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Multifunctional nano-heterostructures (NHSs) with controlled morphology are cardinal in many applications, but the understanding of the nanoscale colloidal chemistry is yet to be fulfilled. The stability of the involved crystalline phases in different solvents at mid- and high-temperatures and reaction kinetics considerably affect the nucleation and growth of the materials and their final architecture. The formation mechanism of manganese ferrite-based core-shell NHSs is herein investigated. The effects of the core size (8, 10, and 11 nm), the shell nature (cobalt ferrite and spinel iron oxide) and the polarity of the solvent (toluene and octanol) on the dissolution phenomena of manganese ferrite are also studied. Noteworthily, the combined use of bulk (powder X-ray diffraction, 57Fe Mössbauer spectroscopy, and DC magnetometry) and nanoscale techniques (HRTEM and STEM-EDX) provides new insights into the manganese ferrite dissolution phenomena, the colloidal stability in an organic environment, and the critical size below which dissolution is complete. Moreover, the dissolved manganese and iron ions react further, leading to an inverted core-shell in the mother liquor solution, paving the way to novel synthetic pathways in nanocrystal design. The MnFe2O4@CoFe2O4 core-shell heterostructures were also employed as heat mediators, exploiting the magnetic coupling between a hard (CoFe2O4) and a soft phase (MnFe2O4).

By combining ErIII and YbIII ions with 3,6-dithiophene-anilate (Th2An) and scorpionate hydrotris(pyrazol-1-yl)borate (HBpz3−) ligands new luminescent dinuclear complexes are obtained. The two materials formulated as [((HB(pz)3)2Yb)2(μ-th2An)]·4DCM·1.3H2O 1Yb and [((HB(pz)3)2Er)2(μ-th2An)]·4DCM·1.8H2O 1Er, respectively, have been structurally characterized by SC-XRD and PXRD studies. This study presents a comprehensive investigation of the photophysical properties of the Th2An ligand for the first time. Our findings reveal the crucial role of the thiophene anilate as an effective optical antenna, which sensitizes near-infrared (NIR)-emitting lanthanide ions, specifically ErIII and YbIII. The significant impact of vibrational quenching on the LnIII NIR emission efficiency has been also highlighted. [ABSTRACT FROM AUTHOR]

Novel heteroleptic anilate-based lanthanide MOFs (LnIII = Tb, Dy, Ho) have been obtained under hydrothermal conditions by the ancillary ligand synthetic strategy. These structurally isomorphous species contain octacoordinated LnIII ions with coordination polyhedra approaching an ideal D2d symmetry, best described by a distorted biaugmented trigonal prismatic C2v geometry. In the whole series, only the Dy-MOF exhibits SMM behaviour. [ABSTRACT FROM AUTHOR]

Dinuclear lanthanide complexes [((HB(pz)3)2Dy)2(μ-Th2An)] (1Dy) and [((HB(pz)3)2Dy)2(μ-ClCNAn)] (2Dy), based on the hydrotris(pyrazol-1-yl)borate (HBpz3−) scorpionate capping ligand and anilate (An2−) bridging linkers, namely homosubstituted dithiophene- and heterosubstituted chlorocyanoanilate, bearing electron-donating and withdrawing substituents at the 3,6-positions of the benzoquinone core, are reported. 1Dy shows an octacoordinated {N6O2} DyIII ion within a D4h distorted square antiprismatic coordination, an ideal geometry for Single-Molecule Magnet (SMM) behavior, given its oblate nature, whereas in 2Dy the octacoordinated DyIII ion adopts a D2d triangular dodecahedron geometry, while maintaining the same {N6O2} coordination sphere. Both complexes show field-induced single molecule magnet (SMM) behaviour, with tuning of the slow magnetic relaxation as a function of the nature of the substituents at the 3,6-positions of the anilate moiety. A comparison of the Arrhenius fitting parameters for 1Dy and 2Dy supports the hypothesis that square antiprismatic DyIII complexes, as 1Dy, exhibit higher energy barriers. This interpretation is supported by ab initio calculations that also shed light on the crucial role of intermolecular dipolar interactions. [ABSTRACT FROM AUTHOR]

A process based on the lixiviant properties of organic mixtures of dihalogen/S,S-ligands, N,N′-dimethyl-perhydrodiazepine-2,3-dithione (Me2dazdt) and tetraalkylthiuramdisulphide (Et4TDS) in the presence of diiodine, for gold recovery from the non-ferrous metal fraction of real shredded waste electric and electronic equipment (WEEE), is presented here. Selective dissolution of metals is achieved through a sequence of three steps where the oxidation of different kinds of metals is achieved by using: (1) refluxing water solutions of HCl 1:5 under Ar atmosphere (Sn, Zn, etc.); (2) water solutions of NH3/(NH4)2SO4 mixtures in the presence of H2O2 on the resting sample(Cu, Ag); and (3) acetone solutions of Me2dazdt or Et4TDS/I2 mixtures on the final residue (Au). Each step is followed by a further treatment for: (1) metal recovery, in the case of Au, Cu, Ag; and (2) inertization, in the case of heavy metals. As a whole, the process is very promising for effective recovery of gold and other valuable noble-metals and for using non harmful reagents in mild conditions.

Research has been conducted on the palladium(II) and platinum(II) dicationic dithiolenes. The synthesis and characterization of these compounds have been carried out based on their reactions with dithiolene metalates and the results are reported.

The study explores reactions of I (sub)2 with title ligands 1,3-dithiacyclohexane-2-thione (ptc) and 4,5-ethylenedithio-1,3-dithiole-2-thione (ttb) in CHCl (sub)3 solutions investigated by means of spectrophotometry. Density functional method has been applied to reproduce the structural features.

Infrared (IR) spectroscopy and X-ray crystallography were performed to characterize the structures and spectroscopic properties of novel nickel dithiolenes and other related complexes. The results revealed that (Ni(super II)(Pr(super i)(sub 2)timdt(super -))2) have a near-IR absorption at about 1000 nm and an exceptionally high extinction coefficient. It was also found to be highly stable in terms of its thermal and photochemical properties, indicating that nickel dithiolenes can serve as good near-IR dyes in Q-switching neodymium lasers that operate at 1064 nm.

The CH2Cl2/CH3Cn solution of the reagents in a 1:2 ebis: TCNQ molecular ratio was utilized to isolate dark-blue crystals of [2(ebis)2+.ebis].2(TCNQ)sub3sup2-]. The mixed-valence compound is a tetracation that is composed of one molecule of a neutral ligand, two dications with an Se-Se bridge and two anions. The molecules of the compound form a triad of negatively charged TCNQ molecules. The crystal structure of the mixed-valence compound is composed of homologous layers of cations and anions.

The compounds ((C5H8N2Se-)2)2+.2Br-, ((C5H8N2Se-)2)2+.2I-, ((C5H8N2Se-)2)2+.Cl-.I(super -)(sub 3), ((C5H10N2Se-)2)2+.Br-.IBr(super -)(sub 2), ((C5H7N2Se-)2)2+.I(super -)(sub 3).1/2I(super -)(sub 4) and ((C5H7N2Se-)2)2+.2I-.CH3CN containing dications and the -Se-Se- bridge are prepared. For all the cations, the bond length of Se-Se varies within 2.409 and 2.440 angstroms. The dicationic compounds are crystallographically analyzed.

The combination of a properly designed organic linker, 3,6-N-ditriazolyl-2,5-dihydroxy-1,4-benzoquinone (trz2An), with CoII ions results in a novel 3D ultramicroporous MOF with high CO2 uptake capacity and separation efficiency, with particular attention to CO2/N2 and CO2/CH4 gas mixtures. This material consists of 1D chains of octahedrally coordinated CoII ions linked through anilato ligands at the equatorial positions and triazole substituents from two neighbouring chains at the two axial positions. This leads to a 3D microporous structure with voids with an affinity for CO2 molecules and channels that enable the selective entry of CO2 but not of molecules with larger kinetic diameters such as N2 or CH4. Adsorption studies revealed that (i) the MOF presents a remarkable carbon dioxide uptake, above 20% in weight; (ii) CO2 adsorptive separation is successfully performed in CO2:N2 and CO2:CH4 gas mixtures, exhibiting high selectivity in a large operation range; (iii) regeneration is easily achieved under mild conditions. [ABSTRACT FROM AUTHOR]

Copper(II) halides coordinate with various polyfunctional sulfur-rich ligands to produce copper(II), copper(I) and mixed valence derivatives. Sulfur-rich donor, 1, 3-dithiolane-2-thione, gives only Cu(I) derivatives. Introduction of an additional CH(2) group in 1,3-dithiolane-2 thione ring leads to mixed valence derivatives. X-ray and EPR techniques are used for the analyses of structural and magnetic properties of these complexes.