Octulene: A Hyperbolic Molecular Belt that Binds Chloride Anions

Octulene, the higher homologue of kekulene and septulene, was synthesized using the fold-in method. This new hydrocarbon macrocycle contains a large 24-membered inner circuit, which is peripherally fused to 24 benzene rings. Such an arrangement produces considerable hyperbolic distortion of the π-conjugated surface. The consequences of distortion in octulene were explored using photophysical methods, which revealed a reduced electronic band gap and greater flexibility of the π system. Octulene contains a functional cavity with a diameter larger than 5.5 Å that is capable of efficiently binding the chloride anion in a nonpolar solvent (K_a = 2.2(4)×10⁴  m^-1 , 1 % dichloromethane (DCM) in benzene). The octulene-chloride interaction is stabilized by eight weak C(sp² )H⋅⋅⋅Cl bonds, providing the first example of a hydrocarbon-based anion receptor.

A Three-Component Reaction for the Synthesis of 1-Azabicyclo[3.1.0]hexane-3-enes

A novel and simple synthesis of 1-azabicyclo[3.1.0]hexane-3-ene derivatives is described. The synthesis is carried out via a simple three-component reaction between aryl aldehydes, malononitrile, and hydroxylamine hydrochloride in water. Eco-friendliness, excellent product yields, short reaction time, inexpensive and readily available starting materials, and interesting reaction and products are the main advantages of this method.

Bandgap Engineering in π-Extended Pyrroles. A Modular Approach to Electron-Deficient Chromophores with Multi-Redox Activity

A family of bandgap-tunable pyrroles structurally related to rylene dyes was computationally designed and prepared using robust, easily scalable chemistry. These pyrroles show highly variable fluorescence properties and can be used as building blocks for the synthesis of electron-deficient oligopyrroles. The latter application is demonstrated through the development of π-extended porphyrins containing naphthalenediamide or naphthalenediimide units. These new macrocycles exhibit simultaneously tunable visible and near-IR absorptions, an ability to accept up to 8 electrons via electrochemical reduction, and high internal molecular free volumes. When chemically reduced under inert conditions, the most electron-deficient of these macrocycles revealed reversible formation of eight charged states, characterized by remarkably red-shifted optical absorptions, extending beyond 2200 nm. Such features make these oligopyrroles of interest as functional chromophores, charge-storage materials, and tectons for crystal engineering.

A triacontanuclear [Zn12Dy18] cluster: a ring of [Dy4] cubes

The reaction between Dy(NO3)3·6H2O, Zn(OAc)2·4H2O, salicylaldehyde and 2-amino-isobutyric acid, in MeOH in the presence of NEt3 under solvothermal conditions, led to the isolation of the triacontanuclear mixed-metal cluster [Zn(II)12Dy(III)18(OH)30(L)12(sal)6(OAc)6(NO3)3(H2O)6](NO3)3·12MeOH·5H2O (1·12MeOH·5H2O), which displays frequency- and temperature-dependent out-of-phase magnetic susceptibility signals.

Multifunctional imine-POSS as uncommon 3D nanobuilding blocks for supramolecular hybrid materials: synthesis, structural characterization, and properties

Imino-functionalized cage-like octasilsesquioxanes provide unique examples of the 3D supramolecular network and their relationship to the assembly of tunable materials from nanobuilding blocks.

Multinuclear Ni(ii), Cu(ii) and Zn(ii) complexes of chiral macrocyclic nonaazamine

Herein, we report the preparation and crystal structures of Ni(ii), Cu(ii) and Zn(ii) complexes. For both the Ni(ii) and Cu(ii) compounds, a magnetostructural correlation was established.

New tetranuclear manganese clusters with [MnII3MnIII] and [MnII2MnIII2] metallic cores exhibiting low and high spin ground state

Two tetranuclear mixed-valent clusters with the metallic [MnII3Mn^III] and [MnII2MnIII2] cores were synthesized as molecular nanomagnets with the low and high spin in the ground state.

Two unique star-like [MnIVMnIII2LnIII] clusters: magnetic relaxation phenomena

Synthesis and magnetic properties of two tetrametallic star-like [Mn^IVMn^III₂Ln] (Ln: Gd, Dy) clusters.

Building 1D lanthanide chains and non-symmetrical [Ln2] “triple-decker” clusters using salen-type ligands: magnetic cooling and relaxation phenomena

Three series of related lanthanide polymers/dimers have been structurally and magnetically investigated.

Dicyclohexylammonium bromoacetate: a low molecular mass organogelator with a one-dimensional secondary ammonium monocarboxylate (SAM) synthon

The asymmetric unit of the title salt, C12H24N(+)·C2H2BrO2(-), contains a dicyclohexylammonium cation connected to a bromoacetate anion by means of an N-H...O hydrogen bond. In the crystal, the ion pairs assemble via N-H...O interactions, forming zigzag infinite chains parallel to the c axis with the (...H-N-H...O-C-O...)n motif that is considered to be a prerequisite for ensuring gelation properties of secondary ammonium monocarboxylate salts. The title salt was characterized by FT-IR, X-ray powder diffraction (XRPD), TG-DTA and (1)H NMR spectroscopy in solution. Gelation experiments revealed that dicyclohexylammonium bromoacetate forms molecular gels with dimethylformamide and dimethyl sulfoxide. Scanning electron microscopy (SEM) was used to reveal morphological features of dried gels.

Crystal structure of a mixed-ligand dinuclear Ba-Zn complex with 2-meth-oxy-ethanol having tri-phenyl-acetate and chloride bridges

The dinuclear barium-zinc complex, μ-chlorido-1:2κ(2) Cl:Cl-chlorido-2κCl-bis-(2-meth-oxy-ethanol-1κO)bis-(2-meth-oxy-ethanol-1κ(2) O,O')bis-(μ-tri-phenyl-acetato-1:2κ(2) O:O')bariumzinc, [BaZn(C20H15O2)2Cl2(C3H8O2)4], has been synthesized by the reaction of barium tri-phenyl-acetate, anhydrous zinc chloride and 2-meth-oxy-ethanol in the presence of toluene. The barium and zinc metal cations in the dinuclear complex are linked via one chloride anion and carboxyl-ate O atoms of the tri-phenyl-acetate ligands, giving a Ba⋯Zn separation of 3.9335 (11) Å. The irregular nine-coordinate BaO8Cl coordination centres comprise eight O-atom donors, six of them from 2-meth-oxy-ethanol ligands (four from two bidentate O,O'-chelate inter-actions and two from monodentate inter-actions), two from bridging tri-phenyl-acetate ligands and one from a bridging Cl donor. The distorted tetra-hedral coordination sphere of zinc comprises two O-atom donors from the tri-phenyl-acetate ligands and two Cl donors (one bridging and one terminal). In the crystal, O-H⋯Cl, O-H⋯O and C-H⋯Cl inter-molecular inter-actions form a layered structure, lying parallel to (001).

Highly strained nonclassical nanotube end-caps. A single-step solution synthesis from strain-free, non-macrocyclic precursors

Nonclassical nanotube end-caps have been constructed from strain-free heterocyclic precursors using a one-step synthetic procedure, involving multiple nickel-mediated Ullmann couplings. These systems consist of tubular macrocyclic sections that are tightly capped on one side with a bridging benzene ring, forming deep, chemically accessible cavities. The end-caps are characterized by exceptionally high internal strain energies reaching 144 kcal/mol. The optical absorption and emission properties of these molecules show a marked dependence on conjugation length and geometrical factors. The mechanism of end-cap formation, investigated using DFT calculations, relies on precise timing of transmetalation and reductive elimination events.

Synthesis, structure, magnetic properties and EPR spectroscopy of a copper(ii) coordination polymer with a ditopic hydrazone ligand and acetate bridges

The synthesis, structure, EPR spectroscopy and magnetic properties of a 1D coordination polymer of Cu(ii) containing two kinds of acetate bridged dimers is reported.

Chrysaorenes: assembling coronoid hydrocarbons via the fold-in synthesis

Two coronoid hydrocarbons, [3]- and [4]chrysaorene, were synthesized from fluorenophane precursors using the fold-in strategy.

Molecular oxygen reduction catalyzed by a highly oxidative resistant complex of cobalt–hydrazone at the liquid/liquid interface

Syntheses, structure and spectroscopic studies of a new cobalt complex with a hydrazine ligand. The first report on a highly oxidative resistant complex in the ORR electrocatalysis at the liquid–liquid interface.

Crystal structure of O-isopropyl [bis-(tri-methyl-sil-yl)amino](tert-butyl-amino)-phosphino-thio-ate

[Bis(tri-methyl-sil-yl)amino](tert-butyl-imino)-thio-phospho-rane reacts in benzene with isopropyl alcohol via 1,2-addition of an (i) PrO-H bond across the P=N bond, resulting in the title compound, C13H35N2OPSSi2. In the mol-ecule, the P atom possesses a distorted tetra-hedral environment involving two N atoms from (Me3Si)2N- and (t) BuNH- groups, one O atom from an (i) PrO group and one S atom, therefore the mol-ecule has a stereocenter on the P atom but crystal symmetry leads to a racemate. In the crystal, a pair of enanti-omers form a centrosymmetric dimer via a pair of N-H⋯S hydrogen bonds.

Dodecanuclear [MnIII6LnIII6] species: synthesis, structures and characterization of magnetic relaxation phenomena

Two dodecametallic heteronuclear manganese–lanthanide [MnIII6LnIII6] (Ln = Gd, Dy) complexes were isolated and characterized by magnetic measurements.

A family of [MnIII6LnIII2] rod-like clusters

A family of octametallic heteronuclear manganese-lanthanide [Mn^III₆Ln₂] complexes were isolated and characterized by magnetic measurements.

Charge density distribution and theoretical analysis of low and high energy phosphate esters

There is a strict relation between the energy of hydrolysis of phosphate esters and the extent of interactions between the p ester oxygen lone pair and the antibonding orbitals of the rest of the molecule. Its impact on experimental charge density distribution is analyzed.

Synthesis and antibacterial properties of pyrimidine derivatives

In this study, a series of syntheses was conducted on the pyrimidine system, obtaining bisulfite carboxyl derivatives 4 and hydroxy derivatives 5. In addition, a series of syntheses were carried out as a result of which both alkyl and aromatic amines were obtained. Then, the attempt was made to cyclize these amines in the Mannich reaction to pyrimido[4,5-d]pyrimidines 11, 12. After determination of chemical structure using physicochemical tests, also by means of crystallographic tests, all the newly obtained derivatives underwent microbiological tests on bacterial strains and fungi. The most interesting results of the microbiological tests are included later in the study.

Solvothermal synthesis of enneanuclear [CuII7LnIII2] clusters

Four enneanuclear heterometallic copper–lanthanide [CuII7LnIII2] (Ln = Gd, Tb, Dy and Y) complexes were isolated and characterized by magnetic measurements.