Science Letter
January 5, 2010

Data from T.S. Kurtikyan and colleagues advance knowledge in inorganic

"Spectroscopic studies demonstrate that the 5-coordinate O-nitrito
complexes Fe(Por)(eta(1)-ONO) (Por - mesotetraphenyl- or
meso-tetra-p-tolyl-porphyrinato dianions) react with the thioethers
(R2S) dimethylsulfide and tetrahydrothiophene to give the 6-coordinate
N-nitrito complexes Fe(Por)(R2S)(NO2). These reactions were conducted
in low-temperature porous layered solids formed in a cryostat;
however, with excess R2S in the atmosphere, the same species are
moderately stable at room temperature," researchers in Yerevan,
Armenia report (see also Inorganic Chemistry).

"Six-coordinate O-nitrito isomers were not observed with the R2S
proximal ligands, even though DFT calculations for the
Fe(P)(DMS)(eta(1)-ONO) and Fe(P)(DMS)(NO2) models (P=porphinato
dianion, DMS=dimethyl sulfide) show the latter to be only modestly
lower energy (similar to 8 kJ/mol) than the former. Leaving this
system at room temperature in the presence of excess R2S leads
eventually to the appearance in the FIR spectra of the nu(NO) band
characteristic of the ferrous nitrosyl Fe(Por)(NO)," wrote T.S.
Kurtikyan and colleagues.

The researchers concluded: "Concomitantly, the mass spectrum of the
gas phase demonstrated the molecular peaks of the sulfoxides R2SO,
indicating oxygen atom transfer reactivity for the ferric porphryinato
complexes of nitrite."

Kurtikyan and colleagues published their study in Inorganic Chemistry
(Six-Coordinate Nitro Complexes of Iron(III) Porphyrins with trans
S-Donor Ligands. Oxo-Transfer Reactivity in the Solid State. Inorganic
Chemistry, 2009;48(23):11236-11241).

For additional information, contact T.S. Kurtikyan, MSRC NAS, Yerevan
0014, Armenia.

Publisher contact information for the journal Inorganic Chemistry is:
American Chemical Society, 1155 16th St., NW, Washington, DC 20036,