Propionic acid side chain hydrogen bonding in the malaria pigment beta-hematin.

Malaria pigment, or beta-hematin, the insoluble heme detoxification product resulting from the intraerythrocitic digestion of hemoglobin by young malaria trophozoites has been structurally characterized by X-ray powder diffraction and shown to contain chains of propionic acid linked dimers. Although there is considerable spectroscopic evidence for a monodentate propionate-iron interaction in this crystalline material, the spectroscopic characterization of the propionic acid dimer is limited. Herein we demonstrate the presence of the propionic acid dimer unit by H/D isotope substitution in carboxylic acid dimer.

Structural and Spectroscopic Studies of Two Phases of the Organometallic Chain Polymer [Ru(2){&mgr;(2):&mgr;(2):eta(2)-O(2)PMe(2)}(2)(CO)(4)](n)().

The microcrystalline organometallic coordination polymer [Ru(2){&mgr;(2):&mgr;(2):eta(2)-O(2)PMe(2)}(2)(CO)(4)](n)() which results from the oxidative addition of dimethylphosphinic acid to triruthenium dodecacarbonyl has been structurally characterized by X-ray powder diffraction, lambda = 1.149 49(1) Å, at 295 and 50 K. At room temperature the crystallites have a monoclinic unit cell with the space group C2/c with lattice constants a = 18.