Structure and properties evolution with inorganic and organic acids of a new organo-chlorocadmate compound (C6H20N3)2[Cd2Cl10] : theoretical approach

This work was supported by the Ministry of Higher Education and Scientific Research of Tunisia.This work describes the theoretical studies of the reactivity, electrical and thermodynamic properties of a novel organo-chlorocadmate complex (C6H20N3)2[Cd2Cl10] and its inorganic and organic acid derivatives. The synthesis and crystal structure are described, with the compound crystallizing in the orthorhombic (Pnma) space group with unit cell parameters: a = 7.25494(11) Å, b = 29.3000(5) Å, c = 7.33927(13) Å. The semi-empirical calculations reveal that not only are all of the derivatives semiconductors, but also that the inclusion of acids in the structure alter the electrical and thermodynamic properties significantly, demonstrating a systematic and easy method for tuning the materials reactivity along with other desirable properties.PostprintPeer reviewe

2D-coordination polymer containing lead(II) in a hemidirected PbO4S3 environment formed by molecular breaking of the 1,3-oxathiolane ligand

new 1,3-oxathiolane-based ligand, 2-(1,3-oxathiolan-2-yl)pyridine, was prepared and its coordination to lead(II) was investigated. Experiments revealed a ligand-breaking reaction during the complexation process, which leads to the formation of a 2D-coordination polymer of lead(II), [Pb(μ3-HME)(μ-OAc)]n; H2ME: 2-mercaptoethanol. The compounds have been characterized by elemental analysis, FT-IR, 1H NMR spectroscopy and single-crystal X-ray diffraction. X-ray analysis revealed a 2D-coordination polymer extending via acetato bridges. The lead(II) center adopts a rare PbO4S3-distorted pentagonal bipyramidal geometry with a hemidirected arrangement. Upon coordination, the thiol group of the H2ME ligand is deprotonated to coordinate as an anionic ligand. The network extends in sheets in the crystallographic ab plane via Pb–S–Pb and Pb–O–Pb bridges, aided by O–H⋯O hydrogen bonds.Publisher PDFPeer reviewe

Constrained phosphine chalcogenide selenoethers supported by peri-substitution

A series of phosphorus and selenium peri-substituted acenaphthene species with the phosphino group oxidized by O, S, and Se has been isolated and fully characterized, including by single-crystal X-ray diffraction. The P(V) and Se(II) systems showed fluxional behavior in solution due to the presence of two major rotamers, as evidenced with solution NMR spectroscopy. Using Variable-Temperature NMR (VT NMR) and supported by DFT (Density Functional Theory) calculations and solid-state NMR, the major rotamers in the solid and in solution were identified. All compounds showed a loss of the through-space JPSe coupling observed in the unoxidized P(III) and Se(II) systems due to the sequestration of the lone pair of the phosphine, which has been previously identified as the major contributor to the coupling pathway.Publisher PDFPeer reviewe

(Decacarbonyl)(1-isopropyl-2-phenyl-1,2,5,6-tetrahydroacenaphtho [5,6-cd][1,2]diphosphole)ditungsten(0) : Molbank

A binuclear tungsten(0) complex with an asymmetric bridging 1,2-diphosphole ligand was prepared by the photolysis of tungsten hexacarbonyl in the presence of 1-isopropyl-2-phenyl-1,2,5,6-tetrahydroacenaphtho [5,6-cd][1,2]diphosphole. The tungsten complex 1 was characterized by high resolution mass spectrometry, multinuclear NMR spectroscopy (1H, 13C, 31P), and elemental microanalysis. The structure of the trans isomer was resolved by single crystal X-ray diffraction, showing a slight elongation of the P−P bond upon coordination to the W(CO)5 groups.Publisher PDFPeer reviewe

Morphology- and size-controlled synthesis of a metal-organic framework under ultrasound irradiation : an efficient carrier for pH responsive release of anti-cancer drugs and their applicability for adsorption of amoxicillin from aqueous solution

Support of this investigation by Tarbiat Modares University is gratefully acknowledged.In this study, we have reported a biocompatible metal-organic framework (MOF) with ultra-high surface area, which we have shown to have uses as both a cancer treatment delivery system and for environmental applications. Using a sonochemical approach, highly flexible organic H3BTCTB and ditopic 4,4́′-BPDC ligands, along with modulators of acetic acid and pyridine were combined to prepare a Zn(II)-based metal-organic framework, DUT-32, [Zn4O(BPDC)(BTCTB)4/3(DEF)39.7(H2O)11.3]. Powder X-ray diffraction (PXRD), field-emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FTIR) were used to characterize, the particle size, shape, and structure of the DUT-32. To show the effects of shape and size of DUT-32 micro/nano-structures on doxorubicin (DOX) drug release and amoxicillin (AMX) adsorption, time of sonication, initial reagent concentrations, irradiation frequency, and acetic acid to pyridine molar ratios were optimized. The drug-loaded DUT-32 was soaked in simulated body fluid (SBF) and the drug release ratio was monitored through release time to perform in vitro drug release test. A slow and sustained release was observed for DUT-32 micro/nano-structures, having a considerable drug loading capacity. At the pH values 7.4-4.5, various profiles of pH-responsive release were achieved. Also, the prepared DUT-32 micro/nano-structures are found to be biocompatible with PC3 (prostate cancer) and HeLa (cervical cancer) cell lines, when tested by MTT assay. Moreover, DUT-32 micro/nano-structures were studied to show AMX adsorption from aqueous solution. Finally, kinetic studies indicated that AMX adsorption and drug release of DOX via this MOF are of first-order kinetics.PostprintPeer reviewe

1,4-Diiodotetrafluorobenzene 3,5-di-(pyridin-4-yl)-1,2,4-thiadiazole <1/1>

The reactivity of 3,5-di-(pyridin-4-yl)-1,2,4-thiadiazole (L1) with 1,4-diiodotetrafluorobenzene (1,4-DITFB) was explored and the halogen-bonded 1:1 co-crystal (1) was successfully isolated and structurally characterized

Thionylimido complexes

An improved route to d-block and main group NSO complexes is presented including the synthesis of the first antimony(V) complexes, (Ar3Sb(NSO)2), and copper examples (CuBipy(PPh3)NSO). The structures of eight complexes are reported. The observed variation in M-N-S bond angles is due to the combination of orbital overlap (ligand-to-metal bonding) and the degree of ionicity of the bonding.Publisher PDFPeer reviewe

Catalytic enantioselective synthesis of heterocyclic vicinal fluoroamines using asymmetric protonation : a method development and mechanistic study

Funding: Leverhulme Trust (Grant Number(s): RPG-2015-308), University of St Andrews, University of Manchester.A catalytic enantioselective synthesis of heterocyclic vicinal fluoroamines is reported. A chiral Brønsted acid promotes aza‐Michael addition to fluoroalkenyl heterocycles to give a prochiral enamine intermediate that undergoes asymmetric protonation upon rearomatization. The reaction accommodates a range of azaheterocycles and nucleophiles, generating the C−F stereocentre in high enantioselectivity, and is also amenable to stereogenic C−CF3 bonds. Extensive DFT calculations provided evidence for stereocontrolled proton transfer from catalyst to substrate as the rate‐determining step, and showed the importance of steric interactions from the catalyst's alkyl groups in enforcing the high enantioselectivity. Crystal structure data show the dominance of noncovalent interactions in the core structure conformation, enabling modulation of the conformational landscape. Ramachandran‐type analysis of conformer distribution and Protein Data Bank mining indicated that benzylic fluorination by this approach has the potential to improve the potency of several marketed drugs.Publisher PDFPeer reviewe

A cascade Suzuki-Miyaura/Diels-Alder protocol : exploring the bifunctional utility of vinyl Bpin

Funding: Industrial CASE studentship awarded from EPSRC and GlaxoSmithKline. The authors thank the EPSRC, GlaxoSmithKline, and the University of St Andrews for studentship funding (DLC), and the University of St Andrews and the EPSRC UK National Mass Spectrometry Facility at Swansea University for analyses.Cascade reactions are an important strategy in reaction design, allowing streamlining of chemical synthesis. Here we report a cascade Suzuki-Miyaura/Diels-Alder reaction, employing vinyl Bpin as a bifunctional reagent in two distinct roles: as an organoboron nucleophile for cross- coupling and as a Diels-Alder dienophile. Merging these two reactions enables a rapid and operationally simple synthesis of functionalized carbocycles in good yield. The effect of the organoboron subtype on Diels- Alder regioselectivity was investigated and post-synthetic modifications were carried out on a model substrate. The potential for a complementary Heck/Diels-Alder process was also assessed.PostprintPeer reviewe

Thermally activated delayed fluorescence emitters with intramolecular proton transfer for high luminance solution-processed organic light-emitting diodes

AKG is grateful to the Royal Society for Newton International Fellowship NF171163. We acknowledge support from the Engineering and Physical Sciences Research Council of the UK (grants EP/P010482/1 and EP/L017008/1). We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. We thank Umicore for providing palladium (II) acetate.We report an organic emitter containing a β-triketone electron acceptor core and phenoxazine as the electron donors ( TPXZBM ) for solution-processed organic light-emitting diodes (OLEDs). The resulting molecule is very unusual because it shows both thermally activated delayed fluorescence (TADF) and intramolecular proton transfer. We compare its performance with the previously reported diketone analogue PXZPDO . Solution-processed OLEDs of PXZPDO and TPXZBM show maximum external quantum efficiencies of 20.1% and 12.7%, respectively. The results obtained for the solution-processed PXZPDO -based device are as good as the previously reported evaporated device. At a very high luminance of 10,000 cd/m2 the efficiency of the OLEDs was 10.6% for PXZPDO and 4.7% for TPXZBM , demonstrating relatively low efficiency roll-off for TADF materials. The low efficiency roll-off was rationalized on the basis of the short delayed lifetimes of 1.35 μs for PXZPDO and 1.44 μs for TPXZBM . Our results suggest that intramolecular proton transfer may be useful for the design of OLED materials with low efficiency roll-off.PostprintPeer reviewe