In this work, we observed a spin-crossover phenomenon in a cesium iron hexacyanochromate, which is a Prussian blue analogue. This compound showed a thermal phase transition with transition temperatures of 211 K (T1/2 downward arrow) and 238 K (T1/2 upward arrow) due to a spin-crossover on FeII sites. This spin-crossover phase transition is accompanied by a lattice contraction of 0.38 A, but mai...

Four Bok globules were studied in the Near-Infrared, through narrow-band filters, centered at the 1.644 μm line of [FeII], the H2-line at 2.122 μm, and the adjacent continuum. We report the discovery of [Feii] and H2 protostellar jets and knots in the globules CB3 and CB230. The [FeII]-jet in CB230 is defined by a continuous elongated emission feature, superimposed on which two knots are seen; ...

The effects of pressure and temperature on the energy (Eop) of the metal-to-metal charge transfer (MMCT, FeII-->CoIII) transition of the cyano-bridged complexes trans-[L14CoNCFe(CN)5]- and cis-[L14CoNCFe(CN)5]- (where L14=6-methyl-1,4,8,11-tetraazacyclotetradecan-6-amine) were examined. The changes in the redox potentials of the cobalt and iron metal centres with pressure and temperature were a...

We report integral-field spectroscopic observations with the Cambridge Infra-Red Panoramic Survey Spectrograph (CIRPASS) mounted on the GEMINI South telescope of the nucleus of the nearby galaxy NGC 5128 (Centaurus A). We detect two-dimensional distributions of the following emission-lines: [PII], [FeII] and Paschen β. We compare our observations with previously published radio observations (VL...

The title iron complex, [Fe(C21H19N3)2], consists of an FeII atom chelated by two tridentate bis-(imino)-pyridine radical anions in a slightly distorted octa-hedral coordination environment. In the solid state, there are two independent half-mol-ecules in the asymmetric unit, and the complete mol-ecular structure is formed by applying twofold rotation symmetry with the twofold rotation axis pas...

We present results from spectral analysis of ASCA data on the strong Feii narrow-line Seyfert 1 galaxy Mrk 507. This galaxy was found to have an exceptionally flat ROSAT spectrum among the narrow-line Seyfert 1 galaxies (NLS1s) studied by Boller, Brandt & Fink (1996). The ASCA spectrum however shows a clear absorption feature in the energy band below 2 keV, which partly accounts for the flat sp...

The ability of tetraazalene radical bridging ligands to mediate exceptionally strong magnetic exchange coupling across a range of transition metal complexes is demonstrated. The redox-active bridging ligand N,N',N'',N'''-tetra(2-methylphenyl)-2,5-diamino-1,4-diiminobenzoquinone (NMePhLH2) was metalated to give the series of dinuclear complexes [(TPyA)2M2(NMePhL2-)]2+ (TPyA = tris(2-pyridylmethy...

The potential utility of paramagnetic transition metal complexes as chemical shift 19F magnetic resonance (MR) thermometers is demonstrated. Further, spin-crossover FeII complexes are shown to provide much higher temperature sensitivity than do the high-spin analogues, owing to the variation of spin state with temperature in the former complexes. This approach is illustrated through a series of...

Pentanuclear, cyanide-bridged clusters [M(tmphen)2]3[M'(CN)6]2 (M/M' = Zn/Cr (1), Zn/Fe (2), Fe/Fe (3), Fe/Co (4), and Fe/Cr (5); tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline) were prepared by combining [M'III(CN)6]3- anions with mononuclear complexes of MII ions with two capping tmphen ligands. The clusters consist of a trigonal bipyramidal (TBP) core with three MII ions in the equatorial ...

Cyclic voltammetry of the non-heme diiron enzyme porcine purple acid phosphatase (uteroferrin, Uf) has been reported for the first time. Totally reversible one-electron oxidation responses (FeIII-FeII --> FeII-FeIII) are seen both in the absence and in the presence of weak competitive inhibitors phosphate and arsenate, and dissociation constants of these oxoanion complexes formed with uteroferr...