1070-4272/01/7410-1641 $25.00 C 2001 MAIK [Nauka/Interperiodica]
Russian Journal of Applied Chemistry, Vol. 74, No. 10, 2001, pp. 1641!1644. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 10, 2001,
Original Russian Text Copyright + 2001 by Perov, Moshchenskaya.
OF SYSTEMS AND PROCESSES
Solubility and State of Elemental Selenium in Hydrocarbons
E. I. Perov and N. V. Moshchenskaya
Altai State University, Barnaul, Russia
Received February 12, 2001
Abstract-The solubility of metallic and amorphous selenium in n-heptane, n-octane, n-nonane, n-decane,
n-undecane, and n-dodecane was determined in the range 2983 493 K. The effect of temperature and al-
kane nature is considered. The average composition of selenium molecules in alkanes was determined from
Our study of the solubility of elemental sulfur in
pure n-alkanes showed that at 1503200oC [low-mo-
lecular-weight] products of thermal dissociation of
rings (down to S
) exist in solution in noticeable
amounts . Also, a saw-tooth dependence of the sul-
fur solubility on the number of carbon atoms in the
hydrocarbon chain was observed for the first time.
Proceeding with studies of synthesis of metal sul-
fides in organic solvents [2, 3], we proposed an envi-
ronmentally safe method for preparing metal selenides
in liquid n-alkanes from elemental selenium and metal
carboxylates as initial reagents . Hydrogen selenide
formed in the reaction of selenium with hydrocarbons
is then converted into a poorly soluble metal selenide.
The hydrogen selenide content in the reactor was less
than 0.8 mg m
We believe that a study of physicochemical trans-
formations of chalcogens in nonaqueous solutions will
allow development of a scientifically substantiated
process for preparing semiconductor materials based
on metal sulfides and selenides.
The primary stage of the interaction of selenium
with n-alkanes is its dissolution. The state and solubil-
ity of selenium in paraffins have been poorly studied.
In this work, we studied the solubility of two se-
lenium modifications (amorphous and crystalline; the
latter is usually termed metallic selenium) in C
saturated hydrocarbons in the temperature range 253
250oC by the method of immersion filtration [5, 6].
Several conical flasks with preliminarily purified
solvent  and an immersion filter with selenium
were placed in a thermostat equipped with a special
vibrator. Samples of saturated solutions were taken
with a sampler, and the selenium concen tration was
determined gravimetrically after isothermal evapora-
tion of the solvent. The curves of paraffin saturation
with metallic and amorphous selenium are shown in
Figs. 1 and 2.
The solubility of metallic selenium in n-nonane in-
creases from 8.67 0 10
M at 298 K to 8.29 0 10
at 418 K (Table 1). The data on solubility of amor-
phous selenium in n-paraffins are listed in Table 2.
Schroeder’s equation describing the temperature
dependence of the solubility was used for thermody-
namic analysis of solubility curves of metallic and
Fig. 1. Curves of solution saturation with metallic sele-
nium at 50oC: (S) solubility; (t) time; the same for Fig. 2.
Solvent: (1) n-heptane, (2) n-octane, and (3) n-nonane.
Fig. 2. Curve of saturation of solution in n-decane with
amorphous selenium at 174oC.