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Overcoming the Crystallization Bottleneck: A Family of Gigantic Inorganic {Pd x } L ( x= 84, 72) Palladium Macrocycles Discovered using Solution Techniques
Author(s) -
Christie Lorna G.,
Surman Andrew J.,
Scullion Rachel A.,
Xu Feng,
Long DeLiang,
Cronin Leroy
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201606005
Subject(s) - palladium , chemistry , crystallization , cluster (spacecraft) , crystallography , supramolecular chemistry , combinatorial chemistry , stereochemistry , crystal structure , organic chemistry , computer science , catalysis , programming language
The {Pd 84 } Ac wheel, initially discovered serendipitously, is the only reported giant palladium macrocycle—a unique structure that spontaneously assembles from small building blocks. Analogues of this structure are elusive. A new modular route to {Pd 84 } Ac is described, allowing incorporation of other ligands, and a new screening approach to cluster discovery. Structural assignments were made of new species from solution experiments, overcoming the need for crystallographic analysis. As a result, two new palladium macrocycles were discovered: a structural analogue of the existing {Pd 84 } Ac wheel with glycolate ligands, {Pd 84 } Gly , and the next in a magic number series for this cluster family—a new {Pd 72 } Prop wheel decorated with propionate ligands. These findings confirm predictions of a magic number rule for the family of {Pd x } macrocycles. Furthermore, structures with variable fractions of functional ligands were obtained. Together these discoveries establish palladium clusters as a new class of tunable nanostructures. In facilitating the discovery of species that would not have been discovered by orthodox crystallization approaches, this work also demonstrates the value of solution‐based screening and characterization in cluster chemistry, as a means to decouple cluster formation, discovery, and isolation.