A Layered, Piedfort-Aggregated Cu(I) Isocyanide Coordination Network Derived from an Encumbering Tritopic Linker.

Isocyanide coordination networks (ISOCNs) are emerging as a distinct class of framework materials capable of organizing low-valent metal centers into metal-organic framework (MOF)-type structural building units (SBUs). To date, most of the reported ISOCN materials have employed linear ditopic diisocyanide linkers. In an effort to expand linker architectures associated with ISOCN formation, reported here is the synthesis of the encumbering tritopic isocyanide linker (CNArDipp2)3Ar3 (ArDipp2 = 2,6-(2,6-(i-Pr)2C6H3)2C6H2; Ar3 = 1,3,5-(C6H4)3C6H3) and its ability to produce network materials with Cu(I) centers. Treatment of (CNArDipp2)3Ar3 with [Cu(NCMe)4]PF6 in THF under solvothermal conditions produced single crystals of the new network, CuISOCN-6, which possesses cationic [Cu(THF)(CNArDipp2)3]+ SBUs linked by a triphenylbenzene core. The lattice structure of CuISOCN-6 revealed a noninterpenetrated two-dimensional honeycomb sheet corresponding to an hcb (6,3) net. The honeycomb sheets of CuISOCN-6 are stacked in an offset, six-layer repeating pattern that possess distinct piedfort aggregates assembled via noncovalent π-π stacking interactions between the triphenylbenzene core of the (CNArDipp2)3Ar3 linker. The piedfort aggregate structural elements compress the lattice structure of CuISOCN-6 such that it is dense packed and nonporous, as determined via gas sorption measurements. However, CuISOCN-6 possesses considerable thermal and chemical stability on account of interlayer piedfort association.