3-(Pyridin-4-yl)acetylacetone: a donor ligand towards mercury(II) halides and a versatile linker for complex materials.

The ditopic organic molecule 3-(pyridin-4-yl)acetylacetone (HacacPy) acts as a pyridine-type ligand towards HgX (X = Cl, Br, I). The nature of the anion and the ligand-to-cation ratio dominate the outcome of the reaction. Two different coordination compounds form with HgCl, namely a ligand-rich mononuclear complex, HgCl(HacacPy), and a ligand-deficient one-dimensional chain polymer, [Hg(μ-Cl)(HacacPy)], with five-coordinated Hg cations.

3-(Pyridin-4-yl)acetylacetone: Cd and Hg compete for nitrogen coordination.

3-(Pyridin-4-yl)acetylacetone (HacacPy) acts as a pyridine-type ligand towards Cd and Hg halides. With CdBr, the one-dimensional polymer [Cd(μ-Br)(HacacPy)Cd(μ-Br)(HacacPy)] is obtained in which five- and six-coordinated Cd cations alternate in the chain direction. Reaction of HacacPy with HgBr results in [Hg(μ-Br)Br(HacacPy)], a polymer in which each Hg centre is tetracoordinated.

Halogen bonds on demand: I···S contacts in cocrystals of trans-bis(thiocyanato-κN)tetrakis(4-vinylpyridine-κN)nickel(II) and 2,3,5,6-tetrafluoro-1,4-diiodobenzene.

Hydrogen bonds are considered a powerful organizing force in designing supramolecular architectures because they are directional, selective and reversible at room temperature. trans-Dithiocyanatotetrakis(4-vinylpyridine)nickel(II) is a popular host for the inclusion of small molecules and 2,3,5,6-tetrafluoro-1,4-diiodobenzene (TFDIB) represents a strong halogen-bond donor. These constituents cocrystallize in a 1:1 stoichiometry, [Ni(NCS)2(C7H7N)4]·C6F4I2, in the tetragonal space group I4₁/a.

3-(4-pyridyl)-acetylacetone--a fully featured substituted pyridine and a flexible linker for complex materials.

3-(4-Pyridyl)-acetylacetone (HacacPy) acts as a pyridine-type ligand towards CdX2 (X = Cl, Br, I). Chain polymers with six-coordinated metal cations are obtained from CdCl2 and with alternating five- and six-coordinated Cd centers from CdBr2. In either case, the formation of these compounds does not depend on the precise stoichiometry.

Bis(cyclo-hexyl-ammonium) tetra-chlorido-diphenyl-stannate(IV).

The title compound, (C6H14N)2[Sn(C6H5)2Cl4], contains cyclo-hexyl-ammonium cations in general positions and a stannate(IV) anion that is located on a twofold rotation axis. The Sn(IV) atom in the complex anion is surrounded by four Cl(-) ligands and two trans-phenyl groups in a distorted octa-hedral configuration. The anions are connected with the cations through N-H⋯Cl hydrogen bonds.

Catalytic enantioselective trifluoromethylthiolation of oxindoles using shelf-stable N-(trifluoromethylthio)phthalimide and a cinchona alkaloid catalyst.

The organocatalytic enantioselective trifluoromethylthiolation of oxindoles employing N-(trifluoromethylthio)phthalimide as a stable, easy to handle CF3S-source has been developed. Optically active products with a quaternary stereogenic center bearing a CF3S-group are obtained in good yields and with good to excellent enantioselectivities.

Asymmetric synthesis of pyrroloindolones by N-heterocyclic carbene catalyzed [2+3] annulation of α-chloroaldehydes with nitrovinylindoles.

NHC-enolate plus 3: N-heterocyclic carbenes (NHCs) serve as organocatalysts for the [2+3] annulation of nitrovinylindoles with α-chloroaldehydes via an intermediate azolium enolate. The method provides trans-disubstituted pyrroloindolones with good yields and excellent diastereo- and enantioselectivities. Further transformations lead to tetracyclic pyrrolo[1,2-a]indoles with potential psychotropic and other bioactivities.

Bifunctional ruthenium(II) hydride complexes with pendant strong Lewis acid moieties: structure, dynamics, and cooperativity.

The synthesis of a novel class of bifunctional ruthenium hydride complexes incorporating Lewis acidic BR(2) moieties is reported. Determination of the molecular structures in the solid state and in solution provided evidence for tunable interaction between the two functionalities. Cooperative effects on the reactivity of the complexes were demonstrated including the activation of small Lewis basic molecules by reversible anchoring at the boron center.

Organocatalytic one-pot asymmetric synthesis of 4H,5H-pyrano[2,3-c]pyrazoles.

An efficient one pot asymmetric synthesis of tetrahydropyrano[2,3-c]pyrazoles has been developed. This class of biologically active heterocycles can be obtained via a secondary amine catalyzed asymmetric Michael/Wittig/oxa-Michael reaction sequence. Remarkably, the title compounds were accessible in good to very good yields and very good to excellent enantioselectivities after a single purification step.

Bimetallic coordination networks based on Al(acacCN)3: a building block between inertness and lability.

The Al(III) complex of 3-cyanopentane-2,4-dionate (acacCN) features peripheric nitrile groups which may coordinate to silver cations. As the Al(acacCN)(3) building block ranges between inertness and lability, its reactivity towards Ag(I) salts depends on the solvent and the weakly or non-coordinating counter anions; an impressive range of different extended structures has been encountered. With AgPF(6), the original building block is retained and hexafluorophosphate remains uncoordinated.

Ordered bimetallic coordination networks featuring rare earth and silver cations.

Three lanthanide complexes of the ditopic ligand 3-cyanopentane-2,4-dionate (acacCN) have been synthesized and structurally characterized. Longer intermolecular contacts result in ninefold coordination of the cation in Ce(acacCN)(3)(H(2)O)(2), whereas mononuclear complexes of the same stoichiometry with coordination number eight are obtained for the smaller Eu(III) and Yb(III) cations. Reaction of these labile compounds with AgPF(6) leads to re-organization of the coordination sphere of the rare earth cations: neutral extended structures are formed in which the peripheric -CN moieties of Ln(acacCN)(4) anions coordinate to silver cations.