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This work reports, for the first time, an efficient and fast microwave-based method for the preparation of CuO aerogels. For that, CuCl 2 , glyoxylic acid and sodium carbonate are employed as reagents. Different experimental conditions such as synthesis temperature, synthesis time and concentration of the precursor solution are investigated to design CuO aerogels with customizable nodular morphologies. The resulting aerogels exhibit well-defined three-dimensional structures and nodular sizes, and therefore, textural properties vary according to the experimental parameters applied in their synthesis.

This study considers the limitations of cobalt violet orthophosphate, Co 3 P 2 O 8 , in the ceramic industry due to its large amount of cobalt. Mg x Co 3-x P 2 O 8 (0 ≤ x ≤ 3) solid solutions with the stable Co 3 P 2 O 8 structure were synthesised via the chemical coprecipitation method. The formation of solid solutions between the isostructural Co 3 P 2 O 8 and Mg 3 P 2 O 8 compounds decreased the toxically large amount of cobalt in this inorganic pigment and increased the melting point to a temperature higher than 1200 °C when x ≥ 1.5. Co 3 P 2 O 8 melted at 1160 °C, and compositions with x ≥ 1.5 were stable between 800 and 1200 °C. The substitution of Co(II) with Mg(II) decreased the toxicity of these materials and decreased their price; hence, the interest of these materials for the ceramic industry is greater. An interesting purple colour with a* = 31.6 and b* = -24.2 was obtained from a powdered Mg 2.5 Co 0.5 P 2 O 8 composition fired at 1200 °C. It considerably reduced the amount of cobalt, thus improving the colour of the Co 3 P 2 O 8 pigment (a* = 16.2 and b* = -20.1 at 1000 °C). Co 3 P 2 O 8 is classified as an inorganic pigment (DCMA-8-11-1), and the solid solutions prepared were also inorganic pigments when unglazed. When introducing 3% of the sample (pigment) together with enamel, spreading the mixture on a ceramic support and calcining the whole in an electric oven, a colour change from violet to blue was observed due to the change in the local environment of Co(II), which could be seen in the UVV spectra of the glazed samples with the displacement of the bands towards higher wavelengths and with the appearance of a new band assigned to tetrahedral Co(II). This blue colour was also obtained with Co 2 SiO 4 , MgCoSiO 4 or Co 3 P 2 O 8 pigments containing a greater amount of cobalt.

The development of synthesis methods to access advanced materials, such as magnetic materials that combine multimetallic phosphide phases, remains a worthy research challenge. The most widely used strategies for the synthesis of magnetic transition metal phosphides (TMPs) are organometallic approaches. In this study, Fe-containing homometallic dendrimers and Fe/Co-containing heterometallic dendrimers were used to synthesize magnetic materials containing multimetallic phosphide phases. The crystalline nature of the nearly aggregated particles was indicated for both designed magnetic samples. In contrast to heterometallic samples, homometallic samples showed dendritic effects on their magnetic properties. Specifically, saturation magnetization ( M s ) and coercivity ( H c ) decrease as dendritic generation increases. Incorporating cobalt into the homometallic dendrimers to prepare the heterometallic dendrimers markedly increases the magnetic properties of the magnetic materials from 60 to 75 emu/g. Ferromagnetism in homometallic and heterometallic particles shows different responses to temperature changes. For example, heterometallic samples were less sensitive to temperature changes due to the presence of Co 2 P in contrast to the homometallic ones, which show an abrupt change in their slopes at a temperature close to 209 K, which appears to be related to the Fe 2 P ratios. This study presents dendrimers as a new type of precursor for the assembly of magnetic materials containing a mixture of iron- and cobalt-phosphides phases with tunable magnetism, and provides an opportunity to understand magnetism in such materials.

The integration of 2D graphene sheets into a porous and macroscopic structure is extremely attractive for application in several electrochemical fields. In this regard, for the first time, the synthesis of 3D graphene aerogels is reported by using a rapid, easy, cost-effective, and scalable at industrial level methodology. These aerogels integrate the intrinsic properties of graphene with a high pore volume. To achieve this ultraporous graphene network, resorcinol/formaldehyde polymer with controllable porosity is employed as a binder and a cross-linker material, and a graphene oxide solution provides the graphene building blocks. Two series of materials with and without catalyst for resorcinol/formaldehyde reaction and with different synthesis conditions and graphene contents are studied. The resulting graphene aerogels present low density, large macroporosity, and electrical conductivity values as high as 852 S m -1 , with 97.58% of porosity, which is the highest value of electrical conductivity reported so far in the literature for ultralight-weight graphene aerogels., (© 2021 The Authors. Small published by Wiley-VCH GmbH.)

In spite of the enormous promise that polymeric carbon nitride (PCN) materials hold for various applications, the fabrication of high-quality, binder-free PCN films and electrodes has been a largely elusive goal to date. Here, we tackle this challenge by devising, for the first time, a water-based sol-gel approach that enables facile preparation of thin films based on poly(heptazine imide) (PHI), a polymer belonging to the PCN family. The sol-gel process capitalizes on the use of a water-soluble PHI precursor that allows formation of a non-covalent hydrogel. The hydrogel can be deposited on conductive substrates, resulting in formation of mechanically stable polymeric thin layers. The resulting photoanodes exhibit unprecedented photoelectrochemical (PEC) performance in alcohol reforming and highly selective (∼100 %) conversions with very high photocurrents (>0.25 mA cm -2 under 2 sun) down to <0 V vs. RHE. This enables even effective PEC operation under zero-bias conditions and represents the very first example of a 'soft matter'-based PEC system capable of bias-free photoreforming. The robust binder-free films derived from sol-gel processing of water-soluble PCN thus constitute a new paradigm for high-performance 'soft matter' photoelectrocatalytic systems and pave the way for further applications in which high-quality PCN films are required., (© 2021 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

A series of tri- and tetrasubstituted spiro-oxaphosphetanes stabilized by ortho -benzamide ( o BA) and N -methyl ortho -benzamide (M o BA) ligands have been synthesized by the reaction of C α ,C ortho -dilithiated phosphazenes with aldehydes and ketones. They include enantiopure products and the first example of an isolated oxaphosphetane having a phenyl substituent at C3 of the ring. Kinetic studies of their thermal decomposition showed that the process takes place irreversibly through a polar transition state (ρ = -0.22) under the influence of electronic, [1,2], [1,3] steric, and solvent effects, with C3/P-[1,2] interactions as the largest contribution to Δ G ⧧ of olefination. Inversion of the phosphorus configuration through stereomutation has been observed in a number of cases. DFT calculations showed that o BA derivatives olefinated through the isolated (N, O)(Ph, C 6 H 4 , C) oxaphosphetanes (Channel A), whereas M o BA compounds decomposed faster via the isomer (C 6 H 4 , O)(C, N, Ph) formed by P-stereomutation involving a M B2 permutational mechanism (Channel B). The energy barrier of P-isomerization is lower than that of olefination. Fragmentation takes place in a concerted asynchronous reaction. The thermal stability of oxaphosphetanes is determined by strong C3/P-[1,2] interactions destabilizing the transition state of olefination. The effect of charge distribution and C3/C4-[1,2] and C4/P-[1,3] steric and solvent interactions on Δ G ⧧ was also evaluated.

A coordination polymer formulated as [Sr(H 2 BTEC)(H 2 O)] n (H 4 BTEC = benzene-1,2,4,5-tetra-carb-oxy-lic acid, C 10 H 6 O 8 ), was synthesized hydro-thermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO 8 ] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxyl-ate groups of the ligand, resulting in a double-layered network extending parallel to (100). O-H⋯O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carb-oxy-lic OH functions was found to be disordered over two sets of sites with half-occupancy., (© Mokhtari et al. 2020.)

In the present work, we synthesized Co x Zn 1-x Fe 2 O 4 spinel ferrite nanoparticles (x= 0, 0.1, 0.2, 0.3 and 0.4) via the precipitation and hydrothermal-joint method. Structural parameters were cross-verified using X-ray powder diffraction (XRPD) and electron microscopy-based techniques. The magnetic parameters were determined by means of vibrating sample magnetometry. The as-synthesized Co x Zn 1-x Fe 2 O 4 nanoparticles exhibit high phase purity with a single-phase cubic spinel-type structure of Zn-ferrite. The microstructural parameters of the samples were estimated by XRD line profile analysis using the Williamson-Hall approach. The calculated grain sizes from XRPD analysis for the synthesized samples ranged from 8.3 to 11.4 nm. The electron microscopy analysis revealed that the constituents of all powder samples are spherical nanoparticles with proportions highly dependent on the Co doping ratio. The Co x Zn 1-x Fe 2 O 4 spinel ferrite system exhibits paramagnetic, superparamagnetic and weak ferromagnetic behavior at room temperature depending on the Co 2+ doping ratio, while ferromagnetic ordering with a clear hysteresis loop is observed at low temperatures (5K). We concluded that replacing Zn 2+ ions with Co 2+ ions changes both the structural and magnetic properties of ZnFe 2 O 4 nanoparticles., Competing Interests: The authors declare no conflict of interest.

A variety of half-sandwich iron(ii) complexes with diprotic acyclic diaminocarbene ligands (pADCs) have been obtained by reaction of the cationic complexes [Fe(Cp)(CO) 2 (CNR)] + and [Fe(Cp)(CO)(CNR) 2 ] + with methylamine, and their acid-base behaviour was studied, revealing an easy reversible deprotonation reaction of both N-H moieties of the carbene ligands. The deprotonation process is frequently followed by a nucleophilic attack of the nitrogen atom on a vicinal carbonyl or isocyanide ligand, affording the corresponding metallacycles. Metalation of one or two N-H groups of the pADC ligands can be accomplished by reaction of the carbene complexes with either [AuCl(PPh 3 )] or [Ru(p-cym)Cl 2 ] 2 in the presence of KOH or LiHMDS as deprotonating agents. A number of Fe(ii)/Au(i) and Fe(ii)/Ru(ii) heterometallic complexes have been prepared in this way, some of them formally containing unique metalla-N-heterocyclic carbene ligands.

Two new mercury(II) coordination supramolecular compounds (CSCs) (1D and 0D), [Hg(L)(I) 2 ] n (1) and [Hg 2 (L') 2 (SCN) 2 ]·2H 2 O (2) (L=2-amino-4-methylpyridine and L'=2,6-pyridinedicarboxlic acid), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or nano-sized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by field emission scanning electron microscope (FESEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on compounds 1 and 2 show that Hg 2+ ions are 4-coordinated and 5-coordinated, respectively. Topological analysis shows that the compound 1 and 2 have 2C1, sql net. The thermal stability of compounds 1 and 2 in bulk and nano-size has been studied by thermal gravimetric (TG), differential thermal analyses (DTA) for 1 and differential scanning calorimetry (DSC) for 2, respectively. Also, by changing counter ions were obtained various structures 1 and 2 (1D and 0D, respectively). The role of different parameters like power of ultrasound irradiation, reaction time and temperature on the growth and morphology of the nano-structures are studied. Results suggest that increasing power ultrasound irradiation and temperature together with reducing reaction time and concentration of initial reagents leads to a decrease in particle size., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Ti 2 O(PO 4 ) 2 ·2H 2 O (1), a three-dimensional titanium oxophosphate, thermally transforms to Ti 2 O(PO 4 ) 2 (2), a fibrous novel compound. The crystal structure of 2 was solved ab initio using powder X-ray diffraction data (triclinic, P1[combining macron], a = 5.0843(1) Å, b = 8.6121(2) Å, c = 9.6766(2) Å, α = 74.501(2)°, β = 76.146(2)°, γ = 74.488(3)°, Z = 2). Compound 2, containing both 4- and 6-fold coordinated titanium atoms, shows measurable thermally activated nitrogen-adsorption. To our knowledge, the process described here constitutes the first example of nitrogen-fixation by an inorganic material at above-ambient temperature.

Nanoparticles of two new coordination compounds, [Hg 2 (L) 2 (Br) 4 ] n (1) and [Hg(L')(SCN) 2 ] (2), (L=2-amino-4-methylpyridine, L'=2,6-pyridinedicarboxlic acid), have been synthesized by use of a sonochemical process and characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy(FESEM), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) spectroscopy and elemental analyses. The single crystal X-ray data of compounds 1 and 2 imply that the Hg(II) ions are four and five coordinated, respectively. Topological analysis shows that 1D and 0D coordination networks of 1 and 2 can be classified as underlying nets of topological types 2C1 and 1,3M4-1, respectively. The thermal stability of compounds has been studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The role of temperature, reaction time and ultrasound irradiation power on the size and morphology of "nano-structures" 1 and 2, has been investigated. Results claim that an increase of temperature, sonication power and decrease in reaction time leads to a decrease of particle size., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Metal-organic frameworks assembled from Ln(III), Li(I) and rigid dicarboxylate ligand, formulated as [LiLn(BDC)₂(H₂O)·2(H₂O)] (MS1-6,7a) and [LiTb(BDC)₂] (MS7b) (Ln = Tb, Dy, Ho, Er, Yb, Y 0.96 Eu 0.04 , Y 0.93 Tb 0.07 , and H₂BDC = terephthalic acid), were obtained under hydrothermal conditions. The isostructural MS1-6 crystallize in monoclinic P 2₁/c space group. While, in the case of Tb 3+ a mixture of at least two phases was obtained, the former one (MS7a) and a new monoclinic C 2/c phase (MS7b). All compounds have been studied by single-crystal and powder X-ray diffraction, thermal analyses (TGA), vibrational spectroscopy (FTIR), and scanning electron microscopy (SEM-EDX). The structures of MS1-6 and MS7a are built up of inorganic-organic hybrid chains. These chains constructed from unusual four-membered rings, are formed by edge- and vertex-shared {LnO₈} and {LiO₄} polyhedra through oxygen atoms O3 (vertex) and O6-O7 (edge). Each chain is cross-linked to six neighboring chains through six terephthalate bridges. While, the structure of MS7b is constructed from double inorganic chains, and each chain is, in turn, related symmetrically to the adjacent one through the c glide plane. These chains are formed by infinitely alternating {LiO₄} and {TbO₈} polyhedra through (O2-O3) edges to create Tb⁻O⁻Li connectivity along the c -axis. Both MS1-6,7a and MS7b structures possess a 3D framework with 1D trigonal channels running along the a and c axes, containing water molecules and anhydrous, respectively. Topological studies revealed that MS1-6 and MS7a have a new 2-nodal 3,10-c net, while MS7b generates a 3D net with unusual β-Sn topology. The photoluminescence properties Eu- and Tb-doped compounds (MS5-6) are also investigated, exhibiting strong red and green light emissions, respectively, which are attributed to the efficient energy transfer process from the BDC ligand to Eu 3+ and Tb 3+ .

In the mol-ecule of title compound, C15H20O6, also known as cynarinin A, the cyclo-pentane ring having twist conformation and a γ-lactone ring assuming an envelope conformation are trans- and cis-fused, respectively, to a cyclo-heptane ring adopting a twist-chair conformation. In the crystal, O-H⋯O hydrogen bonds link neighbouring mol-ecules, forming a three-dimensional network. Theoretical calculations of the mol-ecular structure using the CNDO approximation and MOPAC PM3 geometry optimization are in satisfactory agreement with the results of the X-ray structure analysis.

The crystal structure of the β-polymorph of ZnMoO4 was re-determined on the basis of single-crystal X-ray diffraction data. In comparison with previous powder X-ray diffraction studies [Katikaneani & Arunachalam (2005 ▸). Eur. J. Inorg. Chem. pp. 3080-3087; Cavalcante et al. (2013 ▸). Polyhedron, 54, 13-25], all atoms were refined with anisotropic displacement parameters, leading to a higher precision with respect to bond lengths and angles. β-ZnMoO4 adopts the wolframite structure type and is composed of distorted ZnO6 and MoO6 octa-hedra, both with point group symmetry 2. The distortion of the octa-hedra is reflected by variation of bond lengths and angles from 2.002 (3)-2.274 (4) Å, 80.63 (11)-108.8 (2)° for equatorial and 158.4 (2)- 162.81 (14)° for axial angles (ZnO6), and of 1.769 (3)-2.171 (3) Å, 73.39 (16)-104.7 (2), 150.8 (2)-164.89 (15)° (MoO6), respectively. In the crystal structure, the same type of MO6 octa-hedra share edges to built up zigzag chains extending parallel to [001]. The two types of chains are condensed by common vertices into a framework structure. The crystal structure can alternatively be described as derived from a distorted hexa-gonally closed packed arrangement of the O atoms, with Zn and Mo in half of the octa-hedral voids.

In this study, MgxCu3-xV2O8 (0 ≤ x ≤ 3) and MgyCu2-yV2O7 (0 ≤ y ≤ 2) compositions were synthesized by the chemical coprecipitation method and characterized by X-ray diffraction, UV-vis-NIR spectroscopy and CIE L* a* b* parameters measurements. Melting points of compounds Cu3V2O8 and Cu2V2O7 are 780°C and 790°C, respectively. The addition of small amounts of Mg (II), MgxCu3-xV2O8 (x < 1.0) and MgyCu2-yV2O7 (y < 0.5) fused compositions, was not sufficient to stabilize structures at 800°C. For the Mg2CuV2O8 (x = 2.0) composition fired at 800°C, Mg (II) incorporated into the monoclinic Cu3V2O8 structure stabilizes this crystalline phase. At 1000°C, orthorhombic Mg3V2O8 structure from this composition was obtained. Solid solutions with orthorhombic symmetry were detected from the prepared compositions fired at 1000°C when 1.0 ≤ x ≤ 3.0. The difference of coloration of Cu, Mg vanadates might be explained by the presence of a strong charge transfer band in visible spectra.

A novel set-up has been designed and used for synchrotron radiation X-ray high-resolution powder diffraction (SR-HRPD) in transmission geometry (spinning capillary) for in situ solid-gas reactions and processes in an isobaric and isothermal environment. The pressure and temperature of the sample are controlled from 10(-3) to 1000 mbar and from 80 to 1000 K, respectively. To test the capacities of this novel experimental set-up, structure deformation in the porous material zeolitic imidazole framework (ZIF-8) by gas adsorption at cryogenic temperature has been studied under isothermal and isobaric conditions. Direct structure deformations by the adsorption of Ar and N2 gases have been observed in situ, demonstrating that this set-up is perfectly suitable for direct structural analysis under in operando conditions. The presented results prove the feasibility of this novel experimental station for the characterization in real time of solid-gas reactions and other solid-gas processes by SR-HRPD.

Zinc nitrate hexahydrate, Zn(NO3)2 x 6H2O was used as a precursor with urea NH2CONH2 to prepare hydrozincite Zn5(CO3)2(OH)6 powder using hydrothermal method for 8 h at 90 degrees C. Zinc oxide (ZnO) nanoparticles (NPs) were prepared by thermal annealing of hydrozincite powder at different annealing temperatures, i.e., 350, 550 750 and 950 degrees C in air for 2 h. The resulting materials were characterized by X-ray diffraction, scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The optical properties of the products were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy and photoluminescence (PL) spectra. It was found that the particle size increased from - 33 to 250 nm with increasing in the annealing temperatures. FTIR results showed that the standard peaks of zinc oxide were presented at 428.17 and 532.32 cm(-1). Thermal analysis study showed that the primary weight loss starts at - 93 degrees C is due to solvent evaporation. The secondary weight loss, observed at - 378 degrees C, is due to phase transition from hydrated zinc oxide to zinc oxide. The band gaps of the products were in the range - 3.26-3.30 eV. The PL spectrum showed that the as-synthesized ZnO nanoparticles had UV (381 nm) and green (537 nm) emissions.

Cadmium sulfide (CdS) nanowires with uniform diameter were prepared by the solvothermal method using ethylenediamine (en) as solvent. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scan electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). It was found that the products are hexagonal crystals of CdS nanowires with diameter of 28 nm and length up to several micrometres. Selected area electron diffraction (SAED) and high resolution TEM (HRTEM) studies indicate the single-crystalline nature of CdS nanowires with an oriented growth along the c-axis direction. The absorption spectrum of the as-prepared CdS nanowires shows an absorption peak of around 485 nm. These CdS nanowires exhibit bright photoluminescence (PL) with two distinct emission bands at 502 nm and 696 nm.

Two-dimensional zinc phosphate NH4Zn2(PO4)(HPO4) (), via ammonia vapor interaction at room temperature, transforms to a one-dimensional novel compound NH4Zn(NH3)PO4 (). By ammonia desorption (in air at room temperature) transforms to NH4ZnPO4 () with a well-known ABW-zeolitic topology. The crystal structure of was solved ab initio using synchrotron powder X-ray diffraction data (monoclinic, P21/a, a = 16.5227(2) Å, b = 6.21780(8) Å, c = 5.24317(6) Å, β = 91.000(2)°, Z = 4). The structures of three compounds include extra-framework ammonium cations to the 4-fold coordinated zinc (ZnO4 tetrahedra for and , and ZnO3N tetrahedra for ) and phosphorus (PO4 tetrahedra) with bi-, mono- or three-dimensional linkages, respectively for , or . To our knowledge, the process described here constitutes the first example of dimensionality change in the solid phase promoted by a solid-gas interaction at room temperature in metal phosphates.

A variety of λ(5)-phosphole derivatives bearing up to three distinct peripheral functionalities have been prepared by regiospecific [3+2] cycloaddition reactions of the diphosphinoketenimine (PPh2)2C=C=NtBu (1) with electron-poor alkenes. Selective derivatization of the exocyclic functional groups, including formation of dimetallic complexes with a phosphole core, was subsequently accomplished.

A novel metal-organic framework assembled from Y(iii), Li(i), and terephthalate ligand, formulated as [LiY(BDC)2(H2O)·2(H2O)] (1) (H2BDC = terephthalic acid), has been obtained as single phase under hydrothermal conditions. The crystal structure was solved by single-crystal X-ray diffraction and the bulk was characterized by powder X-ray diffraction (PXRD), thermal analyses (TG-MS and DSC), vibrational spectroscopy (FTIR), scanning/transmission electron microscopy (SEM-EDX, TEM, SAED, and BF-STEM-EDX), and powder X-ray thermodiffractometry (HT-XRD). 1 crystallizes in monoclinic space group (P21/c, with a = 11.6415(7) Å, b = 16.0920(4) Å, c = 13.2243(8) Å and β = 132.23(1)°) and possesses a 3D framework with 1D trigonal channels running along the [101] direction containing water molecules. The structure of 1 is made up of unusual four-membered rings formed by edge- and vertex-shared {YO8} and {LiO4} polyhedra. The four-membered rings are isolated and connected to each other via carboxylate groups. HT-XRD reveals that 1 undergoes phase transformation upon the dehydration process which is a reversible process involving a spontaneous rehydration characterized by fast kinetics. Topological studies were also performed revealing that 1 has a new 2-nodal net.

By choosing the appropriate coupling reactions an isocyanide ligand in complex [Fe(Cp)(CO)(CNxylyl)2](+) is transformed into either a conventional NHC or into a metalla-N-heterocyclic carbene (MNHC), with the stretching frequencies of the CO and CNR ligands attached to the iron center demonstrating the stronger electron-donating ability of the metal-containing carbenes.

Ortho-directed lithiation of P,P-diphenylaminophosphazenes followed by electrophilic quench is described as an efficient process for synthesizing P-chiral ortho-functionalized derivatives in high yields and diastereoselectivities. The method allows the tunable preparation of structurally diverse enantiopure P-chiral compounds including phosphinic and phosphinothioic amides, phosphinic esters, phosphine oxides, and o-aminophosphines.

An exhaustive experimental study based on X-ray diffraction analysis, NMR, FTIR-ATR (attenuated total reflection), and Raman spectroscopy as well as theoretical calculations is reported in order to understand how the non-covalent intermolecular contacts are fundamental to explain structure-property relationships and allowing us to correlate a basic macroscopic property (i.e., the melting point, T(m)) with the structural variables of a family of enantiopure 1,4-dialkyl-1,2,4-triazolium salts. The effect of different structural vectors such as the ring size, the spatial disposition of the substituent, the substitution on the oxygen atom, the nature of the anion, or the N4 alkylation of the triazole on the intermolecular interactions of these chiral salts of a well-defined 3D structure is reported. The non-covalent intermolecular contacts mainly implicating the triazolium H3 proton are fundamental to explain structure-property relationships and, therefore, the physical properties of these new chiral salts, rather than simple anion-cation interactions. Overall, our findings highlight the importance of the specific supramolecular interactions for the understanding of the physical properties of triazolium salts and ionic liquids., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The experimentally observed stereomutation of spiro-1,2-oxaphosphetanes is shown by DFT calculations to proceed through successive M(B2) or M(B4) and M(B3) mechanisms involving two, four, and three Berry pseudorotations at phosphorus, respectively. Oxaphosphetane decomposition takes place in a single step via a polar transition state. The calculated activation parameters for this reaction are in good agreement with those determined experimentally.

The crystal structure of a binuclear Mn(III) complex of a scorpiand-like ligand (L) displays an unsupported single oxo bridging ligand with a Mn(III)-O-Mn(III) angle of 174.7°. Magnetic susceptibility measurements indicate strong antiferromagnetic coupling between the two metal centers. DFT calculations have been carried out to understand the magnetic behavior and to analyze the nature of the observed Jahn-Teller distortion. Paramagnetic (1)H NMR has been applied to rationalize the formation and magnetic features of the complexes formed in solution.

In the title compound, C(9)H(8)Br(2)O, the cyclo-pentene ring adopts an envelope conformation with the brominated C atom as the flap. In the crystal, mol-ecules are linked by strong O-H⋯O hydrogen bonds into zigzag C(4) chains along [010]. In addition, a C-H⋯π inter-action involving the benzene ring and the H atom attached to the hy-droxy-lated C atom is observed.

ortho-Lithiation of N,N-diisopropyl-P,P-diphenylphosphinothioic amide using n-BuLi in the presence of TMEDA in diethyl ether followed by electrophilic trapping is described as an efficient method for the synthesis of ortho-functionalised derivatives in high yields. The structural modification of the phosphinothioic amide includes C-X (X = P, S, Si, Sn, I) and C-C bond forming reactions with a large variety of electrophiles. Additional applications based on functional group transformations are also reported. They include imine formation, desulfurization and Suzuki cross-coupling reactions on selected compounds.

The title mol-ecule, C(26)H(22)N(4)S, is composed of three main parts, viz. a triphenyl-amine group is connected to a phenyl ring by a thio-semicarbazone moiety. The C= N double bond has an E conformation. The crystal packing is dominated by strong hydrogen bonds through the thio-semicarbazone moiety, with pairs of N-H⋯S hydrogen bonds linking the mol-ecules to form inversion dimers with an R(2) (2)(8) ring motif. An intra-molecular N-H⋯N hydrogen bond is also present, generating an S(5) ring motif. Although the structure contains four phenyl rings, π-π stacking inter-actions are not formed between them, probably due to the conformation adopted by the triphenyl-amine group. However, a weak π-π stacking inter-action is observed between the phenyl ring and the delocalized thio-semicarbazone moiety.

In the crystal structure of the title compound, C(9)H(10)ClN(3)S, the mol-ecules form chains parallel to [001] through N-H⋯S hydrogen bonds. In addition, weak inter-molecular N-H⋯Cl hydrogen bonds connect the chains, forming a two-dimensional network parallel to (001).

The title compound, C(25)H(35)N(5)S, has an approximately C-shaped conformation. The dihedral angle between the triazole and phenyl planes is 79.5 (2)°. The crystal structure consists of infinite chains parallel to the b axis, constructed by C-H⋯S hydrogen bonds between translation-related mol-ecules. Adjacent chains are linked via weak C-H⋯C inter-actions between the adamantyl and phenyl groups.

The mol-ecule of the title compound, C(24)H(32)N(4)OS, is a functionalized 1,3,4-oxadiazole-2-thione with substituted piperazine and adamantanyl substituents attached at the 3- and 5-positions, respectively, of the oxadiazole spacer with an approximately C-shaped conformation. In the crystal, mol-ecules form dimers via C-H⋯S inter-action. The piperazine ring has a chair conformation; the substituents S, methyl-ene C and adamantane C of the essentially planar oxadiazole ring are approximately in the same plane, with distances of -0.046 (2), -0.085 (5) and 0.003 (4) Å, respectively. The dihedral angle between the planes of the phenyl and oxadiazole rings is 31.3 (3)°.

The title mol-ecule, C(17)H(20)N(2)O, is a functionalized hydrazine with benzoyl and adamantyl substituents attached to the two hydrazine N atoms. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains propagating along the a-axis direction. There are also C-H⋯O, C-H⋯N and C-H⋯π inter-actions present within the chains.

The successive coupling of an alkoxy(aryl/heteroaryl)carbene complex of chromium with either a ketone or an imide lithium enolate and then a 3-substituted (H, TMS, PhCH(2), PhCH(2)CH(2), Me) propargylic organomagnesium reagent has afforded novel hydroxy-substituted bicyclic [4.3.0]-γ-alkylidene-2-butenolides with three modular points that has allowed the efficient introduction of molecular complexity, including a homopropargylic alcohol core. The selective formation of these five- or six-component heterobicyclisation products is the result of the regioselective integration of the Grignard reagent as a propargyl fragment followed by a cascade CO/alkyne/CO insertion, ketene trapping and elimination sequence. By using lithium enolates of chiral N-acetyl-2-oxazolidinones and the corresponding propargylic organocerium reagents, both enantiomers of these bicyclic heterocycles were efficiently prepared with very high enantiomeric purity. Architecturally, these fused bicyclic butenolides are characterised by a highly unsaturated and oxygenated core and they exhibit strong blue fluorescence in solution., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The asymmetric unit of the title compound, [RhCl(2)(C(10)H(8)N(2))(2)]ClO(4), consists of one unit of the cationic complex [RhCl(2)(bipy)(2)](+) and one uncoordinated perchlorate anion. The Rh(III) atom is coordinated by four N atoms from two bipyridyl ligands and two Cl atoms, forming a distorted octa-hedral environment. The Cl ligands are cis. Two intramolecular C-H⋯Cl hydrogen bonds occur in the cationic complex . In the crystal, mol-ecules are linked together by a hydrogen-bond network involving the H atoms of bipyridyl rings and perchlorate anions. An O atom of the perchlorate anion is disordered over two sites, with an occupancy-factor ratio of 0.78 (3):0.22 (3).

The mol-ecule of the title compound, C(12)H(15)N(3)O(2)S, which belongs to the family of thio-semicarbazones, containing an acid group, adopts a semi-closed conformation with an intramolecular N-H⋯N hydrogen bond. In the crystal, molecules are linked by strong N-H⋯O and O-H⋯S hydrogen bonds between the acid group and thiosemicarbazone unit, with one additional intermolecular hydrogen C-H⋯O interaction. These three interactions form R(2) (2)(8) and a R(2) (1)(7) rings and the molecules related by the c-glide plane are linked into a zigzag chain along [001].

In the crystal structure of the title compound, C(11)H(13)N(3)S, mol-ecules form centrosymmetric synthons with an R(2) (2)(8) graph-set motif, linked by pairs of N-H⋯S hydrogen bonds. The synthons are connected through further N-H⋯S hydrogen bonds, extending the packing to form a two-dimensional network lying parallel to (001). In addition, C-H⋯π inter-actions are observed.

In the title compound, C(13)H(12)O, the cyclo-pentene ring fused with the naphthalene group adopts an envelope conformation. The cyclo-pentene torsion angle, with the fusion bond at the centre, has a magnitude of 1.16 (16)°. In the crystal, neigh-bouring mol-ecules are connected through O-H⋯O hydrogen bonds into an R(4) (4)(8) ring motif. The crystal packing also features weak π-π stacking inter-actions [centroid-centroid distance = 3.8981 (8) Å] and C-H⋯π inter-actions.

In the title compound, C(9)H(8)BrNO, the non-H-atom framework is essentially planar, with a maximum deviation of 0.087 (3) Å. In the crystal, mol-ecules are inter-connected into a three-dimensional network by C-H⋯O and N-H⋯O hydrogen bonds. In addition, C-H⋯π inter-actions and a π-π stacking inter-action, with a centroid-centroid distance of 3.5535 (19) Å, are also observed.

Two series of isoreticular chiral metal-organic frameworks assembled from Ln(III) (Ln = Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb), Na(I), and chiral flexible-achiral rigid dicarboxylate ligands, formulated as [NaLn(Tart)(BDC)(H(2)O)(2)] (S1) and [NaLn(Tart)(biBDC)(H(2)O)(2)] (S2) (H(2)Tart = tartaric acid; H(2)BDC = terephthalic acid; H(2)biBDC = biphenyl-4,4'-dicarboxylic acid), were obtained as single phases under hydrothermal conditions. The compounds have been studied by single-crystal and powder X-ray diffraction, thermal analyses (TG-MS and DSC), vibrational spectroscopy (FTIR), scanning electron microscopy (SEM-EDX), elemental analysis, and X-ray thermodiffractometry. The catalytic activity has been also investigated. The photoluminescence properties of selected compounds have been investigated, exhibiting room temperature tunable UV-vis-IR light emission.

In the title mol-ecule, C(23)H(24)F(2)N(3)O(2)P, the P atom is in a distorted tetra-hedral P(=O)(N)(N)(2) environment, with the bond angles around the P atom in the range 106.78 (11)-114.10 (13)°. The phosphoryl and carbonyl groups, which are separated by an N atom, adopt an anti orientation relative to each other. In the C(=O)NHP(=O) fragment, the P-N bond is longer [1.683 (2) Å] and the O-P-N angle is smaller [106.78 (11)°] than the other P-N bonds [1.613 (2) and 1.632 (2) Å] and O-P-N bond angles [114.10 (13) and 110.83 (12)°], respectively. The N atoms have sp(2) character. In the crystal, pairs of P=O⋯H-N hydrogen bonds form inversion dimers with R(2) (2)(8) ring motifs.

Two new trinuclear copper(II) complexes, [Cu(3)(μ(3)-OH)(daat)(Hdat)(2)(ClO(4))(2)(H(2)O)(3)](ClO(4))(2)·2H(2)O (1) and [Cu(3)(μ(3)-OH)(aaat)(3)(H(2)O)(3)](ClO(4))(2)·3H(2)O (2) (daat = 3,5-diacetylamino-1,2,4-triazolate, Hdat = 3,5-diamino-1,2,4-triazole, and aaat = 3-acetylamino-5-amino-1,2,4-triazolate), have been prepared from 1,2,4-triazole derivatives and structurally characterized by X-ray crystallography. The structures of 1 and 2 consist of cationic trinuclear copper(II) complexes with a Cu(3)OH core held by three N,N-triazole bridges between each pair of copper(II) atoms. The copper atoms are five-coordinate with distorted square-pyramidal geometries. The magnetic properties of 1 and 2 and those of five other related 1,2,4-triazolato tricopper(II) complexes with the same triangular structure (3-7) (whose crystal structures were already reported) have been investigated in the temperature range of 1.9-300 K. The formulas of 3-7 are [Cu(3)(μ(3)-OH)(aaat)(3)(H(2)O)(3)](NO(3))(2)·H(2)O (3), {[Cu(3)(μ(3)-OH)(aat)(3)(μ(3)-SO(4))]·6H(2)O}(n) (4), and [Cu(3)(μ(3)-OH)(aat)(3)A(H(2)O)(2)]A·xH(2)O [A = NO(3)(-) (5), CF(3)SO(3)(-) (6), or ClO(4)(-) (7); x = 0 or 2] (aat =3-acetylamino-1,2,4-triazolate). The magnetic and electron paramagnetic resonance (EPR) data have been analyzed by using the following isotropic and antisymmetric exchange Hamiltonian: H = -J[S(1)S(2) + S(2)S(3)] - j[S(1)S(3)] + G[S(1) × S(2) + S(2) × S(3) + S(1) × S(3)]. 1-7 exhibit strong antiferromagnetic coupling (values for both -J and -j in the range of 210-142 cm(-1)) and antisymmetric exchange (G varying from to 27 to 36 cm(-1)). At low temperatures, their EPR spectra display high-field (g < 2.0) signals indicating that the triangles present symmetry lower than equilateral and that the antisymmetric exchange is operative. A magneto-structural study showing a lineal correlation between the Cu-O-Cu angle of the Cu(3)OH core and the isotropic exchange parameters (J and j) has been conducted. Moreover, a model based on Moriya's theory that allows the prediction of the occurrence of antisymmetric exchange in the tricopper(II) triangles, via analysis of the overlap between the ground and excited states of the local Cu(II) ions, has been proposed. In addition, analytical expressions for evaluating both the isotropic and antisymmetric exchange parameters from the experimental magnetic susceptibility data of triangular complexes with local spins (S) of (1)/(2), (3)/(2), or (5)/(2) have been purposely derived. Finally, the magnetic and EPR results of this work are discussed and compared with those of other tricopper(II) triangles reported in the literature.

The P atom in the title mol-ecule, C(24)H(28)N(3)O(2)P, is in a distorted tetra-hedral P(=O)(N)(N)(2) environment. The phosphoryl group and the NH unit adopt a syn orientation with respect to each other and the N atoms have sp(2) character. The P-N bonds in the P(O)[N(CH(3))(CH(2)C(6)H(5))](2) unit are shorter than the P-N bond in the C(=O)NHP(=O) fragment. An intra-molecular C-H⋯O hydrogen bond occurs. In the crystal, pairs of P=O⋯H-N hydrogen bonds form centrosymmetric dimers. C-H⋯O contacts are also observed. Four C atoms of two benzene rings are disordered over two alternative sites with an occupancy ratio of 0.523 (12):0.427 (12).

The synthesis and characterisation of a tridentate ligand containing two diphenylphosphinic amide side-arms connected through the ortho position to a phenylphosphine oxide moiety and the 1:1 and 2:1 complexes formed with yttrium nitrate are reported for the first time. The free ligand (R(P1)*,S(P3)*)-11 is obtained diastereoselectively by reaction of ortho-lithiated N,N-diisopropyl-P,P-diphenylphosphinic amide with phenylphosphonic dichloride. Complexes [Y((R(P1)*,S(P3)*)-11)(NO(3))(3)] and [Y((R(P1)*,S(P3)*)-11)(2)(NO(3))](NO(3))(2) were isolated by mixing ligand 11 with Y(NO(3))(3)·6H(2)O in acetonitrile at room temperature in a ligand to metal molar ratio of 1:1 and 2:1, respectively. The 1:1 derivative is the product of thermodynamic control when a molar ratio of ligand to yttrium salt of 1:1 is used. The new compounds have been characterised both as the solid (X-ray diffraction) and in solution (multinuclear magnetic resonance). In both yttrium complexes the ligand acts as a tridentate chelate. The arrangement of the two ligands in the 2:1 complex affords a pseudo-meso structure. Tridentate chelation of yttrium(III) in both complexes is retained in solution as evidenced by (89)Y NMR data obtained via(31)P,(89)Y-HMQC, and (89)Y,(31)P-DEPT experiments. The investigation of the solution behaviour of the Y(III) complexes through PGSE NMR diffusion measurements showed that average structures in agreement with the 1:1 and 1:2 stoichiometries are retained in acetonitrile., (This journal is © The Royal Society of Chemistry 2011)

In the title compound, C(19)H(30)N(3)O(2)P, the central P atom has a distorted tetra-hedral configuration. The N atoms in both cyclo-hexyl-amide moieties exhibit a slight deviation [0.32 (7) and 0.44 (6) Å] from planarity, while the benzoyl-amide N atom is planar [0.11 (3) Å]. In the crystal, mol-ecules are linked via N-H⋯O(P) and N-H⋯O(C) hydrogen bonds, forming R(2) (2)(10) rings within linear arrangements parallel to the b axis.

In the title compound, C(13)H(12)N(4)O, the semicarbazone fragment links a benzene and a pyridine ring in the structure. The crystal packing is stabilized by strong inter-molecular N-H⋯O hydrogen bonds, which connect two mol-ecules to form a synthon unit, and by N-H⋯N hydrogen bonds and weak C-H⋯π inter-actions. The mol-ecular conformation is stabil-ized by intra-molecular N-H⋯N and C-H⋯O inter-actions.

The P atom in the title compound, C(23)H(25)N(4)O(4)P, is in a slightly distorted tetra-hedral coordination environment and the N atoms show sp(2) character. The phosphoryl group and the NH unit are syn with respect to each other. In the crystal, pairs of inter-molecular N-H⋯O(P) hydrogen bonds form centrosymmetric dimers.

A three-component reaction involving diphosphinoketenimines, isocyanides and water or ethanol leading to the formation of new five-membered azaphosphaheterocycles is described.

In the title compound, C(11)H(10)O(3), the benzodioxole ring adopts a flattened [puckering parameters: q(2) = 0.107 (2) Å, ϕ(2) = 160 (1)°] envelope conformation with the methylene C atom as the flap. The crystal packing features chains, parallel to the c axis, composed of dimers connected by weak C-H-O hydrogen bonds and extending in layers in the bc plane.