Di-μ-tert-butanolato-bis­[bis­(η5-cyclo­penta­dien­yl)erbium(III)]

Pagano, S.; Schnick, W.

doi:10.1107/S1600536808004248

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 3| March 2008| Page m473

doi:10.1107/S1600536808004248

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Di-μ-tert-butanolato-bis[bis(η⁵-cyclopentadienyl)erbium(III)]

Sandro Pagano ^a and Wolfgang Schnick ^a ^*

^aDepartment Chemie und Biochemie, Ludwig-Maximilians-Universität München, Lehrstuhl für Anorganische Festkörperchemie, Butenandtstrasse 5–13 (D), D-81377 München, Germany
^*Correspondence e-mail: wolfgang.schnick@uni-muenchen.de

(Received 7 February 2008; accepted 11 February 2008; online 15 February 2008)

In the centrosymmetric title compound, [Er₂(C₅H₅)₄(C₄H₉O)₂], each Er atom is in a distorted tetrahedral coordination environment, coordinated by two cyclopentadienyl rings and two tert-butoxy groups, forming a dimeric complex bridged through the tert-butoxy groups.

Related literature

During our search for highly reactive molecular precursors, we characterized a series of lanthanide amide (Baisch, Pagano, Zeuner, Barros et al., 2006 ) and carbamate complexes (Baisch, Pagano, Zeuner & Schnick, 2006 ). The synthesis of [Er₂{μ-η¹:η²-OC(OBu^t)NH}Cp₄] and its application as a precursor is described by Zeuner et al. (2008 ). For related literature and a general overview of cyclopentadienyl-containing compounds of the lanthanides, see: Schumann et al. (1995 ).

Experimental

Crystal data

[Er₂(C₅H₅)₄(C₄H₉O)₂]
M_r = 741.10
Monoclinic, P 2₁ /n
a = 8.3905 (17) Å
b = 15.628 (3) Å
c = 9.950 (2) Å
β = 101.85 (3)°
V = 1276.9 (5) Å³
Z = 2
Mo Kα radiation
μ = 6.55 mm⁻¹
T = 200 (2) K
0.13 × 0.07 × 0.04 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ) T_min = 0.594, T_max = 0.783
5666 measured reflections
2912 independent reflections
2578 reflections with I > \2s(I)
R_int = 0.021

Refinement

R[F² > 2σ(F²)] = 0.022
wR(F²) = 0.053
S = 1.05
2912 reflections
149 parameters
H-atom parameters constrained
Δρ_max = 1.29 e Å⁻³
Δρ_min = −1.23 e Å⁻³

Data collection: COLLECT (Nonius, 2004 ); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor 1997 ); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg 1999 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808004248/su2044sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808004248/su2044Isup2.hkl

checkCIF report

Comment top

By stirring [Er₂{µ-η¹:η²-OC(OBu^t)NH}Cp₄] in THF the carbamato moiety decomposes to [Cp₂Er^tBuO]₂ and an amorphous solid showing strong C=N vibrations (2190 cm^-1) in the IR spectra. It is likely that the tert-butylcarbamato ligand splits up into tert-butanol and cyanate. Attempts to isolate a crystalline cyanato complex were unsuccessful as yet. The structure of [Cp₂Er^tBuO]₂ is in accordance with a series of lanthanide-cyclopentadienyl-alcoholate-complexes synthesized so far (Schumann et al., 1995).

Related literature top

During our search for highly reactive molecular precursors, we characterized a series of lanthanide amide- (Baisch, Pagano, Zeuner, Barros et al., 2006) and carbamate complexes (Baisch, Pagano, Zeuner & Schnick, 2006). The synthesis of [Er₂{µ-η¹:η²-OC(OBu^t)NH}Cp₄] and its application as a precursor is described by Zeuner et al. (2008). For related literature and a general overview on cyclopentadienyl-containing compounds of the lanthanides, see Schumann et al. (1995).

Experimental top

[Er₂{µ-η¹:η²-OC(OBu^t)NH}Cp₄] was dissolved in dry THF and stirred for 12 h at 297 K. After evaporation of the solvent the orange residue was suspended in dry hexane. The filtrate was stored at 279 K to afford [Cp₂Er^tBuO]₂ as pink crystals.

Computing details top

Data collection: COLLLECT (Nonius, 2004); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A view of the title compound showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H– atoms are omitted for clarity.
	Fig. 2. Crystal packing diagram of the title compound viewed along the a axis.

Di-µ-tert-butanolato-bis[bis(η⁵-cyclopentadienyl)erbium(III)] top

Crystal data top

[Er₂(C₅H₅)₄(C₄H₉O)₂]	F(000) = 716
M_r = 741.10	D_x = 1.928 Mg m⁻³
Monoclinic, P2₁/n	Melting point: not measured K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 8.3905 (17) Å	Cell parameters from 14322 reflections
b = 15.628 (3) Å	θ = 3.1–27.5°
c = 9.950 (2) Å	µ = 6.55 mm⁻¹
β = 101.85 (3)°	T = 200 K
V = 1276.9 (5) Å³	Block, pink
Z = 2	0.13 × 0.07 × 0.04 mm

Data collection top

Nonius KappaCCD diffractometer	2912 independent reflections
Radiation source: fine-focus sealed tube	2578 reflections with I > \2s(I)
Graphite monochromator	R_int = 0.021
Detector resolution: 9 pixels mm^-1	θ_max = 27.5°, θ_min = 3.2°
ϕ and ω scans	h = −10→10
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	k = −20→20
T_min = 0.594, T_max = 0.783	l = −12→12
5666 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.022	H-atom parameters constrained
wR(F²) = 0.053	w = 1/[σ²(F_o²) + (0.025P)² + 1.7644P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.002
2912 reflections	Δρ_max = 1.29 e Å⁻³
149 parameters	Δρ_min = −1.23 e Å⁻³
0 restraints	Extinction correction: (SHELXL97; Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0022 (2)

Crystal data top

[Er₂(C₅H₅)₄(C₄H₉O)₂]	V = 1276.9 (5) Å³
M_r = 741.10	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 8.3905 (17) Å	µ = 6.55 mm⁻¹
b = 15.628 (3) Å	T = 200 K
c = 9.950 (2) Å	0.13 × 0.07 × 0.04 mm
β = 101.85 (3)°

Data collection top

Nonius KappaCCD diffractometer	2912 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	2578 reflections with I > \2s(I)
T_min = 0.594, T_max = 0.783	R_int = 0.021
5666 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.022	0 restraints
wR(F²) = 0.053	H-atom parameters constrained
S = 1.05	Δρ_max = 1.29 e Å⁻³
2912 reflections	Δρ_min = −1.23 e Å⁻³
149 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Er1	0.080747 (15)	0.036095 (8)	0.666673 (13)	0.01748 (7)
C15	0.2668 (4)	−0.0762 (3)	0.8373 (4)	0.0332 (8)
H15	0.2131	−0.1176	0.8821	0.040*
C13	0.3898 (5)	0.0464 (3)	0.7888 (5)	0.0385 (9)
H13	0.4331	0.1028	0.7953	0.046*
C23	−0.0655 (5)	0.0983 (3)	0.8573 (4)	0.0396 (10)
H23	−0.0683	0.0605	0.9315	0.048*
C25	−0.1323 (5)	0.1661 (2)	0.6539 (4)	0.0328 (8)
H25	−0.1887	0.1835	0.5653	0.039*
C21	0.0166 (5)	0.1986 (2)	0.7245 (4)	0.0349 (8)
H21	0.0797	0.2414	0.6919	0.042*
C11	0.3101 (4)	−0.0858 (3)	0.7084 (4)	0.0312 (8)
H11	0.2906	−0.1350	0.6513	0.037*
C22	0.0565 (5)	0.1574 (3)	0.8508 (4)	0.0376 (9)
H22	0.1505	0.1679	0.9203	0.045*
C14	0.3175 (5)	0.0055 (3)	0.8874 (4)	0.0391 (9)
H14	0.3053	0.0290	0.9728	0.047*
C12	0.3865 (4)	−0.0107 (3)	0.6790 (4)	0.0339 (8)
H12	0.4288	−0.0001	0.5990	0.041*
C24	−0.1835 (5)	0.1041 (3)	0.7358 (4)	0.0375 (9)
H24	−0.2809	0.0715	0.7134	0.045*
O1	0.0788 (3)	0.06891 (14)	0.4454 (2)	0.0195 (4)
C1	0.1512 (4)	0.1414 (2)	0.3870 (3)	0.0246 (7)
C2	0.0347 (5)	0.2174 (2)	0.3640 (4)	0.0343 (8)
H2A	−0.0665	0.2007	0.3014	0.051*
H2B	0.0853	0.2649	0.3238	0.051*
H2C	0.0106	0.2354	0.4520	0.051*
C4	0.1903 (5)	0.1155 (2)	0.2497 (4)	0.0328 (8)
H4A	0.2719	0.0698	0.2642	0.049*
H4B	0.2331	0.1651	0.2082	0.049*
H4C	0.0910	0.0951	0.1883	0.049*
C3	0.3083 (5)	0.1691 (3)	0.4829 (4)	0.0360 (9)
H3A	0.2863	0.1820	0.5737	0.054*
H3B	0.3512	0.2203	0.4457	0.054*
H3C	0.3886	0.1228	0.4908	0.054*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Er1	0.01723 (10)	0.01828 (10)	0.01704 (10)	0.00043 (5)	0.00380 (6)	−0.00140 (5)
C15	0.0310 (19)	0.038 (2)	0.0284 (19)	0.0078 (16)	0.0010 (14)	0.0104 (16)
C13	0.0205 (18)	0.041 (2)	0.049 (2)	−0.0049 (15)	−0.0040 (16)	0.0010 (19)
C23	0.058 (3)	0.035 (2)	0.033 (2)	0.0116 (19)	0.0257 (19)	0.0020 (17)
C25	0.038 (2)	0.0274 (19)	0.033 (2)	0.0108 (16)	0.0053 (15)	−0.0065 (15)
C21	0.045 (2)	0.0218 (18)	0.042 (2)	−0.0023 (16)	0.0192 (17)	−0.0102 (16)
C11	0.0268 (18)	0.036 (2)	0.0295 (19)	0.0109 (15)	0.0022 (14)	0.0029 (15)
C22	0.042 (2)	0.038 (2)	0.031 (2)	0.0075 (17)	0.0030 (16)	−0.0179 (17)
C14	0.031 (2)	0.054 (3)	0.0276 (19)	0.0070 (19)	−0.0043 (15)	−0.0051 (19)
C12	0.0188 (17)	0.049 (2)	0.035 (2)	0.0079 (16)	0.0079 (14)	0.0053 (18)
C24	0.0297 (19)	0.030 (2)	0.058 (3)	0.0028 (16)	0.0221 (18)	−0.0096 (19)
O1	0.0228 (11)	0.0165 (11)	0.0196 (11)	−0.0040 (9)	0.0050 (8)	0.0020 (9)
C1	0.0294 (17)	0.0178 (16)	0.0278 (17)	−0.0054 (13)	0.0088 (13)	0.0026 (13)
C2	0.045 (2)	0.0182 (17)	0.042 (2)	−0.0002 (16)	0.0144 (17)	0.0095 (16)
C4	0.042 (2)	0.0291 (19)	0.0300 (18)	−0.0063 (16)	0.0147 (15)	0.0041 (16)
C3	0.040 (2)	0.033 (2)	0.036 (2)	−0.0147 (17)	0.0101 (16)	−0.0002 (17)

Geometric parameters (Å, º) top

Er1—O1	2.257 (2)	C25—H25	0.9500
Er1—O1ⁱ	2.262 (2)	C21—C22	1.390 (6)
Er1—C13	2.633 (4)	C21—H21	0.9500
Er1—C12	2.646 (3)	C11—C12	1.397 (6)
Er1—C23	2.646 (4)	C11—H11	0.9500
Er1—C24	2.673 (3)	C22—H22	0.9500
Er1—C22	2.673 (4)	C14—H14	0.9500
Er1—C11	2.679 (4)	C12—H12	0.9500
Er1—C21	2.682 (4)	C24—H24	0.9500
Er1—C14	2.685 (4)	O1—C1	1.461 (4)
Er1—C25	2.692 (4)	O1—Er1ⁱ	2.262 (2)
Er1—C15	2.705 (4)	C1—C3	1.523 (5)
C15—C14	1.405 (6)	C1—C4	1.524 (5)
C15—C11	1.411 (5)	C1—C2	1.525 (5)
C15—H15	0.9500	C2—H2A	0.9800
C13—C12	1.406 (6)	C2—H2B	0.9800
C13—C14	1.409 (6)	C2—H2C	0.9800
C13—H13	0.9500	C4—H4A	0.9800
C23—C22	1.391 (6)	C4—H4B	0.9800
C23—C24	1.399 (6)	C4—H4C	0.9800
C23—H23	0.9500	C3—H3A	0.9800
C25—C24	1.391 (6)	C3—H3B	0.9800
C25—C21	1.397 (5)	C3—H3C	0.9800

O1—Er1—O1ⁱ	78.39 (8)	Er1—C13—H13	114.5
O1—Er1—C13	104.21 (12)	C22—C23—C24	108.3 (4)
O1ⁱ—Er1—C13	134.35 (11)	C22—C23—Er1	75.9 (2)
O1—Er1—C12	85.46 (10)	C24—C23—Er1	75.8 (2)
O1ⁱ—Er1—C12	107.00 (11)	C22—C23—H23	125.8
C13—Er1—C12	30.90 (13)	C24—C23—H23	125.8
O1—Er1—C23	134.74 (11)	Er1—C23—H23	114.7
O1ⁱ—Er1—C23	107.78 (11)	C24—C25—C21	108.1 (4)
C13—Er1—C23	101.80 (14)	C24—C25—Er1	74.2 (2)
C12—Er1—C23	131.01 (13)	C21—C25—Er1	74.6 (2)
O1—Er1—C24	108.69 (11)	C24—C25—H25	126.0
O1ⁱ—Er1—C24	88.69 (11)	C21—C25—H25	126.0
C13—Er1—C24	130.34 (14)	Er1—C25—H25	117.3
C12—Er1—C24	160.99 (13)	C22—C21—C25	108.2 (4)
C23—Er1—C24	30.49 (13)	C22—C21—Er1	74.6 (2)
O1—Er1—C22	121.39 (11)	C25—C21—Er1	75.3 (2)
O1ⁱ—Er1—C22	137.07 (11)	C22—C21—H21	125.9
C13—Er1—C22	81.17 (13)	C25—C21—H21	125.9
C12—Er1—C22	111.94 (13)	Er1—C21—H21	116.3
C23—Er1—C22	30.31 (13)	C12—C11—C15	108.5 (4)
C24—Er1—C22	50.05 (13)	C12—C11—Er1	73.5 (2)
O1—Er1—C11	100.02 (10)	C15—C11—Er1	75.8 (2)
O1ⁱ—Er1—C11	83.92 (11)	C12—C11—H11	125.8
C13—Er1—C11	50.50 (13)	C15—C11—H11	125.8
C12—Er1—C11	30.41 (12)	Er1—C11—H11	116.9
C23—Er1—C11	125.04 (12)	C21—C22—C23	107.8 (4)
C24—Er1—C11	148.22 (12)	C21—C22—Er1	75.3 (2)
C22—Er1—C11	123.46 (12)	C23—C22—Er1	73.8 (2)
O1—Er1—C21	91.86 (10)	C21—C22—H22	126.1
O1ⁱ—Er1—C21	131.93 (10)	C23—C22—H22	126.1
C13—Er1—C21	93.72 (13)	Er1—C22—H22	116.9
C12—Er1—C21	119.13 (13)	C15—C14—C13	107.9 (4)
C23—Er1—C21	49.88 (12)	C15—C14—Er1	75.7 (2)
C24—Er1—C21	49.84 (12)	C13—C14—Er1	72.6 (2)
C22—Er1—C21	30.08 (12)	C15—C14—H14	126.0
C11—Er1—C21	144.01 (12)	C13—C14—H14	126.0
O1—Er1—C14	133.98 (11)	Er1—C14—H14	117.7
O1ⁱ—Er1—C14	122.53 (12)	C11—C12—C13	107.9 (3)
C13—Er1—C14	30.70 (14)	C11—C12—Er1	76.1 (2)
C12—Er1—C14	50.61 (12)	C13—C12—Er1	74.0 (2)
C23—Er1—C14	81.56 (13)	C12—C12—H12	126.1
C24—Er1—C14	111.95 (13)	C13—C12—H12	126.1
C22—Er1—C14	73.34 (13)	Er1—C12—H12	116.0
C11—Er1—C14	50.14 (13)	C25—C24—C23	107.6 (4)
C21—Er1—C14	98.07 (13)	C25—C24—Er1	75.8 (2)
O1—Er1—C25	84.86 (10)	C23—C24—Er1	73.7 (2)
O1ⁱ—Er1—C25	101.80 (10)	C25—C24—H24	126.2
C13—Er1—C25	123.85 (13)	C23—C24—H24	126.2
C12—Er1—C25	147.00 (13)	Er1—C24—H24	116.5
C23—Er1—C25	49.88 (12)	C1—O1—Er1	130.07 (19)
C24—Er1—C25	30.06 (12)	C1—O1—Er1ⁱ	128.22 (18)
C22—Er1—C25	49.74 (12)	Er1—O1—Er1ⁱ	101.61 (8)
C11—Er1—C25	173.19 (12)	O1—C1—C3	110.4 (3)
C21—Er1—C25	30.13 (12)	O1—C1—C4	109.6 (3)
C14—Er1—C25	123.08 (13)	C3—C1—C4	108.6 (3)
O1—Er1—C15	130.36 (10)	O1—C1—C2	110.9 (3)
O1ⁱ—Er1—C15	92.60 (11)	C3—C1—C2	108.6 (3)
C13—Er1—C15	50.45 (13)	C4—C1—C2	108.7 (3)
C12—Er1—C15	50.39 (12)	C1—C2—H2A	109.5
C23—Er1—C15	94.67 (12)	C1—C2—H2B	109.5
C24—Er1—C15	119.92 (13)	H2A—C2—H2B	109.5
C22—Er1—C15	98.37 (12)	C1—C2—H2C	109.5
C11—Er1—C15	30.38 (11)	H2A—C2—H2C	109.5
C21—Er1—C15	126.53 (12)	H2B—C2—H2C	109.5
C14—Er1—C15	30.22 (14)	C1—C4—H4A	109.5
C25—Er1—C15	144.28 (12)	C1—C4—H4B	109.5
C14—C15—C11	107.6 (4)	H4A—C4—H4B	109.5
C14—C15—Er1	74.1 (2)	C1—C4—H4C	109.5
C11—C15—Er1	73.8 (2)	H4A—C4—H4C	109.5
C14—C15—H15	126.2	H4B—C4—H4C	109.5
C11—C15—H15	126.2	C1—C3—H3A	109.5
Er1—C15—H15	117.9	C1—C3—H3B	109.5
C12—C13—C14	108.1 (4)	H3A—C3—H3B	109.5
C12—C13—Er1	75.1 (2)	C1—C3—H3C	109.5
C14—C13—Er1	76.7 (2)	H3A—C3—H3C	109.5
C12—C13—H13	125.9	H3B—C3—H3C	109.5
C14—C13—H13	125.9

Symmetry code: (i) −x, −y, −z+1.

Experimental details

Crystal data
Chemical formula	[Er₂(C₅H₅)₄(C₄H₉O)₂]
M_r	741.10
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	200
a, b, c (Å)	8.3905 (17), 15.628 (3), 9.950 (2)
β (°)	101.85 (3)
V (Å³)	1276.9 (5)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	6.55
Crystal size (mm)	0.13 × 0.07 × 0.04

Data collection
Diffractometer	Nonius KappaCCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2001)
T_min, T_max	0.594, 0.783
No. of measured, independent and observed [I > \2s(I)] reflections	5666, 2912, 2578
R_int	0.021
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.022, 0.053, 1.05
No. of reflections	2912
No. of parameters	149
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.29, −1.23

Computer programs: COLLLECT (Nonius, 2004), DENZO/SCALEPACK (Otwinowski & Minor 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg 1999).

Acknowledgements

The authors are indebted to Dr Peter Meyer for performing the single-crystal X-ray diffractometry. Financial support by the Deutsche Forschungsgemeinschaft (DFG) (Schwerpunktprogramm SPP 1166, Lanthanoidspezifische Funktionalitäten in Molekül und Material, project SCHN377/10) and the Fonds der Chemischen Industrie is also gratefully acknowledged.

References

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