No abstract

No abstract

The title compound, bis(μ‐4‐acetyl‐3‐amino‐5‐methyl­pyrazol­ato‐N1:N2)­bis­[(acetato‐O)­(4‐acetyl‐3‐amino‐5‐methyl­pyraz­ole‐N2)­zinc(II)], [Zn2(C6H8N3O)2(C2H3O2)2(C6H9N3O)2], ex‐ists as a centrosymmetric binuclear mol­ecule with two tetrahedrally coordinated Zn atoms bridged by two pyrazolate anions. The geometry of the terminal and bridging pyrazole ligands are slightly different as a consequence of their differing modes of coordination.

ABSTRACT. The use of aquatic plants to analyze the heavy metal pollution of a lake environment has a number of advantages over the standard chemical methods of the analysis of metal presence in water and sediment. The macrophyta Lemna minor L., sampled from Lake Skadar in Montenegro has been used as a bio-indicator. Floating macrophyte L. minor accumulates metals from water through its submerged roots and floated leaves. The contents of Cd, Cu, Co, Cr, Mn, Ni, Pb, Zn, Sr and V were determined in sediments, water and the plant. The results obtained indicated a very high capacity of L. minor for the accumulation of Mn. In addition, higher Zn concentration was found in root tissue comparing to the sediment. The concentration of the other metals under investigation decreases in the following order: sediment > L. minor (root) > L. minor (leaf) > water. Higher concentrations of all metals in the tissue of L. minor were observed at the end of the growing season. A higher metal content was recorded in the root compared to the leaf. In descending order, the concentrations in plant tissues were found for the following metals: Mn > Zn > Sr > Cu > Ni > Pb > Co > V > Cr > Cd, while the series of bioaccumulation is, in descending order: Mn > Zn > Ni > Co > Pb > Cu > Cr > V > Sr > Cd.

In order to make chemical characterization of two Origanum vulgare L. subspecies in Montenegro, the essential oils of five wild growing populations were analyzed. Among 67 oil constituents, in O. vulgare subsp. hirtum dominant one was oxygenated monoterpene carvacrol (74.3%), while in O. vulgare subsp. vulgare prevailed sesquiterpene hydrocarbons: germacrene D (15.4-27.9%) and β-caryophyllene (7.7-14.6%), and among oxygenated monoterpenes: α-terpineol (4.8-17.8%), linalyl acetate (0.5-9.6%), linalool (3.0-8.8%), thymol (0.2-8.3), terpinene 4-ol (1.5-8.3%). Several of the main essential oil constituents appeared to be highly intercorrelated. Strong positive correlations (r > 0.70; P < 0.01) were observed between α-terpineol and linalyl acetate, αterpineol and thymol, linalyl acetate and thymol, γ-terpenene and carvacrol, (E)-β-ocimene and β-bisabolene, while strong negative correlations (r <-0.70; P < 0.01) were evidenced between γ-terpenene and β-caryophyllene, γ-terpenene and germacrene D, p-cymene and germacrene D. Multivariate analyses allowed the grouping of the populations into three distinct chemotypes. Population P5 (Origanum vulgare subsp. hirtum) was distinguished from O. vulgare subsp. vulgare populations by predominance of carvacrol, while within the typical subspecies the population P1 (Boljevići) separated from P2 (Radovče), P3 (Lipovo) and P4 (Grahovo) by high oil levels of α-terpineol, linalyl-acetate and thymol.

This is the first study, 10 years after the war activities, to report about the content of heavy metals and metalloids, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) found in samples of soils from selected playgrounds in Sarajevo. Due to the fact that children are in direct contact with surface soils, it has been recommended that children's playgrounds should be given special consideration in this respect. Basic properties (pH in HO, pH in 1 mol dm KCl, humus, and CaCO) of the examined soils were determined. Samples for the determination of heavy metals and metalloids were prepared by microwave-assisted acid digestion and determined by using an inductively coupled plasma optical emission spectrometer. Fluorine was determined potentiometrically. Gas chromatography with mass spectrometry was used for determination of PAHs and PCBs. Determined contents (mg kg) for Cd, Pb, Hg, Cr, Ni, Cu, Zn, Co, Mo, Fe, Se, As, B, and F were in the ranges from: 0.031 ± 0.03 to 0.52 ± 0.05; 26.1 ± 2.5 to 47.7 ± 4.5; 0.07 ± 0.01 to 0.50 ± 0.08; 26.2 to 50; 19.5 ± 1.6 to 33.3 ± 2.7; 12.8 ± 1.8 to 31.9 ± 4.5; 56.0 ± 4.0 to 89.0 ± 6.5; 6.7 ± 0.6 to10.6 ± 1.0; <0.8; 3.05 to 7.35; 1.98 to 2.60; 6.5 ± 0.8 to 17.2 ± 2.0; 0.4 to 3.6, and 286 to 575, respectively. The total PAHs ranged between 0.184 ± 0.32 mg kg and 7.983 ± 1.389 mg kg. The total PCBs was <0.002 mg kg. Our preliminary results may contribute to more accurate health risk assessments of the soils, and may be included in projects planning children's health risk assessments and adopting environmental legislation which has not been sufficiently regulated in Bosnia and Herzegovina so far.

In the continuation of our systematic research of pyrazole coordination compounds, complexes of Cu(II), Ni(II), Co(II) and Zn(II) with 4-nitro-3-pyrazolecarboxylic acid ligand (L) were synthesized in the reaction of warm ethanolic solutions of the ligand and CuCl 2 Á2H 2 O, Ni(CH 3 COO) 2 , CoCl 2 Á6H 2 O and Zn(CH 3 COO) 2 , mixed in the metal-to-ligand ratio of 1:2. As the compounds could not be obtained in the form suitable for single-crystal structure analysis, their bis(ligand) structures, ML 2 (M = Cu II , Ni II , Co II and Zn II ) were proposed on the basis of elemental analysis, IR spectrometry, conductometric and TG-MS measurements. The low conductivity of the compounds additionally supports the deprotonation of the ligand and the formation of neutral complexes. The solvent content was calculated using the thermogravimetric (TG) data. According to TG data, the copper(II) compound crystallizes with 8 while nickel(II) complex with 4 water molecules, CuL 2 Á8H 2 O, NiL 2 Á4H 2 O. Complexes of Co(II) and Zn(II) contain 1 and 1.5 water molecules. Despite the differences in solvation properties, the high similarity in the course of the decomposition refers to the similar coordination mode of the organic ligand. The crystal and molecular structures of HLÁH 2 O and NH 4 [LHL] were determined by single-crystal X-ray structure analysis. Biological research based on determining the inhibition effect of commercial fungicide Cabrio top, ligand, and all newly synthesized complexes on Ph. viticola has been carried out using the phytosanitary method.

No abstract