IMPREGNATED TYPE SORBENTS
1179
on a Boetius PHMK 05 apparatus. Elemental analysis
was carried out on a Carlo Erba Strumentazione CHN
analyzer (Italy).
IR absorption spectra were registered on a Bruker
Vertex 70 spectrometer (as Nujol mull) and a FSM-
2202 Fourier-transform IR spectrometer (as KBr pel-
lets) in the range 400–4000 cm–1.
O
O
O
O
O
O
P
P
Ph
Ph
Ph
Ph
Thermogravimetric study was carried out on an
Intestech Q-600 derivatograph and Analitpribor Ter-
moscan-2 instrument in an argon atmosphere in tem-
perature range 20–500°C at heating rate 10 deg/min.
Fig. 1. Chemical structure of 1,8-bis[2-(diphenylphos-
phorylmethyl)phenoxy]-3,6-dioxaoctane.
Materials. Impregnated sorbents were obtained
using DTBDCH18C6 of >98% purity and compound
L prepared by procedure described below.
LPS-500 styrene–divinylbenzene support (parti-
cles 150–250 μm) manufactured by Sintez Polim-
ernykh Sorbentov Corp. (Moscow, Russia) and hydro-
phobized silica gel (HSG) (particles 250–500 μm)
manufactured by Sorbent-Tekhnologii, Ltd. (Mos-
cow, Russia) were used as supports.
O
O
O
O
O
O
t-Bu
t-Bu
Fig. 2. Chemical structure of 4,4',(5')-di(tert-butyl)dicy-
clohexyl-18-crown-6.
Nitric acid, hydrochloric acid, sodium hydroxide,
sodium iodide, phosphorus(V) oxide, dioxane, meth-
anol, acetone, chloroform, octanol-1, nitrobenzene
(ReaKhim, Russia), 1,8-dichloro-3,6-dioxaoctane
(ReaRus, Russia), and telomer alcohol n3 (1,1,7-tri-
hydrododecafluoroheptanol-1) (GaloPolimer, Rus-
sia) were of analytical grade.
Experimental and calibration solutions were pre-
pared using concentrated nitric or hydrochloric acids
and a standard sample of Pb metal solution MSO
0526:2003.
possibility for the directed modification of their com-
plexing properties.
Potentially hexadentate compound 1,8-bis[2-
(diphenylphosphorylmethyl)phenoxy]-3,6-dioxaoc-
tane (L) (Fig. 1) refers to the phosphoryl podands of
neutral type. Stability constants for complexes with
alkali metal 2,4-dinitrophenolates in THF–CHCl3
(4 : 1 v/v) solutions are not lower than those with such
crown ethers as 18-crown-6, dibenzo-18-crown-6,
and dicyclohehyl-18-crown-6 [11]. Moreover, this
compound is patented as a selective carrier of Pb2+ cat-
ions within polymeric membrane of lead-selective
electrode [12]. However, compound L was not studied
previously as extractant in impregnated type sorbents
for Pb2+ cations recovery.
In this work, we report a modified method for
compound L preparation. We synthesized for the first
time complex L · Pb(NO3)2 · H2O and studied it by ele-
mental analysis and IR spectroscopy. On the basis of
L, we obtained and studied a new impregnated type
sorbent for selective recovery of Pb2+. To compare the
efficiency and conditions of Pb2+ sorption, we also
obtained a series of impregnated sorbents based on
isodentate crown ether DTBDCH18C6 (Fig. 2). We
determined optimal synthesis conditions for sorbents
based on DTBDCH18C6 for lead recovery: effect of
diluent and support type, support pretreatment proce-
dure, impregnation temperature and time, solvent for
impregnation on sorption characteristics.
Synthesis
of
1,8-bis[2-(diphenylphosphoryl-
methyl)phenoxy]-3,6-dioxaoctane L. A suspension of
4.5 g (14 mmol) of 2-diphenylphosphorylmethylphe-
nol [12] and 0.56 g (14 mmol) of finely divided NaOH
in 35 mL of dry dioxane was stirred for 0.5 h at 95°C,
next 1.3 g (7 mmol) of 1,8-dichloro-3,6-dioxaoctane
was added, the mixture was refluxed for 8 h, concen-
trated under reduced pressure, 50 mL of water was
added to the residue, the mixture was acidified with
concentrated HCl to pH 1 and extracted with CHCl3
(3 × 25 mL). The extract was washed with diluted (1 : 2)
HCl (2 × 30 mL), water (2 × 30 mL), and concen-
trated under reduced pressure. The residue was dissolved
in 40 mL of anhydrous acetonitrile, 2.25 g (15 mmol) of
dry NaI was added, the mixture was refluxed for 1 h,
cooled to 8°C, the precipitate was separated by filtra-
tion, washed with boiling acetonitrile (10 mL) and
dried in a vacuum. The precipitate was identified as a
1 : 1 complex of L with NaI. Yield 4.3 g, 77%. For
C44H44INaO6P2 anal. calcd. (%): C, 60.01; H, 5.04; P,
7.03. Found (%): C, 59.81, 59.73; H, 4.52, 4.90;
P, 6.63, 6.91.
EXPERIMENTAL
Structure determination. 1H and 31P NMR spectra
were recorded on a Bruker CХP-200 spectrometer
using TMS and 85% H3PO4 as internal and external
Fifty milliliters of diluted (1 : 1) HCl was added to
the obtained complex and the mixture was stirred for
2 h at 50°C, cooled to ambient temperature, the pre-
references, respectively. Melting points were measured cipitate was separated by filtration, washed with water
RUSSIAN JOURNAL OF INORGANIC CHEMISTRY Vol. 64 No. 9 2019