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1.
Ultrason Sonochem ; 52: 428-436, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30573435

RESUMO

Under mode of ultrasonic vibration, the neutral octahedral mononuclear [trans-CuBr2(N ∩ N)2]·3H2O complex with N ∩ N = 2,2-dimethylpropane-1,3-diamine was obtained. The structure of the desired complex was characterized by UV-Vis. spectroscopy, FT-IR, EDX, MS, SEM, TG/DTA and CHN-analysis. The octahedral-structure of the desired Cu(II) complex was proven via XRD single-crystal diffraction and its molecular interactions were computed by Hirschfeld surface analysis. Alcohol (as solvent) and short ultrasonic vibration dose period played a critical role in sonochemistry synthesis of octahedral neutral trans-CuBr2(N ∩ N)2 complex instead of trigonal bi-pyramidal monocation [CuBr(N ∩ N)2]Br one. Due to the Jahn-Teller effect, the complex exhibited a trans bonds elongation along Br-Cu-Br axis originating a distorted-octahedral Cu(II), as revealed by the XRD measurements (Br-Cu = 3.04 Å). Therefore, the Solvatochromic behavior of the complex was successfully performed since the trans di-bromide ions are loosely coordinated to Cu(II) center, the change in complex solutions colors by using different solvents which can be detected even by naked-eye supported atypical Jahn-Teller elongation effect formation. TG/DTA and Flynn Wall Ozawa (FWO) isoconversional kinetic methods were applied for the complex to figure out the thermal behavior, kinetic of the ligands de-structured and estimate its Ea/α relation. The complex binding mode to the CT-DNA was examined by UV-vis. spectroscopic, melting curve, CV and viscosity tests. The complex exhibited very strong DNA binding via an intercalation mode of coordination with Kb = 6.5 × 105 value.


Assuntos
Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Cobre/química , DNA/metabolismo , Solventes/química , Ondas Ultrassônicas , Animais , Bovinos , Técnicas de Química Sintética , Cristalografia por Raios X , Diaminas/química , Eletroquímica , Cinética , Ligantes , Modelos Moleculares , Conformação Molecular , Estereoisomerismo
2.
J Environ Monit ; 7(12): 1200-6, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16307072

RESUMO

Distribution of antimony and its inorganic species in soil samples along two traffic routes (A14, Rankweil and S36, Knittelfeld) in Austria was determined, since vehicle emissions are an important anthropogenic source of Sb in soil. The samples were taken along three parallel lines at about 0.2, 2 and 10 m distances from the edge of the road and in two depths range (0-5 and 5-10 cm from the soil surface). The optimized extraction was carried out using 100 mmol L(-1) citric acid at pH 2.08 applying an ultrasonic bath for 45 min at room temperature. Speciation analyses were done using on-line isotope dilution after a chromatographic separation of Sb species. Results of the two traffic routes confirmed significant accumulations of Sb at surface (0-5 cm depth) exceeding the natural background values by more than ten times at the S36 or four times at the A14. Concentrations of the extractable inorganic species decreased to natural background levels within a few meters from the edge of the traffic lane. The predominant Sb species was Sb(V). The Sb(III) concentrations at 5-10 cm depths range are nearly constant with distance from the edges of the two roads. Magnetic susceptibility data of all soil samples show the same distribution pattern as Sb and Sb(V) concentrations along the two traffic roads with an excellent correlation. This is an evidence for an anthropogenic source of Sb such as abrasions of motor vehicles surfaces or braking linings. The input of Sb and its inorganic species at one of the sampling sites (Knittelfeld) in samples taken in 2002 and in those taken recently (2005) was monitored. An increase in Sb (>or=30%), Sb(v)(>or=51%) and Sb(iii)(>or=10%) concentrations was only observed near the edge (

Assuntos
Antimônio/análise , Poluentes do Solo/análise , Antimônio/química , Áustria , Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental , Espectrometria de Massas , Veículos Automotores , Emissões de Veículos
3.
Anal Bioanal Chem ; 383(7-8): 1052-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16136301

RESUMO

Speciation analysis of Sb(III) and Sb(V) in a soil sample was performed through extraction and on-line isotope dilution concentration determination after a chromatographic separation. The total Sb concentration found in a through traffic contaminated soil sample was (4.17 microg g(-1), 0.3 microg g(-1) SD, n=6). It was determined using ICP-MS after soil digestion using the sodium peroxide sintering method. The optimized extraction procedure for speciation analysis was carried out using 100 mmol L(-1) citric acid at pH 2.08 by applying an ultrasonic bath for 45 min at room temperature. The effects of citric acid concentration (0-500 mmol L(-1)), pH (1-6), and temperature (30-60 degrees C) on inorganic antimony species distribution in the examined sample were studied and optimized. The separation of Sb(III) and Sb(V) was achieved using an anion exchange column (PRP-X100) and 10 mmol L(-1) EDTA and 1 mmol L(-1) phthalic acid at pH 4.5 as a mobile phase. The eluent from the HPLC was mixed with an enriched (94.2%) (123)Sb spike solution that was pumped by a peristaltic pump with a constant flow rate (0.5 mL min(-1)) in a three-way valve. The blend passed directly to the Conikal nebulizer of the ICP-MS. By using the above extraction procedure and methodology, 43.2% Sb(V) (2.9% RSD, n=3) and 6.0% Sb(III) (1.3% RSD, n=3) of total Sb found in the sample could be detected. The detection limits achieved by the proposed method were 20 ng L(-1) and 65 ng L(-1) for Sb(V) and Sb(III), respectively. The precision, evaluated by using RSD with 100 ng L(-1) calibration solutions, was 2.7% and 3.2% (n=6) for Sb(V) and Sb(III), respectively, in aqueous solutions.


Assuntos
Antimônio/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Espectrometria de Massas/métodos , Solo/análise , Antimônio/química , Cátions , Ácido Cítrico/química , Concentração de Íons de Hidrogênio , Técnica de Diluição de Radioisótopos , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Solventes/química , Temperatura , Fatores de Tempo
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