Reactions of [Ru(NO)Cl-5](2-) with pseudotrilacunary {XW9O33}(9-) (X = As-III, Sb-III) anions

摘要

Reactions of [Ru(NO)Cl-5](2-) with pseudotrivacant B-alpha-[XW9O33](9-) (X = As-III, Sb-III) at 160 degrees C result in the rearrangement of polyoxometalate backbones into {XM18} structures. In the case of arsenic, oxidation of As-III to As-V takes place with the formation of a mixture of plenary and monosubstituted Dawson [As2W18O62](6-) and [As2W17Ru(NO)O-61](7-) anions, of which the latter was isolated as Me2NH2+ (DMA-1a and DMA-1b) and Bu4N+ (Bu4N-1) salts and fully characterized. Both alpha(1) and alpha(2) isomers of [As2W17Ru(NO)O-61](7-) were present in the reaction mixture; pure [alpha(2)-As2W17Ru(NO)O-61](7-) was isolated as the Bu4N+ salt. In the case of antimony, [SbW9O33](9-) is converted into a mixture of [SbW18O60](9-) and [SbW17{Ru(NO)}O-59](10-). The formation of trisubstituted [SbW15{Ru(NO)}(3)O-57](12-) as a minor byproduct was detected by HPLC-ICP-AES. The monosubstituted [SbW17{Ru(NO)}O-59](10-) anion was isolated as DMAH(+) (DMA-2) and mixed inorganic cation (CsKNa-2) salts and characterized by XRD, HPLC-ICP-AES, EA and TGA techniques. X-ray analysis shows the presence of the {Ru(NO)}-group in the 6-membered ("equatorial") belt of the Sb-free hemisphere. The experimental findings were confirmed and interpreted by means of quantum chemical calculations.