(NBu4)[PtIII(C6Cl5)4], fully characterized by crystallographic, spectral, and magnetic measurements has been isolated by oxidation with halogens or TICl3 of the parent compound (NBu4)2[PtII(C6CL5)4], which has also been analysed by X-ray crystallography

Bau, Robert

Forniés, Juan

Menjón, Babil

Sünkel, Karlheinz

Tomás, Milagros

Usón, Rafael

English

Universität München: Elektronischen Publikationen

J .  CHEM. S O C . ,  CHEM. COMMUN.,  1984 75 1 
The First Mononuclear PtlIl Complex. Molecular Structures of ( N B u ~ ) [ P ~ ~ ~ ~ ( C ~ C I ~ ) ~ ]  and 
of Its Parent Compound ( N B u ~ ) ~ [  Pt11(C6C15)4]*2CH2C12 
Rafael Uson,*a Juan Fornies,a Milagros Tomas,a Babil Menjon,a Karlheinz Sunkel,b and Robert Baub 
a Department of Inorganic Chemistry, University of Zaragoza, Zaragoza, Spain 
Department of Chemistry, University of Southern California, Los Angeles, California, U.S.A. 
(N6U,)[Ptll1(C6CI,),], fully characterized by crystallographic, spectral, and magnetic measurements has been isolated 
by oxidation with halogens or TIC13 of the parent compound (N6U4)2[Pt"(C,CI,),], which has also been analysed by 
X-ray crystallography. 
Several bi- or poly-nuclear complexes containing platinum 
formally in the Pt"1 oxidation state have been characterized.' 
All of them have Pt-Pt bonds. The preparation of 
Pt(NH3)2(SCN)21, which according to its e.s.r. spectrum could 
be a PtlI1 compound, has been claimed.2 
Now we report the preparation and structural characteriza- 
tion of the first well authenticated monomeric Pt"' complex. A 
systematic study of the reactions between halogens and a 
series of anionic mono- or bi-nuclear pentafluoro- or 
pentachloro-phenyl derivatives of Pd or Pt, recently described 
by some of us,3 has revealed that only the Pt" complex 
( N B ~ ~ > ~ [ P t ( c ~ c l , ) , ]  can be oxidized to a stable MI11 complex. 
Thus, if C12 or Br2 (in CC14 solution) was added to the 
colourless dichloromethane solution of the Pt" complex, the 
instantaneous development of a deep-blue colour was obser- 
ved and a blue Pt"' complex, formed according to equation 
( l ) ,  was isolated in 90% yield. 
N B u ~ X  (1) 
The same Pt"' compound was obtained by treating the Pt" 
precursor with iodine or thallium(m) chloride, albeit in lower 
yields. With iodine a brown solution was formed, which after 
evaporation to dryness and extraction with chloroform (in 
which the Pt"' complex is only slightly soluble), gave blue 
(NBu4)[Pt(C6C15),] (60% yield). With T1Cl3 [equation (2)], a 
blue solution was formed and the TlCl precipitated. Partial 
evaporation of the solution allowed separation of some of the 
Pt"' complex (52% yield) from the co-soluble (NBu4)[T1Cl4] 
complex. 
At room temperature ( N B ~ ~ ) [ P t ( c ~ c l , ) ~ ]  is air- and 
moisture-stable, both as a solid and in solution. It melts (with 
decomposition) at 210 "C. In acetone solution it behaves as a 
1 : 1 electrolyte (A, = 125 S2-1 cm2mol-1).4Thei.r. spectrum 
of the compound (Nujol) shows the absorptions due to C6C15 
shifted 10-15 cm-1 towards higher energies relative to the 
corresponding ones of the Pt" parent complex 
( N B u ~ ) ~ [ P ~ ( C ~ C ~ ~ ) ~ ] .  A single absorption at 830 cm-l (X- 
sensitive mode5) along with another at 602 cm-1 [assignable 
to v(Pt-C)6] are in agreement with the square-planar 
752 J .  CHEM. SOC., CHEM. COMMUN.,  I984 
Figure 1. The molecular geometry of the [Pt(C,CI,),]- anion in the 
PtI" complex (NBu,)[Pt(C,Cl,),]. Average Pt-C, C-C, and C-CI 
distances in the anion are 2.094(8), 1.388(12), and 1.725(9) A, 
respectively. 
Figure 2. The molecular geometry of the [Pt(C,C1,),]2- anion in the 
PtlI complex (NBU,)~[P~(C,C~~)~]-~CH~C~~. Note that this is essen- 
tially identical to that of the PtIII  complex shown in Figure 1. Average 
Pt-C, C-C, and C-CI distances in this anioin are 2.086(14), 1.393(16), 
and 1.731(12) A, respectively. 
symmetry of the anion (D4h,  E, mode). The Pt"' compound is 
paramagnetic: two independent magnetic susceptibility 
measurements7 yield peff 2.4-2.5 pB at low temperature ( T  = 
6-80 K), consistent with a spin 1/2 system with a large orbital 
contribution. This observation is also consistent with a d7 
electronic configuration for the [Pt( C6C1s)4] - anion. 
The crystal structures of both (NBu4)[Pt(C6ClS),] (Figure 
l)$ and its parent complex (NBU~)~[P~(C~C~S)~].~CH~C~~ 
(Figure 2)$ show virtually identical square-planar geometries. 
The average Pt-C, C-C, and C-C1 distances, and interatomic 
angles of the two anions, all agree within experimental error. 
{For (NBu,)[P;(C6Cls),], Pt-C 2.094(8), C-C 1.388(12), 
C-C1 1.725(9) A; for ( N B U ~ ) ~ [ P ~ ( , C ~ C ~ ~ ) ~ ] ,  Pt-C 2.086(14), 
C-C 1.393(16), C-C1 1.731(12) A.}  Even the average tilt 
angles (i .e. ,  the angles between the C6C15 rings and the central 
PtC, square plane) are essentially the same: 63.0" for the 
dark-blue Pt"' anion, [Pt(C,Cl,),]- (Figure l ) ,  and 63.1" for 
the pale yellow (nearly colourless) Pt" precursor, 
[Pt(C6Cl5),]2- (Figure 2). The [Pt(C,Cl,),]- anions in the 
crystal structure of (NBu4)[Pt(C6C15), are widely separated 
t Crystal data for (NBu&)[Pt(C,Cl,),], C40H36C12,,NPtr M = 1434.88, 
triclinic, space group P1 (No. 2), a = 9.747(8), b = 16.170(8), c = 
17.675(8) A,  a = 104.95(3), p = 92.09(5), y = 77.67(5)", U = 2629(2) 
A3, D, = 1.79 g cm-3, Z = 2. X-Ray data were collected on a 
NicoletiSyntex P2, diffractometer using Mo-K, radiation. The struc- 
ture was solved by standard heavy-atom techniques and refined to a 
final R factor of 3.3% for 4786 reflections. 
(NBU,)~[P~(C,C~~)~].~CH~CI~, C5X 76C124N2Pt. M = 1847.22, tetra- 
onal, space group P4/nnc (No. 126), a = b = 14.407(6), c = 19.929(8) 1, U = 4135(3) A3, D, = 1.49 g cm--', Z = 2. X-Ray data were 
collected as in the previous case, and the structure refined to a final R 
factor of 4.6% for 951 reflections. The structure determination of this 
compound was complicated by disorder effects, not only in the n-butyl 
groups of the cations but also in the CH2C12 molecules of crystalliza- 
tion. The atomic co-ordinates for this work are available on request 
from the Director of the Cambridge Crystallographic Data Centre, 
University Laboratory, Lensfield Road, Cambridge CB2 1EW. Any 
request should be accompanied by the full literature citation for this 
communication. 
and show no evidence for the presence of Pt - . Pt stacking 
interactions (the closest Pt . 
Both the dark blue (almost black) crystals and the solutions 
of (NBu4>[Pt(C6Cl5),] show notable stability, which is pro- 
bably unique to the C6C15 ligand since oxidation with halogens 
of other [PtIIX4]2- precursors did not lead to similar Pt"' 
complexes. A steric shielding of the Pt"1 atom by the bulky 
C6C15 ligands cannot be invoked since the geometries of the 
Pt" and Pt"' complexes are virtually identical. However, a 
steric barrier could be responsible for the lack of any 
observable dimerisation and therefore for the paramagnetic 
behaviour of the complex. 
One of us (R. B.) thanks the U.S. National Science 
Foundation for financial support. R. U. thanks the C.A.- 
I.C.Y.T. (Spain) for a grant. 
- Pt distance is 9.7 A). 
Received, 12th March 1984; Corn. 324 
References 
1 J.  Kuyper and K. Vrieze, Transition Met. Chem., 1976, 1, 208; 
B. R .  Steele and K. Vrieze, ibid., 1977,2,169; H .  L. Conder, F. A. 
Cotton, L. R. Falvello, S.  Han, and R .  A .  Walton, Znorg. Chem., 
1983,22,1887, and references therein; L. S.  Hollis, M.  M. Roberts, 
and S.  J .  Lippard, ibid., p. 3637; K. Matsumoto, H.  Takahashi. and 
K. Fuwa, ibid., p. 4086. 
2 G. S. Muraveiskaya, G. M. Larin, a n d V .  F. Sorokina, Zh. Neorg. 
Khim., 1968, 13, 1466; Russ. J .  Znorg. Chem., 1968, 13, 771; F. R.  
Hartley in, 'The Chemistry of Platinum and Palladium,' Applied 
Science, London, 1973. p. 21. 
3 R .  Uson, J .  ForniCs, F.  Martinez. and M. Tomiis, J .  Chem. SOC., 
Dalton Trans., 1980, 888; R. Uson, J .  Forniks, F. Martinez. 
M. Tomhs, and I. Reoyo, Organometallics, 1983, 2, 1386. 
4 W. J .  Geary, Coord. Chem. Rev., 1971, 7. 81. 
5 E. Maslowsky. Jr., 'Vibrational Spectra of Organometallic Com- 
6 J .  Casabo, J .  M. Coronas, and J .  Sales, Znorg. Chim. Actu, 1974, l l .  
7 F. Palacio, unpublished results: K. Sunkel and C. A. Reed, 
pounds,' Wiley, New York, 1977, p.  437. 
5.  
unpublished results. 


The first mononuclear PtIII complex. Molecular structures of (NBu4)[PtIII(C6Cl5)4] and of its parent compound {NBu4}2[PtII(C6Cl5)4]·2CH2Cl2

Rafael Usón

Juan Forniés

Milagros Tomás

Babil Menjón

Karlheinz Sünkel

Robert Bau

Crossref

The first mononuclear Pt
                    III

Open Access LMU

J .  CHEM. S O C . ,  CHEM. COMMUN.,  1984 75 1 The First Mononuclear PtlIl Complex. Molecular Structures of ( N B u ~ ) [ P ~ ~ ~ ~ ( C ~ C I ~ ) ~ ]  and of Its Parent Compound ( N B u ~ ) ~ [  Pt11(C6C15)4]*2CH2C12 Rafael Uson,*a Juan Fornies,a Milagros Tomas,a Babil Menjon,a Karlheinz Sunkel,b and Robert Baub a Department of Inorganic Chemistry, University of Zaragoza, Zaragoza, Spain Department of Chemistry, University of Southern California, Los Angeles, California, U.S.A. (N6U,)[Ptll1(C6CI,),], fully characterized by crystallographic, spectral, and magnetic measurements has been isolated by oxidation with halogens or TIC13 of the parent compound (N6U4)2[Pt"(C,CI,),], which has also been analysed by X-ray crystallography. Several bi- or poly-nuclear complexes containing platinum formally in the Pt"1 oxidation state have been characterized.' All of them have Pt-Pt bonds. The preparation of Pt(NH3)2(SCN)21, which according to its e.s.r. spectrum could be a PtlI1 compound, has been claimed.2 Now we report the preparation and structural characteriza- tion of the first well authenticated monomeric Pt"' complex. A systematic study of the reactions between halogens and a series of anionic mono- or bi-nuclear pentafluoro- or pentachloro-phenyl derivatives of Pd or Pt, recently described by some of us,3 has revealed that only the Pt" complex ( N B ~ ~ > ~ [ P t ( c ~ c l , ) , ]  can be oxidized to a stable MI11 complex. Thus, if C12 or Br2 (in CC14 solution) was added to the colourless dichloromethane solution of the Pt" complex, the instantaneous development of a deep-blue colour was obser- ved and a blue Pt"' complex, formed according to equation ( l ) ,  was isolated in 90% yield. N B u ~ X  (1) The same Pt"' compound was obtained by treating the Pt" precursor with iodine or thallium(m) chloride, albeit in lower yields. With iodine a brown solution was formed, which after evaporation to dryness and extraction with chloroform (in which the Pt"' complex is only slightly soluble), gave blue (NBu4)[Pt(C6C15),] (60% yield). With T1Cl3 [equation (2)], a blue solution was formed and the TlCl precipitated. Partial evaporation of the solution allowed separation of some of the Pt"' complex (52% yield) from the co-soluble (NBu4)[T1Cl4] complex. At room temperature ( N B ~ ~ ) [ P t ( c ~ c l , ) ~ ]  is air- and moisture-stable, both as a solid and in solution. It melts (with decomposition) at 210 "C. In acetone solution it behaves as a 1 : 1 electrolyte (A, = 125 S2-1 cm2mol-1).4Thei.r. spectrum of the compound (Nujol) shows the absorptions due to C6C15 shifted 10-15 cm-1 towards higher energies relative to the corresponding ones of the Pt" parent complex ( N B u ~ ) ~ [ P ~ ( C ~ C ~ ~ ) ~ ] .  A single absorption at 830 cm-l (X- sensitive mode5) along with another at 602 cm-1 [assignable to v(Pt-C)6] are in agreement with the square-planar 752 J .  CHEM. SOC., CHEM. COMMUN.,  I984 Figure 1. The molecular geometry of the [Pt(C,CI,),]- anion in the PtI" complex (NBu,)[Pt(C,Cl,),]. Average Pt-C, C-C, and C-CI distances in the anion are 2.094(8), 1.388(12), and 1.725(9) A, respectively. Figure 2. The molecular geometry of the [Pt(C,C1,),]2- anion in the PtlI complex (NBU,)~[P~(C,C~~)~]-~CH~C~~. Note that this is essen- tially identical to that of the PtIII  complex shown in Figure 1. Average Pt-C, C-C, and C-CI distances in this anioin are 2.086(14), 1.393(16), and 1.731(12) A, respectively. symmetry of the anion (D4h,  E, mode). The Pt"' compound is paramagnetic: two independent magnetic susceptibility measurements7 yield peff 2.4-2.5 pB at low temperature ( T  = 6-80 K), consistent with a spin 1/2 system with a large orbital contribution. This observation is also consistent with a d7 electronic configuration for the [Pt( C6C1s)4] - anion. The crystal structures of both (NBu4)[Pt(C6ClS),] (Figure l)$ and its parent complex (NBU~)~[P~(C~C~S)~].~CH~C~~ (Figure 2)$ show virtually identical square-planar geometries. The average Pt-C, C-C, and C-C1 distances, and interatomic angles of the two anions, all agree within experimental error. {For (NBu,)[P;(C6Cls),], Pt-C 2.094(8), C-C 1.388(12), C-C1 1.725(9) A; for ( N B U ~ ) ~ [ P ~ ( , C ~ C ~ ~ ) ~ ] ,  Pt-C 2.086(14), C-C 1.393(16), C-C1 1.731(12) A.}  Even the average tilt angles (i .e. ,  the angles between the C6C15 rings and the central PtC, square plane) are essentially the same: 63.0" for the dark-blue Pt"' anion, [Pt(C,Cl,),]- (Figure l ) ,  and 63.1" for the pale yellow (nearly colourless) Pt" precursor, [Pt(C6Cl5),]2- (Figure 2). The [Pt(C,Cl,),]- anions in the crystal structure of (NBu4)[Pt(C6C15), are widely separated t Crystal data for (NBu&)[Pt(C,Cl,),], C40H36C12,,NPtr M = 1434.88, triclinic, space group P1 (No. 2), a = 9.747(8), b = 16.170(8), c = 17.675(8) A,  a = 104.95(3), p = 92.09(5), y = 77.67(5)", U = 2629(2) A3, D, = 1.79 g cm-3, Z = 2. X-Ray data were collected on a NicoletiSyntex P2, diffractometer using Mo-K, radiation. The struc- ture was solved by standard heavy-atom techniques and refined to a final R factor of 3.3% for 4786 reflections. (NBU,)~[P~(C,C~~)~].~CH~CI~, C5X 76C124N2Pt. M = 1847.22, tetra- onal, space group P4/nnc (No. 126), a = b = 14.407(6), c = 19.929(8) 1, U = 4135(3) A3, D, = 1.49 g cm--', Z = 2. X-Ray data were collected as in the previous case, and the structure refined to a final R factor of 4.6% for 951 reflections. The structure determination of this compound was complicated by disorder effects, not only in the n-butyl groups of the cations but also in the CH2C12 molecules of crystalliza- tion. The atomic co-ordinates for this work are available on request from the Director of the Cambridge Crystallographic Data Centre, University Laboratory, Lensfield Road, Cambridge CB2 1EW. Any request should be accompanied by the full literature citation for this communication. and show no evidence for the presence of Pt - . Pt stacking interactions (the closest Pt . Both the dark blue (almost black) crystals and the solutions of (NBu4>[Pt(C6Cl5),] show notable stability, which is pro- bably unique to the C6C15 ligand since oxidation with halogens of other [PtIIX4]2- precursors did not lead to similar Pt"' complexes. A steric shielding of the Pt"1 atom by the bulky C6C15 ligands cannot be invoked since the geometries of the Pt" and Pt"' complexes are virtually identical. However, a steric barrier could be responsible for the lack of any observable dimerisation and therefore for the paramagnetic behaviour of the complex. One of us (R. B.) thanks the U.S. National Science Foundation for financial support. R. U. thanks the C.A.- I.C.Y.T. (Spain) for a grant. - Pt distance is 9.7 A). Received, 12th March 1984; Corn. 324 References 1 J.  Kuyper and K. Vrieze, Transition Met. Chem., 1976, 1, 208; B. R .  Steele and K. Vrieze, ibid., 1977,2,169; H .  L. Conder, F. A. Cotton, L. R. Falvello, S.  Han, and R .  A .  Walton, Znorg. Chem., 1983,22,1887, and references therein; L. S.  Hollis, M.  M. Roberts, and S.  J .  Lippard, ibid., p. 3637; K. Matsumoto, H.  Takahashi. and K. Fuwa, ibid., p. 4086. 2 G. S. Muraveiskaya, G. M. Larin, a n d V .  F. Sorokina, Zh. Neorg. Khim., 1968, 13, 1466; Russ. J .  Znorg. Chem., 1968, 13, 771; F. R.  Hartley in, 'The Chemistry of Platinum and Palladium,' Applied Science, London, 1973. p. 21. 3 R .  Uson, J .  ForniCs, F.  Martinez. and M. Tomiis, J .  Chem. SOC., Dalton Trans., 1980, 888; R. Uson, J .  Forniks, F. Martinez. M. Tomhs, and I. Reoyo, Organometallics, 1983, 2, 1386. 4 W. J .  Geary, Coord. Chem. Rev., 1971, 7. 81. 5 E. Maslowsky. Jr., 'Vibrational Spectra of Organometallic Com- 6 J .  Casabo, J .  M. Coronas, and J .  Sales, Znorg. Chim. Actu, 1974, l l .  7 F. Palacio, unpublished results: K. Sunkel and C. A. Reed, pounds,' Wiley, New York, 1977, p.  437. 5.  unpublished results. 

Hartley in, 'The Chemistry of Platinum and Palladium,' Applied Science,

Vibrational Spectra of Organometallic Com-

http://epub.ub.uni-muenchen.de/5402/1/Suenkel_Karlheinz_5402.pdf

The first mononuclear PtIII complex. Molecular structures of (NBu4)[PtIII(C6Cl5)4] and of its parent compound {NBu4}2[PtII(C6Cl5)4]·2CH2Cl2

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