om950691l_si_002.pdf (1.59 MB)
Chemistry of C-Trimethylsilyl-Substituted Heterocarboranes. 19. Synthetic and Structural Studies on Trinuclear Ln(III) Carborane Clusters [Ln(III) = Sm, Gd, Tb, Dy, Ho]. I. Conversion to Sandwiched Manganese(II) and Cobalt(III) Carborane Complexes
journal contribution
posted on 1996-01-23, 00:00 authored by Narayan S. Hosmane, Ying Wang, Aderemi R. Oki, Hongming Zhang, John A. MaguireThe reaction of
closo-exo-4,5-Li(THF)2-1-Li(THF)2-2,3-(SiMe3)2C2B4H4
with anhydrous LnCl3
(Ln = Sm, Gd, Tb, Dy, Ho), in a molar ratio of 2:1 in dry benzene
(C6H6), produced the
sandwiched paramagnetic species
{[η5-1-Ln-2,3-(SiMe3)2-2,3-C2B4H4]3[(μ2-1-Li-2,3-(SiMe3)2-2,3-C2B4H4)3(μ3-OMe)][μ2-Li(C4H8O)]3(μ3-O)}
(Ln = Sm (1), Gd (2), Tb (3), Dy
(4), Ho (5)) in
59%, 58%, 49%, 52%, and 59% yields, respectively. All
compounds were characterized by
IR spectroscopy and by single-crystal X-ray diffraction studies;
compound 1 was also
characterized by 1H, 11B, and 13C
NMR spectroscopy. Compounds 1−5 are
isostructural
clusters consisting of three half-sandwich lanthanacarboranes, three
lithiacarboranes, three
bridging lithium atoms, and three THF molecules of solvation.
Their structures are such
that the nine metal atoms form a tricapped trigonal prism with the
lanthanide metals at
the capping positions. The reaction of 2 with
MnCl2 in benzene, followed by the addition of
TMEDA, gave a dinuclear manganacarborane sandwich complex,
4,4‘,5,5‘-Mn(TMEDA)-1,1‘-commo-Mn[2,3-(SiMe3)2-2,3-C2B4H4]2
(6). Compound 6 was characterized on
the basis of its
elemental analysis and IR spectrum and also by X-ray diffraction.
The reaction of 1 with
CoCl2 in dry benzene, followed by the addition of
TMEDA, gave the cobalt(III) sandwich
complex,
Li(TMEDA)2{1,1‘-commo-Co[2,3-(SiMe3)2-2,3-C2B4H4]2}
(7). Complex 7 was characterized on the basis of 1H,
7Li,11B, and 13C NMR spectra
and IR spectra and also by X-ray
diffraction.
