Youzhi

The crystallization problem is an outstanding challenge in the chemistry of porous covalent organic frameworks (COFs). Their structural characterization has been limited to modeling and solutions based on powder x-ray or electron diffraction data. Single crystals of COFs amenable to x-ray diffraction characterization have not been reported. Here, we developed a general procedure to grow large single crystals of three-dimensional imine-based COFs (COF-300, hydrated form of COF-300, COF-303, LZU-79, and LZU-111). The high quality of the crystals allowed collection of single-crystal x-ray diffraction data of up to 0.83-angstrom resolution, leading to unambiguous solution and precise anisotropic refinement. Characteristics such as degree of interpenetration, arrangement of water guests, the reversed imine connectivity, linker disorder, and uncommon topology were deciphered with atomic precision—aspects impossible to determine without single crystals.

Angewandte Chemie International Edition, EarlyView.

Coherent exciton-vibrational dynamics and energy transfer in conjugated organics

Coherent exciton-vibrational dynamics and energy transfer in conjugated organics, Published online: 13 June 2018; doi:10.1038/s41467-018-04694-8

Interference patterns in photoexcited dynamics of many materials have historically been attributed to electronic and vibrational coherences. Here, the authors demonstrate a simple model based on wavefunction symmetry suggesting these coherences originate from non-adiabatic transitions for optically active molecules.

Angewandte Chemie International Edition, EarlyView.

An artificial molecular machine that builds an asymmetric catalyst

An artificial molecular machine that builds an asymmetric catalyst, Published online: 02 April 2018; doi:10.1038/s41565-018-0105-3

The ring of a rotaxane molecule traverses a polymer track picking up leucine amino acids and synthesizing a homo-leucine oligomer, which in turn folds into an alpha helix and catalyses a chemical reaction.