Search results for "Alate"
showing 10 items of 695 documents
Supramolecular Design of Low-dimensional Carbon Nano-hybrids encoding a Polyoxometalate-bis-Pyrene Tweezer
2014
A novel bis-pyrene tweezer anchored on a rigid polyoxometalate scaffold fosters a unique interplay of hydrophobic and electrostatic supramolecular interactions, to shape carbon nanostructures (CNSs)-based extended architectures.
Synthesis and characterisation of a novel ferrimagnetic chain based on copper(II) and rhenium(IV)
2019
Abstract A novel one-dimensional copper(II)–rhenium(IV) coordination polymer of formula {[ReIVBr4(μ-ox)CuII(pyim)2]·MeCN}n (1) [ox = oxalate anion, pyim = 2-(2′-pyridyl)imidazole] has been prepared and characterised. Powder X-ray diffraction measurements on a sample of 1 support the purity of the bulk sample, whereas single-crystal X-ray diffraction shows that 1 crystallises in the orthorhombic system with space group Pbca. The crystal structure of 1 is made up of [CuII(pyim)2]2+ cations and [ReBr4(ox)]2− anions linked through bridging bromide and oxalate groups, which generate alternating CuII and ReIV chains. Variable-temperature magnetic susceptibility measurements performed on 1 reveal …
Insertion of single-ion magnets based on mononuclear Co(II) complexes into ferromagnetic oxalate-based networks
2021
The 1 : 2 and 1 : 1 Co(ii) complexes of the L ligand (L = 6-(3,5-diamino-2,4,6-triazinyl)2,2'-bipyridine) with formulas [CoII(L)2](ClO4)2·0.5MeCN·Et2O (1) and [CoII(L)(CH3CN)2(H2O)](ClO4)2·MeCN (2) have been prepared. The structural and magnetic characterization of the two compounds shows that they contain octahedral high-spin Co(ii) and present a field-induced slow relaxation of the magnetization. 1 has been inserted into a bimetallic oxalate-based network leading to a novel achiral 3D compound of formula [CoII(L)2][MnIICrIII(ox)3]2·(solvate) (3) exhibiting ferromagnetic ordering below 4.6 K. EPR measurements suggest a weak magnetic coupling between the two sublattices.
Multifunctionality in hybrid magnetic materials based on bimetallic oxalate complexes.
2011
This tutorial review illustrates the design of multifunctional oxalate-based magnetic materials through the combination of the intrinsic magnetism of the metal–organic framework and the additional properties introduced by several organic/inorganic functional cations.
Evolution of the sp2 content and revealed multilayer growth of amorphous hydrogenated carbon (a-C:H) films on selected thermoplastic materials
2017
Amorphous hydrogenated carbon (a-C:H) films were gradually deposited on high-density polyethylene (HDPE), polyethylene terephthalate (PET) and polyoxymethylene (POM) via an indirect (f-type) and a direct (r-type) plasma-enhanced chemical vapor deposition (PECVD) process with acetylene plasma. The surface morphologies of the thicker r-depositions on the three different thermoplastics have been analyzed by atomic force microscopy (AFM) at varying micrometer scales. Absorbance spectroscopy has been used to characterize the optical properties of all coatings. Intrinsic stress release phenomena are revealed on thicker layers through the detection of characteristic surface corrugations. Based on …
Study of the defects in La3Ta0.5Ga5.5O14 single crystals
2016
Abstract Defects that are formed during crystal growth pose a serious obstacle for potential application of La 3 Ga 5.5 Ta 0.5 O 14 (LGT) as a laser or piezoelectric crystal. We have performed the study of the defects origin in LGT crystals grown in different atmospheres using optical, EPR and time-resolved luminescence characterization methods. The absorption bands detected in the transparency region at 290, 360 and 490 nm ( T =300 K) demonstrate different dependence on crystal annealing in vacuum and air. EPR analysis demonstrated that the defects responsible for these bands are non-paramagnetic. X-ray irradiation results in hole trapping by oxygen ions thus forming O − centers perturbed …
Field-induced slow relaxation of magnetisation in an anionic heterotetranuclear [ZnIIReIV3] system
2019
The compound (NBu4)4[ZnII{ReIVCl4(μ-ox)}3] (1) [NBu4+ = tetra-n-butylammonium cation and ox2− = oxalate dianion] is the first example of an oxalato-bridged ZnII system coordinated to a 5d metal ion that exhibits slow relaxation of magnetisation.
Nonlinear Disorder Mapping via Wave Mixing in poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, specifically periodically poled Lithium Tantalate with random mark-to space ratio.
Nonlinear Disorder Mapping via Three Wave Mixing in Poled Lithium Tantalate
2010
We introduce and test a simple approach for the characterization of domain distribution in bulk quadratic ferroelectric crystals, such as periodically poled Lithium Tantalate with random mark-to space ratio.
Heterogeneous photo-assisted catalytic hydration/dehydration reactions based on Keggin and Wells-Dawson type heteropolytungstates
2021
Polyoxometalates (POMs) are a wide class of metal-oxygen clusters that can be applied in acid and oxidation catalysis, medicine, electrochemistry, materials design, or models for self-assembling nanoscale systems as long as green and cheap photocatalysts. Heteropolyacids (HPAs) are a POM subclass extensively used as homogeneous photocatalysts for the oxidation of organic substrates. Dispersing HPAs onto solid supports with a high surface area increases their specific surface area and hence (photo)catalytic activity. This chapter reports the use of selected HPAs, heteropolytungstates, immobilized on different supports as heterogeneous photocatalysts.