Physical chemistry
Morteza Vatanparast; Nabi Javadi; Rasoul Pourtaghavi Talemi; Elahe Parvini
Volume 2, Issue 4, pp. 236-325, Serial No. 5 , October 2014, , Pages 316-325
Abstract
The character of the intermolecular interactions in Cl2-HX (X =F, Cl and Br) complexes has been investigated by means of the second-order Möller–Plesset perturbation theory (MP2) and the density functional theory (DFT) calculations. The results show that there are two types of lowest interaction ...
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The character of the intermolecular interactions in Cl2-HX (X =F, Cl and Br) complexes has been investigated by means of the second-order Möller–Plesset perturbation theory (MP2) and the density functional theory (DFT) calculations. The results show that there are two types of lowest interaction potential equilibrium structures in the interactions between Cl2 and HX: X∙∙∙Cl type geometry and hydrogen-bonded geometry. The calculated interaction energies show that the X∙∙∙Cl type structures are more stable than the corresponding hydrogen-bonded structures. The nature of the intermolecular interactions has been also investigated by natural bond orbital (NBO) and atoms in molecules (AIM). The AIM analysis reveals that both types of intermolecular interactions are “closed-shell” noncovalent interactions.
Analytical chemistry
Rasoul Pourtaghavi Talemi; Sajjad Bakhtiari; Nabi Javadi; Morteza Vatanparast
Volume 2, Issue 2, pp. 82-163, Serial No. 3 , April 2014, , Pages 93-105
Abstract
In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-Ethylmino-5-Mercapto-1,3,4-Thiadiazole (EAMT) and 2-Acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT) self-assembled on gold nano-paricle (GNP) as ionophore. Then, the results ...
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In the present study, we investigate the potentiometric behavior of Cu2+ carbon paste electrodes based on two mercapto compounds 2-Ethylmino-5-Mercapto-1,3,4-Thiadiazole (EAMT) and 2-Acetylamino-5-mercapto-1,3,4-thiadiazole (AAMT) self-assembled on gold nano-paricle (GNP) as ionophore. Then, the results obtained from the modified electrodes are compared. The self-assembled ionophores exhibit a high selectivity for Copper ion (Cu2+), in which the sulfur and nitrogen atoms in their structure play a role as the effective coordination donor site for the Copper ion. Among these electrodes, the best performance was obtained with the sensor with a EAMT/graphite powder/paraffin oil weight ratio of 4.0/68/28 with 200 µL of GNP exhibits the working concentration range of 1.6×10−9 to 6.3×10−2 M and a Nernstian slope of 28.9±0.4 mVdecade−1 of copper (II) activity. The detection limit of electrode was 8.9(±0.2)×10−10 M and potential response was pH independent across the range of 2.8–6.3. The proposed electrode presented very good selectivity and sensitivity towards the Cu2+ ions over a wide variety of cations including alkali, alkaline earth, transition and heavy metal ions. Also the proposed electrode was successfully applied as an indicator electrode in the potentiometric titration of Cu (II) ions with EDTA and the potentiometric determination of copper ions in spiked water samples.
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