STUDY ON DIOXOMOLYBDENUM(VI) COMPLEX
163
acterized. The hydrazone ligand coordinates to the Mo atoms
through the phenolic O, imino N, and ethanolic O atoms. The
Mo atom is in an octahedral coordination. The complex has
effective catalytic property to the oxidation of sulfides.
SUPPLEMENTARY MATERIALS
CCDC 813898 contains the supplementary crystallographic
data for the complex. These data can be obtained free of
the Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: (+44)1223-336-033; or e-mail:
REFERENCES
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Schiff base dioxo-molybdenum(VI) complex: Synthesis, crystal structure
and catalytic performance in green oxidation of sulfides by urea hydrogen
peroxide. Polyhedron 2009, 28, 733–738.
FIG. 2. Molecular packing of (1), viewed along the a axis.
coordination. The strong band indicative of the C = N–N = C
group in the complex is shifted to 1606 cm−1 for the complex.
The νC = N appear at 1620 cm−1 in the complex. The new weak
peaks observed in the range 400–800 cm−1 may be attributed to
the Mo–O and Mo–N bonds in the complex. The comparison of
the IR spectra of the free hydrazone ligand and the dioxomolyb-
denum(VI) complex confirms the enolate coordination mode of
the ligand.
6. Rao, S.N.; Kathale, N.; Rao, N.N.; Munshi, K.N. Catalytic air oxidation
of olefins using molybdenum dioxo complexes with dissymmetric triden-
tate O,N,S-donor Schiff base ligands derived from o-hydroxyacetophenone
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2007, 360, 4010–4016.
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11. Debel, R.; Buchholz, A.; Plass, W. Structural and catalytic aspects of
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salicylidene hydrazides. Z. Anorg. Allg. Chem. 2008, 634, 2291–2298.
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Catalytic Property
The catalytic oxidation test of the complex on the oxidation
of sulfides under homogeneous conditions in solution using
methyl phenyl sulfide (thioanisol) as substrate was carried out
according to the literature method.[12] As oxidant hydrogen per-
oxide was used in a slight excess of 1.25 equivalents based on
the sulfide substrate. Reactions are run with 1 mol% of catalyst
based on the substrate at a temperature of 10◦C. The reaction
was started by the addition of hydrogen peroxide. A control
reaction under the same condition without any complex present
leads to less than 1% sulfide conversion within 4 h. In the pres-
ence of both complexes a conversion of about 70% of sulfide
to the corresponding sulfoxide within 30 min reaction time was
observed. After about 2 h in all cases the conversion of total
amount of sulfide was complete. Under the given conditions no
over oxidation to the sulfone could be detected.
CONCLUSION
In summary, a new dioxomolydenum(VI) complex with
the hydrozone ligand N’-[1-(2-hydroxynaphthyl)ethylidene]-3-
methylbenzohydrazide has been prepared and structurally char-
13. Allen, F.H. The Cambridge Structural Database: a quarter of a million
crystal structures and rising. Acta Crystallogr. 2002, B58, 380–388.