Tetrabenzononacene: “Butterfly Wings” Stabilize the Core

In combination with bulky substituents at the core, fourfold benzannulation at the cata‐positions stabilizes a nonacene sufficiently to allow its isolation and characterization by ¹H NMR and X‐ray analysis. The four benzo units blueshift the absorption spectrum in comparison to a solely linear nonacene, but significantly increase the stability in the solid state.     

Modular Synthesis of Spirocyclic Germafluorene–Germoles: A New Family of Tunable Luminogens

The zirconium‐mediated synthesis of a new class of air‐stable spirocyclic germafluorene–germole (SGG) luminogens is reported. These species contain ring‐fused germafluorene and germole units that display color‐tunable fluorescence when peripheral aryl substituents are appended. Three distinct pathways are introduced for SGG modification (Stille, Suzuki–Miyaura, and zirconocene‐mediated couplings), which enable the preparation of new libraries of molecular and polymeric SGG light‐emitters with tunable luminescence and desirable thermal‐ and photo‐stability.     

A Stable Bis(benzocyclobutadiene)‐Annelated Tetraazapentacene Derivative

Biphenylene‐2,3‐dione is a powerful reagent to build up cyclobutadiene‐containing azapolyheterocycles. The target structures are formed in high yields through classical condensation of suitable aromatic diamines with the biphenylenedione. To achieve the title compound, the biphenylenedione is coupled with a diaminobenzothiadiazole derivative. Reductive cleavage of the thiadiazole ring and subsequent condensation with the biphenylenedione gives the title compound in which a central tetraazapentacene is flanked by two benzocyclobutadiene units. This compound is stable despite its extended π‐system and its optical features are blueshifted in comparison to those of the symmetrical tetraazapentacene.     

Synthesis, chemical properties, and antimicrobial activity of 2- and 2,3-substituted [(tetrahydro-2,4-dioxopyrimidin-1(2H)-yl)phenoxy]naphthalene-1,4-diones

Abstract  

Mono- and disubstituted [(tetrahydro-2,4-dioxopyrimidin-1(2H)-yl)phenoxy]naphthalene-1,4-diones were synthesized by the reaction of dihydro-1-(3-hydroxy- and 4-hydroxyphenyl)pyrimidine-2,4(1H,3H)-diones and their 5- and 6-methyl derivatives with 2,3-dichloro-1,4-naphthoquinone. Their stability in alkaline and acidic media was investigated. Four of the compounds exhibited good antimicrobial activity against Staphylococcus aureus, Mycobacterium luteum, Candida tenuis, and Aspergillus niger.     

Quinoidal Azaacenes: 99 % Diradical Character

Quinoidal azaacenes with almost pure diradical character (y=0.95 to y=0.99) were synthesized. All compounds exhibit paramagnetic behavior investigated by EPR and NMR spectroscopy, and SQUID measurements, revealing thermally populated triplet states with an extremely low-energy gap ΔE_ST′ of 0.58 to 1.0 kcal mol⁻¹. The species are persistent in solution (half-life≈14–21 h) and in the solid state they are stable for weeks.     

Interpolation with Specified Error of a Point Series Belonging to a Monotone Curve

The paper addresses the problem of modeling a smooth contour interpolating a point series belonging to a curve containing no special points, which represents the original curve with specified accuracy. The contour is formed within the area of possible location of the parts of the interpolated curve along which the curvature values are monotonously increased or decreased. The absolute interpolation error of the point series is estimated by the width of the area of possible location of the curve. As a result of assigning each intermediate point, the location of two new sections of the curve that lie within the area of the corresponding output section is obtained. When the interpolation error becomes less than the given value, the area of location of the curve is considered to be formed, and the resulting point series is interpolated by a contour that lies within the area. The possibility to shape the contours with arcs of circles specified by characteristics is investigated.     

Dinuclear 3D metal complexes based on a carbacylamidophosphate ligand: redetermination of the ligand crystal structure

Dinuclear Ni(II), Co(II) and Zn(II) complexes of general formula $ \left[ {{\text{M}}_{ 2}^{\text{II}} {\text{Cl}}_{ 4} \left( {\text{HL}} \right)_{ 4} \left( {\text{i-PrOH}} \right)_{ 2} \cdot 2\left( {\text{i-PrOH}} \right)} \right] $ with a carbacylamidophosphate ligand, namely 2,2,2-trichloro-N-(dipiperidine-1-yl-phosphoryl)acetamide (CCl₃C(O)N(H)P(O)[N(CH₂)₅]₂), were synthesized and characterized by physicochemical and spectroscopic methods. Electronic absorption spectra of the nickel and cobalt complexes were measured at room temperature in toluene and in the solid state. The crystal structures of HL and [Ni₂Cl₄(HL)₄(i-PrOH)₂·2(i-PrOH)] have been determined by single-crystal XRD studies. Earlier, the structure of a monoclinic C2/c modification of HL was reported. In this paper, redetermination of the structure of HL with triclinic crystal system, P $ \overline{1} $ , was made. The nickel complex is a chloro-bridged dimer, in which the Ni(II) centers are in a distorted octahedral geometry and the neutral HL is coordinated via its phosphoryl oxygen atom. This coordination mode was determined for the first time for 3D metal carbacylamidophosphate complexes.     

Synthesis of 3‐Substituted 2‐Thioxo‐2,3‐dihydro‐1H‐benzofuro[3,2‐ d ] pyrimidin‐4(1H)‐ones

With the purpose of searching for new biologically active compounds, a method of synthesis of new heterocyclic systems [3‐alkyl(aryl)‐2‐thioxo‐2,3‐dihydro‐1H‐benzofuro[3,2‐d]pyrimidin‐4(1H)‐ones] has been developed. The method is based on the interaction of ethyl 3‐isothiocyanato‐1‐benzofurane‐2‐carboxylate in 2‐propanol with amines in the presence of an equimolecular quantity of triethylamine.     

Highly Efficient Phase Boundary Biocatalysis with Enzymogel Nanoparticles

The enzymogel nanoparticle made of a magnetic core and polymer brush shell demonstrates a novel type of remote controlled phase‐boundary biocatalysis that involves remotely directed binding to and engulfing insoluble substrates, high mobility, and stability of the catalytic centers. The mobile enzymes reside in the polymer brush scaffold and shuttle between the enzymogel interior and surface of the engulfed substrate in the bioconversion process. Biocatalytic activity of the mobile enzymes is preserved in the enzymogel while the brush‐like architecture favors the efficient interfacial interaction when the enzymogel spreads over the substrate and extends substantially the reaction area as compared with rigid particles.