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Title: Manipulation of organolanthanide coordinative unsaturation synthesis, structures, structural dynamics, comparative reactivity, and comparative thermochemistry of dinuclear. mu. -hydrides and. mu. -alkyls and (. mu. -R sub 2 Si(Me sub 4 C sub 5 )(C sub 5 H sub 4 )) sub 2 supporting ligation

Journal Article · · Journal of the American Chemical Society; (United States)
DOI:https://doi.org/10.1021/ja00182a015· OSTI ID:5731047
; ;  [1]
  1. Northwestern Univ., Evanston, IL (United States)

This contribution describes lutetium and yttrium hydrocarbyl and hydride chemistry based upon the chelating R{sub 2}Si({eta}{sup 5}-C{sub 5}H{sub 4})({eta}{sup 5}-Me{sub 4}C{sub 5}){sup 2{minus}} ligand (R = Me, Et; abbreviated R{sub 2}SiCpCp{double prime}). The ligand is prepared by reaction of the corresponding R{sub 2}Si(CP{double prime})Cl derivative with NaC{sub 5}H{sub 5}. Subsequent metalation and reaction with MCl{sub 3}{center dot}3THF (M = Y, Lu) yields R{sub 2}SiCpCp{double prime}MCl{sub 2}{sup {minus}}Li(OEt{sub 2}){sub 2}{sup +} complexes, which in turn can be alkylated to yield R{sub 2}SiCpCp{double prime}MCHTMS{sub 2} derivatives (TMS = SiMe{sub 3}). Pertinent crystallographic data for Me{sub 2}SiCpCp{double prime}LuCHTMS{sub 2} at {minus}120C: P{ovr 1} (no. 2), z = 4, a = 16.049 (3) {angstrom}, b = 17.945 (4) {angstrom}, c = 8.993 (3) {angstrom}, {alpha} = 93.36 (2){degree}, {beta} = 90.92 (2){degree}, and {gamma} = 82.54 (2){degree}; R(F) = 0.030 for 6085 independent reflections with I > 3{sigma}(I). The structure is of a 'bent-sandwich' Cp{prime}MX-type (Cp{prime} = {eta}{sup 5}-Me{sub 5}C{sub 5}) with relaxed interligand nonbonded interactions vis-a-vis the Cp{prime}{sub 2}M and Me{sub 2}SiCP{double prime}M analogs (Lu-CHTMS{sub 2} = 2.365 (7) {angstrom}) and having one close Lu{center dot}{center dot}{center dot}MeSi (Lu-C = 2.820 (8) {angstrom}) secondary interaction. These alkyls initiate the polymerization of ethylene and undergo relatively slow hydrogenolysis to yield dihydrides of stoichiometry (R{sub 2}SiCpCp{double prime}MH){sub 2} via detectable intermediates of stoichiometry (R{sub 2}SiCpCp{double prime}){sub 2}M{sub 2}(H)(CHTMS{sub 2}). 90 refs.

OSTI ID:
5731047
Journal Information:
Journal of the American Chemical Society; (United States), Vol. 112:26; ISSN 0002-7863
Country of Publication:
United States
Language:
English