Structural characterisation and photoluminescence of a pyridine–diimine compound

A pyridine–diimine compound N,N′-[pyridine-2,6-diyldi(E)methylylidene]bis(4-chloroaniline) is synthesised by a Schiff base condensation of 2,6-diformylpyridine with 4-chloroaniline in methanol and characterised by spectroscopic and analytical techniques. The molecular structure of the compound is determined by the single crystal X-ray diffraction study. The compound crystallizes in the monoclinic crystal system, I2/c space group with unit cell parameters a = 7.0843(12) Å, b = 6.1909(11) Å, c = 36.262(6) Å, β = 91.576(3)°, V = 1589.8(5) ų and Z = 4. There is an intermolecular hydrogen bonding in the molecule resulting in a 1D hydrogen bonding chain and these hydrogen bonding chains are linked by Cl…HC(aromatic) interactions forming a 2D network. Crystal packing of the compound is determined by Cl…HC and π–π interactions. In the fluorescence emission spectra in CH₃CN, DMF, DMSO and EtOH, the compound shows only one emission maximum.     

1,7-difluoro-1,1,3,5,7,7-hexanitro-3,5-diazaheptane: Crystal structure and sensitivity to mechanical actions

The X-ray crystallographic analysis of 1,7-difluoro-1,1,3,5,7,7-hexanitro-3,5-diazaheptane has been carried out. We have also determined its sensitivity to mechanical actions and a set of calculated and experimental data on explosion characteristics.     

Selective assembly of Au-Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> nanoparticle hetero-dimers

Hetero-dimeric magnetic nanoparticles of the type Au-Fe₃O₄ have been synthesised from separately prepared, differently shaped (spheres and cubes), monodisperse nanoparticles. This synthesis was achieved by the following steps: (a) Mono-functionalising each type of nanoparticles with aldehyde functional groups through a solid support approach, where nanoparticle decorated silica nanoparticles were fabricated as an intermediate step; (b) Derivatising the functional faces with complementary functionalities (e.g. amines and carboxylic acids); (c) Dimerising the two types of particles via amide bond formation. The resulting hetero-dimers were characterised by high-resolution TEM, Fourier transform IR spectroscopy and other appropriate methods.

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Graphical Abstract Nano-LEGO: Assembling two types of separately prepared nanoparticles into a hetero-dimer is the first step towards complex nano-architectures. This study shows a solid support approach to combine a gold and a magnetite nanocrystal.

     

Molecular characterization and first report of Cryptosporidium genotypes in human population in the Slovak Republic

In our study, we examined 91 fecal samples from five different groups of people containing HIV patients, hemodialysis patients, kidney transplant recipients, immunocompetent humans without clinical signs, and humans with suspected cryptosporidiosis. The purpose of our study was to determine species and genotype composition of representatives of Cryptosporidium spp. using PCR analysis of small subunit ribosomal RNA gene and 60‐kDa glycoprotein gene and examine their phylogenetic relationship. In HIV‐positive/AIDS‐infected group of patients and in hemodialysis patients, no presence of Cryptosporidium species was detected. In two kidney transplant recipients, we detected species/genotypes Cryptosporidium parvum IIaA13G1T1R1 (KT355488) and Cryptosporidium hominis IaA11G2R8 (KT355489) and in two immunocompetent patients with clinical symptoms, we identified Cryptosporidium muris and C. hominis IbA10G2T1 (KT355490). In the group of healthy immunocompetent individuals without clinical signs, we identified species/genotype C. hominis IbA11G2 (KT355491) in one sample.