Abstract
It is our great pleasure as Guest Editors of the journal ‘Current Organic Chemistry’ to present you with a ‘hot topic issue’ on supramolecular chemistry, 'chemistry beyond the molecule'. Supramolecular chemistry examines the weaker interactions that hold groups of molecules together, no bonds that hold atoms together in a molecule [1]. The weaker interactions provide control, which allows the development of functional molecular and supramoleclar devices, defined as structurally organized and functionally integrated systems built from suitably designed molecular components performing a given action and endowed with the structural features required for assembly into an organized supramolecular architecture [1, 2]. The purpose of this special issue is to underscore the concepts and techniques of modern supramolecular chemistry, demonstrating how these paradigms evolve into nanometric size systems, nanotechnology, and materials science. The supramolecular self-assembly of polymer chains by specific, directional, and dynamic non-covalent interactions, including H-bond interaction, host-guest interaction, and amphiphilic association, has led to the development of novel polymeric supramolecular materials (PSMs). The first review of this issue is written by Drs. Liao, Zhang and their colleagues, who summarized the main strategies for the construction of PSMs and their applications in biomedical fields, such as drug delivery, tissues engineering, and biosensors. As they mentioned, it is still a challenge to finely control the process of selfassembly to produce PSMs with well-controlled properties. In the following article, Dr. Liang and his colleagues summarized recent advances in nanopore DNA sequencing, DNA Sequencing by Recognition, evolution of recognition molecules applied in Sequencing by Recognition, and discussed the opportunities and challenges in this rapidly growing field. Proposed interactions between recognition molecules and DNA bases in the nanopore should be investigated in detail by supramolecular chemist to help understand Sequencing by Recognition technique. In the third article of this issue, Dr. Fang and his colleagues highlighted the recent advances in the development of electronic sensors, in which the active conducting/semiconducting materials are incorporated with specific supramolecular receptors. Depending on the nature of the active conducting layer, these devices can be categorized into carbon materials-based sensors and organic semiconductor-based sensors. As they noted, recent groundbreaking developments of conductive Covalent Organic Frameworks (COFs)/ Metal Organic Frameworks (MOFs), supramolecular host-incorporated MOFs, and surface grown COFs have paved the way to the next generation electronic sensing materials. In the forth article of this issue, Dr. Wang and his colleagues summarized the recent research progress in the field of Organic Molecular Cages (OMCs) from synthesis, functionalization, and applications aspects. Since the gained specific surface areas are now comparable to those of MOFs and COFs, OMCs will definitely play a distinct role in the future of porous materials. In the fifth review, Dr. Zhang and his colleagues outlined the common design strategies and synthetic approaches used for the preparation of Ionic MOFs (I-MOFs), which are a unique type of MOFs that are composed of charged (positive or negative) frameworks containing mobile or loosely bound extra-framework counter ions. Enhanced gas adsorption and small molecules uptake due to the ionic feature of I-MOFs was discussed in detail. Recently reported potential applications for IMOFs in catalysis, optics, and photonics were also addressed. In the sixth article, Dr. Gassensmith and his colleagues discussed the chemistry within confined spaces. It was noted that the field is moving more toward solid-state and naturally porous systems in the short-term future; in particular, catalysis and reactivity within porous solids will likely dominate the landscape. Self-healing or self-repairing materials are a kind of ‘smart material’ that are able to repair their damage caused by mechanical force, and represent the forefront developments of 21st century in materials chemistry and engineering. In the seventh review, Dr. Liu and his colleagues described a few excellent examples of self-healing supramolecular polymers based on host–guest interactions, and discussed their advantages and versatility. In the last article of this issue, Drs. Yuan, and Liang reviewed the recent advances in the development and application of amphiphilic photomicroreactors with “soft” cavities in terms of supramolecular chemistry. In the limited space of the article, attention was focused primarily upon the microreactors bearing “soft” cavities including micelles, vesicles, polymers and dendrimers. Contrary to the “hard” cavities that usually show specific selectivity to the guests, “soft” cavities have a large applicability towards the substrates, since the size, shape and other properties of the “soft” cavities can be easily altered by such conditions as temperature, solvent, light or by the guest molecules themselves. We would like to sincerely thank all authors for their excellent work, and thank all reviewers for their scrutiny of manuscripts published in this special issue. It was a great opportunity for us to cooperate with researchers involved in this special issue. We hope that readers will enjoy this issue, obtain useful information, and be inspired with new ideas for future research on molecular recognition and supramolecular devices.