A New Class of Metallacarboranes:  Synthesis and Molecular Structure of the First Example of an Organolanthanide Compound Bearing an η⁷-Carboranyl Ligand

Abstract

The first organolanthanide compound containing an η 7-carboranyl ligand, [{[η 5:η 7-Me2C(C5H4)(C2B10H11)]Er}2{Na4(THF)9}] n (3), has been achieved by treatment of [η5-Me2C(C5H4)(C2B10H11)]ErCl2(THF)3 (1) or [η 5:η 6-Me2C(C5H4)(C2B10H11)]Er(THF)2 (2) with excess Na metal in THF. The Na+ ions in 3 can be replaced by Er3+ ions, giving the novel tetranuclear cluster [{η 5:η 7-Me2C(C5H4)(C2B10H11)}Er2(μ-Cl)(THF)3]2 (4).

A Journey from 12-Vertex to 14-Vertex Carboranes and to 15-Vertex Metallacarboranes

“…The terminal Er−Cl distance of 2.542(4) Å is comparable to those normally observed in organoerbium chloride complexes . The average Er−cage atom distance of 2.77(2) Å is comparable to that of 2.705(7) Å found in [η 5 :η 6 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er(THF) 2 . The chloro group in these complexes can be substituted by other moieties, leading to the isolation of 4-[(μ-H) 3 BH]-4,4,4-(THF) 3 -μ-1,2-[ o -C 6 H 4 (CH 2 ) 2 ]-4,1,2-NdC 2 B 10 H 10 and 4-(η 5 -C 5 H 5 )-4-THF-μ-1,2-[ o -C 6 H 4 (CH 2 ) 2 ]-4,1,2-YC 2 B 10 H 10 (Scheme ) …”

“…Indeed, it reacted with an excess of Na metal in THF to generate the new 13-vertex species [{[η 5 :η 7 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er} 2 {Na 4 (THF) 9 }] n , having an arachno -carborane ligand (Scheme ), whose structure was confirmed by single-crystal X-ray analyses . This complex was, on the other hand, also synthesized by the direct interaction of [η 5 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]ErCl 2 (THF) 3 with an excess of sodium metal (Scheme ) . These results strongly support the reaction pathway suggested above.…”

“…To test this hypothesis, the 13-vertex erbacarborane [η 5 :η 6 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er(THF) 2 , bearing a CAp nido -carborane ligand, was prepared and subsequently used as a starting material . Indeed, it reacted with an excess of Na metal in THF to generate the new 13-vertex species [{[η 5 :η 7 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]Er} 2 {Na 4 (THF) 9 }] n , having an arachno -carborane ligand (Scheme ), whose structure was confirmed by single-crystal X-ray analyses . This complex was, on the other hand, also synthesized by the direct interaction of [η 5 -Me 2 C(C 5 H 4 )(C 2 B 10 H 11 )]ErCl 2 (THF) 3 with an excess of sodium metal (Scheme ) .…”

Synthesis and Reaction of Neutral and Cationic Alkyltantalum Complexes with a Linked Cyclopentadienyl-Carboranyl Ligand

“…All manipulations involving air- and moisture-sensitive organometallic compounds were operated using the standard Schlenk or glovebox techniques under argon. Complexes TaCl 2 Me 3 and [Li 2 {C 5 H 4 CMe 2 (C 2 B 10 H 10 )}(OEt 2 ) 2 ] were prepared according to the literature. Toluene, hexane, tetrahydrofuran, and diethyl ether were dried and deoxygenated by distillation over sodium benzophenone ketyl under argon or by using Grubbs columns (Glass Counter Solvent Dispensing System, Nikko Hansen & Co., Ltd., Konohana, Osaka, Japan).…”

A Novel Full-Sandwich Lanthanacarborane Complex Bearing an η7-Carboranyl Ligand, {{[η7-Me2Si(C13H9)(C2B10H11)]2YbIII}2YbII}{Na8(THF)20}

“…We have recently reported a brand new coordination mode for carboranes. [1][2][3][4] The tetraanionic [arachno-R 2 C 2 B 10 H 10 ] 4ligands are capable of being η 7 -bound to actinides, 2 lanthanides, 3,4 and the yttrium ion, 4 leading to a novel class of 13-vertex closo-metallacarboranes. In all these metallacarboranes, the metal ion is bonded to only one arachno-carboranyl ligand.…”