In this work, linear and cyclic disulfide heptapeptides of Longicalycinin A have been successfully synthesized by solid phase methodology with Fmoc /t-Bu and solution phase, respectively. 2-Chlorotrityl chloride resin (2-CTC) was used as a solid support. The synthesized linear disulfide analogue of Longicalycinin A was cleaved from the resin as a protected peptide. The final deprotection was pe...

The title compound, [Fe(4)(C(5)H(5)OS)(2)S(CO)(12)], was prepared by the direct reaction of Fe(3)(CO)(12) and 2-furyl-methane-thiol in tetra-hydro-furan. Desulfurization took place readily to form an Fe(4)S(3) cluster. The mol-ecule consists of two similar [(μ-2-C(4)H(3)O-CH(2)S)Fe(2)(CO)(6)] moieties joined to a spiro-type four-coordinate μ(4)-S atom such that this bridging sulfur is tetra-hed...

Protonation of [{(mu-SCH2)2N(C6H4-p-NO2)}{Fe(CO)2(PMe3)}2] in the presence of 4 equiv. of HOTf afforded two species, a micro-hydride diiron complex, the molecular structure of which was crystallographically characterized, and a micro-S-protonated species, which was readily deprotonated in the presence of pyridine.

Electron-rich polyisocyano derivatives Fe(2)(S(2)C(n)H(2n)(CO)(6-x)(CNMe)(x) (x approximately 4) undergo oxidatively induced (FeCp(2)(+)) reaction with additional CNMe to give [Fe(2)(SR)(2)(CNMe)(7)](PF(6))(2), a new class of iron thiolates. Crystallographic characterization established that the 34 e(-) dinuclear core resembles the oxidized (H(2)-binding) form of the active sites of the Fe-only...

Neuroglobin and cytoglobin reversibly bind oxygen in competition with the distal histidine, and the observed oxygen affinity therefore depends on the properties of both ligands. In the absence of an external ligand, the iron atom of these globins is hexacoordinated. There are three cysteine residues in human neuroglobin; those at positions CD7 and D5 are sufficiently close to form an internal d...

The conventional theory of superconductivity holds that Cooper pairs form due to electron–phonon coupling; however, this description may not be adequate describe certain unconventional superconductors such as cuprates and iron chalcogenides. In these superconductors, it has been proposed spin fluctuations responsible for the formation pairs. study, we explore interactions in transition metal, d...

Changes effected in purple uteroferrin’s resonance Raman spectrum by mercaptoethanol reduction suggest that the protein’s single iron atom is coordinated to more than one tyrosyl residue. Detection of a conservative pair of visible CD bands, indicative of exciton splitting of a tyrosinate-to-iron charge transfer band, strongly supports this suggestion. Additional features in the protein’s visib...