ic9700157_si_001.cif (108.51 kB)

Volatile Donor-Functionalized Alkoxy Derivatives of Lutetium and Their Structural Characterization1

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posted on 30.07.1997 by Reiner Anwander, Florian C. Munck, Thomas Priermeier, Wolfgang Scherer, Oliver Runte, Wolfgang A. Herrmann
Reaction of β-functionalized alcohols of type HOCR2CH2do (1a, do = OMe, R = Me; 1b, do = OMe, R = Et; 1c, do = NMe2, R = Me) with Ln[N(SiMe3)3]3 yields highly volatile (sublimation < 100 °C/10-3 Torr) and n-hexane-soluble homoleptic alkoxide complexes [Ln(OCR2CH2do)3] (2ad, Ln = Y, Lu). A single-crystal X-ray diffraction study of Lu(OCMe2CH2OMe)3 (2a) revealed a dinuclear complex with significantly polarized metal centers originating from asymmetrical ligand association (triple-bridging). Unintentional employment of “water-contaminated” alcohol 1a resulted in the formation of n-hexane-soluble 3 exhibiting a substantially increased sublimation temperature (>220 °C/10-3 Torr). Crystallization of 3 affords single crystals 3a featuring the tetranuclear constitution Lu4(O)(OH)(OCMe2CH2OMe)9. 3a represents an unprecedented lanthanide alkoxide comprising both oxo and hydroxo units in addition to alkoxide ligands. The Lu4O15-core structure of 3a adopts a “butterfly” rather than a tetrahedral geometry. Potentially tridentate alcohols HOCtBu(CH2OiPr)2 (4) and HOCiPr2CH2OCH2OMe (5) afford alkoxide complexes “Nd(OR)3” (6, 7) of reduced volatility. 2a crystallizes from n-hexane at ambient temperature in space group P21/n with a = 13.510(1) Å, b = 15.130(1) Å, c = 38.953(4) Å, β = 93.11(1)°, V = 7950 Å3, and Z = 8. Least-squares refinement of the model based on 11 747 reflections (I > 2.0 σ(I)) converged to a final R = 3.5%. 3a crystallizes from n-hexane at −35 °C in space group Cc with a = 21.63(1) Å, b = 14.49(3) Å, c = 21.04(2) Å, β = 109.70(3)°, V = 6209 Å3, and Z = 4. Least-squares refinement of the model based on 6057 reflections (I > 3.0 σ(I)) converged to a final R = 6.7%.