greater distortion from Td symmetry in the former cases as might be expected.…”

Bidentate chelate compounds. 3. Cobalt(III) chemistry of 2,2'-dipyridylamine

“…The compound [Co(HDPA)(H20)2C03]-0.5H20 was obtained as a byproduct in the attempted preparation of " 8, 4 8; (5) 2 ,; (6) The complex [Co(HDPA)3(H20)2](C104)2 was obtained when the peroxo complex was treated with HDPA in hydrochloric acid solution in the hope of preparing Co-(HDPA)33+. This complex differs from that of Goodgame by containing two molecules of water that appear to be coordinated (see below).…”