Search results for "Manga"
showing 10 items of 743 documents
Slow Relaxation of the Magnetization in a {Co <sup>III</sup>Mn <sup>III</sup>} Heterometallic Brick-Wall Network
2021
The use of the cyanide-bearing dicobalt(III) complex (PPh 4 ) 2 [Co 2 III (m-2,5-dpp)(CN) 8 ] as a metalloligand towards [Mn(salen)(H 2 O)]ClO 4 afforded the heterobimetallic two-dimensional compound of formula [{Mn III (salen)} 2 {(m-NC) 4 Co 2 III (m-2,5-dpp)(CN) 4 }] n (1) [PPh 4 + = teraphenylphosphonium cation, 2,5-dpp = 2,5-bis(2-pyridyl)pyrazine and H 2 salen = N,N’ -ethylenebis(salicylideneimine)] whose structure has been determined by single crystal X-ray diffraction. Compound 1 exhibits a neutral brick-wall structure, where each [Co 2 III (m-2,5-dpp)(CN) 8 ] 2- unit adopts a tetrakis-monodentate bridging mode towards four {Mn III (salen)} + fragments through four of its eight cyan…
Atrane complexes chemistry as a tool for obtaining trimodal UVM-7-like porous silica
2018
[EN] The use of atrane complexes as hydrolytic precursors enables the homogeneous incorporation of manganese (25Si/Mn48) throughout the porous walls of the nanoparticles of a surfactant-templated bimodal mesoporous silica (UVM-7). The subsequent leaching of the manganese nanodomains allows adding controlled microporosity to the host silica framework. The resulting final silica material presents three pore systems structured at different length scales: interparticle textural-type macroporosity (ca. 43.2nm), ordered intraparticle mesoporosity (ca. 2.63nm; after template removal), and well-dispersed microporosity (< 2nm; as consequence of the lixiviation of the Mn-rich domains). The good dispe…
Influence of Mn site doping on electrical resistivity of polycrystalline La1-yAyMn1-xBxO3 (A=Ba, Sr; B=Cu, Cr, Co) Manganites
2008
We have the measured electrical resistivity of La1-yBayMn1-xCuxO3 (0.17?y?0.30; 0.04?x?0.10), La1-ySryMn1-xCrxO3 and La1-ySryMn1-xCoxO3 (0.270?y?0.294; 0.02?x?0.10) polycrystalline samples in the 25-325 K temperature range. The increase of Mn site doping concentration leads to an increase of the electrical resistivity of the samples and the appearance of a ?double-peak? structure in the electrical resistivity versus temperature graphs. The first peak represents the insulator-metal transition in vicinity of the paramagnetic-ferromagnetic transition (TC). We have found that the intensity of the second peak increases with an increase of concentration of Mn substituents, due to the hole scatter…
Electrocatalytic properties of manganese and cobalt polyporphine films toward oxygen reduction reaction
2018
International audience; Novel member of polymetalloporphines, namely manganese polymetalloporphine of type I (pMnP-I) obtained by ion exchange from magnesium polyporphine of type I (pMgP-I) is reported for the first time and compared to its cobalt analogue (pCoP-I). Both polymer films have been obtained via two-step procedure: demetaladon of the pMgP-I electrode film via its exposure to trifluoroacetic acid solution, resulting in formation of the metal-free polyporphine of type I (pH(2)P-I) followed by electrochemically induced incorporation of Co or Mn ions from the acetonitrile solution of cobalt and manganese perchlorates. A further oxidative transformation of pCoP-I, polymer films has l…
Crystal structure ofcis-1-phenyl-8-(pyridin-2-ylmethyl)dibenzo[1,2-c:2,1-h]-2,14-dioxa-8-aza-1-borabicyclo[4.4.0]deca-3,8-diene
2017
The present work describes the synthesis and crystal structure of the new B-phenyloxazaborocine, C26H23BN2O2. The title compound adopts a zwitterionic form with a significant intramolecular N→B dative bond and intermolecular C—H⋯O interactions connecting molecules parallel to the b axis.
Poly[1-ethyl-3-methylimidazolium [tri-μ-isothiocyanato-manganate(II)]]
2019
The title compound, {(C9H11N2)[Mn(NCS)3]} n , has been obtained as a side product of the salt metathesis reaction of 1-ethyl-3-methylimidazolium bromide, (EMIm)Br, and K2[Mn(NCS)4]. The structure consists of discrete 1-ethyl-3-methylimidazolium cations and an anionic two-dimensional network of manganese(II)-based complex anions, interconnected by thiocyanate ions. Every Mn2+ ion is coordinated by three S atoms of three NCS− ions and three N atoms of further three NCS− ions in a meridional octahedral fashion.
CCDC 882806: Experimental Crystal Structure Determination
2013
Related Article: F.Reuter,E.Rentschler|2013|Polyhedron|52|788|doi:10.1016/j.poly.2012.07.050
CCDC 882811: Experimental Crystal Structure Determination
2013
Related Article: F.Reuter,E.Rentschler|2013|Polyhedron|52|788|doi:10.1016/j.poly.2012.07.050
Application of field portable EDXRF spectrometry to analysis of pigments of Levantine rock art
2010
The results of the analyses of elemental composition of red and black pigments of Levantine rock art from La Saltadora rock shelters (Valltorta gorge, Castellon, Spain) are presented in this paper. Nondestructive analyses were carried out using a portable energy dispersive X-ray fluorescence (EDXRF) spectrometer developed for in situ analysis. The results revealed the strong presence of calcium in all the analyzed locations due to the contribution of the underlying calcareous bedrock and the overlying crust. Iron is the main element detected in red pigments and manganese in black pigments. Iron and calcium ratios have been found indicative of the degree of preservation of the pictorial laye…