Three new Hg metal-organic polymers generated from 1,4-bis(n-pyridyl)-3,4-diaza-2,4-hexadiene ligands

Three new polymeric mercury(II) thiocyanate coordination polymers, {[Hg₂(L₄)(SCN)₄]_n (1), [Hg₂(μ-L₅)(μ-SCN)₄]_n[Hg₂(μ-L₅)(μ-SCN)₄]_2n (2) and [Hg(L₆)(SCN)₂]_n (3); L₄ = 2,5-bis(2-pyridyl)-3,4-diaza-2,4-hexadiene, L₅ = 2,5-bis(3-pyridyl)-3,4-diaza-2,4-hexadiene and L₆ = 2,5-bis(4-pyridyl)-3,4-diaza-2,4-hexadiene) were prepared from reactions of mercury(II) thiocyanate with three organic nitrogen donor-based ligands under thermal gradient conditions using the branched tube method and fully characterized by infrared spectroscopy, elemental analysis, thermo gravimetric analysis, and single crystal X-ray diffraction. The compounds are structurally diverse and show very interesting structural motifs: the compound 1 is one-dimensional heterochiral double-chains. In compound 2, the bridging ligand L₅ adopts a transoid conformation and the network contains two interpenetrating coordination polymers, a 2D net and a 1D double-chain. The crystal structure of 3 consists of one-dimensional zigzag chains. Solid-state luminescent spectra of the compounds 1 and 3 indicate intense fluorescent emissions at ca. 393 nm and 363 nm, respectively.     

Mercury(II) acetate/thiocyanate coordination polymers with n-donor ligands, spectroscopic, thermal and structural studies

Three new mercury(II) coordination polymers, [Hg₂(μ-bpa)(μ-SCN)₂(μ-CH₃COO)₂]_n (1), [Hg₂(μ-4-bpdb)_1.5(μ-CH₃COO)(μ_1,1- SCN)(μ_1,3-SCN)(SCN)]_n · CH₃CN (2) and [Hg(μ-3-bpdb)(CH₃COO)₂]_n (3) {(bpa = 1,2-bis(4-pyridyl)ethane, 4-bpdb) = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene and 3-bpdb = 1,4-bis(3-pyridyl)-2,3-diaza-1,3-butadiene, have been synthesized and characterized by CHN elemental analysis and IR spectroscopy. The single crystal X-ray data show the compound 1 is two-dimensional coordination polymer as a result of simultaneously bridging 1,2-bis(4-pyridyl)ethane, acetate and thiocyanate ligands. The single-crystal X-ray data of the compound 2 show that the complex to be a two-dimensional polymer, one of Hg atoms has four-coordinate and one of them has seven-coordinate. Three SCN⁻ anions show three different coordination modes with terminal, μ_1,1-bridge and μ_1,3-bridge fashions. The structural studies of compound 3 show the structure may be considered a one-dimensional coordination polymer of mercury(II) consisting of linear chains formed by a bridging 3-bpdb ligand. The thermal stabilities of these compounds were studied by thermal gravimetric (TG) and differential thermal analyses (DTA).     

On the trophic spectrum of Pelophylax ridibundus (Pallas, 1771) (Amphibia: Anura: Ranidae) in western Iran

Using the stomach flushing technique, a total of 188 specimens of the Marsh Frog, Pelophylax ridibundus, were flushed, of which 129 had at least one food item in the stomach. The diet consisted of Annelida, Mollusca, Arthropoda and Chordata with Arthropoda being the most abundant group. Both diet volume and number of food items per stomach were significantly larger in April than in August. The proportion of frequency of occurrence (FOi%) of food categories did not show a constant food item in flushed materials. Pelophylax ridibundus prefers Diptera, Coleoptera, Amphipoda and Hymenoptera over other food categories. The Index of Relative Importance (IRI) for food categories differs between sexes and seasons. Differences were found in the food volume and the number of food items between seasons, but not between sexes. Prey volume is positively correlated with frog size.     

Polymorphism detection of promoter region of IFN-$$\gamma $$ and IL-2 genes and their association with productive traits in Mazandaran native breeder fowls

To identify polymorphism in interferon gamma (IFN-\(\upgamma \)) and interleukin-2 (IL-2) genes, blood samples were collected from 380 breeder hens of the Mazandaran native fowls breeding station. DNA extraction was performed through a modified salting-out method and fragments of 670 and 659 bp from the promoter regions of IFN-\(\upgamma \) and IL-2 genes were amplified by using specific primers, respectively. Following genotyping in the IFN-\(\upgamma \) gene using the Tsp509I restriction enzyme, two alleles of A and G with the frequencies of 0.55 and 0.45 and three genotypes of AA, AG and GG were observed with the frequencies of 0.32, 0.46 and 0.22, respectively. For the IL-2 gene, two alleles of A and G were also detected using the MnlI restriction enzyme with the frequencies of 0.58 and 0.42 and three genotypes of AA, AG and GG with the frequencies of 0.33, 0.50 and 0.17, respectively. Statistical analysis revealed significant associations between IL-2 gene single-nucleotide polymorphism and productive traits including the average egg weight (EW) at 345–375 days of age, egg number (EN) at 345–375 days of age and body weight (BW) at 8 weeks of age traits (\(P{<}0.05\)). Further, in a mean comparison analysis, there were also significant differences between different genotypes of the IL-2 gene in average EW at 28 and 30 weeks of age, in which AG genotypes showed higher performance. Additionally, for the IFN-\(\upgamma \) gene, a significant difference was found between the genotypes in average EW at 28 weeks of age trait. Therefore, it can be concluded that the above-mentioned polymorphisms could be considered as the pivotal genetic makers to improve Mazandaran native fowl breeding programmes to achieve the optimum performance in productive traits more efficiently.     

[Hg(μ-4,4′-bipy)(μ-AcO)(AcO)]n · n/2H2O, one-dimensional double-chain coordination polymer, syntheses, characterization, thermal, fluorescence, porous and structural studies

A new Hg^II coordination polymer with 4,4′-bipyridine and acetate anions, [Hg(μ-4,4′-bipy)(μ-AcO)(AcO)]_n · n/2H₂O (1), has been synthesized, characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR spectroscopy and its structure determined by single-crystal X-ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric (TG) and differential thermal analyses (DTA). The structural studies of compound 1 show that the structure may be considered as a coordination polymer of mercury(II) consisting of linear double chains formed by a bridging 4,4′-bipy ligand and by connecting acetate-bridged centrosymmetric {Hg₂(OAc)₂}²⁺ nodes. Solid-state luminescent spectra of the ligand 4,4′-bipyridine and compound 1 indicate a fluorescent broad emission band with the maximum intensity at ca 468.2 and 446.4 nm upon excitation at 295 nm, respectively. The stability of porous network after removal of guest water molecules is not confirmed by X-ray powder diffraction.     

New iridium bis‐terpyridine complexes: synthesis,characterization, antibiofilm and anticancer potentials

BioMetals - This study represents synthesis, characterization, screening of antibiofilm efficacy, and cytotoxicity of iridium bis-terpyridine complexes. The complexes were characterized by NMR, MS,...