Spheroid Metallacycles and Metallocavitands with Calixarene- and/or Cleft-Shaped Receptors on the Surface

Flexible
hexatopic ligands, 1,2,3,4,5,6-hexakis­(1H-naphtho­[2,3-d]­imidazol-1-ylmethyl)­benzene (L2) and 1,2,3,4,5,6-hexakis­(4,5-diphenylimidazol-1-ylmethyl)­benzene
(L3), containing six neutral naphthanoimidazolyl and 4,5-diphenylimidazolyl
N donors were synthesized and used to assemble M6L6L′-type [M = Re­(CO)3, L = anionic angular
rigid NN donors, and L′ = flexible hexatopic N donors] spheroid
metallacycles. These molecules with a diameter of ∼17 Å
were obtained from Re2(CO)10, H–L (imidazole,
benzimidazole, and naphthanoimidazole), and L′ [1,2,3,4,5,6-hexakis­(benzimidazol-1-ylmethyl)­benzene
(L1), L2, and L3] in a one-step process.
Ligands L2 and L3 were characterized by elemental
analysis, electrospray ionization time-of-flight mass spectrometry
(ESI-TOF-MS), and 1H NMR spectroscopy. Metallacycles 1–5 were characterized by elemental analysis,
ESI-TOF-MS, Fourier transform infrared spectroscopy, and single-crystal
X-ray diffraction analysis. Molecules 1, 2, and 4 can be considered as metallocavitands and contain
multiple solvent-accessible receptors, i.e., two metallocalix[3]­arene
units and six/four calix[4]­arene-/cleft-shaped receptors, on the surface.
Guests such as acetone molecules could be accommodated in the calix[4]­arene/cleft-shaped
receptor of the metallocavitands.

灵活型六拓扑配体，包括1,2,3,4,5,6-六氨基-1H-萘[2,3-d]咪唑-1-基甲基苯（L2）和1,2,3,4,5,6-六氨基-4,5-二苯基咪唑-1-基甲基苯（L3），其中含有六个中性萘基咪唑和4,5-二苯基咪唑N供体，已合成并用于组装M6L6L′型[其中M = Re(CO)3，L = 阴离子角形刚性NN供体，L′ = 灵活型六拓扑N供体]球形金属环。这些直径约为17 Å的分子通过Re2(CO)10、H-L（咪唑、苯并咪唑和萘基咪唑）以及L′[1,2,3,4,5,6-六氨基-苯并咪唑-1-基甲基苯（L1）、L2和L3]在一步法中制备。配体L2和L3通过元素分析、电喷雾电离飞行时间质谱（ESI-TOF-MS）和1H NMR光谱进行表征。金属环1-5通过元素分析、ESI-TOF-MS、傅里叶变换红外光谱和单晶X射线衍射分析进行表征。分子1、2和4可被视为金属笼状化合物，含有多个溶剂可及的受体，即两个金属localix[3]arene单元和六个/四个calix[4]arene-/cleft形受体分布于表面。客分子如丙酮分子可以被容纳在金属笼状化合物的calix[4]arene/cleft形受体中。