Synthesis and characterization of [(CH3)2NH2][Na0.5Cr0.5(HCOO)3]: a rare example of luminescent metal–organic frameworks based on Cr(iii) ions. Issue 15 (16th March 2015)

• Record Type: Journal Article
• Authors: Mączka, Mirosław; Bondzior, Bartosz; Dereń, Przemysław; Sieradzki, Adam; Trzmiel, Justyna; Pietraszko, Adam; Hanuza, J.
• Is Part Of: Dalton transactions. Volume 44:Issue 15(2015)
• Page Start: 6871
• Page End: 6879
• Publication Date: 2015-03-16
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c5dt00060b
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : A novel chromium(iii )-based luminescent metal–organic framework with perovskite architecture, [(CH3 )2 NH2 ][Na0.5 Cr0.5 (HCOO)3 ], was synthesized. Abstract : A novel formate [(CH3 )2 NH2 ][Na0.5 Cr0.5 (HCOO)3 ] (DMNaCr) was prepared by a solvothermal method. This compound crystallizes in the perovskite-type metal formate framework (space group R 3̄) with disordered dimethylammonium (DMA + ) cations. X-ray diffraction, DSC, Raman and IR studies show that in contrast to the isostructural iron analogue [(CH3 )2 NH2 ][Na0.5 Fe0.5 (HCOO)3 ] (DMNaFe), DMNaCr does not exhibit any structural phase transition at low temperatures. This behavior has been attributed to the smaller flexibility of the perovskite-like framework in DMNaCr when compared with that of DMNaFe. Dielectric permittivity data reveal pronounced dielectric relaxation that is attributed to the dynamical rotation of DMA + ions. Electron absorption and photoluminescence studies show that this material exhibits efficient emission at low temperatures. A detailed analysis of the optical properties shows that chromium ions are located at the site of intermediate crystal field strength with Dq/ B = 2.29.