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Solutions of [CuCl 2 L OH ], and other reaction mixtures containing L OH and Cu( II ) or Cu( I ) salts, degrade to yield dark green or brown residues containing the L H ligand . In contrast, [MCl 2 L OH ] (M = Zn, Ni, Co) are indefinitely stable in solution and the solid state.

Propeller-like [Fe 4 (L) 2 (dk) 6 ] complexes, in which Hdk is a β-diketone and H 3 L is a tripodal alcohol , R–C(CH 2 OH) 3 , exhibit tunable magnetic anisotropy barriers and retain their magnetic memory effect when chemically anchored on metal surfaces. Heteronuclear analogues of these M 4 complexes have been sought to afford a library of compounds with different total spin ( S ) values, but synthetic efforts described so far gave solid solutions containing M 4 in addition to the desired M 3 M′ species. We now present a novel synthetic route to M 3 M′ complexes featuring a central chromium( III ) ion. The three-step preparation goes through coordination of Cr III by two equivalents of tripodal alkoxide (R = Et and Ph), followed by reaction of this complex “core” with the peripheral +III metal ions. Products have been characterised by chemical analyses together with 1 H-NMR , FTIR , W-band EPR , DC/AC magnetic susceptibility measurements and single crystal X-ray diffractometry . Due to the chemical inertness of Cr III , this route yields 100% pure Fe 3 Cr complexes without metal scrambling; what is more, it is suitable for designing novel heteronuclear single molecule magnets (SMMs) with a variety of d- and f-metals and R groups.

In this work, zinc aryloxides supported by monodentate hydroxybiphenyls [ArOH: ortho -phenylphenol ( o -XenOH), meta -phenylphenol ( m -XenOH), or para -phenylphenol ( p -XenOH] and N , N , N ′, N ′-tetramethylethylenediamine (TMEDA) were used to develop active polymeric materials for antifungal agents for agricultural use. The direct reaction of ligand precursor ArOH with ZnEt 2 (1?:?2) in a toluene/TMEDA mixture (1?:?10) afforded a series of three isostructural monomeric compounds, namely [Zn( o -XenO) 2 (TMEDA)] ( 1 ), [Zn( m -XenO) 2 (TMEDA)] ( 2 ), and [Zn( p -XenO) 2 (TMEDA)] ( 3 ). These were characterized by single-crystal X-ray diffraction, and spectroscopic and other analytical methods. The results show that 1–3 are effective initiators for the ring-opening polymerization (ROP) of L -lactide ( L -LA) via bifunctional activation of the monomer with Lewis pairs to give polymers terminated with TMEDA and Zn(OAr) 2 as the α- and ω-chain ends, respectively. Combinations of ZnEt 2 with two molar equivalents of ArOH proligands were used to synthesize polylactides containing fungicide molecules covalently bonded via ester linkers. The ROP of L -LA initiated by these zinc-based systems could be used for the preparation of polyesters with promising antifungal activities.

A highly active and regioselective catalyst obtained from a novel dicationic ligand ( 1 ) and Rh(CO) 2 (acac) for hydroformylation of 1-hexene and 1-octene in ionic liquids is reported. Optimisation studies of various reaction parameters led to an unprecedentedly active (TOFs 6200 mol mol ?1 h ?1 , T = 100 °C), selective (l/b ratios 40) and stable hydroformylation procedure. No catalyst leaching (Rh-loss 0.07% of initial rhodium intake, P-loss 0.4% of the initial phosphorus intake) or losses in performance could be measured during 1-octene hydroformylation recycle experiments in 1-butyl-3-methylimidazolium hexafluorophosphate . At low catalyst loadings activities and regioselectivities competitive with one-phase catalysis in conventional solvents were observed. At high catalyst loadings the system is extremely stable and has a long shelf-life as a result of the formation of stable, if inactive rhodium dimers. catalysis: homogeneous

A novel 3D metal–organic framework based on Ni 4 clusters as nodes has been synthesized using a tetrahedral linker of 5,5′,5′′-(methylsilanetriyl)triisophthalic acid (H 6 L). The compound possesses 1D channels with potential pore volumes that can accommodate guest molecules. Investigations on the coupling reaction of epoxides and CO 2 indicate that the compound can be used as an efficient catalyst for CO 2 chemical fixation, and its catalytic performance is greatly superior to most MOF-based catalysts. Additionally, compound 1 can be recycled at least five times without compromising its activity.

A new non-interpenetrating 3D metal–organic framework {[Ni 4 (μ 6 -MTB) 2 (μ 2 -H 2 O) 4 (H 2 O) 4 ]·10DMF·11H 2 O} n (DMF = N , N ′-dimethylformamide) built from nickel( II ) ions as connectors and methanetetrabenzoate ligands (MTB 4? ) as linkers has been synthesized and characterized. The single crystal X-ray diffraction showed that complex exhibits CaF 2 -like fluorite structure topology and four types of 3D channels with sizes about 12.6 × 9.4 ? 2 , 9.4 × 8.0 ? 2 , 12.6 × 11.7 ? 2 and 14.9 × 14.9 ? 2 , which are filled with guest molecules. Conditions of the activation of the compound have been studied and optimized by powder X-ray diffraction during in situ heating, thermogravimetric analysis and infrared spectroscopy. Nitrogen and carbon dioxide adsorption showed that the activated sample exhibits a BET specific surface area of 700 m 2 g ?1 and a carbon dioxide uptake of 12.36 wt% at 0 °C, which are the highest values reported for the compounds of the MTB 4? series. The complex was tested in Knoevenagel condensation of aldehydes and active methylene compounds. Straightforward dependence of the substrate conversion on the size of used aldehyde was established. A possible mechanism of Knoevenagel condensation over a MTB 4? containing a metal–organic framework was proposed.

We describe here the synthesis and characterization of a ternary cluster compound [As 3 Nb(As 3 Sn 3 )] 3? ( 1 ), in which a niobium( V ) atom is coordinated by an As 3 3? triangle and a bowl-type As 3 Sn 3 5? ligand. Cluster 1 was synthesized by dissolving K 8 NbSnAs 5 ( 2 ) in the presence of [2.2.2]crypt in ethylenediamine solution, filtered and layered with toluene, then crystallized in the form of [K([2.2.2]crypt)] 3 [As 3 Nb(As 3 Sn 3 )]·en·tol. The flower-vase shaped compound 1 features a new structure type, rather different from the known Zintl phases. The stability and bonding of 1 are elucidated via extensive bonding analyses. The Sn 3 ring is found to have σ-aromaticity featuring a delocalized Sn–Sn–Sn σ bond. Electronic structure calculations confirm the Nb( V ) oxidation state and weak Nb–Sn and Sn–Sn bonding, in addition to the normal Nb–As and As–As bonds.

With a 4-aminostyryl group introduced at its 3-position, a BODIPY BDP-ODTAC was derived as a new ratiometric sensor for Ag + by modifying 4-amino group as a Ag + chelator, 1-oxa-4,10-dithia-7-azacyclododecane (ODTAC). In addition to the specific Ag + -induced hypsochromic absorption shift from 606 to 562 nm, this sensor demonstrated an excitation shift from 600 to 560 nm due to the internal charge transfer (ICT) effect endowed by the introduced α-4-aminostyryl group. The Ag + -induced recovery and enhancement of the intrinsic local emission band was also observed. The different sensing behavior of ODTAC-BDP with chelator ODTAC substituting on the meso -phenyl group infers that the ratiometric sensing behavior of BDP-ODTAC is correlated to the amino group in ODTAC acting as the electron donor for the ICT effect. With high Ag + selectivity over interfering cations such as Hg 2+ and Pb 2+ , BDP-ODTAC displays a fluorometric limit of detection (LOD) of ～17 nM (～0.002 ppm), which is distinctly lower than EPA and WHO standards for drinking water (500 nM, ～0.055 ppm). Moreover, the BDP-ODTAC -doped PVC film shows the Ag + sensitivity of 1 ppm with a color switch from blue to purple, providing this sensor the ability to determine Ag + in totally aqueous solution sensitively via naked-eye detection.

A sterically demanding iminophosphonamine ligand [(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )(N t Bu)]H (LH) and its lithium derivative [(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )(N t Bu)](Li·2THF) ( 1 ) were used to prepare complexes of group 13 elements. The reaction of LH with AlH 3 ·NMe 2 Et and AlMe 3 respectively, affords [LAlH 2 ] 2 ( 2 ) and LAlMe 2 ( 3 ). The lithium derivative 1 when treated with the MCl 3 compound of group 13 yields [(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )(N t Bu)]MCl 2 (M = B ( 4 ); Al ( 5 ); and Ga ( 6 ). Compound 3 on reaction with a Lewis acid B(C 6 F 5 ) 3 generates the cationic complex [{(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )(N t Bu)}AlMe] + [MeB(C 6 F 5 ) 3 ] ? ( 7 ) that slowly undergoes rearrangement to yield [(2,6-iPr 2 C 6 H 3 N)P(Ph 2 )(N t Bu)]AlMe(C 6 F 5 ) ( 8 ) and MeB(C 6 F 5 ) 2 . Compounds 1–8 were characterized using multinuclear NMR, EI-MS and IR techniques and the solid state structure of 1–6 and 8 was elucidated by single crystal X-ray diffraction analyses.

Calcium sulfate hydrates receive significant attention due to numerous large scale industrial applications. There has been a long debate on the possible existence of two gypsum hemi-hydrate polymorphs, denoted α- and β-CaSO 4 ·0.5H 2 O. In this work, a new crystal structure of calcium sulfate hemi-hydrates is presented, denoted β-CaSO 4 ·0.5H 2 O. The structure was solved using powder neutron diffraction data, the space group is P 3 1 and the unit cell in a hexagonal setting a = 6.9268(1), c = 12.7565(3) ?. The structure has two calcium – oxygen coordination polyhedra: Ca1 is eight coordinated and has Ca–O bond lengths in the range 2.31(3) to 2.89(2) ? and Ca2 is nine coordinated and has one Ca–O water bond length of 2.43(3) ?, and eight Ca–O bonds in the range 2.30(4) to 2.86(4) ?. Two sulfate ions have S–O bonds in the range 1.47(3) to 1.49(4) ?, and 1.47(3) to 1.50(3) ?, respectively. The water molecule forms a hydrogen bond of 2.55(4) ? to an oxygen atom in one of the sulfate ions. The structure of the hemi-hydrate β-CaSO 4 ·0.5H 2 O has one-dimensional channels running parallel to the c -axis where the water molecules are located. This relates the structures of α- and β-CaSO 4 ·0.5H 2 O and soluble anhydrite AIII-CaSO 4 , which all have similar channel structures. The water molecules in the structure of β-CaSO 4 ·0.5H 2 O are packed in the channels with a three fold (3 1 ) symmetry in a different way as compared to the pseudo hexagonal found in the structure of α-CaSO 4 ·0.5H 2 O.