elemental analyses
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2022 ◽  
Author(s):  
Eman M. Sayed ◽  
Reda Hassanien ◽  
Nasser Farhan ◽  
Hanan F. Aly ◽  
Khaled Mahmoud ◽  
...  

Abstract Regioselective cyclocondensation of 2,4-diacetyl-5-hydroxy-5-methyl-3-(3-nitrophenyl/4-nitrophenyl)cyclohexanones 1a,b with cyanothioacetamide afforded the corresponiing 7-acetyl-4-cyano-1,6-dimethyl-6-hydroxy-8-(3-nitrophenyl/4-nitrophenyl)-5,6,7,8-tetrahydro-soquinoline-3(2H)-thiones 2a,b in 93-96% yield. Reaction of compounds 2a,b with some ethyl iodide, 2-chloroacetamide (4a) or its N-aryl derivatives 4b-e by refluxing in ethanol, in the presence of slightly excess molar amounts of sodium acetate trihydrate, for one hour gave 3-ethylthio-5,6,7,8-tetrahydro-isoquinoline 3 and (5,6,7,8-tetrahydroisoquinolin-3-ylthio)acetamides 5a-i, respectively. On heating compounds 5b-d,f,g in ethanol containing a catalytic amount of sodium carbonate, they converted into their isomeric 1-amino- 6,7,8,9-tetrahydrothieno[2,3-c]isoquinoline-2-carboxamides 6b-d,f,g. Structural formulae of all synthesized compounds were characterized on the basis of their elemental analyses and spectroscopic data. Also, the biological evaluation of the synthesized isoquinolines as anticancer and antioxidant agents have been carried out and the obtained results are reported herein.


Author(s):  
Shao-Dong Li ◽  
Feng Su ◽  
Cheng-Yong Zhou ◽  
Qi-Long Hu ◽  
Ya-Qi Li ◽  
...  

Two new isostructural complexes, namely, poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)cobalt(II)], [Co(C15H8O7)(C12H8N2)(H2O)] n or [Co(μ3-Hcpota)(phen)(H2O)] n , I, and poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)nickel(II)], [Ni(C15H8O7)(C12H8N2)(H2O)] n or [Ni(μ3-Hcpota)(phen)(H2O)] n , II, have been synthesized by solvothermal reactions. Complexes I and II were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, and powder and single-crystal X-ray diffraction. They both present two-dimensional structures based on [M 2(μ-COO)2]2+ (M = CoII or NiII) dinuclear metal units with a fes topology and a vertex symbol (4·82). Interestingly, the positions of the two dimeric metal motifs and the two partially deprotonated Hcpota2− ligands reproduce regular flying butterfly arrangements flipped upside down and sharing wings in the ab plane. Magnetic studies indicate antiferromagnetic interactions (J = −5.21 cm−1 for I and −11.53 cm−1 for II) in the dimeric units, with Co...Co and Ni...Ni distances of 4.397 (1) and 4.358 (1) Å, respectively, that are related to double syn–anti carboxylate bridges.


Author(s):  
Xue Bai ◽  
Ran Hai ◽  
Zhonglin He ◽  
Xueyan Wang ◽  
Ding Wu ◽  
...  

Quantitative in-situ elemental analyses of the impure deposited layer on the plasma-facing components (PFCs) of magnetically confined fusion devices such as EAST are crucial and challenging. Laser-induced breakdown spectroscopy (LIBS)...


2022 ◽  
Author(s):  
Alexandros Mortis ◽  
Caecilia Maichle-Moessmer ◽  
Reiner Anwander

A series of tris(trimethylsilylmethyl) yttrium donor adduct complexes was synthesized and fully characterized by X-ray diffraction, 1H/13C/29Si/31P/89Y heteronuclear NMR and DRIFT spectroscopy as well as elemental analyses. Treatment of Y(CH2SiMe3)3(thf)x...


2021 ◽  
Vol 83 (4) ◽  
pp. 141-150
Author(s):  
Alexandra Tsalickis ◽  
Matthew Waters ◽  
Joshua Campbell

Whereas bat guano is gaining viability in accurately reconstructing local paleoenvironmental and climatic conditions, overall reviews of methods for analyzing and collecting bat guano cores have received less attention. Guano cores have been collected from several locations (e.g., United States, Romania, Philippines, and southeast Asia), and the processing and collection methods are quite similar despite a lack of standardized techniques. Physical, chemical, and elemental analyses on guano samples have focused on the interpretation of precipitation changes over time, with additional applications from stable isotope analysis being used for other paleoenvironmental conditions. We obtained three bat guano cores from Alabama and Tennessee to evaluate the collecting and processing techniques of guano. Climatic temperature changes were not analyzed in this study. The purpose of this investigation was to summarize multiple techniques and approaches used to process and analyze bat guano cores with a focus on reconstructing paleoclimate in cave environments throughout the globe. From these three cores, we describe challenges and make recommendations for improving guano analysis.


2021 ◽  
Vol 68 (4) ◽  
pp. 961-969
Author(s):  
Shuang Han ◽  
Yuan Wang

Urease inhibitors can inhibit the decomposition rate of urea, and decrease the air pollution caused by ammonia. In this paper, four new copper(II) complexes [CuL(ONO2)]n (1), [Cu2L2(μ1,3-N3)2] (2), [CuBrL] (3), and [CuClL] (4), where L = 5-bromo-2-(((2-methylamino)ethyl)imino)methyl)phenolate, have been synthesized and characterized. The complexes were characterized by elemental analyses, IR and UV-Vis spectroscopy, molar conductivity, and single crystal X-ray diffraction. X-ray analysis reveals that Cu atoms in complexes 1 and 2 are in square pyramidal coordination, and those in complexes 3 and 4 are in square planar coordination. The molecules of the complexes are linked through hydrogen bonds and π···π interactions. The inhibitory effects of the complexes on Jack bean urease were studied, which showed that the complexes have effective activity on urease.


2021 ◽  
Vol 68 (4) ◽  
pp. 921-929
Author(s):  
Wei-Guang Zhang ◽  
Ji-Hong Liang

Three new zinc complexes [Zn3L2(μ2-η1:η1-CH3COO)2(μ2-η2:η0-CH3COO)2] (1), [ZnCl2(HL)] (2) and [ZnBr2(HL)] (3), where L = 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-isopropylammonio) ethyl)imino)methyl)phenolate, have been synthesized under microwave irradiation. The complexes were characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. X-ray analysis revealed that the Zn atoms in complex 1 are in square pyramidal and octahedral coordination, and those in complexes 2 and 3 are in tetrahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π···π interactions. In order to evaluate the biological activity of the complexes, in vitro antibacterial against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa was assayed.


Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7392
Author(s):  
Dmitry I. Pavlov ◽  
Alexey A. Ryadun ◽  
Andrei S. Potapov

A luminescent coordination polymer with the overall formula {[Zn(tr2btd)(bpdc)]∙DMF}n (where tr2btd = 4,7-di(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole; bpdc = 4,4′-biphenyldicarboxylate) was synthesized and characterized by single-crystal and powder X-ray diffraction, thermogravimetric, infrared spectroscopy, and elemental analyses. Luminescent properties of the obtained compound were studied in detail both in the solid state and as a suspension in N,N-dimethylacetamide (DMA). It was found that {[Zn(tr2btd)(bpdc)]∙DMF}n exhibits bright turquoise luminescence with excellent quantum efficiency and demonstrates turn-on fluorescence enhancement effect upon soaking in DMA Al3+ solution. Fluorescence titration experiments were carried out and the detection limit for Al3+ ions was calculated to be 120 nM, which is among the lowest reported values for similar materials. Moreover, compound demonstrated excellent selectivity and reusability, and the mechanism of the response is discussed. These results indicate that {[Zn(tr2btd)(bpdc)]∙DMF}n is a promising probe for sensitive fluorescent Al3+ detection.


2021 ◽  
Author(s):  
Jean Milot ◽  
et al.

Method of elemental analyses, a description of the Iberian galena deposits, and Figure S1 (Pb ratios of coins and Iberian galena samples from the various mining provinces).<br>


2021 ◽  
Author(s):  
Jean Milot ◽  
et al.

Method of elemental analyses, a description of the Iberian galena deposits, and Figure S1 (Pb ratios of coins and Iberian galena samples from the various mining provinces).<br>


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