SYNTHESIS AND REACTIVITY OF THE CATIONIC ORGANOSAMARIUM(III) COMPLEX [(C5ME5)2SM(THF)2][BPH4], INCLUDING THE SYNTHESIS AND STRUCTURE OF A METALLOCENE WITH AN ALKOXY-TETHERED C5ME5 RING, (C5ME5)2SM[O(CH2)4C5ME5](THF)

(C5Me5)2Sm(THF)2 (1) reacts with AgBPh4 in THF to form Ag and [(C5Me5)2Sm(THF)2][BPh4] (2) in high yield. 2 crystallizes from THF in space group P2/c (C42h; No. 13) with unit cell parameters a = 10.594 (2) Å, b = 14.254 (3) Å, c = 16.199 (3) Å, β = 107.32 (1)°, V = 2335.3 (8) Å3, and Z = 2 for Dcalcd = 1.260 g cm-3. Least-squares refinement of the model based on 2342 observed reflections converged to RF = 6.7%. The C5Me5 ring centroids (Cn) and the THF oxygen atoms in (C5Me5)2Sm(THF)2+ form a distorted tetrahedron with a Cn–Sm–Cn angle of 134.2°, a 2.46 (1) Å Sm–O distance, and a 2.69 (2) Å Sm–C(C5Me5) average distance. Complex 2 reacts with KC≡CR to form KBPh4 and (C5Me5)2Sm(C≡CR)(THF) (R = Ph (3), CMe3 (4)). 3 crystallizes from hexane at -34 °C in space group P21/n with a = 14.257 (5) Å, b = 16.983 (4) Å, c = 25.221 (8) Å, β = 104.61 (3)°, V = 5909 (3) Å3, and Z = 8 for Dcalcd = 1.335 g cm-3. Least-squares refinement of the model based on 5345 reflections converged to a final RF = 8.1%. The two ring centroids, the THF oxygen atom, and the terminal carbon of the alkynide ligand form a distorted tetrahedron with an average 137.7° Cn–Sm–Cn angle, a 2.71 (3) Å Sm–C(C5Me5) average distance, and 2.47 (2) Å Sm–O and 2.49 (2) Å Sm–C distances. The average alkynide C≡C bond distance in the two molecules in the unit cell is 1.12 (2) Å. Complex 2 reacts with KC5H5, LiPh, and LiMe to form (C5Me5)2Sm(C5H5), (C5Me5)2SmPh(THF), and (C5Me5)2SmMe(THF), respectively. The reaction of 2 with KC5Me5 generates (C5Me5)2Sm(OCH2CH2CH2CH2C5Me5)(THF) (5). 5 crystallizes from hexane in space group C2/c (No. 15; C62h) with unit cell parameters a = 30.009 (6) Å, b = 13.996 (2) Å, c = 17.460 (3) Å, β = 90.25 (2)°, V = 7333 (2) Å3, and Z = 8 for Dcalcd = 1.268 g cm-3. Least-squares refinement of the model based on 3925 observed reflections converged to RF = 7.3%. The structure of 5 is similar to that of 3 except that it contains the alkoxide ligand O(CH2)4(C5Me5) instead of an alkynide group. The Sm–O(alkoxide) distance is 2.081 (8) Å, and the Sm–O–C angle is 165.2 (7)°. © 1990, American Chemical Society. All rights reserved.