Organometallics 1993, 12, 5016-5019
5016
Interaction of the Zirconocene Alkyne Complex Cp2Zr(THF)(Me3SiCzSiMe3) and the Binuclear Zirconium a-Alkenyl Complex (Cp[p-(q1:q5-CsH4)]Zr[C(SiMe3)=CH(SiMe3)])2 with Carbon Dioxide and Water Uwe Rosenthal,**tAndreas Ohff,t Manfred Michalik,z Helmar Gorls,s Vladimir V. Burlakov,ll and Vladimir B. Shurll Max-Planck-Gesellschaft, Arbeitsgruppe "Komplexkatalyse" an der Universitat Rostock, Buchbinderstrasse 5-6, 18055 Rostock, FRG Received August 24, 1993"
SiMe3
Summary: It has beenshown that the bis(trimethylsily1)acetylene complex of zirconocene CpzZr(THF)(Me&CzSiMe3) ( 1 ) and the binuclear a-alkenyl complex of zirconium (Cp[p- (71.75- CsH4)]Zr[C(SiMe3)=CH(SiMe31112 (2)readily react with carbon dioxide at room temperature to form the dimeric zirconafuranone metallacycle ~Cp~rC(SiMe3)=C(SiMe3)C(O)O], (3). Under similar conditions the reaction of Cp2Zr(THF)(MesSiCzSiMe3) and { Cp [p - (71:75- C&)] Zr [C (SiMe3)=CH (SiMe31112 with water affords the zirconoxane complex [Cp2ZrC(SiMe3)=CH(SiMe3)~120(4). The structures of the obtained complexes have been established by X - r a y structure analysis. Recently we have reported the synthesis and structure of the first alkyne complex of zirconocene, CpZZr(THF)(Me3SiCzSiMe3)(l),which does not contain a stabilizing phosphine ligand.' Complex 1 was obtained by the reaction of Cp2ZrClz with equimolar amounts of magnesium and bis(trimethylsily1)acetylene in THF at room temperature under argon.
\i' Zr' c 'SiMe, / \
I (2 )
(1)
Here we wish to report the reactions of complexes 1and 2 with carbon dioxide and water.
Results and Discussion Although the interaction of carbon dioxidewith titanium alkyne complexes has been well studied (see e.g. refs 2-7), similar reactions have not been described for alkyne complexesof zirconium until now. We found that 1reacts readily with CO2 at room temperature and atmospheric pressure to give the dimeric zirconafuranone metallacycle 3 in 76% yield. SiMe
P M e 3
Cp,ZrC12
+
Mg
+
Me,SiC=CSiMeS
THF
*
- MgCI,
CplZr\)) / c-
I
c.
THF
'SiMe,
2
+
/c CP2Zr\II
I C
THF
2c0,
- 2 THF
Max-Planck-Gesellschaft,Arbeitagruppe 'Komplexkatalyse" an der Universitit Rostock. 8 Institut fur Organische Katalyseforschung an der Universitgt Rostock e.V., Rostock, FRG. I Max-Planck-Gesellschaft, AG "Cot-Chemie" an der UniversitAt Jena, Jena, FRG. 11 Institute of Organoelement Compounds of the Russia Academy of Sciences, Moscow, Russia. 0 Abstract published in Advance ACS Abstracts, November 15,1993. (1) Rosenthal, U.; Ohff,A,; Michalik, M.; Gdrls, H.; Burlakov, V. V.; Shur, V. B. Angew. Chem. 1993,105, 1228.
0276-733319312312-5016$04.00/0
/c-o t o
Me%=( CPlZr,
o*c/
'SiMe,
(1)
An X-ray diffraction study of 1 has shown that the structure is close to that of a zirconacyclopropene and contains a weakly bonded THF molecule. As a remarkable feature, 1 on dissolving in benzene or hexane at room temperature is readily transformed into the binuclear a-alkenyl complex2 due to hydrogen transfer from the .rl5-C5H5 ring to the acetylene ligand.' The reaction is reversible, and dissolution of 2 in THF results in a gradual back-formation of 1. According to X-ray data and NMR spectra 2 exhibits an agostic interaction between the zirconium atoms and the alkenyl C-H b0nd.l
CP
MeJSi (1)
"
0
K' SIMe,
(3)
Complex 3 is also formed in high yield by the reaction of 2 with carbon dioxide in THF under similar conditions. If the reaction of 2 with COz is carried out in benzene the yield of 3 decreases. Complex 3 is a light-yellow crystalline solid (mp 177178 "C (dec) under argon) stable in air and practically insoluble in hydrocarbons and ethereal solvents. (2) Demerseman, B.; MahB, R.; Dixneuf, P. H. J. Chem. SOC., Chem. Commun. 1984, 1394. (3)Alt, H. G.; Herrmann, G. S.; Rausch, M. D.; Mallin, D. T. J. Organomet. Chem. 1988,356, C53. (4) Alt, H. G.; Herrmann, G. S. J.Organomet. Chem. 1990,390,159. ( 5 ) Burlakov, V. V.; Rosenthal, U.; Yanovskii, A. I.; Stuchkov, Yu. T.; Ellert, 0. G.; Shur, V. B.; Vol'pin, M. E. Metallorg. Khim. 1989,2,1193 [English translation: Organomet. Chem. USSR, 1989, 2, 6331. (6) Burlakov, V. V.; Rosenthal, U.; Dolgushin, F. M.; Yanovskii, A. I.; Stuchkov, Yu. T.; Ellert, 0. G.; Shur, V. B.; Vol'pin, M. E. Metallorg. Khim. 1992,5,1213 [English translation: Organomet. Chem. USSR, 1992, 5, in press]. (7) Shur, V. B.; Burlakov, V. V.; Yanovskii, A. I.; Struchkov, Yu. T.; Vol'pin, M. E. Metallorg. Khim. 1988, 1, 475 [English translation: Organomet. Chem. USSR 1988,1, 2611.
0 1993 American Chemical Society
Organometallics, Vol. 12, No. 12, 1993 5017
Notes Table
Figure 1. SHELXTL plot showing the molecular structure of 3. Table I. Crystallographic Data for Complexes 3 and 4 3
chem formula molecular weight cryst system space group cell params at 293 K a (A)
b (A)
c (A) a (deg)
B (deg)
Y (deg)
V (A3)
cryst dimens (mm) no. of formula units (2) 4 (g/cm3) abs coeff p(Mo Ka) (cm-1) 20 range (deg) no. of unique data no. of obsd data with I5 241) no. of variables R R W
rest electron density (e A-3)
C36HaOS4Zr4 801.6 monoclinic C 2 / m (No. 12)
10.254(3) 10.806(3) 11.041(3) 69.1 l(2) 67.61(2) 66.39(2) 1006.1(5) 0.40 X 0.40 X 0.16
17.063(2) 12.403(2) 10.452(1)
1
1.44 6.6 2-55 4806 4567 217 0.042 0.055 1.47
Zr-0( 1) Zr-O 1a Zr43 Zr-CPl Si142 Si243
2.197(2) 2.330(2) 2.376(3) 2.243(3) 1.923(4) 1.895(4)
C1-C2 Zr-CP2 Ol-Cl 0 2 41 C243
Zr-O 1-Zra Zr-Ol-Cl 01-cl-02 014142 Si14243 C14243
116.8(1) 121.2(2) 120.4(3) 116.4(3) 138.4(3) 115.9(3)
Zr-C3-C2 Si24342 01-Zr-01a Ol-Zr-C3 CP1-Zr-CPZ
2005.4(5) 0.40 X 0.24 2 1.33 6.5 2-55 4821 1940 113 0.033 0.048 0.43
Zr-O Zr-C 1 Zr42 Zr-H2 Si141 Si2422
a
X
0.20
An X-ray structure analysis of 3 revealed two zirconafuranone units linked with each other by two coordinative Zr-0 bonds (Figure 1). Table I lists crystallographic data. Positional parameters and selected bond lengths and angles of 3 are given in Tables I1 and IV. The moleculehas Ci symmetrywith the symmetry center in the middle of a four-membered Zr-0-Zr-0 ring. This ring is planar, and the 0 atoms are parts of five-membered zirconafuranone units. The zirconium atoms have a distorted trigonal-bipyramidal coordination sphere having the Cp ring centers and the 01atom in equatorial positions and the atoms Ola and C3 in axial positions. The whole tricyclic system is almost planar. The angle of distortion of ClOlZrOla amounts to 178.9(2)'. The SiMea groups are in cis positions. Analogous titanafuranone metallacycles but having a monomeric structure were obtained previously in the reaction of carbon dioxide with titanium alkyne complexes CpCp*Ti(PhCzPh), Cp2Ti(HC2H)(PMes), and Cp2TiJ. L.Inorg. Chem. 1980,19, 3817. (9) Shur, V. B.; Bemadyuk, S. Z.;Burlakov, V. V.; Andrianov, V. G.; Yanovekii. A. I.: Stuchkov, Yu.T.:. Vol'Din, - . M. E. J. Organornet. Chem. 1983, 243,.157..
(10) Shur, V. B.; Burlakov, V. V.; Vol'pin, M. E. J. Organomet. Chem.
1988, 347,77.
(11)Herrmann, G. S.;Alt, H. G.; Thewalt, U. Organomet. Chem. 1990, 393, 83. (12) Alt, H. G.; Herrmann, G. S.; Rausch, M.D. Organomet. Chem. 1988, 356, C50.
114.5(2) 116.8(2) 63.2( 1) 71.7(1) 130.4(2)
(A) and Angles (deg) for
Table III. Selected Bond Lengths 4' 1.973(1) 2.299(4) 3.017(5) 2.72(1) 1.87 l(4) 1.874(5)
0-Zr-Cl CP1-Zr-CPla Si14142
114.96(1)
1.488(5) 2.254(3) 1.342(4) 1.223(4) 1.360(5)
a CP1 is the centroid of the Cpring ClOX14, and CP2 is the centroid of the Cpring C15-Cl9.
4
C38H%.O84Zrz 871.6 triclinic Pi (No. 2)
II. Selected Bond Lengths (A) and Angles (deg) for 9
Cl-CZ Zr-CPl 0 4 2 0-H2 C2-H2
104.7(1) 128.1(1) 120.3(3)
Zr-Cl-C2 Si24241 Cl-C2-H2
1.349(6) 2.263(4) 3.294(5) 2.44(1) 1.01(1) 108.8(3) 140.3(4) 109.6(3)
CP1 and CPla are the centroids of the Cp rings.
Table IV. Positional Parameters and Their Estimated Standard Deviations for 3 atom X Y 2 B (A2) ~
Zr Si 1 Si2 01 02 c1 c2 c3 c4 c5 C6 c7 C8 c9 c10 c11 c12 C13 C14 C15 C16 C17 C18 C19
-0.20527(31 0.0253( i)' -O.3637(1) 0.0253(2) 0.1880(3) 0.0600(3) -0).0644(3) -0.2020(3) 0.1208(5) 0.1567(5) -0.0850(6) -0.3620(6) 4.3536(6) -0).5560(6) -0.4370(4) -0.3782(4) -0).2479(4) -0).2228(4) -0).3416(4) 4.4018(4) -0.3389(4) -0.1955(4) -O.1684(4) -0.2951(5)
0.57461(31 0.7929( i)' 0.8300(1) 0.5673(2) 0.6394(3) 0.6397(3) 0.7190(3) 0.7194(3) 0.9138(5) 0.6420(6) 0.8906(6) 1.0154(4) 0.7556(5) 0.8420(6) 0.7477(5) 0.6568(5) 0.6784(4) 0.7809(4) 0.8248(4) 0.4896(4) 0.3919(4) 0.3233(4) 0.3770(4) 0.4785(4)
~
~~~
0.5929813) 0.7684( i) 0.8214(1) 0.5481(2) 0.5708(3) 0.6015(3) 0.6968(3) 0.7103(3) 0.6297(5) 0.8520( 5 ) 0.9040( 5) 0.7492( 5) 1.OO 13(5) 0.8348(6) 0.5332(5) 0.4493(4) 0.3588(4) 0.3884(4) 0.4965(4) 0.7925(5) 0.7126(4) 0.7198(4) 0.8007(4) 0.8464(4)
2.308161 3.66(i) ' 4.02(3) 2.78(5) 4.92(7) 3.18(7) 2.77(7) 2.69(7) 6.3(1) 6.4( 1) 8.4( 1) 5.9(1) 6.4(1) 7.2(2) 5.0( 1) 5.0( 1) 4.2(1) 4.00(9) 4.3(1) 4.8(1) 4.7(1) 4.3(1) 4.2(1) 4.3(1)
(MeCzMe).24 It is interesting that the alkyne complexes CpzTi(PhC2Ph) and CpzTi(MesSiC2SiMes) react with carbon dioxide differently from the above compounds. Here the reaction leads to the displacement of 0.5 mol of alkyne from the coordination sphere of titanium accompanied by formation of the binuclear titanium(II1) u-vinylcarboxylate derivatives Cp2TiC(R)=C(R)COOTiCpz (R = Ph, SiMe3).5 The monomeric titanafuranone metallacycles are formed only in a further reaction with air oxygen.6J Upon reaction of 1 or 2 with water in THF at room temperature the zirconoxane complex 4 containing two cr-alkenyl groups is formed. Similar titanoxane u-alkenyl complexes have been described.Gl2
Notes
5018 Organometallics, Vol. 12, No. 12, 1993 SiMe3
P M e 3
2 C,,Zr
