Conductometric Studies of the Thermodynamics of Complexation of Zn2+, Ni2+, Co2+, Pb2+, Mn2+, Cu2+ Ions with 1,13-Bis(8-Quinolyl)-1,4,7,10,13-Pentaoxatridecane in Binary Solvent Mixtures

Document Type: Research Article


Department of Chemistry, Payame Noor University, PO BOX 19395-3697 Tehran, I.R. IRAN


The complexation reaction between 1,13-bis(8-quinolyl)-1,4,7,10,13-pentaoxatridecane (Kryptofix5) ligand with Zn2+, Ni2+, Co2+, Pb2+, Mn2+ and Cu2+ ions were studied conductometrically in different AcetoNitrile-NitroMethane (AN-NM) and AcetoNitrile-Methanol (AN-MeOH) mixtures. The formation constants of the resulting 1:1 complexes were calculated from the computer fitting of the molar conductance in various mole ratios. The enthalpy and entropy changes of the complexation reactions were derived from conductometric titrations in different AN-NM mixtures at various temperatures. The results revealed that Kryptofix5 forms very stable 1:1 complexes with mentioned cations in all AN-NM and AN-MeOH mixtures. It was found that the stability of the resulting complexes decreased with increasing nitromethane or methanol in the solvent mixture. The TΔS° vs. ΔH° plot of all thermodynamic data obtained shows a fairly good linear correlation indicating the existence of enthalpy-entropy compensation in the complexation reactions.  


Main Subjects

[1] Moore C., Pressman B.C., Mechanism of Action of Valinomycin on Mitochondria, Biochem. biophys. Res. Commun., 15, p. 562 (1964).

[2] Tuemmler B., Maass G., Weber E., Wehner W., Voegtle, F., Noncyclic Crown-Type Polyethers, Pyridinophane Cryptands, and Their Alkali Metal Ion Complexes: Synthesis, Complex Stability, and Kinetics, J. Am. Chem. Soc., 99, p. 4683 (1977).

[3] Tummler B., Maass G., Vogtle F., Sieger H., Heimann U., Weber E., Open-Chain Polyethers. Influence of Aromatic Donor End Groups on Thermodynamics and Kinetics of Alkali Metal Ion Complex Formation, J. Amer. Chem. Soc., 101, p. 2588 (1979).

[4] Madrakian T., Shamsipur M., Spectrophotometric Study of Some Transition Metal Complexes with Tetraethyleneglycol-bis-(8-quinolyl) Ether in Dimethylsulfoxide Solution Using Murexide as a Metallochromic Indicator, Polish J. Chem.,73, p. 1405 (1999).

[5] Rofouei M.K., Ahmadalinezhad A., Taghdiri M., Complexation Thermodynamics of Some Alkali-Metal Cations with 1,13-Bis(8-Quinolyl)-1,4,7,10,13-Pentaoxatridecane in Acetonitrile,J. Incl. Phenom., 58, p. 377 (2007).

[6] Payehghadr M., Zamani A., Salehi Sadaghiani A., Taghdiri M., Spectrophotometric and Conductometric Studies of the Thermodynamics Complexation of Zn2+, Ni2+, Co2+, Pb2+ and Cu2+ Ions with 1,13-Bis(8-Quinolyl)-1,4,7,10,13-Pentaoxatridecane Ligand in Acetonitrile Solution., J. Incl. Phenom.,62, p. 255 (2008).

[7] Greenberg M.S., Popov A.I., Spectroscopic Studies of Ionic Solvation- XVII Studies of Preferential Solvation of the Sodium Ion in Nonaqueous Mixed Solvents by Sodium-23 Nuclear Magnetic Resonance, Spectrochim. Acta Part A, 31, p. 697 (1975).

[8] Wu Y.C., Koch W.F., Absolute Determination of Electrolytic Conductivity for Primary sStandard KCl Solutions from 0 to 50ºC, J. Solution Chem., 20, p. 391 (1991).

[9] Amini M.K., Shamsipur M., Complex Formation of Silver, Thallium and Alkali Cations with Dibenzo-30-Crown-10 in Some Non-Aqueous Solutions, Inorg. Chim. Acta., 183, p. 65 (1991).

[10] Amini M.K., Shamsipur M., Complex Formation of Hydronium Ion with Several Crown Ethers in 1,2-Dichloroethane, Acetonitrile, and Nitrobenzene Solutions, J. Solution Chem., 21, p. 275 (1992).

[11] Ganjali M.R., Rouhollahi A., Moghimi, A., Shamsipur, M., Conductance Study of Alkali Metal Complexes with 4¢-Carboxy-Benzo-24-Crown-8 and 4¢-Amido-Benzo-24-Crown-8 in Nitromethane, Acetonitrile and Dimethyle Formamide Solutions, Pol. J. Chem., 70, p. 1172 (1996).

[12] Weber E., Toner J.L., Goldberg I., Voegtle F., Laidler D.A., Stoddart J.F., Bartsch R.A., Liotta, C.L., "Crown Ethers and Analogs". Wiley (1989).

[13] Pourghobadi Z., Seyyed-Majidi F., Daghighi-Asli M., Parsa F., Moghimi A., Ganjali M.R., Aghabozorgand H., Shamsipur M., Synthesis of a New Triazine Derived Macrocycle and a Thermodynamic Study of Its Complexes with Some Transition and Heavy Metal Ions in Acetonitrile Solution, Pol. J. Chem., 74, p. 837 (2000).

[14] Takeda Y., Thermodynamic Study for Dibenzo-24-Crown-8 Complexes with Alkali Metal Ions in Nonaqueous Solvents, Bull. Chem. Soc. Jpn., 56, p. 3600 (1983).

[15] Gutmann V., "The Donor-Acceptor Approach to Molecular Interactions", Plenum,New York, (1978).

[16] Taghdiri M.,   Rofouei M.K.,   Shamsipur M., Conductance Study of the Thermodynamics of Complexation of K+, Rb+, Cs+ and Tl+ Ions with Dibenzo-24-Crown-8 in Binary Acetonitrile-Nitromethane Mixtures, J. Incl. Phenom., 58, p. 181 (2007).