A Hexamethyl Derivative of [9]Mercuracarborand-3: Synthesis, Characterization, and Host−Guest Chemistry

Hexamethyl[9]mercuracarborand-3,
[(CH3)2C2B10H8Hg]3
(3), was isolated in 60% yield from the
reaction
of
closo-1,2-Li2-9,12-(CH3)2-1,2-C2B10H8
with mercuric acetate. The title compound was characterized by
multinuclear
NMR spectroscopy and its halide ion complexes by negative ion FAB mass
spectrometry. Both 3 and its complexes
are air-stable and soluble in poorly or noncoordinating solvents such
as CH2Cl2 and toluene. Compound
3 crystallized
from acetonitrile in the triclinic space group P1̄ with
a = 13.362(6) Å, b = 14.071(6) Å,
and c = 14.303(6) Å, α
= 105.15(1)°, β = 95.77(1)°, and γ =
110.14(1)°, V = 2383 Å3, and
Z = 2. The final discrepancy indexes
were
R = 0.059, Rw = 0.064 for 5987
independent reflections with (I > 3σ(I)).
Halide ion complexes of 3 were formed
upon treatment of 3 with salts of the corresponding halide
ions. The complexation behavior of 3 in acetone
was
studied by 199Hg NMR spectroscopy, and the guest/host
ratio of the resulting complexes has been established to
be
1, 2, and 2 for chloride, bromide, and iodide,
respectively.

六甲基[9]汞杂碳硼烷-3（Hexamethyl[9]mercuracarborand-3），化学式为[(CH₃)₂C₂B₁₀H₈Hg]₃（编号为3），以60%的产率由闭式-1,2-二锂-9,12-二甲基-1,2-碳硼烷（closo-1,2-Li₂-9,12-(CH₃)₂-1,2-C₂B₁₀H₈）与乙酸汞反应分离得到。标题化合物通过多核核磁共振波谱法（multinuclear NMR spectroscopy）进行结构表征，其卤离子配合物则通过负离子快原子轰击质谱法（negative ion FAB mass spectrometry）进行表征。化合物3及其所有配合物均具有空气稳定性，可溶于弱配位或非配位溶剂，如二氯甲烷（CH₂Cl₂）与甲苯。化合物3从乙腈中结晶析出，所属晶系为三斜晶系，空间群为P1̄，晶胞参数如下：a=13.362(6) Å，b=14.071(6) Å，c=14.303(6) Å，α=105.15(1)°，β=95.77(1)°，γ=110.14(1)°，晶胞体积V=2383 ų，晶胞内分子数Z=2。针对满足I>3σ(I)条件的5987个独立衍射点，最终偏差因子R=0.059，加权偏差因子Rw=0.064。通过使用对应卤离子的盐类处理化合物3，可得到其相应的卤离子配合物。本研究采用¹⁹⁹Hg核磁共振波谱法（¹⁹⁹Hg NMR spectroscopy）探究了化合物3在丙酮中的配位行为，结果证实，所生成配合物的客体/宿主比分别为：氯离子体系1、溴离子体系2、碘离子体系2。