A metal-organic framework [Mn(4,4′-bipy)(1,3-BDC)]n (MnMOF, 1,3-BDC = 1,3-benzene dicarboxylate, 4,4′-bipy = 4,4′-bipyridine) has been synthesized hydrothermally and characterized by single crystal XRD and FT-IR spectrum. The low-temperature molar heat capacities of MnMOF were measured by temperature-modulated differential scanning calorimetry for the first time. The thermodynamic parameters such as entropy and enthalpy relative to reference temperature 298.15 K were derived based on the above molar heat capacity data. Moreover, the thermal stability and the decomposition mechanism of MnMOF were investigated by thermogravimetry analysis-mass spectrometer. A two-stage mass loss was observed in air flow. MS curves indicated that the gas products of oxidative degradation were H2O, CO2, NO, and NO2.
Authors:S. Shibata, Y. Takashima, R. Gensho, and M. Honda
The nuclide53Mn was produced by the following three nuclear reactions,52Cr(d, n)53Mn,51V(3He n)53Mn and50Cr(α, n), (α, p)53Mn. Enriched52Cr and50Cr metal targets were prepared on copper plate holder by electrodeposition. The commercially available natural vanadium foil
was used for the51V(3He, n)53Mn reaction. Each target was bombarded in a cyclotron. Manganese was extracted and purified without using carrier from the
bombarded targets by anion and cation exchanges and solvent extraction. The isotopic ratio53Mn/55Mn was measured by mass spectrometry and the amount of55Mn was determined by neutron activation analysis. The activity of53Mn obtained was 7 dpm by 750 millicoulombs in3He bombardment (E3He=20 MeV). The activity due to by-product54Mn was about several thousands times higher than that of53Mn in3He and deuteron bombardments, which were produced through51V(3He, γ)54Mn and53Cr(d, n)54Mn. In alpha bombardment (Eα=15 MeV), the activity of53Mn produced was 8 dpm by 95 millicoulombs. The activity ratio, dpm54Mn/dpm53Mn, was about 3, and this ratio was the best one among the results so far obtained.
Keggin ion-pillared buserite was prepared by ion-exchanging the hexylammonium ion-expanded buserite with Keggin ions, [Al13O4(OH)24(H2O)12]7+. The starting material was synthetic Na-buserite, which is a layered manganese oxide of composition Na4Mn14O26xH2O. The thermal and redox properties of this oxide and its pillared derivative were compared in O2, N2 and H2 environments using TG, DSC and XRD. The results indicated an improvement in thermal stability of pillared compound relative
to Na-buserite in all gaseous environments. By using these compounds in catalysing the oxidation of ethane, it was found that
they were very active for complete oxidation.
Authors:Máté Zsigmond Leskó, Richárd Zoltán Papp, Boglárka Anna Topa, Ferenc Kristály, Tamás Vigh, and Norbert Zajzon
The sediment-hosted Úrkút manganese ore deposit is the largest manganese accumulation in Hungary. Mining activity lasted almost 100 years (1917–2017). The area was continuously under scientific investigation
Authors:Varghese Mathew, Lizymol Xavier, C. K. Mahadevan, and K. E. Abraham
different carboxylate binding coordination modes like syn-syn, syn-anti, and anti-anti. Its ability to mediate ferromagnetic interactions between the metal ions that it bridges, is reported [ 1 , 2 ]. Manganese complexes remain a center of interest because
Authors:Agnieszka Jabłońska–Wawrzycka, Małgorzata Zienkiewicz, Maciej Hodorowicz, Patrycja Rogala, and Barbara Barszcz
), structural, and magnetic characterization of different [Mn(H 2 O) 3 (2,3pydc)] n ( 1 ) and [Mn(H 2 O) 6 ][Mn(2,3pydcH) 3 ] 2 ( 2 ) manganese(II) complexes with pyridine-2,3-dicarboxylic acid (2,3pydcH 2 ), which acts as a monodicarboxylate anion (2,3pydcH