Organometallic Compounds of the Lanthanides. 127 [1] Synthesis of Monomeric Bis(cyclopentadienyl)lanthanide Tetrahydroborates with Bulky Cyclopentadienyl Ligands. Single Crystal X-ray Structures of [(η5-C5Me5)2SmBH4(THF)] and [(η5-C5Me4Et)2Y(μ-H)2BH2(THF)]

The trichlorides of yttrium, samarium, and lutetium react with 2 equivalents of Na[C₅H₄ ^tBu] and 1 equivalent of NaBH₄ to give [(η⁵-C₅H₄ ^tBu)₂LnBH₄(THF)] (Ln = Y ( 1 ), Sm ( 2 ), Lu ( 3 )) or with 2 equivalents of Na[C₅Me₄R] and 1 equivalent of NaBH₄ to form [(η⁵-C₅Me₄R)₂ · LnBH₄(THF)] (R = H, Ln = Y ( 4 ), Sm ( 5 ), Lu ( 6 ); R = Me, Ln = Y ( 7 ), Sm ( 8 ), Lu ( 9 ); R = Et, Ln = Y ( 10 ), Sm ( 11 ), Lu ( 12 ); R = ⁱPr, Ln = Y ( 13 ), Sm ( 14 ), Lu ( 15 )). The new compounds have been characterized by elemental analysis, NMR spectroscopy and mass spectrometry. The crystal structures of 8 and 10 were determined by single crystal X-ray diffraction.     

Beiträge zur Chemie des Phosphors. 227. HP4º als Komplexligand: Bildung und Eigenschaften von [(η5-C5H5)2ZrCl(P4H)], [(η5-C5Me5)2ZrCl(P4H)] und [(η5-C5H5)3Zr(P4H)]

Contributions to the Chemistry of Phosphorus. 227. HP₄º as a Complex Ligand: Formation and Properties of [(η⁵-C₅H₅)₂ZrCl(P₄H)], [(η⁵-C₅Me₅)₂ZrCl(P₄H)], and [(η⁵-C₅H₅)₃Zr(P₄H)] The novel complexes [(η⁵-C₅H₅)₂ZrCl(P₄H)] ( 1 ), [(η⁵-C₅Me₅)₂ZrCl(P₄H)] ( 2 ), and [(η⁵-C₅H₅)₃Zr(P₄H)] ( 3 ) have been obtained by reaction of a solution of (Na/K)HP₄ with the zirconocen derivatives [(η⁵-C₅H₅)₂ZrCl₂], [(η⁵-C₅Me₅)₂ZrCl₂], and [(η⁵-C₅H₅)₃(η¹-C₅ H₅)Zr] under suitable conditions. The structure of the compounds 1 – 3 , which are only stable in solution, has been elucidated by means of ³¹P-NMR spectroscopy. It is highly probable that the exo,endo isomer exists in each case. In addition, further isomers of lower relative abundancies have been observed, in which the ligands presumably exhibit a different spatial orientation relatively to each other.     

Structure of ansa-dimethylsilyl-bis(η5-cyclopentadienyl)titana(IV) cyclohexasulfane,Ti[Me2Si(η5-C5H4)2]S5

The X-ray crystal structure of Ti[Me₂Si(η⁵-C₅H₄)₂]S₅ has been determined. The coordination about the titanium may be described as a distorted tetrahedron. The (centroid)? Ti? (centroid) angle is 129.2° and the S? Ti? S bond angle 96.1°. The cyclopentadienyl rings are linked by a dimethylsilyl bridge. The sixmembered ring TiS₅ has a cyclohexane-like chair configuration. The four S? S distances range from 2.048 to 2.059 Å. Important structural dimensions are compared to those of similar type compounds.