Iron complexes magnetic behavior

Iron, tris(hexafluoroacetylacetone)-structure, 65 Iron, tris(oxalato)-chemical actinometer, 409 Iron, tris(l,10-phenanthroline)-absorptiometry, 549 racemization, 466 solid state, 467 structure, 64 Iron(O) complexes magnetic properties, 274 Iron(II) complexes magnetic behavior, 273 spectra, 253 Iron(III) complexes equilibrium constant solvent effect, 516 liquid-liquid extraction, 539 magnetic behavior, 272 spectra, 253 Iron(IV) complexes magnetic behavior, 272 Isocyanates metal complexes hydrolysis, 429 Isokinetic effect ligand exchange solid state, 469 Isomerism, 179-208 configurational, 180, 188 constitutional, 180,182 coordination, 183 detection, 180 history, 24... 

The iron(II) complexes [Fe(pppp)X]BPh4 (X=Br , I") showed unusual magnetic behavior, which was interpreted as being due to a singlet triplet spin transition [16]. 

Fe(abptrz)2(tcnq)2] is an iron(II) complex of the triazole 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole (abptrz) and the 7,7, 8,8 -tetracyanoquinodimethane (tcnq) radical anion whose structure, (132), Mossbauer and IR spectra, and magnetic behavior (thermally induced (280 K) spin crossover -S = 2 -S = 0) have been established. " ... 

The cyclic Schiff base terimine ligand (161) forms a spin cross-over ternary iron(II) complex [Fe(161)(CN)2]. This has intermediate magnetic behavior, indicating a 50 50 mixture of high-spin... 

An iron complex can be formed by using the ethyl derivative of triphos, p3Etg [(triphos)Co(n3-P3)Fe(p3Etg)]2+. Many of the complexes here presented are paramagnetic. The number of valence electrons range from 30 to 34. This unprecedented magnetic behavior can be accounted for by a molecular orbital treatment of the type suggested by Hoffmann. 

Mackinawite, Fei+xS, with (x = 0.01-0.07) is a tetragonal iron sulfide with excess of iron. Morice et al. [153] reported a complex Mossbauer spectrum consisting of at least three sextets with hyperfine fields 29.8, 26.2 and 22.8 T and small quadrupole shifts of about 0.09, 0.06 and 0.09 mm/s respectively. On the other hand, only a singlet spectrum, even down to 4 K, has been observed by Vaughan and Ridout [154]. Probably the concentration of Co and Ni found to be present in the involved natural samples is decisive for the different magnetic behavior. 

Figure 52. Different magnetic behavior of iron(III) pyrrole and pyrroUdene dithiocarbamate complexes.

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