The interaction of guanosine 5 -monophosphate, GMP, with the thallium(I) ion was studied by UV-vis and potentiometric titration methods and 31 P NMR spectroscopy. Both NMR spectra and UV-vis titration data have shown that GMP coordinates via guanine to the thallium(I) ion in the pH range 1.5-10. Our study of the system Tl(I) + GMP was performed in water-methanol mixtures with different volume ratios of methanol. The complexation equilibrium in the pH range of study led to the following mononuclear species: TlH 2 (GMP) + , TlH(GMP) and Tl(GMP) − , where (GMP) 2− represents the fully dissociated ligand. The formation constants of the species were calculated in the various media at constant temperature (25 • C) and constant ionic strength of sodium perchlorate (0.1 mol dm −3 ) using a suitable computer program. The formation constants were analyzed in terms of Kamlet and Taft's parameters. A single-parameter correlation of the formation constants, β 121 , β 111 and β 101 vs α (hydrogen-bond donor acidity), β (hydrogen-bond acceptor basicity) and for π * (dipolarity/polarizability) are relatively poor in all solutions, but multi-parameter correlations represent significant improvements with regard to the single-parameter model. In this work, we have also used the normalized polarity parameter, E T N , alone and in combination with some of the Kamlet-Taft parameters to find a better correlation of the formation constants in different methanol-water mixtures.
In this work, fourier transform infrared spectroscopy (FT-IR) is used to identify and detection the adulteration of pistachio oil with cheap edible oils of corn, sunflower and soybean. For this purpose, pistachio oil was blended with cheap oils at concentration level of 10 to 60% (w/w). Then, FT-IR spectra of pure and adulterated pistachio oil samples were obtained. The fingerprints region was found to be useful in investigation of the adulteration of pistachio oil. At this region, the absorbance peaks of FT-IR decreased by increasing the adulterant amount with a linear relation that can be applied for the quality and quantity purposes. The obtained results showed that the proposed method can be considered and used as an alternative method in the detection and semi-quantization of adulteration in pistachio oil.
A novel environmentally benign method toward the synthesis of some novel tetrasubstituted 2,4‐diaminopyrimidine derivatives using an aqueous glucose‐mediated one‐pot three‐component reaction of malononitrile with various benzaldehyde and amidine derivatives is reported. Some pyrimidine derivatives possessing α‐amino acid moiety were synthesized by the present protocol for the first time. This protocol offers advantages including facile reaction conditions, using naturally occurring glucose as promoter and water as solvent, simple work‐up, relatively short reaction times, and high yields of the products.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.