6533b837fe1ef96bd12a29ba

RESEARCH PRODUCT

Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers.

Marvin JohnsonManu LahtinenKari RissanenOla F. WendtMårten S. G. AhlquistMario CetinaLars ÖHrströmZoran Džolić

subject

crystal structuretermoanalyysichemistry.chemical_elementCrystal structurekiderakenne010402 general chemistryjauhe röntgen diffraktioCrystallography X-Ray01 natural scienceshuokoiset materiaalitpalladium kompleksiInorganic ChemistryMolecular recognitionOrganometallic CompoundsMoleculePincer ligandta116palladium pincer complexes; hexagonal channels; self-assembly; weak interactionssingle crystal X-ray diffractionpowder X-ray diffractionorganometalliMolecular Structure010405 organic chemistryChemistryStereoisomerismpalladium complexyksikide röntgen diffraktio0104 chemical sciencesPincer movementChemistryCrystallographySelf-assemblyporous materialsPorosityPalladiumMonoclinic crystal systemPalladium

description

Understanding the mechanism by which advanced materials assemble is essential for the design of new materials with desired properties. Here, we report a method to form chiral, potentially porous materials through spontaneous resolution of conformers of a PCP pincer palladium complex ({2,6-bis[(di-t-butylphosphino)methyl]phenyl}palladium(II)halide). The crystallisation is controlled by weak hydrogen bonding giving rise to chiral qtz-nets and channel structures, as shown by 16 such crystal structures for X = Cl and Br with various solvents like pentane and bromobutane. The fourth ligand (in addition to the pincer ligand) on palladium plays a crucial role; the chloride and the bromide primarily form hexagonal crystals with large 1D channels, whereas the iodide (presumably due to its inferior hydrogen bonding capacity) forms monoclinic crystals without channels. The hexagonal channels are completely hydrophobic and filled with disordered solvent molecules. Upon heating, loss of the solvent occurs and the hexagonal crystals transform into other non-porous polymorphs. Also by introducing a strong acid, the crystallisation process can be directed to a different course, giving several different non-porous polymorphs. In conclusion, a number of rules can be formulated dictating the formation of hexagonal channel structures based on pincer palladium complexes. Such rules are important for a rational design of future self-assembling materials with applications in storage and molecular recognition. peerReviewed

10.1039/c3dt50190fhttps://pubmed.ncbi.nlm.nih.gov/23625006