Perspectives

A new concept termed 'robust dynamics' is presented as the intellectual centerpiece to the union between metal–organic frameworks (MOFs) and mechanically interlocking molecules. Robust dynamics allows highly flexible entities, which are bound covalently to MOF backbones, to carry out repeated movements without affecting the integrity of the overall structure.

Altering the properties of materials by using an external signal, such as light, heat or mechanical stress, is attractive for the preparation of functional materials in diverse fields. This Perspective focuses on liquid and solid materials that change the colour of their luminescence under mechanical pressure, and highlights the structural changes involved.

The two established models of chemical bonding, covalent and ionic, do not accurately describe all forms of bonds. This article explains how 'charge-shift' bonds — with a large covalent–ionic resonance interaction energy — are a third type of bond, and discusses some examples.

Small anions can be used to modulate the physical properties of supramolecular gels by interacting with the low-molecular-weight gelators from which such materials are composed. A better understanding of this anion-tuning effect will aid in the rational design of responsive gels that may prove useful for a number of practical applications.

The direct transfer of molecules onto surfaces to form specific patterns has had a significant impact in a number of areas of science and technology, ranging from biomedical diagnostics to nanoelectronics. This Perspective compares and contrasts different lithographic approaches to molecular printing and considers future directions for this field.

The 1,2-diamine motif is found in a number of bioactive natural products, pharmaceuticals, and ligands for organometallic chemistry. Here, the recent advances in the synthesis of such structures by direct metal-catalysed diamination of alkenes are considered, and opportunities for future research in the area identified.

Fragment-based drug discovery is an approach that relies on the ability to identify weakly binding drug fragments using sophisticated screening techniques. Binding can be optimized while maintaining favourable physical properties of the drug, which should have a positive impact on the attrition rates of new drug candidates.

The vast number of known organic compounds and the reactions that connect them together can be thought of as a complex network. Analysing the organic chemistry universe in this manner may prove useful for both fundamental and practical purposes, such as predicting chemical reactivity or improving how regulated substances are monitored.