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Novel modification of anhydrous transition metal oxalates from powder diffraction
Author(s) -
Puzan An.,
Baumer Vyacheslav N.,
Mateychenko Pavel V.
Publication year - 2017
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229617012839
Subject(s) - isostructural , orthorhombic crystal system , crystallography , oxalate , crystal structure , anhydrous , chemistry , powder diffraction , tetragonal crystal system , transition metal , metal , atom (system on chip) , materials science , inorganic chemistry , organic chemistry , computer science , embedded system , catalysis
The known metal–C 2 O 4 structures may be divided into two modifications, α and β. The α‐modification has an order–disorder struxture, revealing one‐dimensional disordering of the metal–oxalate chains, and the β‐modification is ordered. The crystal structures of orthorhombic γ‐MnC 2 O 4 {poly[μ‐oxalato‐manganese(II)]; space group Pmna , a = 7.1333 (1), b = 5.8787 (1), c = 9.0186 (2) Å, V = 378.19 (1) Å 3 , Z = 4 and D x = 2.511 Mg m −3 } and γ‐CdC 2 O 4 {poly[μ‐oxalato‐cadmium(II)]; space group Pmna , a = 7.3218 (1), b = 6.0231 (1), c = 9.2546 (2) Å, V = 408.13 (1) Å 3 , Z = 4 and D x = 3.262 Mg m −3 } have been obtained from powder diffraction patterns. The structures are isostructural. Each metal atom in each structure is coordinated by seven O atoms which belong to five oxalate ions. The crystal packing, which contains noticeable cavities in the [101] and [001] directions, is not close packed and essentially differs from the known disordered α‐ and ordered β‐modifications of transition metal oxalates. This modification seems to be metastable. It was found that a spontaneous γ→β phase transition takes place for γ‐CdC 2 O 4 .