With the help of computer algorithms, we improve the lower bound on the edge Folkman number Fe(3, 3; 5) and vertex Folkman number Fv(3, 3; 4), and thus show that the exact values of these numbers are 15 and 14, respectively. We also present computer enumeration of all critical graphs.

Earth's core may contain C, and it has been suggested that C in the core could stabilize the formation of a solid inner core composed of Fe 3 C. We experimentally examined the Fe-C system at a pressure of 5 GPa and determined the Fe-C phase diagram at this pressure. In addition, we measured solid metal/liquid metal partition coefficients for 17 trace elements and examined the partitioning behav...

The treatment of Fe(ClO(4))(2)·6H(2)O or Fe(ClO(4))(3)·9H(2)O with a benzimidazolyl-rich ligand, N,N,N',N'-tetrakis[(1-methyl-2-benzimidazolyl)methyl]-1,2-ethanediamine (medtb) in alcohol/MeCN gives a mononuclear ferrous complex, [Fe(II)(medtb)](ClO(4))(2)·½CH(3)CN·½CH(3)OH (1), and four non-heme alkoxide-iron(III) complexes, [Fe(III)(OMe)(medtb)](ClO(4))(2)·H(2)O (2, alcohol = MeOH), [Fe(III)(...

The title compound, [Fe(C(12)H(8)N(2))(3)][Fe(2)Cl(6)O]·0.5CH(3)CH(2)OH, consists of one [Fe(phen)(3)](2+) cation (phen = 1,10-phen-anthroline), one [Fe(2)Cl(6)O](2-) anion and one half-mol-ecule of ethanol. In the cation, the Fe(II) atom is coordinated by six N atoms from three phen ligands in a distorted octa-hedral geometry. In the bent anion, two Fe(III) atoms are connected by a bridging ox...

To evaluate the extent to which daily oral Fe supplements may block Fe absorption from a subsequent dose, we compared effects of oral and intraperitoneal (i.p.) Fe supplementation on Fe status in anaemic rats (haemoglobin (Hb) 90 g/l). A ligated duodenal loop technique was used to assess the effects of the Fe supplements administered either orally or i.p. at different frequencies on Fe absorpti...

The reaction of NiBr(2)(EtOH)(4) with a 1:2-3 mixture of FeBr(2)(CO)(4) and Na(SPh) generated a linear trinuclear Fe-Ni-Fe cluster (CO)(3)Fe(mu-SPh)(3)Ni(mu-SPh)(3)Fe(CO)(3), 1, whereas the analogous reaction system FeBr(2)(CO)(4)/Na(S(t)Bu)/NiBr(2)(EtOH)(4) (1:2-3:1) gave rise to a linear tetranuclear Fe-Ni-Ni-Fe cluster [(CO)(3)Fe(mu-S(t)Bu)(3)Ni(mu-Br)](2), 2. By using this tetranuclear clus...

A Mössbauer powder diffractometer was used to measure diffraction patterns from polycrystalline foils of Fe3Al. The intensities of Bragg diffractions were measured as a function of the energy of the incident photon. The bcc fundamental diffractions showed large changes in intensity as the incident energy was tuned through the nuclear resonances. These variations of diffraction intensity with in...

In order to obtain suitable precursors for iron complexes that model the reactivity of the active sites of nitrogenases, the coordination chemistry of the [Fe('N2H2S2')] fragment was systematically investigated ('N2H2S2' 2 = 1,2-ethanediamine-N,N'-bis(2-benzenethiolate)(2-)). One-pot reactions of FeCl2 4H2O with the tetradentate amine-thiolate ligand 'N2H2S2' 2 and CO, PR3, or P(OR)3 yielded th...