Synthesis and Structures of the First Cationic Perfluoroaryllanthanoid(II) Complexes

Abstract

Tetraphenylborate salts of solvated pentafluorophenyllanthanoid(II) cations [Ln(C(6)F(5))(thf)(n)](+) (Ln=Eu, n=6 (1); Ln=Yb, n=5 (2)) were readily synthesized in high yield by reactions of ytterbium or europium with HgPh(C(6)F(5)) and Me(3)NHBPh(4) in THF. The structures of 1.THF and 2 confirmed the existence of well-separated ions and both 1 and 2 show notable thermal stability at room temperature. The cation in 2 was also observed in the remarkable mixed-valent complex [Yb(II)(C(6)F(5))(thf)(5)][Yb(III)(C(6)F(5))(2)[N(SiMe(3))(2)](2)] (3), fortuitously isolated in low yield from a reaction of ytterbium metal, HgPh(C(6)F(5)), and HN(SiMe(3))(2) in THF, and which additionally has an unusual bis(pentafluorophenyl)bis[bis(trimethylsilyl)amido)]ytterbate(III) anion. (171)Yb-(19)F coupling has been observed in the low-temperature (171)Yb NMR spectra of 2 and [Yb(C(6)F(5))(2)(thf)(4)].

Intramolecular Metal–Fluorocarbon Coordination, CF Bond Activation and Lanthanoid–Fluoride Clusters with Tethered Polyfluorophenylamide Ligands

“…4 ppm) may be attributed to M···FÀC interactions that are observed in the crystal structures (see below) and would lead to inequivalent fluorine atoms. No YbÀF coupling [33] was observed in 171 Yb NMR spectra, although at À80 8C the resonance for 4 a was very broad (ca. 300 Hz) and showed evidence of a shoulder.…”

“…www.chemeurj.org alkoxysilylamido complexes (Na 2.450(6), 2.451(7); K 2.853(4), 2.892(3) ), [33] whereas the M À NA C H T U N G T R E N N U N G (amine) bond lengths are typical for M-tmeda complexes, for example, Na 2.511(2), 2.510(6) and K 2.824(2), 2.906 (3) …”

Benzyl Complexes of Lanthanide(II) and Lanthanide(III) Metals: Trends and Comparisons

“…1. 1-Eu represents the first benzyleuropium(II) complex and complements the series of other known homoleptic aryl, allyl, and alkyl-europium(II) compounds: (C 6 F 5 ) 2 Eu [6], [ [9]. On account of the high deprotonating power of the benzyl anion it is anticipated that this complex is a convenient precursor for the syntheses of a large variety of Eu(II) compounds.…”

“…The combined extracts were concentrated under high vacuum to 25 % of their original volume, and the solution was slowly cooled to −30 • C. The product was isolated in the form of lightyellow crystals (0.32 g, 24 %) -M. p. 136 • C (decomp.) -1 H NMR (300 MHz, C 6 …”

η6:η6 Coordination of Tetraphenylborate to Ytterbium(II): A New Class of Lanthanoid ansa‐Metallocenes

“…[1][2][3] Readily available tetraphenylborate (BPh 4 -) can act as a chelating 12 e -donor through π bonding of two of the phenyl rings to a metal as in [Nb(RCϵCR)(η 6 -Ph) 2 BPh 2 ], [4,5] but not in lanthanoid tetraphenylborates, which almost exclusively have the BPh 4 -simply in its classical counterion role (recent examples [6][7][8][9][10][11][12][13] ). Two exceptions of note are [La(C 5 Me 5 ){CH(SiMe 3 ) 2 }-BPh 4 ], for which the solid-state NMR spectra shows evidence of La-Ph interactions, [14] and structurally characterised [Sm(C 5 Me 5 ) 2 (Ph) 2 BPh 2 ], which shows two of the Ph groups bound (η 2 :η 2 ) to Sm 3+ .…”