Pressure-Induced Spin Crossover at Room Temperature in a Nanoporous Host-Guest Framework Structure.

The two-dimensional (2D) metal-organic framework compound Fe (azpy) (NCS) (azpy=trans-4,4'-azopyridine, NCS=thiocyanate) has been pressurized in isopropanol and ethanol that act as guest molecules and pressure-transmitting media. Room temperature conversion of metal-ion sites from high-spin to low-spin states under high-pressure-driven uptake of guest molecules was investigated. Upon isopropanol guest inclusion, spin conversion of ∼66 % low-spin abundance is attained by ∼3 GPa.

(Phenoxyimidazolyl-salicylaldimine)iron complexes: synthesis, properties and iron catalysed ethylene reactions.

The reaction of 2-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol (L1), 2,4-di-tert-butyl-6-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol (L2) or 4-tert-butyl-2-{[2-(1H-imidazol-4-yl)-ethylimino]-methyl}-phenol (L3) with iron(ii) precursors produced either iron(ii) or iron(iii) complexes, depending on the nature of the anions in the iron(ii) precursor and the ligand. When the anion is chloride and the ligand L1, the product is [(L1)2Fe][FeCl4] (1), but when the anion is triflate (OTf(-)) and the ligand is L2, the product is [(L2)2Fe][OTf]2 (2). With iron(ii) halides and tert-butyl groups on the phenoxy ligands L2 and L3, the iron(iii) complexes [(L2)FeX2] {where X = Cl (3), Br (4) and I = (5)} and [(L3)FeCl2] (6) were formed.

On the physico-chemical and physiological requirements of hemozoin formation promoted by perimicrovillar membranes in Rhodnius prolixus midgut.

Triatomine insects are obligatory blood-feeders that detoxify most of the hemoglobin-derived heme through its crystallization into hemozoin (Hz). Previous evidence demonstrates the key role of midgut perimicrovillar membranes (PMVM) on heme crystallization in triatomines. Here, we investigated some of the physico-chemical and physiological aspects of heme crystallization induced by Rhodnius prolixus PMVM.

Thermally induced two-step, two-site incomplete 6A1<-->2T2 crossover in a mononuclear iron(III) phenolate-pyridyl Schiff-base complex: a rare crystallographic observation of the coexistence of pure S=5/2 and 1/2 metal centers in the asymmetric unit.

The six-coordinate mononuclear iron(III) complexes [Fe(salpm)2]ClO(4).0.5EtOH, [Fe(salpm)2]Cl, [Fe{(3,5-tBu2)-salpm}2]X (X=ClO4- or Cl-), and [Fe{(3,5-tBu2)-salpm}2]NO(3).

Fate of haem iron in the malaria parasite Plasmodium falciparum.

Chemical analysis has shown that Plasmodium falciparum trophozoites contain 61+/-2% of the iron within parasitized erythrocytes, of which 92+/-6% is located within the food vacuole. Of this, 88+/-9% is in the form of haemozoin. (57)Fe-Mössbauer spectroscopy shows that haemozoin is the only detectable iron species in trophozoites.

Structural, Conformational, and Spectroscopic Studies of Primary Amine Complexes of Iron(II) Porphyrins.

Three novel bis(primary amine)iron(II) porphyrins [Fe(TPP)(RNH(2))(2)], where RNH(2) = 1-butylamine, benzylamine, and phenethylamine, have been synthesized and characterized by X-ray crystallography and IR, electronic, and Mössbauer spectroscopy. The compounds provide unprecedented structural data for the coordination of primary amines by iron(II) porphyrins. The Fe-N(ax) distances of [Fe(TPP)(1-BuNH(2))(2)], [Fe(TPP)(BzNH(2))(2)], and [Fe(TPP)(PhCH(2)CH(2)NH(2))(2)] are 2.