ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 11, pp. 1816!1819. + Pleiades Publishing, Inc., 2006.
Original Russian Text + V.I. Dzhabarov, A.A. Knyazev, Yu.G. Galyametdinov, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79, No. 11,
AND CORROSION PROTECTION OF METALS
Lanthanide Tris(>-diketonates) as Ionophores
for Chloride Ion-Selective Electrodes
V. I. Dzhabarov, A. A. Knyazev, and Yu. G. Galyametdinov
Kazan State Technological University, Kazan, Tatarstan, Russia
Received April 26, 2006
Abstract-Lanthanide tris(>-diketonates) were used as ionophores for plasticized polymer membranes of
ion-selective electrodes. Electrochemical properties of the membranes were characterized, and the possibility
of their use as components of chloride ion-selective electrodes was studied.
Surface waters and wastewaters are analyzed using
various chemical, physical, and physicochemical
methods. Currently used analytical methods and
devices for monitoring the composition of surface
waters and wastewaters are either too expensive or in-
sufficiently prompt. There is a great need in develop-
ing sensors for prompt analysis of the ionic composi-
tion of aqueous solutions, including chemical sensors
such as electrodes with ion-selective plasticized mem-
branes. The use of ion-selective membrane electrodes
is confined by the complexity of synthesis of suffi-
ciently selective and sensitive ionophores as their
basic components. Among the most efficient iono-
phores used in ion-selective electrodes are quaternary
ammonium salts , vitamin B
metal porphyrins , and fluorinated polyethers .
Because of their high selectivity, ionophores based
on lanthanide tris(b-diketonates) are of particular
interest . However, there is only limited informa-
tion on the dependences of the selectivity and other
electrode characteristics of these compounds on the
composition and properties of aqueous solutions.
In this study we used lanthanide tris(b-diketonates)
as ionophores for plasticized polymer membranes of
ion-selective electrodes for prompt analysis of various
aqueous systems for chloride.
Lanthanide tris(b-diketonates) were synthesized
from the corresponding lanthanide chlorides and
b-diketones (Aldrich). For preparation of the mem-
branes, we used THF after purification.
(TPE). An aqueous-alcoholic solution containing 9 ml
O and 9 ml of 95% EtOH was heated to 50oC.
O (0.122 g, 0.33 mmol) was added with
stirring to obtain a clear solution. To the resulting
solution, 1,1,1-trifluoro-2,4-pentanedione (0.154 g,
1 mmol) was added, and pH was adjusted to 6.5
by adding ammonia dropwise. White crystals were
filtered off and vacuum-dried over P
0.147 g (68%); mp 1423146oC.
Found, %: C 28.58, H 2.19, O 19.78, F 26.99, Eu 24.19.
Calculated, %: C 28.63, H 2.24, O 17.79, F 27.17,
): 1620 (C=O), 1280 (C3F), and 410
europium (PBE) was prepared by adding dropwise
O (0.216 g, 1 mmol) to a hot alcoholic
solution containing 4,4,4-trifluoro-1-phenyl-1,3-bu-
tanedione (0.122 g, 0.33 mmol) with stirring. Then
aqueous ammonia was added to adjust pH to 6.5. The
precipitated white solid was filtered off, washed with
alcohol, and vacuum-dried over P
. Yield 0.493 g
(59.18%); mp 1303134oC.
Found, %: C 45.11, H 2.57, O 12.08, F 21.41, Eu 19.03.
Calculated, %: C 45.17, H 2.59, O 12.04, F 21.44,