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Synthesis of a New Thiourea Derivative Substituted 5,6-Diamino-1,10-phenanthroline and Crown Ether and Its Complexes with Copper(II), Nickel(II) and Cobalt(II)

Elmal F. T., Avclata U., Demirhan N., Gül A.

Polish Journal of Chemistry

2007

Vol. 81, nr 10

1725-1725

A new thiourea derivative ligand (LH2), 6-amino-5-ylamino-benzo[15-crown-5]-15- ylaminoethanethione[1,10]phenanthroline has been synthesized in the reaction of 5,6-diamino-1,10-phenanthroline with 15-isothiocyanatobenzo[15-crown-5] and its metal complexes with Cu(II), Ni(II) and Co(II) have been prepared. The structures and compositions of the ligand and the complexes have been confirmed by elemental analyses, UV-vis, FTIR, 1H NMR (DMSO-d6), 13C NMR (DMSO-d6), mass spectra (LC-MS) andmagnetic measurements. The metal to the ligand ratio of the Cu(II), Ni(II) and Co(II) complexes have been found to be 1:2. Protonation constants of the ligand and overall formation constants of the complexes have been calculated from potentiometric data using the computer program.

Potentiometric and spectrophotometric determination of the stability constants of luteolin (3',4',5,7-tetrahydroxyflavone) complexes with aluminium(III) and iron(III)

Karadag R.

Chemia Analityczna

2003

Vol. 48, No. 6

931-937

In this study, one determined stability constants of the complexes of luteolin with aluminium (III) and iron(lll). Potentiometric methods of Calvin-Bjerrum and Irving-Rossotti, and spec-trophotometric assay have been utilised. The evaluated protonation constants of the ligand were: logk(1) = 8.95, logk(2) = 8.10, and logk(3) = 6.85 at the 25°C. For the aluminium and iron complexes the subsequent logarithms of formation constants were found: for Al 17.50, 15.00, 4.75 and for iron: 19.60, 19.40, 17.82.

Spektrofotometrycznie i potencjometrycznie stosując metody Calvina-Bjerruma i Irvinga-Rossottiego, wyznaczono stale wartości kompleksów luteoliny z glinem(III) i żelazem(III). Wyznaczone stałe protonowania ligandu wynosiły log k(2) = 8,95; log k2 = 8,10; log k(3) = 6,85 w temperaturze 25°C. Dla kompleksów glinu kolejne wartości logarytmów stałych tworzenia wynosiły: 17,50; 15,00; 4,75, zaś dla kompleksów żelaza: 19,60; 19,40; 17,82.