Stereoview Images of Hydrogen-Bonded Quinoxalines with a Helical Axis; Pyrimidines and a Pyridazine That Form Extended Tapes.

Different supramolecular motifs are formed by the crystallisation of amino-substituted derivatives of quinoxaline, pyrimidine and pyridazine. These were made from the corresponding mono- or dichlorinated heterocycles by a nucleophilic displacement reaction. The pyridine-type nitrogen atoms activate the chlorine atoms because they can stabilise a negative charge, which forms when the amine attacks the ring.

Alzheimer disease-like neuropathologic changes in a geriatric baboon ().

Importance: Alzheimer's disease (AD) is the most common cause of dementia in the elderly with the incidence rising exponentially after the age of 65 years. Unfortunately, effective treatments are extremely limited and definite diagnosis can only be made at autopsy. This is in part due to our limited understanding of the complex pathophysiology, including the various genetic, environmental, and metabolic contributing factors.

Sequential Nucleophilic Aromatic Substitution Reactions of Activated Halogens.

Building blocks have been identified that can be functionalised by sequential nucleophilic aromatic substitution. Some examples are reported that involve the formation of cyclic benzodioxin and phenoxathiine derivatives from 4,5-difluoro-1,2-dinitrobenzene, racemic quinoxaline thioethers, and sulfones from 2,3-dichloroquinoxaline and (2-aminophenylethane)-2,5-dithiophenyl-4-nitrobenzene from 1-(2-aminophenylethane)-2-fluoro-4,5-dinitrobenzene. Four X-ray single-crystal structure determinations are reported, two of which show short intermolecular N-ON "π hole" contacts.

Poly[3-methyl-pyridinium [(μ-di-hydrogen phosphito)bis(μ-hydrogen phosphito)dizinc]].

In the title compound, {(CHN)[Zn(HPO)(HPO)]}, the constituent ZnO, HPO and HPO polyhedra of the inorganic component are linked into (010) sheets by Zn-O-P bonds (mean angle = 134.4°) and the layers are reinforced by O-H⋯O hydrogen bonds. The protonated templates are anchored to the inorganic sheets bifurcated N-H⋯(O,O) hydrogen bonds.

Chiral Thianthrenes.

The absolute configuration and stability of two thianthrene chiral sulfoxides has been determined by means of X-ray single-crystal structure determinations. The analyses and configurations allow verification that the diastereomeric sulfoxides are stable in solution and are not interconverting, which has been suggested in some studies of sulfoxides. The two thianthrene sulfoxides have slightly different values, which allowed their separation using flash chromatography on silica.

New Functionalized Phenoxazines and Phenothiazines.

The reaction of either 2-aminophenol or 2-(-methylamino)phenol with 1,2-difluoro-4,5-dinitrobenzene and sodium carbonate in EtOH gives 2,3-dinitrophenoxazines. One nitro group, conjugated to the aryl ether, was displaced from 2,3-dinitro-10-methylphenoxazine with different nucleophiles: BuNH, KOEt, and KOH. The reaction of 2-aminothiophenol with 1,2-difluoro-4,5-dinitrobenzene under the same conditions gives 2,3-dinitrophenothiazine.

Porous and Close Packed Supramolecular Assemblies from 2,4-Difluoronitrobenzene with Three Different Linkers and an -Butylamine Cap.

A porous structure formed from sheets with cavities and two close packed structures were crystallised from building blocks prepared from 2,4-difluoronitrobenzene, a diamine linker and -butylamine. The porous structure crystallised from a flexible building block prepared using 1,4-diaminobutane as linker. The close packed structures were prepared using either piperazine or 1,4-bis(aminomethyl)benzene as a linker and have less conformational freedom.

Consistent zincophosphite 4-ring 'ladder' chain structural motif with isomeric ligands.

The syntheses and crystal structures of four hydro-thermally prepared organo-zinc phosphites, . poly[[(2-amino-3-methyl-pyridine)-μ-phospho-nato-zinc] hemihydrate], {[Zn(HPO)(CHN)]·0.5HO} , (I), poly[(2-amino-4-methyl-pyridine)-μ-phospho-nato-zinc], [Zn(HPO)(CHN)] , (II), poly[(2-amino-5-methyl-pyridine)-μ-phospho-nato-zinc], [Zn(HPO)(CHN)] , (III), and poly[bis-(2-amino-4-methyl-pyridinium) [tetra-μ-phospho-nato-trizinc] monohydrate], {(CHN)[Zn(HPO)]·HO} , (IV), are described.

Heterocyclic Synthesis of Crowded Aposafranones: Structure of 1-Methyl-8-dimethylamino-10-phenylphenazin-2-(10H)one and Related Compounds.

Oxidative condensation of three p-phenylenediamines with 3-hydroxy-2-methyl-N-(phenylamino)benzene gives new coloured aposafranones. 2-Methylresorcinol is easy to convert into the asymmetric building block 3-hydroxy-2-methyl-N-(phenylamino)benzene with aniline. The aposafranones are sterically crowded because of the 1-methyl and N-phenyl groups.

Different conformations and packing motifs in the crystal structures of four thio-phene-carbohydrazide-pyridine derivatives.

The crystal structures of four thio-phene-carbohydrazide-pyridine derivatives, '-[()-pyridin-3-yl-methyl-idene]thio-phene-2-carbohydrazide, CHNOS, (I), '-[()-pyridin-2-yl-methyl-idene]thio-phene-2-carbohydrazide, CHNOS, (II), -methyl-'-[()-pyridin-2-yl-methyl-idene]thio-phene-2-carbohydrazide, CHNOS, (III) and '-[()-pyridin-2-yl-methyl-idene]-2-(thio-phen-2-yl)ethano-hydrazide, CHNOS, (IV) are described. The dihedral angles between the thio-phene ring and the pyridine ring are 21.4 (2), 15.

Flux syntheses and single-crystal structures of CsNa (AsO) ( = Zr, Hf).

The isostructural compounds caesium deca-sodium tetra-zirconium nona-arsenate, CsNaZr(AsO), and caesium deca-sodium tetra-hafnium nona-arsenate, CsNaHf(AsO), arose as unexpected single-crystal products from the reactions of NaCO, MO ( = Zr, Hf) and AsO in a eutectic flux of NaCl and CsCl. They consist of O octa-hedra and AsO tetra-hedra sharing vertices to generate three-dimensional polyhedral networks encapsulating the caesium and sodium ions. The MO groups share all their vertices with adjacent As atoms but the As atoms have one or two 'terminal' O atoms not bonded to Zr or Hf.

Potential Building Blocks for 1,4-Dihydro-N-heteroacenes.

Studies have been performed aimed at the synthesis of N-heteroacenes via substitution reactions of 4,5-difluoro-1,2-dinitrobenzene with a diamine. The fluorine atoms are displaced first, followed by an activated nitro group. Two intermediates have been characterised by X-ray single-crystal structure determinations.

Sensitization of Endothelial Cells to Ionizing Radiation Exacerbates Delayed Radiation Myelopathy in Mice.

Delayed radiation myelopathy is a rare, but significant late side effect from radiation therapy that can lead to paralysis. The cellular and molecular mechanisms leading to delayed radiation myelopathy are not completely understood but may be a consequence of damage to oligodendrocyte progenitor cells and vascular endothelial cells. Here, we aimed to determine the contribution of endothelial cell damage to the development of radiation-induced spinal cord injury using a genetically defined mouse model in which endothelial cells are sensitized to radiation due to loss of the tumor suppressor p53.

Crystalline Forms of Trazodone Dihydrates.

In this study, treatment of anhydrous trazodone powder with ammonium carbamate in warm water crystallised two new polymorphs or dihydrates of trazodone after 5 h, whose structures were determined by X-ray single crystal diffraction. Each dihydrate contains infinite zigzag hydrogen-bonded chains of water molecules, which are stabilised by the N4 acceptor atom of the piperazine ring and the pendant carbonyl O1 atom of the triazole ring, as well as other water molecules. The strong dipole moment expected for the O1 atom makes it a good hydrogen bond acceptor for stabilising the chains of water molecules.

A Potential Iterative Approach to 1,4-Dihydro-N-Heteroacene Arrays.

A new method for the synthesis of substituted 1,4-dihydrophenazines is reported and the structure of N-butyl-5-methyl-3-nitro-5,10-dihydrophenazine is proven by an X-ray single-crystal structure determination.

Understanding the remarkable difference in liquid crystal behaviour between secondary and tertiary amides: the synthesis and characterisation of new benzanilide-based liquid crystal dimers.

A number of liquid crystal dimers have been synthesised and characterised containing secondary or tertiary (N-methyl) benzanilide-based mesogenic groups. The secondary amides all form nematic phases, and we present the first example of an amide to show the twist-bend nematic (NTB) phase. Only two of the corresponding N-methylated dimers formed a nematic phase and with greatly reduced nematic-isotropic transition temperatures.

Sudden Unexpected Death in a Child From Acute Myeloid Leukemia.

Acute myeloid leukemia can rarely cause sudden, unexpected death in children. Presentation may be non-specific and death may occur in children with no prior medical history. Herein we present the case of a previously healthy 2-year and 2 month-old White girl, who on autopsy, was found to have acute myeloid leukemia with KMT2A rearrangement extensively involving all major thoracic and abdominal organs.

Hydro-thermal synthesis and crystal structure of poly[bis-(μ-3,4-di-amino-benzoato)manganese], a layered coordination polymer.

The hydro-thermal synthesis and crystal structure of the title two-dimensional coordination polymer, poly[bis-(μ-3,4-di-amino-benzoato-κ ,,')manganese(II)], [Mn(CHNO)] , are described. The Mn cation (site symmetry ) adopts a tetra-gonally elongated -MnNO octa-hedral coordination geometry and the μ-,,' ligand (bonding from both carboxyl-ate O atoms and the -N atom) links the metal ions into infinite (10) layers. The packing is consolidated by intra-layer N-H⋯O and inter-layer N-H⋯N hydrogen bonds.

Different packing motifs in the crystal structures of three mol-ecular salts containing the 2-amino-5-carb-oxy-anilinium cation: CHNO ·Cl, CHNO ·Br and CHNO ·NO ·HO.

The syntheses and crystal structures of three mol-ecular salts of protonated 3,4-di-amino-benzoic acid, . 2-amino-5-carb-oxy-anilinium chloride, CHNO ·Cl, (I), 2-amino-5-carb-oxy-anilinium bromide, CHNO ·Br, (II), and 2-amino-5-carb-oxy-anilinium nitrate monohydrate, CHNO ·NO ·HO, (III), are described. The cation is protonated at the -N atom (with respect to the carb-oxy group) in each case.

Synthesis, crystal structures and, magnetic and photoluminescence properties of lanthanide-based metal-organic frameworks constructed with 2,5-dihydroxybenzene-1,4-dicarboxylic acid.

Four new lanthanide(iii) coordination polymers (1-4) have been synthesized by using 2,5-dihydroxybenzene-1,4-dicarboxylate (Dhbdc, CHO ) as a ligand and characterized by elemental analysis, infrared spectroscopy, TGA-DSC (Thermogravimetric Analysis-Differential Scanning Calorimetry) and single crystal X-ray diffraction studies. The isolated complexes include; [Ce(Dhbdc)(HO)Cl] (1) and [Ln(Dhbdc)(HO)] ·3(CHO)·HO [Ln = Eu (2), Gd (3) and Tb (4)]. The structural analysis reveals that compound 1 is a two-dimensional polymer in which the cerium atoms are coordinated by six oxygen and two bridging chloride ions adopting a dodecahedral geometry.