Oxozinc Carboxylate Complexes: A New Synthetic Approach and the Carboxylate Ligand Effect on the Noncovalent-Interactions-Driven Self-Assembly

An atom-efficient and mild synthesis of a series of oxozinc
carboxylates
[Zn4(μ4-O)­(O2CR)6] [where R = Ph (2a), p-PhC6H4 (2b), p-MeC6H4 (2c), and p-MeSC6H4 (2d)] from well-defined alkylzinc
precursors and H2O is described. The molecular and crystal
structures of the resulting complexes have been determined by single-crystal
X-ray diffraction. A closer examination of their crystal structure
provides a direct picture of the effect of the nature of substituents
on the molecular self-assembly of the octahedral oxozinc through noncovalent
interactions. It was revealed that these discrete oxozinc clusters
can form diverse types of noncovalent assemblies ranging from structures
representing zeolitic topologies in the case of 2a to
soft porous materials with gated voids or open channels for the remaining
molecular clusters.