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Synthesis and structural study of cyclopentadienyl lanthanide derivatives containing the 2-naphthoyltrifluoroacetonato ligand
Pergamon
SYNTHESIS AND STRUCTURAL STUDY OF CYCLOPENTADIENYL LANTHANIDE DERIVATIVES CONTAINING THE 2-NAPHTHOYLTRIFLUOROACETONATO LIGAND FUREN
Institute
SHEN,”
of Organic
MEIHUA
Chemistry,
XIE,
Anhui
JIPING
Normal P.R.C.
HU and SHAOWU
University,
Wuhu,
WANG
Anhui
241000,
Fujian
350002,
and XIAOYING
Fujian
Institute
of Research
(Received
HUANG
on the Structure P.R.C.
17 January
of Matter,
Fuzhou,
1995 ; accepted 26 July 1995)
Abstract-Six
new organolanthanide complexes, Cp,Ln(ClOH,COCHCOCF,) [Ln = Dy Tb (2), Gd (3) Eu (4), Tm (5)] and CpzYb(C,,H,COCHCOCF,)(THF) (6) (Cp = cyclopentadienyl, THF = tetrahydrofuran), have been synthesized. All these complexes are identified by elemental analysis and IR. The crystal structure of Cp,Yb (CrOH,COCHCOCF,)(THF) has been determined by single-crystal X-ray diffraction. The central ytterbium atom is surrounded by two gs-cyclopentadienyl ligands, two oxygen atoms of the 2-naphthoyltrifluoroacetonato ligand and one oxygen atom of the solvated THF molecule. (l),
The chemistry of cyclopentadienyl lanthanide derivatives containing P-diketonato ligands have been studied previously.’ 3 However, articles concerning single-crystal structures of this type of complex are rare.4.5 In our previous work, we reported the synthesis and structure of organolanthanide complexes with the 2-naphthoyltrifluoroacetonato chelate ligand.” In order to extend the scope of the studies. we synthesized six new complexes and determined the single-crystal structure of CpzYb (C,,,H,COCHCOCF,)(THF).
All solvents were dried over sodium and distilled under argon immediately before use. 2-Naphthoyltrifluoroacetonatone,’ LnCl,,X Cp,Ln’ and Cp,Eu (THF)‘” were all prepared by the published procedures. Decomposition temperatures were determined in sealed argon-filled capillaries and were uncorrected. IR spectra were recorded on a Perkin Elmer 983(G) spectrometer (CsI crystal plate, Nujol and Fluorolube mulls). The elemental analysis for C and H were carried out with a Yanaco MT-2 analyser, the analysis for Ln were obtained by a published method.”
EXPERIMENTAL
Preparation All reactions and operations using Schlenk techniques under
*Author to whom correspondence
were carried out ultra-pure argon.
should be addressed.
qf’Cp,Yb(C,,,H,COCHCOCF,)(THF)
A mixture of Cp,Yb (1.70 mmol) and 2naphthoyltrifluoroacetonatone (1.70 mmol) was stirred in n-hexane (50 cm3) at room temperature for 3 days. n-Hexane was removed from the reaction mixture in vacua. The resulting solid was 1151
1152
F. SHEN et ul. of which 1963 reflections with I > 30(Z) were considered observed and used in the structure determination. The intensities were corrected for Lp effects and empirical absorptions. The structure was solved by direct methods and refined by full-matrix least-squares to final R = 0.025, Rw = 0.034 [w = 1/82(1F01)], S = 1.30, (A/a),,, = 0.03 and Ap = -0.46-0.32 e A-‘. The views of the molecule were produced by the ORTEP program. All calculations were made on a micro VAX-3 100 computer using the TEXSAN V.2.1 program package.
recrystallized twice from THF/n-hexane and dried in vacua and the product Cp,Yb (C,,H,COCHCOCF,)(THF) was obtained. Some of the product was dissolved in THF and drops of n-hexane added. Cooling the solution at - 10’C for a few days gave fine crystals suitable for X-ray diffraction. Preparation of‘Cp,Ln(C,,,H,COCHCOCF,) Dy, Tb, Gd, Eu, Tm)
(Ln =
A mixture of Cp,Ln (1.80 mmol Ln = Dy, Tb, Gd, Tm) or Cp,Eu(THF) and 2-naphthoyltrifluoroacetonatone (1.80 mmol) was stirred in toluene (40 cm3). After stirring for 3 days at room temperature, toluene was removed from the mixwere recrysture in vacua. The crude products tallized twice from toluene/n-hexane and dried in vacua and the products Cp,Ln(ClOH,COC HCOCF,) (Ln = Dy, Tb, Gd, Eu, Tm) were obtained. Physical data, elemental analyses and IR spectra of the six complexes are presented in Table 1.
RESULTS AND DISCUSSION Table 1 shows that the elemental analysis for the six complexes are in compliance with the general formula Cp,Ln(C,,H,COCHCOCF,) (Ln = Dy, Tb, Gd, Eu, Tm) or Cp,Yb(C,,H,COCH COCF,) (THF). These complexes are thermally unstable and the decomposition temperatures are listed in Table 1. The IR spectra of these complexes show characteristic Cp absorptions at ca 3 100, 1440, 1010 and 780 cm-‘.12 and an absorption peak at ca 250 cm-’ for Ln-C of the n-bonded Cp All complexes exhibit the characteristic group.” C-O and C-C multiple absorption of 0-chelate complexes at 1600-1500 cm1’.13 The IR spectra of Cp,Yb(C,,H,COCHCOCF,)(THF) also show the characteristic absorption of the solvated THF at ca 1065 and 913 cm-‘.‘4 Upon the above analysis and the crystal structure analysis of Cp,Yb(C,,H,COCHCOCF,)(THF) mentioned later, we propose the structure of complexes 1-5 could be described as follows : The central atom is coordinated by two cyclopentadienyls
X-ray crystallography Single crystals of Cp,Yb(C,,H,COCHCOCF,) (THF) used for structural analysis were sealed under argon in thin-walled capillaries. A single crystal with the dimensions 0.28 x 0.22 x 0.20 mm was selected for X-ray data collection. Data collection was performed on an Enraf-Nonius CAD-4 X-ray diffractometer with graphite-monochromated MoK, radiation (j_ = 0.71069 A). A total of 2655 unique reflections were collected in the range 20 < 49.9” by the ~20 scanning technique at 23”C,
Table 1. Analytical and partial IR data of the six complexes
Complex
Colour
Yield
D.T.” (“C)
1 (DY)
Yellow
38.5
I68
29.5 (29.1)
51.4 (51.7)
2 (Tb)
Yellow
33.4
164
28.5 (28.7) 28.8 (28.5) 27.7 (27.8)
51.4 (52.0) 52.8 (52.2) 52.4 (52.7)
(3.3)
30.2 (29.9) 27.1 (27.0)
51.0 (51.1) 52.7 (52.5)
3.2 (3.2) 4.4 (4.1)
3 (Gd)
Yellow
33.2
142
4 (Eu)
Brown
28.3
180
5 Pm)
Yellow
38.5
122
6 (Yb)
Orange
40.5
120
”D.T. = decomposition
temperature.
Ln
Found (Calc.) C H 3.1 (3.3) 3.1 (3.3) 3.3 (3.3) 3.4
IR (cm-‘) l596m 515~ 595m 517~ 595m 515~ 595m 515~ 1596m 1515~ l595m 1515~
1570s 1530s 1505m 1570s 1530s 1505m 1570s 1529s l505m 1570s 1529s 1507m 1570s 1532s 1505m 1570s 1530s 1505m
Cyclopentadienyl
lanthanide
in an $-fashion and two oxygen atoms of 2naphthoyltrifluoroacetonato in a bidentate fashion. The coordination number of Ln is 8. molecular structure of The CpzYb (CloH,COCHCOCF,)(THF) is shown in Fig. 1. Selected bond distances and angles of all nonhydrcgen atoms are listed in Tables 2 and 3, respectively. Figure I shows that Cp2Yb(C,,H,COCHCOCF,) (THF) is a monomeric ytterbium complex. The ytterbium is coordinated by two cyclopentadienyl ligand in an $-mode, two oxygen atoms of the 2naphthoyltrifluoroacetonato ligand in a bidentate fashion and one oxygen atom of the solvated THF molecule. The coordination number is 9 and the geometry around the ytterbium atom can be described as a distorted trigonal bipyramid with the centres of the two cyclopentadienyl rings and the three oxygen atoms forming the apices of the bipyramid. 0( 1) and the centres of the two cyclopentadienyl rings occupy equatorial positions and O(2) and O(3) occupy axial positions. The O(2)-Yb-O(3) bond angle is 146.4 The two cyclopentadienyl rings are planar with mean deviations of 0.0045 and 0.0082 A, respectively. The two planes form a dihedral angle of 49.94 ‘. The C-C distance for adjacent carbon
Fig. 1. Molecular
structure
derivatives
1153
atoms within cyclopentadienyl ligands range from 1.35(l) to 1.41(2) 8, (an average of 1.372 A). The C-C-C angles within the cyclopentadienyl rings range from 105(l) to 112(l)’ (an average of 108.1 ). Here, we make a simple comparison of significant structural parameters of the following complexes: Cp,Yb(C,,H,COCHCOCF,)(THF) (I), Cp2Ho(C,,,H,COCHCOCF,)(THF) (IQh CpzYb (CH,COCHCOCF,) (III)‘; see Table 4. With regard to the complexes I and II, which have the same ligands coordinating to the central metal atom, Table 4 shows that the bond distances between the central atom and the ligands of CpzYb (C,,H,COCHCOCF,) (THF) are shorter than that of Cp,Ho(C,,,H,COCHCOCF,) (THF); the bond angles formed by the central atom and the ligands of Cp,Yb(C,,,H,COCHCOCF,) (THF) are similar to or larger than that of Cp,Ho (C,,,HCOCHCOCF,) (THF). These results may be due to the lanthanide contraction effects. With regard to complexes I and III which have the same central metal atom, I is solvated but III is non-solvated. The bond distances between the central atom and the ligands of Cp,Yb (C,,,HCOCHCOCFJ (THF) are longer than those of Cp,Yb(CH,COCHCOCF,). The bond angles formed by the central atom and the ligands of
of Cp,Yb(C,,,H,COCHCOCF,)(THF)
F. SHEN et al. Table 2. Selected bond distances Y&0( I) Yb-O(2) Yb-O(3) Yb-C(21) Yb-C(22) Yb-C(23) Yb-C(24) Yb-C(25) YtwC(31) Yb-C(32) Yb-C(33) YIP-C(34) Yb-C(35)
2.221(S) 2.279(5) 2.471(6) 2.62(I) 2.63(l) 2.64( 1) 2.63( 1) 2.62(2) 2.609(8) 2.63 l(7) 2.63(l) 2.62( 1) 2.59( 1) 1.310(8)
F(l)-C(4) F(2)-C(4) F(3)-C(4) 0(1)-C(l) 0(2)-C(3) O(3)-C(44) O(3)-C(41)
(A)
C(l)-C(2) C(l)-C(4) C(2)-C(3) C(3)-C( 13) C(21)-C(25) C(21)-C(22) C(22)-C(23) C(23)-C(24) C(24)-C(25) C(31)-C(32) C(31)-C(35) C(32)-C(33) C(33)-C(34) C(34)-C(35) C(41)-C(42) C(42)-C(43) C(43)-C(44) Yb-Centl” Yb-Cent2h
1.335(9) 1.31(2) 1.276(7) 1.273(7)
1.428(9)
1.36(l) 1.51(2) 1.41(l) 1.49(1) 1.35( 1) 1.37(l) 1.37(l) I .36(2) I .36(l) 1.41(l) I .36(2) 1.37(l)
1.36(2) 1.41(2) 1.47(l) 1.48(l) 1.41(2) 2.352 2.334
1.43(l)
0 Cent 1 indicates ’Cent2 indicates
the centroid the centroid
of C(21)-C(25). of C(3 l)-C(35).
Table 3. Selected bond angles (“) O(l)-Yb-O(2) O(l)-Yb-O(3) O(2)-Yb-O(3) c(21)-Yb-c(22) C(21)-Yb-C(23) C(21)-Yb-C(24) C(21)-Yb-C(25) C(22)-Yb-C(23) C(22)-Yb-C(24) C(22)-Yb-C(25) C(23)-Yb-C(24) C(24)-Yb-C(25) C(23)-Yb-C(25) C(31)-Yb-C(32) C(31)-Yb-C(33) C(31)-Yb-C(34) C(31)-Yb-C(35) C(32)-Yb-C(33) C(32)-Yb-C(34) C(32)-Yb-C(35) C(33)-Yb-C(34) C(33)-Yb-C(35) C(34)-Yb-C(35) C(21)-Yb-C(31) C( I)-0( I)-Yb C(3)-O(2)-Yb C(41)-O(3)-Yb C(44)-O(3)-Yb c(44)-0(3)-c(41) O( I)-C(l)-C(2) ’Cent1 indicates ’Cent2 indicates
74.6(2) 72.8(2) 146.4(2) 30.3(3) 49.2(3) 49.1(3) 29.9(3) 30.2(3) 49.9(3) 50.2(3) 29.9(3) 30. I (3) 49.6(3) 31.2(3) 49.7(3) 50.8(3) 30.3(4) 30.2(3) 51.1(4) 51.2(4) 30.1(5) 50.1(4) 3 1.4(4) 135.84 133.8(6) 136.3(6) 125.7(4) 126.6(6) 107.7(7) 128(l) the centroid the centroid
of C(21)-C(25). of C(3 I)-C(35).
O(l)-C( 1)-C(4) C(2)-C(l)-C(4) C( I)-C(2)-C(3) O(2)-C(3)-C(2) O(2)-C(3)-C( 13) C(2)-C(3)-C( 13) c(14)-c(l3)-c(3) C(12)-C(13)-C(3) C(25)-C(21)-C(22) C(23)-C(22)-C(21) C(22)-C(23)-C(24) C(32)-C(31)-C(35) C(23)-C(24)-C(25) C(21)-C(25)-C(24) C(33)-C(32)-C(31) C(32)-C(33)-C(34) C(33)-C(34)-C(35) C(34)-C(35)-C(31) O(3)-C(41)-C(42) C(43)-C(42)-C(41) C(44)-C(43)-C(42) O(3)-C(44)-C(43) O(l)-Yb-Centl” 0( l)-Y&Cent2n O(2)-Yb-Cent1 O(2)-Yb-Cent2 O(3)-Yb-Cent I O(S)-Yb-Cent2 Centl-Yb-Cent2
I12.6(9) 119.3(7) 121.7(7) 122.7(8) 114.5(9) 122.8(6) 120.6(8) 120.2(7) 110(l) 106( 1) 109(l) 109(l) 109(l) 107( 1) 105( 1) 112(l) 106(I) 108(l) 107.6(7) 105.1(8) 106.2(9) 109.3(8) 121.82 108.80 94.39 97.57 96.35 99.87 129.36
Cyclopentadienyl Table 4. Some bond distances (A) and of Cp,Yb(C,,H,COCHCOCF,)(THF)(I), (C,,,H,COCHCOCF,)(THF)(II) and (CHjCOCHCOCF,) (III) I
lanthanide
angles ( ) CpzHo CpzY b
II
lanthanide contraction effects and steric effects caused the difference between bond distances and angles of complexes II and III. REFERENCES
III I. G. Bielang
Ln-0” Ln-O(THF)” Ln-Cent” O( I)-Ln-O(2)” Cent-Ln-0’ Centl-Ln-Cent?”
2.225 2.471 2.343 14.6 105.6 129.36
2.278 2.480 2.386 13.2 106.0 128.53
2.213 ~
2.
2.302 78.0 108.7 131.1
3. 4. 5.
“Cent1 and Cent2 indicate the centroids of the two cyclopentadienyl rings. 0( 1) and O(2) are the two oxygen atoms of fi-diketonato. ’ Ln-0 and Ln-Cent represent the average of Ln-0( I) and Ln-O(2) and the average of Ln-Cent1 and Ln-Cent2, respectively. ’Cent-Ln-0 is the average of Cent I-Ln-O(l), Centl-Ln-O(2). Cent2-Ln-O(1) and Cent2 -Ln-O(2)
6. 7. 8. 9. IO. Il.
are smaller than those of Cp,Yb(CH3COCHCOCF3) and it is proposed that these results are caused by steric effects. Complex II has longer bond distances and smaller bond angles than complex III. According to the conclusions mentioned above. we think that both Cp,Yb(C,,H,COCHCOCF,)(THF)
1155
derivatives
12. 13.
14.
and R. D. Fischer. Znorq. Ch~?j. Actu 1979.36. L389. H. Ma and Z. Ye, J. Or,gunomet. Chem. 1987. 326, 369. Z. Ye. Y. Yu and H. Ma. Po/yhe&on 1988, 7, 1095. L. Shi, H. Ma, Y. Yu and Z. Ye. J. Organomet. Chrm. 1988, 339, 277. Z. Ye, Y. YU and S. Wang, J. O~q~nomet. Chem. 1993. 448, 9 I. F. Shen, J. Hu, M. Xie, S. Wang and X. Huang, J. Organomet. Chem. 1995, 485, C&C9. J. c’. Reid and M. Calvin, J. Am. Chem. Sot. 1950, 72, 2948. M. D. Taylor and C. P. Carter, J. Inw9. Nucl. Chem. 1962, 24, 387. J. M. Birminham and G. Wilkinson, J. Am. Chem. SW. 1956, 78, 42. M. ‘Tsutsui. T. Takino and D. Lorene, Z. Naturfi?rsch 1966, 2lb, 1. C. Qian, C. Ye, H. Lu, Y. Li, J. Zhou and Y. Ge, J. Organomet. Chem. 1983, 247, 161. N. M. Ely and M. Tsutsui, Inorg. Chem. 1975, 14, 2680. K. Nakamoto, Iyfiared and Raman Spectra Of’Inorganic and Coordination Compounds, 3rd edn, pp. 249% New York (1977). 258, Wiley-Interscience, W. Cheng, G. Yu, S. Xiao, J. Huang and X. Gao. KeXue TongBao 1983, 28, 1043.
SYNTHESIS AND STRUCTURAL STUDY OF CYCLOPENTADIENYL LANTHANIDE DERIVATIVES CONTAINING THE 2-NAPHTHOYLTRIFLUOROACETONATO LIGAND FUREN
Institute
SHEN,”
of Organic
MEIHUA
Chemistry,
XIE,
Anhui
JIPING
Normal P.R.C.
HU and SHAOWU
University,
Wuhu,
WANG
Anhui
241000,
Fujian
350002,
and XIAOYING
Fujian
Institute
of Research
(Received
HUANG
on the Structure P.R.C.
17 January
of Matter,
Fuzhou,
1995 ; accepted 26 July 1995)
Abstract-Six
new organolanthanide complexes, Cp,Ln(ClOH,COCHCOCF,) [Ln = Dy Tb (2), Gd (3) Eu (4), Tm (5)] and CpzYb(C,,H,COCHCOCF,)(THF) (6) (Cp = cyclopentadienyl, THF = tetrahydrofuran), have been synthesized. All these complexes are identified by elemental analysis and IR. The crystal structure of Cp,Yb (CrOH,COCHCOCF,)(THF) has been determined by single-crystal X-ray diffraction. The central ytterbium atom is surrounded by two gs-cyclopentadienyl ligands, two oxygen atoms of the 2-naphthoyltrifluoroacetonato ligand and one oxygen atom of the solvated THF molecule. (l),
The chemistry of cyclopentadienyl lanthanide derivatives containing P-diketonato ligands have been studied previously.’ 3 However, articles concerning single-crystal structures of this type of complex are rare.4.5 In our previous work, we reported the synthesis and structure of organolanthanide complexes with the 2-naphthoyltrifluoroacetonato chelate ligand.” In order to extend the scope of the studies. we synthesized six new complexes and determined the single-crystal structure of CpzYb (C,,,H,COCHCOCF,)(THF).
All solvents were dried over sodium and distilled under argon immediately before use. 2-Naphthoyltrifluoroacetonatone,’ LnCl,,X Cp,Ln’ and Cp,Eu (THF)‘” were all prepared by the published procedures. Decomposition temperatures were determined in sealed argon-filled capillaries and were uncorrected. IR spectra were recorded on a Perkin Elmer 983(G) spectrometer (CsI crystal plate, Nujol and Fluorolube mulls). The elemental analysis for C and H were carried out with a Yanaco MT-2 analyser, the analysis for Ln were obtained by a published method.”
EXPERIMENTAL
Preparation All reactions and operations using Schlenk techniques under
*Author to whom correspondence
were carried out ultra-pure argon.
should be addressed.
qf’Cp,Yb(C,,,H,COCHCOCF,)(THF)
A mixture of Cp,Yb (1.70 mmol) and 2naphthoyltrifluoroacetonatone (1.70 mmol) was stirred in n-hexane (50 cm3) at room temperature for 3 days. n-Hexane was removed from the reaction mixture in vacua. The resulting solid was 1151
1152
F. SHEN et ul. of which 1963 reflections with I > 30(Z) were considered observed and used in the structure determination. The intensities were corrected for Lp effects and empirical absorptions. The structure was solved by direct methods and refined by full-matrix least-squares to final R = 0.025, Rw = 0.034 [w = 1/82(1F01)], S = 1.30, (A/a),,, = 0.03 and Ap = -0.46-0.32 e A-‘. The views of the molecule were produced by the ORTEP program. All calculations were made on a micro VAX-3 100 computer using the TEXSAN V.2.1 program package.
recrystallized twice from THF/n-hexane and dried in vacua and the product Cp,Yb (C,,H,COCHCOCF,)(THF) was obtained. Some of the product was dissolved in THF and drops of n-hexane added. Cooling the solution at - 10’C for a few days gave fine crystals suitable for X-ray diffraction. Preparation of‘Cp,Ln(C,,,H,COCHCOCF,) Dy, Tb, Gd, Eu, Tm)
(Ln =
A mixture of Cp,Ln (1.80 mmol Ln = Dy, Tb, Gd, Tm) or Cp,Eu(THF) and 2-naphthoyltrifluoroacetonatone (1.80 mmol) was stirred in toluene (40 cm3). After stirring for 3 days at room temperature, toluene was removed from the mixwere recrysture in vacua. The crude products tallized twice from toluene/n-hexane and dried in vacua and the products Cp,Ln(ClOH,COC HCOCF,) (Ln = Dy, Tb, Gd, Eu, Tm) were obtained. Physical data, elemental analyses and IR spectra of the six complexes are presented in Table 1.
RESULTS AND DISCUSSION Table 1 shows that the elemental analysis for the six complexes are in compliance with the general formula Cp,Ln(C,,H,COCHCOCF,) (Ln = Dy, Tb, Gd, Eu, Tm) or Cp,Yb(C,,H,COCH COCF,) (THF). These complexes are thermally unstable and the decomposition temperatures are listed in Table 1. The IR spectra of these complexes show characteristic Cp absorptions at ca 3 100, 1440, 1010 and 780 cm-‘.12 and an absorption peak at ca 250 cm-’ for Ln-C of the n-bonded Cp All complexes exhibit the characteristic group.” C-O and C-C multiple absorption of 0-chelate complexes at 1600-1500 cm1’.13 The IR spectra of Cp,Yb(C,,H,COCHCOCF,)(THF) also show the characteristic absorption of the solvated THF at ca 1065 and 913 cm-‘.‘4 Upon the above analysis and the crystal structure analysis of Cp,Yb(C,,H,COCHCOCF,)(THF) mentioned later, we propose the structure of complexes 1-5 could be described as follows : The central atom is coordinated by two cyclopentadienyls
X-ray crystallography Single crystals of Cp,Yb(C,,H,COCHCOCF,) (THF) used for structural analysis were sealed under argon in thin-walled capillaries. A single crystal with the dimensions 0.28 x 0.22 x 0.20 mm was selected for X-ray data collection. Data collection was performed on an Enraf-Nonius CAD-4 X-ray diffractometer with graphite-monochromated MoK, radiation (j_ = 0.71069 A). A total of 2655 unique reflections were collected in the range 20 < 49.9” by the ~20 scanning technique at 23”C,
Table 1. Analytical and partial IR data of the six complexes
Complex
Colour
Yield
D.T.” (“C)
1 (DY)
Yellow
38.5
I68
29.5 (29.1)
51.4 (51.7)
2 (Tb)
Yellow
33.4
164
28.5 (28.7) 28.8 (28.5) 27.7 (27.8)
51.4 (52.0) 52.8 (52.2) 52.4 (52.7)
(3.3)
30.2 (29.9) 27.1 (27.0)
51.0 (51.1) 52.7 (52.5)
3.2 (3.2) 4.4 (4.1)
3 (Gd)
Yellow
33.2
142
4 (Eu)
Brown
28.3
180
5 Pm)
Yellow
38.5
122
6 (Yb)
Orange
40.5
120
”D.T. = decomposition
temperature.
Ln
Found (Calc.) C H 3.1 (3.3) 3.1 (3.3) 3.3 (3.3) 3.4
IR (cm-‘) l596m 515~ 595m 517~ 595m 515~ 595m 515~ 1596m 1515~ l595m 1515~
1570s 1530s 1505m 1570s 1530s 1505m 1570s 1529s l505m 1570s 1529s 1507m 1570s 1532s 1505m 1570s 1530s 1505m
Cyclopentadienyl
lanthanide
in an $-fashion and two oxygen atoms of 2naphthoyltrifluoroacetonato in a bidentate fashion. The coordination number of Ln is 8. molecular structure of The CpzYb (CloH,COCHCOCF,)(THF) is shown in Fig. 1. Selected bond distances and angles of all nonhydrcgen atoms are listed in Tables 2 and 3, respectively. Figure I shows that Cp2Yb(C,,H,COCHCOCF,) (THF) is a monomeric ytterbium complex. The ytterbium is coordinated by two cyclopentadienyl ligand in an $-mode, two oxygen atoms of the 2naphthoyltrifluoroacetonato ligand in a bidentate fashion and one oxygen atom of the solvated THF molecule. The coordination number is 9 and the geometry around the ytterbium atom can be described as a distorted trigonal bipyramid with the centres of the two cyclopentadienyl rings and the three oxygen atoms forming the apices of the bipyramid. 0( 1) and the centres of the two cyclopentadienyl rings occupy equatorial positions and O(2) and O(3) occupy axial positions. The O(2)-Yb-O(3) bond angle is 146.4 The two cyclopentadienyl rings are planar with mean deviations of 0.0045 and 0.0082 A, respectively. The two planes form a dihedral angle of 49.94 ‘. The C-C distance for adjacent carbon
Fig. 1. Molecular
structure
derivatives
1153
atoms within cyclopentadienyl ligands range from 1.35(l) to 1.41(2) 8, (an average of 1.372 A). The C-C-C angles within the cyclopentadienyl rings range from 105(l) to 112(l)’ (an average of 108.1 ). Here, we make a simple comparison of significant structural parameters of the following complexes: Cp,Yb(C,,H,COCHCOCF,)(THF) (I), Cp2Ho(C,,,H,COCHCOCF,)(THF) (IQh CpzYb (CH,COCHCOCF,) (III)‘; see Table 4. With regard to the complexes I and II, which have the same ligands coordinating to the central metal atom, Table 4 shows that the bond distances between the central atom and the ligands of CpzYb (C,,H,COCHCOCF,) (THF) are shorter than that of Cp,Ho(C,,,H,COCHCOCF,) (THF); the bond angles formed by the central atom and the ligands of Cp,Yb(C,,,H,COCHCOCF,) (THF) are similar to or larger than that of Cp,Ho (C,,,HCOCHCOCF,) (THF). These results may be due to the lanthanide contraction effects. With regard to complexes I and III which have the same central metal atom, I is solvated but III is non-solvated. The bond distances between the central atom and the ligands of Cp,Yb (C,,,HCOCHCOCFJ (THF) are longer than those of Cp,Yb(CH,COCHCOCF,). The bond angles formed by the central atom and the ligands of
of Cp,Yb(C,,,H,COCHCOCF,)(THF)
F. SHEN et al. Table 2. Selected bond distances Y&0( I) Yb-O(2) Yb-O(3) Yb-C(21) Yb-C(22) Yb-C(23) Yb-C(24) Yb-C(25) YtwC(31) Yb-C(32) Yb-C(33) YIP-C(34) Yb-C(35)
2.221(S) 2.279(5) 2.471(6) 2.62(I) 2.63(l) 2.64( 1) 2.63( 1) 2.62(2) 2.609(8) 2.63 l(7) 2.63(l) 2.62( 1) 2.59( 1) 1.310(8)
F(l)-C(4) F(2)-C(4) F(3)-C(4) 0(1)-C(l) 0(2)-C(3) O(3)-C(44) O(3)-C(41)
(A)
C(l)-C(2) C(l)-C(4) C(2)-C(3) C(3)-C( 13) C(21)-C(25) C(21)-C(22) C(22)-C(23) C(23)-C(24) C(24)-C(25) C(31)-C(32) C(31)-C(35) C(32)-C(33) C(33)-C(34) C(34)-C(35) C(41)-C(42) C(42)-C(43) C(43)-C(44) Yb-Centl” Yb-Cent2h
1.335(9) 1.31(2) 1.276(7) 1.273(7)
1.428(9)
1.36(l) 1.51(2) 1.41(l) 1.49(1) 1.35( 1) 1.37(l) 1.37(l) I .36(2) I .36(l) 1.41(l) I .36(2) 1.37(l)
1.36(2) 1.41(2) 1.47(l) 1.48(l) 1.41(2) 2.352 2.334
1.43(l)
0 Cent 1 indicates ’Cent2 indicates
the centroid the centroid
of C(21)-C(25). of C(3 l)-C(35).
Table 3. Selected bond angles (“) O(l)-Yb-O(2) O(l)-Yb-O(3) O(2)-Yb-O(3) c(21)-Yb-c(22) C(21)-Yb-C(23) C(21)-Yb-C(24) C(21)-Yb-C(25) C(22)-Yb-C(23) C(22)-Yb-C(24) C(22)-Yb-C(25) C(23)-Yb-C(24) C(24)-Yb-C(25) C(23)-Yb-C(25) C(31)-Yb-C(32) C(31)-Yb-C(33) C(31)-Yb-C(34) C(31)-Yb-C(35) C(32)-Yb-C(33) C(32)-Yb-C(34) C(32)-Yb-C(35) C(33)-Yb-C(34) C(33)-Yb-C(35) C(34)-Yb-C(35) C(21)-Yb-C(31) C( I)-0( I)-Yb C(3)-O(2)-Yb C(41)-O(3)-Yb C(44)-O(3)-Yb c(44)-0(3)-c(41) O( I)-C(l)-C(2) ’Cent1 indicates ’Cent2 indicates
74.6(2) 72.8(2) 146.4(2) 30.3(3) 49.2(3) 49.1(3) 29.9(3) 30.2(3) 49.9(3) 50.2(3) 29.9(3) 30. I (3) 49.6(3) 31.2(3) 49.7(3) 50.8(3) 30.3(4) 30.2(3) 51.1(4) 51.2(4) 30.1(5) 50.1(4) 3 1.4(4) 135.84 133.8(6) 136.3(6) 125.7(4) 126.6(6) 107.7(7) 128(l) the centroid the centroid
of C(21)-C(25). of C(3 I)-C(35).
O(l)-C( 1)-C(4) C(2)-C(l)-C(4) C( I)-C(2)-C(3) O(2)-C(3)-C(2) O(2)-C(3)-C( 13) C(2)-C(3)-C( 13) c(14)-c(l3)-c(3) C(12)-C(13)-C(3) C(25)-C(21)-C(22) C(23)-C(22)-C(21) C(22)-C(23)-C(24) C(32)-C(31)-C(35) C(23)-C(24)-C(25) C(21)-C(25)-C(24) C(33)-C(32)-C(31) C(32)-C(33)-C(34) C(33)-C(34)-C(35) C(34)-C(35)-C(31) O(3)-C(41)-C(42) C(43)-C(42)-C(41) C(44)-C(43)-C(42) O(3)-C(44)-C(43) O(l)-Yb-Centl” 0( l)-Y&Cent2n O(2)-Yb-Cent1 O(2)-Yb-Cent2 O(3)-Yb-Cent I O(S)-Yb-Cent2 Centl-Yb-Cent2
I12.6(9) 119.3(7) 121.7(7) 122.7(8) 114.5(9) 122.8(6) 120.6(8) 120.2(7) 110(l) 106( 1) 109(l) 109(l) 109(l) 107( 1) 105( 1) 112(l) 106(I) 108(l) 107.6(7) 105.1(8) 106.2(9) 109.3(8) 121.82 108.80 94.39 97.57 96.35 99.87 129.36
Cyclopentadienyl Table 4. Some bond distances (A) and of Cp,Yb(C,,H,COCHCOCF,)(THF)(I), (C,,,H,COCHCOCF,)(THF)(II) and (CHjCOCHCOCF,) (III) I
lanthanide
angles ( ) CpzHo CpzY b
II
lanthanide contraction effects and steric effects caused the difference between bond distances and angles of complexes II and III. REFERENCES
III I. G. Bielang
Ln-0” Ln-O(THF)” Ln-Cent” O( I)-Ln-O(2)” Cent-Ln-0’ Centl-Ln-Cent?”
2.225 2.471 2.343 14.6 105.6 129.36
2.278 2.480 2.386 13.2 106.0 128.53
2.213 ~
2.
2.302 78.0 108.7 131.1
3. 4. 5.
“Cent1 and Cent2 indicate the centroids of the two cyclopentadienyl rings. 0( 1) and O(2) are the two oxygen atoms of fi-diketonato. ’ Ln-0 and Ln-Cent represent the average of Ln-0( I) and Ln-O(2) and the average of Ln-Cent1 and Ln-Cent2, respectively. ’Cent-Ln-0 is the average of Cent I-Ln-O(l), Centl-Ln-O(2). Cent2-Ln-O(1) and Cent2 -Ln-O(2)
6. 7. 8. 9. IO. Il.
are smaller than those of Cp,Yb(CH3COCHCOCF3) and it is proposed that these results are caused by steric effects. Complex II has longer bond distances and smaller bond angles than complex III. According to the conclusions mentioned above. we think that both Cp,Yb(C,,H,COCHCOCF,)(THF)
1155
derivatives
12. 13.
14.
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