ISSN 1070-4272, Russian Journal of Applied Chemistry, 2007, Vol. 80, No. 2, pp. 272!274. + Pleiades Publishing, Ltd., 2007.
Original Russian Text + I.S. Faizrakhmanov, L.F. Zainullina, R.F. Talipov, A.Kh. Sharipov, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80,
No. 2, pp. 273!275.
Oxidation of Organic Sulfides with Atmospheric Oxygen
in the Presence of Phthalocyanine Complexes as Catalysts
I. S. Faizrakhmanov, L. F. Zainullina, R. F. Talipov, and A. Kh. Sharipov
Bashkir State University, Ufa, Bashkortostan, Russia
Institute of Petrochemistry and Catalysis, Ufa Research Center, Russian Academy of Sciences, Bashkortostan, Russia
Received March 29, 2006; in final form, September 2006
Abstract-Catalytic oxidation of a mixture of low-molecular-weight sulfides with atmospheric oxygen
was studied. The catalytic activity of poly(cobalt phthalocyanine) in this process is higher than that of
monomeric cobalt phthalocyanine.
The use of the gas condensate of the Karachagansk
deposit in natural gas processing increased the sulfur
content in the isopentane and pentane fractions to 0.02
and 0.2 wt %, respectively . The total sulfur con-
tent of the isopentane and pentane fractions used in
production of synthetic rubbers should not exceed
0.003 and 0.01 wt %, respectively .
An analysis of pentanes for sulfur-containing com-
pounds showed the presence of mercaptans and sul-
fides . The mercaptan fraction consists mainly of
ethyl isopropyl, and butyl mercaptans. The sulfide
fraction contains dimethyl sulfide as the major com-
ponent and a minor amount of methyl ethyl sulfide.
One of the procedures for removing sulfur-contain-
ing compounds is their catalytic oxidation with atmo-
spheric oxygen . Therefore, a search for effective
catalysts for this reaction is a topical problem.
The amount of sulfide sulfur in the pentane3iso-
pentane fractions ranges from 35 to 50 wt % relative
to the total sulfur content . The efficiency of desul-
furization by alkali treatment and demercaptanization
in the presence of cobalt disulfophathalocyanine de-
creases when both sulfides and mercaptan are present
in the substrate . We studied comparatively the ox-
idation of a mixture of sulfur-containing compounds
in the presence of cobalt(II) phthalocyanine [PhCo(II)]
and its polymer [PPcCo(II)] as catalysts. For this pur-
pose, we used isooctane solutions of a mixture of sul-
fides with a sulfide sulfur content of 0.0523 0.059 wt %
and of a sulfide-mercaptan mixture with a mercaptan
sulfur content of up to 0.055 wt %. The phthalocya-
nine complexes were used in the form of a suspen-
sion or a solution in aqueous sodium hydroxide.
The PPcCo(II) and PcCo(II) concentration in the al-
kaline solution was 0.025 and 0.033 wt %, respective-
ly. A suspension or a solution (50 ml) of the phthalo-
cyanine complex and a solution of sulfur-containing
compounds in isooctane (100 ml) were placed in
a 250-ml conical flask. Air was bubbled through
a glass tube. The mixture was vigorously stirred for
30 min at 40oC and then the sulfide sulfur content
in isooctane was determined.
Sulfur-containing compounds were analyzed by
gas chromatography3mass spectrometry on a Finnigan
4021 spectrometer. The total sulfur content of the pen-
tane3isopentane fraction was determined in accor-
dance with GOSTs (State Standards) 22 986378 and
13 3803 81. The experimental results are presented in
Table 1. It is seen that PPcCo(II) is a more efficient
catalyst for oxidation of low-molecular-weight sul-
fides that PcCo(II). At the same time, the catalytic
activity of poly(metal phthalocyanines) (PPcM) in
oxidation may be lower, higher, or equal to that of
the monomers (PcM) . The reasons for this phe-
nomenon were not understood. However, the catalytic
activity of PPcM was believed to be due to structural
features of the intermediates and to the influence of
the reaction medium.
Because the PcM3S bond formed by s electrons
of the sulfur atom and donation of d
the metal ion to the unoccupied s-orbital of the sul-