1545
A. K. Shrimal • Aminocyclophosphazene Derivatives of Tungsten Carbonyl
tion. The supernatant solution was dried in vacuo to give
the yellow product which was recrystallized in benzene.
Yield 52.4 %.
region exhibit a close resemblance [2 1 ] to the spec-
tra of (arene)tricarbonyltungsten(O) derivatives. So,
it seems that the 7r-contribution of the ring plays an
important role in the case of the [(N3P3Lö)W(CO)3]
derivatives as was predicted on the basis of M.O.
theory by Brown [22] in 1966. The CO stretching
modes may be assigned as Ai+E in agreement with
the C3V local symmetry of the W(CO)3 moiety.
N4P4L8 react with W(CO)ö to give cis-
[(N4P4Lg)W(CO)4] derivatives when refluxed in
xylene for 3-8 h under argon. The IR spectra of
C36H64N120,2P4W ( 1164.48)
Calcd C 37.11 H 5.50 N 14.43 P 10.05 %,
Found C 37.14 H 5.52 N 14.40 P 10.62 %.
Preparation o f (o-phenanthroline)ihexamorpholino-
cyclotriphosphazene)tricarbonyltungsten(O)
(o-Phenanthroline)tetracarbonyltungsten(O) (0.20 g)
and hexamorpholinocyclotriphosphazene (0.27 g) were
refluxed for 20 h in xylene under argon atmosphere dur-
ing which the mixture turned violet and a black solid these derivatives exhibit four CO stretching bands
began to separate. The solid was filtered off and washed
with benzene to remove unreacted ligand and (o-phenan-
throline)tetracarbonyltungsten(O). The black product was
dried in vacuo. Yield 52.2 %.
in the ranges 1985-1995, 1925-1935, 1842-1854
and 1812-1825 cm- 1 (Table II) attributable to
2Ai+Bi+B2 modes of C2v symmetry. The spec-
tra of these derivatives closely resemble [1 2 ] the
spectra of [{N4P4 (NMe2)8 }W(CO)4 ], {vCO\ 1994,
1928, 1838, 1809 cm-1) for which an X-ray study
[10] is available. Hence, it is believed that these
derivatives also have one ring nitrogen and one
exocyclic nitrogen as the donor sites analogous to
Ci9H56N ,i09P3W (1099.50)
Calcd C 42.58 H 5.09 N 14.01 P 8.46 %,
Found C 42.62 H 5.02 N 13.98 P 8.42 %.
Other derivatives prepared are given in Table I.
Results and Discussion
[{N4P4 (NMe2)8}W(CO)4].
The mixed ligand derivatives [(N3P3L6 or
N4P4 L8)(o-phen)W(CO)3 ] were prepared by pro-
tracted reflux in xylene for 16-24 h under argon.
These derivatives are black crystalline solids, insol-
uble in hydrocarbons and light petroleum but sol-
uble in methanol to give violet solution. The ami-
nated phosphazenes act as monodentate ligands by
donation through exocyclic nitrogen rather than by
the ring nitrogen atoms or the ring itself, as inferred
on the basis of the IR spectra. Their IR spectra
show three strong CO stretching bands in the ranges
1900-1915, 1778-1790 and 1750-1765 cm "1. These
bands show a close resemblance to the reported
[20] structurally similar [(o-phen)(amine)W(CO)3 ]
derivatives.
N3P3L6 and N4P4 L8 react with W(CO)ö in boil-
ing xylene under argon to give products of differ-
ent compositions. N3P3L6 displaces three carbonyl
groups while N4P4L8 displaces two carbonyl groups
from W(CO)ö. The reactivity order of cyclophosp-
hazene ligands is:
-H N C gH n > -H N C 6H n > -N C 4H 80 > -N C 5H 10.
All [(N3P3L6)W(CO)3] derivatives are yellow
crystalline solids soluble both in polar and non-
polar organic solvents and are fairly stable both in
solid state as well as in solution. The IR spectra
exhibit two strong CO stretching bands in the re-
gion 1970-1975 and 1880-1886 cm“ 1 (Table II).
The CO bands of these derivatives appear in much
higher regions than those of tricarbonyl deriva-
tives containing nitrogen donor ligands in which
the metal-nitrogen a-links have been inferred [2 0 ],
e.g., [(C6H1 ,NH2)3W(CO)3], v CO\ 1874s, 1718s
cm“ 1 and [(C6H5t H 2NH2)3W(CO)3], KX): 1887s,
1724s cm-1 . Hence, involvement of exocyclic ni-
trogen atoms in bonding can also be ruled out.
The IR spectra of these derivatives in the CO
Acknowledgement
The financial support from University Grants Commis-
sion, New Delhi, is thankfully acknowledged. The author
is thankful to the Head of the Department of Chemistry,
University of Gorakhpur, for providing necessary labora-
tory facilities.
[1] B. Lakatos, J. H. Bohus, H. Arpael, Magyar Kem.
[2] T. Moeller, S. G. Kokalis, J. Inorg. Nucl. Chem. 25,
875 (1963).
Foly. 67, 374(1961).
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