title: Preparation, structural characterization, and decomposition studies of two new γ-octamolybdates of 4-methylpyridine.
abstract: We synthesized two new γ-octamolybdates, and determined their crystal structures from single-crystal X-ray diffraction data. Orange-yellow tetrakis(4-methylpyridinium) bis(4-methylpyridine)-γ-octamolybdate1crystallizes in space group P21/c witha= 11.586(2) Å,b= 15.526(2) Å,c= 16.247(2) Å,β= 118.753(1)º,Z= 2. White tetrakis(4-methylpyridinium) bis(4-methylpyridine)-γ-octamolybdate hydrate2crystallizes in space group C2/c witha= 27.086(4) Å,b= 11.917(2) Å,c= 19.332(2) Å,β= 124.427(1)º,Z= 4. Results of crystal structure determinations are presented and discussed in this paper. Thermal stability and decomposition studies of the obtained two new γ-octamolybdates were performed using TG/DSC and XRPD methods. Both compounds decomposed with the formation of 4-methylpyridinium β-octamolybdate. The two compounds are pseudo-polymorphs, exhibiting both striking similarities as well as significant differences in their structures and properties.
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Szymańska
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Nitek
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Rutkowska-Zbik
authors.affiliation: Jerzy Haber Institute of Catalysis and Surface Chemistry PAS, Niezapominajek 8, 30-239 Krakow, Poland ; Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Krakow, Poland.
authors.forename: Wiesław
authors.initials: W
authors.lastname: Łasocha
keywords: Crystal structure; Polyoxometalates; Thermal decomposition; Transition metals compounds; X-ray structure determination