Search

Metal–organic frameworks (MOFs) form a unique platform for operation with data using ReRAM technology. Here we report on a large-scale fabrication of a MOF-based ReRAM array with 6 × 6 cells, demonstrating 50% variation in their electronic parameters. Despite this inhomogeneity, such a "non-ideal" ReRAM array is used for recording binary information followed by deep learning processes to achieve 95% accuracy of reading. Next, the same ReRAM array is used to record numbers (from 0 to 15) followed by the operation of addition. For the correct performance of such an analogue algorithm, we determine a set of unique coefficients for each ReRAM cell, allowing us to use this set as an encrypted key to get access to logical operations. The obtained results, thereby, demonstrate the possibility of "non-ideal" MOF-based ReRAM for low error reading of information coupled with encrypted logical operations. [ABSTRACT FROM AUTHOR]

We report the synthesis and single-crystal X-ray diffraction, magnetic, and luminescence measurements of a novel family of luminescent cage-like tetranuclear silsesquioxanes (PhSiO15)8(LnO15)4(O)(C5H8O2)6(EtOH)2(CH3CN)2-2CH3CN (where Ln = Tb, 1; Tb/Eu, 2; and Gd, 3), featuring seven-coordinated lanthanide ions arranged in a one-capped trigonal prism geometry. Compounds 1 and 2 exhibit characteristic Tb[sup 3+] and Tb[sup 3+]/Eu[sup 3+]-related emissions, respectively, sensitized by the chelating antenna acetylacetonate (acac) ligands upon excitation in the UV and visible spectral regions. Compound 3 is used to assess the energies of the triplet states of the acac ligand. For compound 1, theoretical calculations on the intramolecular energy transfer and multiphonon rates indicate a thermal balance between the [sup 5]D4 Stark components, while the mixed Tb[sup 3+]/Eu[sup 3+] analog 2, with a Tb:Eu ratio of 3:1, showcases intra-cluster Tb[sup 3+]-to-Eu[sup 3+] energy transfer, calculated theoretically as a function of temperature. By utilizing the intensity ratio between the [sup 5]D4^[sup 7]F5 (Tb[sup 3+]) and [sup 5]D0^[sup 7]F2 (Eu[sup 3+]) transitions in the range 11-373 K, we demonstrate the realization of a ratiometric luminescent thermometer with compound 2, operating in the range 11-373 K with a maximum relative sensitivity of 2.0% K[sup -1] at 373 K. These findings highlight the potential of cage-like silsesquioxanes as versatile materials for optical sensing-enabled applications. [ABSTRACT FROM AUTHOR]

The first Ni(ii)-based metallagermaniumsesquioxane cage compound [(PhGeO1.5)10(NiO)4(NaO0.5)2] presents a sandwich-like structure where two germsesquioxane cages are linked through an {NiO}4 core and exhibits slow dynamics of the magnetization. [ABSTRACT FROM AUTHOR]

The self-assembly synthesis of copper-sodium phenylsilsesquioxane in the presence of 1,1-bis(diphenylphosphino)methane (dppm) results in an unprecedented cage-like product: [(PhSiO1,5)6]2[CuO]4[NaO0.5]4[dppmO2]21. The most intriguing feature of the complex 1 is the presence of two oxidized dppm species that act as additional O-ligands for sodium ions. Two cyclic phenylsiloxanolate (PhSiO1,5)6 ligands coordinate in a sandwich manner with the copper(II)-containing layer of the cage. The structure of 1 was established by X-ray diffraction analysis. Complex 1 was shown to be a very good catalyst in the oxidation of alkanes and alcohols with hydrogen peroxide or tert-butyl hydroperoxide in acetonitrile solution. Thus, cyclohexane (CyH), was transformed into cyclohexyl hydroperoxide (CyOOH), which could be easily reduced by PPh3 to afford stable cyclohexanol with a yield of 26% (turnover number (TON) = 240) based on the starting cyclohexane. 1-Phenylethanol was oxidized by tert-butyl hydroperoxide to give acetophenone in an almost quantitative yield. The selectivity parameters of the oxidation of normal and branched alkanes led to the conclusion that the peroxides H2O2 and tert-BuOOH, under the action of compound (1), decompose to generate the radicals HO• and tert-BuO• which attack the C-H bonds of the substrate. [ABSTRACT FROM AUTHOR]

Unprecedented germanium-based sesquioxane exhibits an extremely high nuclearity (Cu42Ge24Na4) and unusual encapsulation features. The compound demonstrated a high catalytic activity in the oxidative amidation of alcohols, with cost-effective catalyst loading down to 400 ppm of copper, and in the oxidation of cyclohexane and other alkanes with H2O2 in acetonitrile in the presence of nitric acid. Selectivity parameters and the mode of dependence of initial cyclohexane oxidation rate on initial concentration of the hydrocarbon indicate that the reaction occurs with the participation of hydroxyl radicals and alkyl hydroperoxides are formed as the main primary product. Alcohols have been transformed into the corresponding ketones by the catalytic oxidation with tert-butyl hydroperoxide. [ABSTRACT FROM AUTHOR]

New luminescent cage-like tetranuclear silsesquioxanes [NEt 4 ][(Ph 4 Si 4 O 8 ) 2 (Tb 3 Eu)(NO 3 ) 4 (OH)(EtOH) 3 (H 2 O)]·4(EtOH) (1) and [NEt 4 ] 2 [(Ph 4 Si 4 O 8 ) 2 (Tb 2 Eu 2 )(NO 3 ) 6 (EtOH) 2 (MeCN) 2 ]·4(MeCN) (2) present a tunable thermosensitive Tb 3+ -to-Eu 3+ energy transfer driven by Tb 3+ and Eu 3+ emission and may be used as temperature sensors operating in the range 41-100 °C with excellent linearity ( R 2 = 0.9990) and repeatability (>95%). The thermometer performance was evidenced by the maximum relative sensitivity of 0.63% °C -1 achieved at 68 °C., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A new representative of an unusual family of metallagermaniumsesquioxanes, namely the heterometallic cagelike phenylgermsesquioxane (PhGeO 2 ) 12 Cu 2 Fe 5 (O)OH(PhGe) 2 O 5 (bipy) 2 (2), was synthesized and structurally characterized. Fe(III) ions of the complex are coordinated by oxa ligands: (i) cyclic (PhGeO 2 ) 12 and acyclic (Ph 2 Ge 2 O 5 ) germoxanolates and (ii) O 2- and (iii) HO - moieties. In turn, Cu(II) ions are coordinated by both oxa (germoxanolates) and aza ligands (2,2'-bipyridines). This "hetero-type" of ligation gives in sum an attractive pagoda-like molecular architecture of the complex 2. Product 2 showed a high catalytic activity in the oxidation of alkanes to the corresponding alkyl hydroperoxides (in yields up to 30%) and alcohols (in yields up to 100%) and in the oxidative formation of benzamides from alcohols (catalyst loading down to 0.4 mol % in Cu/Fe).

The synthesis, composition, and catalytic properties of a new family of hexanuclear Cu(II)-based phenylsilsesquioxanes are described here. Structural studies of 17 synthesized compounds revealed the general principle underlying their molecular topology: viz., a central metal oxide layer consisting of two Cu 3 trimers is coordinated by two cyclic [PhSiO 1.5 ] 5 siloxanolate ligands to form a skewed sandwich architecture with the composition [(PhSiO 1.5 ) 10 (CuO) 6 ] 2+ . In addition to this O ligation by the siloxanolate rings, two opposite copper ions are additionally coordinated by the nitrogen atoms of corresponding N ligand(s), such as 2,2'-bipyridine (compounds 1-9), 1,10-phenanthroline (compounds 10-13), mixed 1,10-phenanthroline/2,2'-bipyridine (compound 14), or bathophenanthroline (compounds 15-17). Finally, the charge balance is maintained by two HO - (compounds 1-7, 10-13, and 15-17), two H 3 CO - (compound 8), or two CH 3 COO - (compounds 9 and 14) anions. Complexes 1 and 10 exhibited a high activity in the oxidative amidation oxidation of alcohols. Compounds 1, 10, and 15 are very efficient homogeneous catalysts in the oxidation of alkanes and alcohols with peroxides.