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Synthesis and air stability of mixed ligand lanthanide organometallics involving both indenyl and cyclopentadienyl ligands
0277-5387/89 s3.00 + 30 0 1988 Pergamon Press plc
Po/yhedron Vol. 8, No. 1, pp. 17-20, 1989 Printed in Great Britain
SYNTHESIS AND AIR STABILITY OF MKED LIGAND LANTHANIDE ORGANOMETALLICS INVOLVING BOTH INDENYL AND CYCLOPENI’ADIENYL LIGANDS ZHOU ZHENNAN,*
WU ZHONGZHI,
DU BAOI-IU and YE ZHONGWEN
Institute of Organic Chemistry, Anhui Normal University, Wuhu, China (Received 3 May 1988 ; accepted 21 June 1988) Abstract-By
the reaction of Cp,LnCl (Cp = CsHs ; Ln = Sm, Dy, Ho, Er, Yb) with IndNa (Ind = CgH7), five new organolanthanides containing Cp and Ind groups have been synthesized. Comparing their air stability by exposure to air, we found these complexes were more stable in air than the corresponding Cp,Ln, and their relative stability increased with a decrease of the metal ionic radii. All the complexes were characterized on the basis of their analytical and spectral data.
Tricyclopentadienyl and triindenyl organolanthanides have been presented previously in the literature,‘v2 but literature involving both cyclopentadienyl (Cp) and indenyl (Ind) mixed ligand organolanthanides have not been reported as yet. In this paper, we report the synthesis of five new mixed ligand organolanthanides by the following equation :
soluble in benzene, n-hexane and other hydrocarbon solvents. Complexes I-V were characterized by IR and MS spectroscopy. All complexes in Table 2 exhibited a characteristic absorption of the aromatic C-H vibrations of Cs and C6 rings at 3000-3100 cm-’ and 700-850 cn- ‘. In addition, an aliphatic C-H stretching vibration was observed between 2800 and 3000 cm- ’ . This indicated the presence of a a-metalto-carbon bonding in all complexes.3-5 In the mass Cp,LnCl + IndNa z Cp,Ln(Ind)(THF) + NaCl spectra (see Table 3), the molecular ion peaks and main resulting ion fragment peaks were all shown. Ln = Sm’, Dy”, HOI”, ErtV, YbV. Based on the above results, we could clearly demThese new complexes were characterized by onstrate that the five new mixed ligand organoelemental analysis (Table 1) , IR (Table 2) and mass lanthanides were positively obtained. Since the spectroscopy (Table 3), and their air stability was metal-indenyl complexes”g showed a remarkable compared as follows. similarity in structure to their cyclopentadienyl homologues, the structure of complexes I-V could not yet be elucidated from IR and MS. Almost all the organolanthanides were sensitive RESULTS AND DISCUSSION to air and moisture. The coordinated unsaturation By the reaction of Cp,LnCl (Ln = Sm, Dy, Ho, of the lanthanide complexes may be one of the Er, Yb) with IndNa in THF at room temperature, important factors for their instability. Recently, the five new organolanthanides have been synthesized. method of using bulky ligands to decrease the coorElemental analysis data (Table 1) on all complexes dinated unsaturation of the organolanthanides has were consistent with the formulation Cp,Ln(Ind) become favourable for the stabilization of lan(THF). These complexes contained one solvated thanide-carbon bonds. ‘&I 2The synthesis of the five THF molecule which could not be removed under new complexes reported in this paper could actually vacuum at room temperature. All the complexes were be regarded as substituting one Ind group for one soluble in THF and ether but were only sparingly Cp group of Cp,Ln. Since the steric volume of the Ind group was bigger than the Cp group, the coordinated unsaturation of the new complexes *Author to whom correspondence should be addressed. decreased ; the mixed ligand complexes should be 17
Z. ZHENNAN et al.
18
Table 1. Analytical and other physical data for complexes I-V Elemental analysis’ Complex
Colour
M.p. (C)o Yield (%)
Cp,Sm(Ind)(THF)
(H
Yellow-orange
115
80
CpzDy(Ind)(THF)
(Irr)
Pale yellow
112
45
Cp,Ho(Ind)(THF)
(III)
Yellow
126
50
Cp,Er(Ind)(THF)
(Iv)
Pink
125
55
CpzYb(Ind)(THF)
0’)
Deep green
200’
30
%Ln
%C
32.2 (32.6) 33.9 (34.3) 34.2 (34.5) 34.5 (34.4) 35.3 (35.2)
59.1 (58.8) 57.6 (57.5) 57.3 (57.2) 57.0 (56.8) 56.3 (56.1)
%H
(Z) 5.3 (5.2) 5.2 (5.4) 5.2 (5.3) (:::)
0Melting points were determined in sealed argon-filled capillaries. bElemental analysis results were obtained on a Yanaco-MT-2 analyser. The elemental analysis data for Ln were obtained by a published method.3 Found values are given in parentheses. ‘Decomposition temperature.
more stable than their corresponding homogeneous ligand complexes (Cp,Ln). In order to compare the stability of Cp,Ln and Cp,LnInd, five known complexes of Cp,Ln (THF) of an identical metal were also synthesized according to the literature method.’ The two different kinds of complexes (mixed and homogeneous) were exposed to air (temperature = 2O”C, relative humidity = 78%). When their colour changed or major characteristic absorption peaks in the IR disappeared, it was considered an indication of the decomposition of the complexes. The exposure time
recorded for the complexes to decompose was specified as a criterion for their relative stability. We found that the order of their relative stability was (i) CprLnInd > Cp,Ln, (ii) Cp,YbInd > Cp,ErInd Cp,DyInd > Cp,SmInd.
> Cp,HoInd
From the above order, it was obvious that : (i) by replacing one Cp group from Cp,Ln with an Ind group, the new complexes would be more stable.
Table 2. IR spectral data” for complexes I-V(4000-200 cm- ') Complex
Cp2WW(THF)
Main absorptions (cm- ‘)
0
3085(w), 3062(m), 2923(m), 2853(m), 1605(m), 1485(m), 1453(m), 1393(m), 1320(m), 1220(w), 1045(m), 1011(s), 914(m), 840(m), 770(s), 740(s), 720(s), 255(w).
Cp,Dy(Ind)(THF)
01)
3090(w), 3068(m), 2921(m), 2853(m), 1602(m), 1485(m), 1445(s), 1395(m), 1320(m), 1218(w), 1054(w), 1011(s), 914(m), 840(m), 780(s), 767(s), 720(s), 249(w).
Cp,Ho(Ind)(THF)
(III)
3080(w), 3065(m), 2923(m), 2852(m), 1605(m), 1480(m), 1445(s), 1395(m), 1320(m), 1217(w), 1054(w), 1010(s), 914(m), 838(m), 780(s), 765(s), 718(s), 242(w).
Cp&(Ind)(THF)
(Iv)
3085(w), 3060(m), 2920(m), 2853(m), 1602(m), 1485(m), 1446(s), 1393(m), 1321(s), 1217(m), 1053(w), 101 l(s), 914(m), 840(m), 780(s), 767(s), 718(s), 240(w).
CpzYb(Ind)(THF)
(v)
3080(w), 3065(m), 2925(m), 2853(m), 1605(m), 1480(m), 1445(s), 1390(m), 1300(m), 1210(w), 1055(w), 101 l(s), 914(m), 845(m), 777(s), 765(s), 724(s), 250(w).
‘The IR spectra were recorded on a Perkin-Elmer
>
983(G) spectrometer as Nujol or fluorocarbon
oil mulls.
19
Mixed ligand lanthanide organometallics *Table 3. Mass spectra data” for complexes I-V
Complex M=Cp,Sm(Ind)(THF)
M=Cp,Dy(Ind)(THF)
M=Cp,Ho(Ind)(THF)
M=Cp,Er(Ind)(THF)
M=CpzYb(Ind)(THF)
Main peaks (m/e)* (I)
@)
(III)
(IV)
(V)
397(M-THF), 332(M-Cp-THF), 282(M-Ind-THF), 267(M-2Cp-THF), 1lS(Ind), 72(THF), 65(Cp)
152(Sm),
409(M-THF), 344(M-Cp-THF), 294(M-Ind-THF), 279(M-2Cp_THF), 1lS(Ind), 72(THF), 65(Cp)
164(Dy),
410(M-THF), 345(M--Cp-THF), 295(M-Ind-THF), 280(M-2Cp_THF), 1lS(Ind), 72(THF), 65(Cp)
165(Ho),
41 l(M-THF), 346(M-Cp-THF), 296(M-Ind-THF), 281(M-2Cp-THF), 1lS(Ind), 72(THF), 65(Cp)
166(Er),
419(M-THF), 354(M-Cp-THF), 304(M-Ind-THF), 289(M-2Cp-THF), 11S(Ind), 72(THF), 65(Cp)
174(Yb),
a MS spectra were recorded on VG ZAB-HS mass spectrometer. bMS data are given for the isotopes ls2Sm, ‘64Dy, 16’Ho, ‘66Er, ‘74Yb, the peak patterns correspond to theoretical values based on the natural abundance of isotopes.
(ii) The air stability of these new complexes increased with decrease of the metal ionic radii. These results agreed well with our previous report. ’ 3 Based on the above conclusions, the method of using steric bulky ligands to stabilize the coordinated unsaturation complexes was usually successful.
cm3. By addition of 50 cm3 of n-hexane, a solid precipitated out which was recrystallized twice from THF/n-hexane and was dried in vacua to obtain the product. Yields, analyses and physical properties of all five complexes are listed in Table 1. Acknowledgements--We wish to acknowledge Prof. Wang Xiuran and Mr Wang Shaov, who assisted with this research.
EXPERIMENTAL All operations were performed in an atmosphere of prepurified argon using Schlenk techniques or in a glove-box. All solvents were refluxed and distilled over blue sodium benzophenone or finely divided LiAlH4 under argon immediately prior to use. The reactants, Cp,LnCl14 and IndNa,’ were prepared according to the literature methods. Indene was distilled in a commercial reagent and the 182°C distillate was collected.
General method of the synthesis of complexes I-V A 60 cm3 THF solution of 3 mmol of Cp,LnCl was placed in a Schlenk flask and an equivalent amount of sodium indenide was added. The reaction mixture was allowed to stir at room temperature for 24 h. After the NaCl was removed from the reaction mixture by centrifugation, the resulting solution was concentrated in vacua to about 20
REFERENCES 1. G. Wilkinson and J. M. Birmingham, J. Am. Chem. Sot. 1956,78,42.
2. M. Tsutsui and H. J. Gysling, J. Am. Chem. Sot. 1969,91,3175. 3. C. T. Qian, C. Q. Ye, H. Z. Lu, Y. Q. Li and J. L. Zhou, J. Organomet. Chem. 1983,247,161. 4. E. Samuel and M. Bigorgne, J. Organomet. Chem. 1969, 19,9. 5. H. P. Fritz, F. H. Kohler and K. E. Schwarzhans, J. Organomet. Chem. 1969,19,4. 6. E. 0. Fischer and D. Seus, Z. Naturfirsch. B. 1954, 9, 386.
7. E. 0. Fischer and D. Seus, Z. Naturforsch. B. 1953, 8, 694.
8. E. Samuel and R. Settm, J. Organomet. Chem. 1965, 4, 156. 9. E. Samuel, Bull. Sot. Chem. Fr. 1966, 11, 3548. 10. A. L. Wayda and W. J. Evans, Znorg. Chem. 1980, 19, 2190.
20
Z. ZHENNAN
11. T. D. Tilley and R. A. Anderson, Znorg. Chem. 1981, 20, 3267. 12. M. Tsutsui, L. B. Chen, D. E. Bergbreiter and T. K. Miyamoto, J. Am. Chem. Sot. 1982,104,855.
et al.
13. Z. W. Ye, Z. N. Zhou, Z. Y. Lou, X. R. Wang and F. R. Shen, Sinicu. Chim. Acta. 1986,44, 707. 14. R. E. Maginn, S. Manastryrskyj and M. Dubeck, J. Am. Chem. Sot. 1963,85,672.
Po/yhedron Vol. 8, No. 1, pp. 17-20, 1989 Printed in Great Britain
SYNTHESIS AND AIR STABILITY OF MKED LIGAND LANTHANIDE ORGANOMETALLICS INVOLVING BOTH INDENYL AND CYCLOPENI’ADIENYL LIGANDS ZHOU ZHENNAN,*
WU ZHONGZHI,
DU BAOI-IU and YE ZHONGWEN
Institute of Organic Chemistry, Anhui Normal University, Wuhu, China (Received 3 May 1988 ; accepted 21 June 1988) Abstract-By
the reaction of Cp,LnCl (Cp = CsHs ; Ln = Sm, Dy, Ho, Er, Yb) with IndNa (Ind = CgH7), five new organolanthanides containing Cp and Ind groups have been synthesized. Comparing their air stability by exposure to air, we found these complexes were more stable in air than the corresponding Cp,Ln, and their relative stability increased with a decrease of the metal ionic radii. All the complexes were characterized on the basis of their analytical and spectral data.
Tricyclopentadienyl and triindenyl organolanthanides have been presented previously in the literature,‘v2 but literature involving both cyclopentadienyl (Cp) and indenyl (Ind) mixed ligand organolanthanides have not been reported as yet. In this paper, we report the synthesis of five new mixed ligand organolanthanides by the following equation :
soluble in benzene, n-hexane and other hydrocarbon solvents. Complexes I-V were characterized by IR and MS spectroscopy. All complexes in Table 2 exhibited a characteristic absorption of the aromatic C-H vibrations of Cs and C6 rings at 3000-3100 cm-’ and 700-850 cn- ‘. In addition, an aliphatic C-H stretching vibration was observed between 2800 and 3000 cm- ’ . This indicated the presence of a a-metalto-carbon bonding in all complexes.3-5 In the mass Cp,LnCl + IndNa z Cp,Ln(Ind)(THF) + NaCl spectra (see Table 3), the molecular ion peaks and main resulting ion fragment peaks were all shown. Ln = Sm’, Dy”, HOI”, ErtV, YbV. Based on the above results, we could clearly demThese new complexes were characterized by onstrate that the five new mixed ligand organoelemental analysis (Table 1) , IR (Table 2) and mass lanthanides were positively obtained. Since the spectroscopy (Table 3), and their air stability was metal-indenyl complexes”g showed a remarkable compared as follows. similarity in structure to their cyclopentadienyl homologues, the structure of complexes I-V could not yet be elucidated from IR and MS. Almost all the organolanthanides were sensitive RESULTS AND DISCUSSION to air and moisture. The coordinated unsaturation By the reaction of Cp,LnCl (Ln = Sm, Dy, Ho, of the lanthanide complexes may be one of the Er, Yb) with IndNa in THF at room temperature, important factors for their instability. Recently, the five new organolanthanides have been synthesized. method of using bulky ligands to decrease the coorElemental analysis data (Table 1) on all complexes dinated unsaturation of the organolanthanides has were consistent with the formulation Cp,Ln(Ind) become favourable for the stabilization of lan(THF). These complexes contained one solvated thanide-carbon bonds. ‘&I 2The synthesis of the five THF molecule which could not be removed under new complexes reported in this paper could actually vacuum at room temperature. All the complexes were be regarded as substituting one Ind group for one soluble in THF and ether but were only sparingly Cp group of Cp,Ln. Since the steric volume of the Ind group was bigger than the Cp group, the coordinated unsaturation of the new complexes *Author to whom correspondence should be addressed. decreased ; the mixed ligand complexes should be 17
Z. ZHENNAN et al.
18
Table 1. Analytical and other physical data for complexes I-V Elemental analysis’ Complex
Colour
M.p. (C)o Yield (%)
Cp,Sm(Ind)(THF)
(H
Yellow-orange
115
80
CpzDy(Ind)(THF)
(Irr)
Pale yellow
112
45
Cp,Ho(Ind)(THF)
(III)
Yellow
126
50
Cp,Er(Ind)(THF)
(Iv)
Pink
125
55
CpzYb(Ind)(THF)
0’)
Deep green
200’
30
%Ln
%C
32.2 (32.6) 33.9 (34.3) 34.2 (34.5) 34.5 (34.4) 35.3 (35.2)
59.1 (58.8) 57.6 (57.5) 57.3 (57.2) 57.0 (56.8) 56.3 (56.1)
%H
(Z) 5.3 (5.2) 5.2 (5.4) 5.2 (5.3) (:::)
0Melting points were determined in sealed argon-filled capillaries. bElemental analysis results were obtained on a Yanaco-MT-2 analyser. The elemental analysis data for Ln were obtained by a published method.3 Found values are given in parentheses. ‘Decomposition temperature.
more stable than their corresponding homogeneous ligand complexes (Cp,Ln). In order to compare the stability of Cp,Ln and Cp,LnInd, five known complexes of Cp,Ln (THF) of an identical metal were also synthesized according to the literature method.’ The two different kinds of complexes (mixed and homogeneous) were exposed to air (temperature = 2O”C, relative humidity = 78%). When their colour changed or major characteristic absorption peaks in the IR disappeared, it was considered an indication of the decomposition of the complexes. The exposure time
recorded for the complexes to decompose was specified as a criterion for their relative stability. We found that the order of their relative stability was (i) CprLnInd > Cp,Ln, (ii) Cp,YbInd > Cp,ErInd Cp,DyInd > Cp,SmInd.
> Cp,HoInd
From the above order, it was obvious that : (i) by replacing one Cp group from Cp,Ln with an Ind group, the new complexes would be more stable.
Table 2. IR spectral data” for complexes I-V(4000-200 cm- ') Complex
Cp2WW(THF)
Main absorptions (cm- ‘)
0
3085(w), 3062(m), 2923(m), 2853(m), 1605(m), 1485(m), 1453(m), 1393(m), 1320(m), 1220(w), 1045(m), 1011(s), 914(m), 840(m), 770(s), 740(s), 720(s), 255(w).
Cp,Dy(Ind)(THF)
01)
3090(w), 3068(m), 2921(m), 2853(m), 1602(m), 1485(m), 1445(s), 1395(m), 1320(m), 1218(w), 1054(w), 1011(s), 914(m), 840(m), 780(s), 767(s), 720(s), 249(w).
Cp,Ho(Ind)(THF)
(III)
3080(w), 3065(m), 2923(m), 2852(m), 1605(m), 1480(m), 1445(s), 1395(m), 1320(m), 1217(w), 1054(w), 1010(s), 914(m), 838(m), 780(s), 765(s), 718(s), 242(w).
Cp&(Ind)(THF)
(Iv)
3085(w), 3060(m), 2920(m), 2853(m), 1602(m), 1485(m), 1446(s), 1393(m), 1321(s), 1217(m), 1053(w), 101 l(s), 914(m), 840(m), 780(s), 767(s), 718(s), 240(w).
CpzYb(Ind)(THF)
(v)
3080(w), 3065(m), 2925(m), 2853(m), 1605(m), 1480(m), 1445(s), 1390(m), 1300(m), 1210(w), 1055(w), 101 l(s), 914(m), 845(m), 777(s), 765(s), 724(s), 250(w).
‘The IR spectra were recorded on a Perkin-Elmer
>
983(G) spectrometer as Nujol or fluorocarbon
oil mulls.
19
Mixed ligand lanthanide organometallics *Table 3. Mass spectra data” for complexes I-V
Complex M=Cp,Sm(Ind)(THF)
M=Cp,Dy(Ind)(THF)
M=Cp,Ho(Ind)(THF)
M=Cp,Er(Ind)(THF)
M=CpzYb(Ind)(THF)
Main peaks (m/e)* (I)
@)
(III)
(IV)
(V)
397(M-THF), 332(M-Cp-THF), 282(M-Ind-THF), 267(M-2Cp-THF), 1lS(Ind), 72(THF), 65(Cp)
152(Sm),
409(M-THF), 344(M-Cp-THF), 294(M-Ind-THF), 279(M-2Cp_THF), 1lS(Ind), 72(THF), 65(Cp)
164(Dy),
410(M-THF), 345(M--Cp-THF), 295(M-Ind-THF), 280(M-2Cp_THF), 1lS(Ind), 72(THF), 65(Cp)
165(Ho),
41 l(M-THF), 346(M-Cp-THF), 296(M-Ind-THF), 281(M-2Cp-THF), 1lS(Ind), 72(THF), 65(Cp)
166(Er),
419(M-THF), 354(M-Cp-THF), 304(M-Ind-THF), 289(M-2Cp-THF), 11S(Ind), 72(THF), 65(Cp)
174(Yb),
a MS spectra were recorded on VG ZAB-HS mass spectrometer. bMS data are given for the isotopes ls2Sm, ‘64Dy, 16’Ho, ‘66Er, ‘74Yb, the peak patterns correspond to theoretical values based on the natural abundance of isotopes.
(ii) The air stability of these new complexes increased with decrease of the metal ionic radii. These results agreed well with our previous report. ’ 3 Based on the above conclusions, the method of using steric bulky ligands to stabilize the coordinated unsaturation complexes was usually successful.
cm3. By addition of 50 cm3 of n-hexane, a solid precipitated out which was recrystallized twice from THF/n-hexane and was dried in vacua to obtain the product. Yields, analyses and physical properties of all five complexes are listed in Table 1. Acknowledgements--We wish to acknowledge Prof. Wang Xiuran and Mr Wang Shaov, who assisted with this research.
EXPERIMENTAL All operations were performed in an atmosphere of prepurified argon using Schlenk techniques or in a glove-box. All solvents were refluxed and distilled over blue sodium benzophenone or finely divided LiAlH4 under argon immediately prior to use. The reactants, Cp,LnCl14 and IndNa,’ were prepared according to the literature methods. Indene was distilled in a commercial reagent and the 182°C distillate was collected.
General method of the synthesis of complexes I-V A 60 cm3 THF solution of 3 mmol of Cp,LnCl was placed in a Schlenk flask and an equivalent amount of sodium indenide was added. The reaction mixture was allowed to stir at room temperature for 24 h. After the NaCl was removed from the reaction mixture by centrifugation, the resulting solution was concentrated in vacua to about 20
REFERENCES 1. G. Wilkinson and J. M. Birmingham, J. Am. Chem. Sot. 1956,78,42.
2. M. Tsutsui and H. J. Gysling, J. Am. Chem. Sot. 1969,91,3175. 3. C. T. Qian, C. Q. Ye, H. Z. Lu, Y. Q. Li and J. L. Zhou, J. Organomet. Chem. 1983,247,161. 4. E. Samuel and M. Bigorgne, J. Organomet. Chem. 1969, 19,9. 5. H. P. Fritz, F. H. Kohler and K. E. Schwarzhans, J. Organomet. Chem. 1969,19,4. 6. E. 0. Fischer and D. Seus, Z. Naturfirsch. B. 1954, 9, 386.
7. E. 0. Fischer and D. Seus, Z. Naturforsch. B. 1953, 8, 694.
8. E. Samuel and R. Settm, J. Organomet. Chem. 1965, 4, 156. 9. E. Samuel, Bull. Sot. Chem. Fr. 1966, 11, 3548. 10. A. L. Wayda and W. J. Evans, Znorg. Chem. 1980, 19, 2190.
20
Z. ZHENNAN
11. T. D. Tilley and R. A. Anderson, Znorg. Chem. 1981, 20, 3267. 12. M. Tsutsui, L. B. Chen, D. E. Bergbreiter and T. K. Miyamoto, J. Am. Chem. Sot. 1982,104,855.
et al.
13. Z. W. Ye, Z. N. Zhou, Z. Y. Lou, X. R. Wang and F. R. Shen, Sinicu. Chim. Acta. 1986,44, 707. 14. R. E. Maginn, S. Manastryrskyj and M. Dubeck, J. Am. Chem. Sot. 1963,85,672.