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Isocyanato-complexes of palladium(II)
INORG. NUCL.
CHEM. LETTERS
Yel.
3,
pp.
U5-3S7,
1967.
PeqlamN
Press Ltd.
Printed In
Gs~et Britain.
ISOCYANAT0-CGMPLEXES OF P ~ I U M ( I I ) A.H. Norbury and A.I.P. Sinha Department of Chemistry, Loughborough University of Technology, Loughborough, England. {Received 20 June 1957)
ALTHOUGH ISOCYANATES are well-known the first organic cyanate was synthesised I only recently by Hoyer .
In inorganic chemistry, the only examplas where
oxygen takes part in bond formation are in the suggested 2 bridge formation by NC0- in the compound Co(4-CN-py)2(NUO)2 and in the possible existence 3 of a small proportion of the cyanato-isomer in Pt(Et3P)~(NC0 ).
No pure
cyanato-complex appears to have been isolated, whereas the ambidentate nature of the homologous NCS- and NCSe- is well established.
Following the suggestion of Turco and Pecile 4, that (L) direct the equilibrium M-SCN # M - N C S
11"-bonding ligands
to the right in the systems
PdL2(SCN) 2 and PtL2(SCN)2, Burmeister and Basolo 5 studied these systems for a variety of @"- and ~-bonding ligands.
These workers noted that, due
allowance being made for the static factors, the T~-bonding ligands render the normally 'soft' Pd(II) and Pt(II) 'harder' favouring coordination of the SCN- through its 'harder' nitrogen end:
they also succeeded in isolating
linkage isomers for Pd(bipy)(SCN)2 and Pd(~3As)2(SCN)2.
However, Burmeister
and A1-Janabi 6 found that in both Pd(blpy)(SeCN)2 and Pt(blpy)(SeCN)2, the SeCN- is co-ordinated only through the Se atom.
It is, therefore, of interest
to see how far the mode of coordination of the NC0 affected by
to palladium (II) is
IT-bondlng ligands.
We have prepared a number of mixed ligand complexes of the type PdL2(NC0)2 where L = pyridine, ~- and y-picollne, ½ (blpyrldyl), trlphenylphosphine,
trlphenylarsine or triphenylstibine.
The electrical
conductivity of each complex correaponds to that of a non-electrolyte in 355
356
ISOCYAMATO-COMPLEXES OF PALLADIUM(II)
Vol. 3, He. 9
nitromethane, establishing these as neutral species of the type
pd.L2(NC0)2 J
o
I
and eliminating the possibility of
FPd Ll]
IPd(NC0)~ I species. L.
~]
TABLE Infra-red Spectral Bands Of Isocyanato-Complexes Of Palladium (II), (cm-1).
.
f 637vw ~ 6 ] 3m ] 6 O4m ~594s
(Me4N)2Pd(NC0)4
2190-2200s
1319m
Pd( py)2 (NC0)2
2180-2210s
1332m, sp
586m, sp
Pd(~-plc )2 (NO0) 2
2200-2240s
1338s
590m, sp
Pd( y -plc)2(NC0)2
2195-221 5s
1332m, sp
585m, sp
Pd(bipy) (NC0) 2
2195-221 5s
1340m
587m, s p
Pd(~3P)2 (NC0) 2
2212-2218s
1350m, sp
Pd(~3As)2(NC0)2
2200-2210s
1325-1340m, br
582m,br
Pd(@3Sb)2(NCO) 2 @
2170s, 2210sh
1330m
600w, br
61 5 w , b r
*
~610w L59Om, s p
Forster and Goodgame, Ref. 8 Slightly decomposed. The infra-red spectra of these complexes are presented in the table and
show three principal bands. C-N stretching mode.
The bands at ~2200 cm
The bands at ~1330 cm
the blue shift of these bands from
%0
-I
-I
correspond to t h e
are assigned to C-0 stretching;
for the free NC0- at 12~ L cm -I indicates 7
N-coordination of the cyanate ion. The third band at ~ 6 0 0 to the N-C-0 bending mode.
cm
-I
corresponds
The three fundamental frequencies of the NC0
group in every case are very similar to those found by Forster and Goodgame for the complex ion
8
[~ ~]2d(NC0)~, and are entirely consistent with N-bonded
species.
Thus, although the effect of ~T-bonding ligands on the mode of coordination of thiecyanate group is to change the donor atom from sulphur in [~ d(SCN)4 ] 2 -
Vol. 3, Fie. 9
ISOCYAHATO-COMPLEXES
to nitrogen in
[PdL2(NCS)2]
OF PALLADIUM(II)
357
(where L = ~3 P, @3As, pyridine, or ½ bipyridyl) 5,
no such effect is observed for cyanato-
and selenocyanato-complexes.
complexes remain bonded through nitrogen in and the corresponding selenocyanato
d(NC0)4
]
Cyanato-
and
complexes, by contrast, bond through
6
selenium in each case .
Work is in progress on further Pd(II)-
and the corresponding Pt(ll)
complexes.
EXPERIMENTAL The compounds, except for Pd(@3P)2(NC0)2,
were prepared by metathesis
between the corresponding chloro-complex and silver cyanate. was prepared by interaction of
~3 P
with Pd(py)2(NC0)2.
were carried out in dry, non-aqueous solvents.
Pd(~3P)2(NC0)2 The reactions
Satisfactory carbon, hydrogen
and nitrogen analyses were obtained.
IR spectra were recorded on an SP 100 spectrophotometer
using nujol
and halocarbon oil mulls.
References I .
H. HOYF/q, Chem. Ber. 94, 1042 (]961).
2.
H.C.A. KING, K. KOROS, and S.M. NEI~0N, Nature,
3.
J. POWELL and B.L. SHAW, J. Chem. Soc. 3879 (1965).
4.
A. TURC0 and C. PECILE, Nature,
5.
J.L. BUBMEISTER and F. BASOL0, Inorg. Chem. 3, 1587 (1964).
6.
J.L. BUEMEISTER and M.Y.AL-JANABI,
7.
A. SABATINI and I. BERTINI, Inorg. Chem. 4, 959 (1965).
8.
D. FORSTER and D.M.L. GOODGAME, J. Chem. Soc. 1286 (1965).
196, 572 (1962).
191, 66 (1961).
Inorg. Chem. 4, 962 (1965).
CHEM. LETTERS
Yel.
3,
pp.
U5-3S7,
1967.
PeqlamN
Press Ltd.
Printed In
Gs~et Britain.
ISOCYANAT0-CGMPLEXES OF P ~ I U M ( I I ) A.H. Norbury and A.I.P. Sinha Department of Chemistry, Loughborough University of Technology, Loughborough, England. {Received 20 June 1957)
ALTHOUGH ISOCYANATES are well-known the first organic cyanate was synthesised I only recently by Hoyer .
In inorganic chemistry, the only examplas where
oxygen takes part in bond formation are in the suggested 2 bridge formation by NC0- in the compound Co(4-CN-py)2(NUO)2 and in the possible existence 3 of a small proportion of the cyanato-isomer in Pt(Et3P)~(NC0 ).
No pure
cyanato-complex appears to have been isolated, whereas the ambidentate nature of the homologous NCS- and NCSe- is well established.
Following the suggestion of Turco and Pecile 4, that (L) direct the equilibrium M-SCN # M - N C S
11"-bonding ligands
to the right in the systems
PdL2(SCN) 2 and PtL2(SCN)2, Burmeister and Basolo 5 studied these systems for a variety of @"- and ~-bonding ligands.
These workers noted that, due
allowance being made for the static factors, the T~-bonding ligands render the normally 'soft' Pd(II) and Pt(II) 'harder' favouring coordination of the SCN- through its 'harder' nitrogen end:
they also succeeded in isolating
linkage isomers for Pd(bipy)(SCN)2 and Pd(~3As)2(SCN)2.
However, Burmeister
and A1-Janabi 6 found that in both Pd(blpy)(SeCN)2 and Pt(blpy)(SeCN)2, the SeCN- is co-ordinated only through the Se atom.
It is, therefore, of interest
to see how far the mode of coordination of the NC0 affected by
to palladium (II) is
IT-bondlng ligands.
We have prepared a number of mixed ligand complexes of the type PdL2(NC0)2 where L = pyridine, ~- and y-picollne, ½ (blpyrldyl), trlphenylphosphine,
trlphenylarsine or triphenylstibine.
The electrical
conductivity of each complex correaponds to that of a non-electrolyte in 355
356
ISOCYAMATO-COMPLEXES OF PALLADIUM(II)
Vol. 3, He. 9
nitromethane, establishing these as neutral species of the type
pd.L2(NC0)2 J
o
I
and eliminating the possibility of
FPd Ll]
IPd(NC0)~ I species. L.
~]
TABLE Infra-red Spectral Bands Of Isocyanato-Complexes Of Palladium (II), (cm-1).
.
f 637vw ~ 6 ] 3m ] 6 O4m ~594s
(Me4N)2Pd(NC0)4
2190-2200s
1319m
Pd( py)2 (NC0)2
2180-2210s
1332m, sp
586m, sp
Pd(~-plc )2 (NO0) 2
2200-2240s
1338s
590m, sp
Pd( y -plc)2(NC0)2
2195-221 5s
1332m, sp
585m, sp
Pd(bipy) (NC0) 2
2195-221 5s
1340m
587m, s p
Pd(~3P)2 (NC0) 2
2212-2218s
1350m, sp
Pd(~3As)2(NC0)2
2200-2210s
1325-1340m, br
582m,br
Pd(@3Sb)2(NCO) 2 @
2170s, 2210sh
1330m
600w, br
61 5 w , b r
*
~610w L59Om, s p
Forster and Goodgame, Ref. 8 Slightly decomposed. The infra-red spectra of these complexes are presented in the table and
show three principal bands. C-N stretching mode.
The bands at ~2200 cm
The bands at ~1330 cm
the blue shift of these bands from
%0
-I
-I
correspond to t h e
are assigned to C-0 stretching;
for the free NC0- at 12~ L cm -I indicates 7
N-coordination of the cyanate ion. The third band at ~ 6 0 0 to the N-C-0 bending mode.
cm
-I
corresponds
The three fundamental frequencies of the NC0
group in every case are very similar to those found by Forster and Goodgame for the complex ion
8
[~ ~]2d(NC0)~, and are entirely consistent with N-bonded
species.
Thus, although the effect of ~T-bonding ligands on the mode of coordination of thiecyanate group is to change the donor atom from sulphur in [~ d(SCN)4 ] 2 -
Vol. 3, Fie. 9
ISOCYAHATO-COMPLEXES
to nitrogen in
[PdL2(NCS)2]
OF PALLADIUM(II)
357
(where L = ~3 P, @3As, pyridine, or ½ bipyridyl) 5,
no such effect is observed for cyanato-
and selenocyanato-complexes.
complexes remain bonded through nitrogen in and the corresponding selenocyanato
d(NC0)4
]
Cyanato-
and
complexes, by contrast, bond through
6
selenium in each case .
Work is in progress on further Pd(II)-
and the corresponding Pt(ll)
complexes.
EXPERIMENTAL The compounds, except for Pd(@3P)2(NC0)2,
were prepared by metathesis
between the corresponding chloro-complex and silver cyanate. was prepared by interaction of
~3 P
with Pd(py)2(NC0)2.
were carried out in dry, non-aqueous solvents.
Pd(~3P)2(NC0)2 The reactions
Satisfactory carbon, hydrogen
and nitrogen analyses were obtained.
IR spectra were recorded on an SP 100 spectrophotometer
using nujol
and halocarbon oil mulls.
References I .
H. HOYF/q, Chem. Ber. 94, 1042 (]961).
2.
H.C.A. KING, K. KOROS, and S.M. NEI~0N, Nature,
3.
J. POWELL and B.L. SHAW, J. Chem. Soc. 3879 (1965).
4.
A. TURC0 and C. PECILE, Nature,
5.
J.L. BUBMEISTER and F. BASOL0, Inorg. Chem. 3, 1587 (1964).
6.
J.L. BUEMEISTER and M.Y.AL-JANABI,
7.
A. SABATINI and I. BERTINI, Inorg. Chem. 4, 959 (1965).
8.
D. FORSTER and D.M.L. GOODGAME, J. Chem. Soc. 1286 (1965).
196, 572 (1962).
191, 66 (1961).
Inorg. Chem. 4, 962 (1965).