Synthesis of Open and Closed Metallacages Using Novel Tripodal Ligands: Unusually Stable Silver(I) Inclusion Compound

The tripodal ligand 1,3,5-(CH3)3C6[CH2OCH2C(pz)3]3 (L1, pz =
pyrazolyl ring) reacts with AgBF4 to yield {[L12Ag3(CH3CN)](BF4)3}·(CH3CN)4, an inclusion complex in which the encapsulated
acetonitrile cannot escape the triangular cage unit in either the
solid or solution phase. The analogous hexatopic ligand C6[CH2OCH2C(pz)3]6 forms a 2-dimensional polymer composed of similar
triangular cage units, again with the encapsulation of one
acetonitrile molecule, linked by the additional tris(pyrazolyl)methane
units. In contrast, the complex formed with L1 and Cd2+ has a
double, open cage structure holding two diethyl ether molecules.