Efficient Synthesis + Extraordinary Molecules = Future Advanced Materials
Although there is still the occasional new inorganic material composition constructed
from combining atomistic components, the vast majority of new emerging materials are
built from the bottom-up by the connection and assembly of molecules. Chemistry has
produced a dazzling array of synthetic methods, spectroscopies, and theoretical understanding
that can be broadly practiced to create materials with complex geometric structures,
electronic characteristics, optical properties, and chemical potentials. It is tempting
to compare the evolution of the synthetic materials world to that of nature, wherein
molecular subunits such as amino acids, nucleotide bases, and carbohydrates are connected
and arranged, often with the assistance of inorganic ions and water, into functional
assemblies. Although nature’s amazing evolutionary accomplishments defy comprehension,
chemists have already shown the power of applying a much more diverse set of building
blocks to create extraordinary materials. Aromatic amides, for example, give hydrogen
bonding networks and mechanical strength in the material KevlarTM, which exceeds all natural proteins. However, we are still struggling to create materials
that translate the properties of microscopic spider silk fibers to bulk systems. Some
systems are simply tough to scale. Perhaps a clever chemist will develop the proper
molecules with the proper balance of mechanics and conformational complexity to effect
this transition.
The chemistry toolbox is full of important opportunities for materials creation. Anisotropic
molecules can be made to assemble in predictable ways. Carefully tailored intermolecular
potentials can be used similar to the base-pairing in nucleotides, but need not be
limited to hydrogen bonding and can include halogen bonding, metal–ligand associations,
charge transfer, π-stacking, and host–guest complexation. Chemistry has an armada
of systems with designed reactivity and structural changes that can be powered (actuated)
chemically, electrochemically, thermally, or by light, that are certain to create
new generations of autonomous self-regulating systems. The unraveling of complex biomolecular
reaction networks with feedback mechanisms, agonists and antagonists, is presenting
chemistry with many grand challenges.
We need not limit our inspiration for the design of synthetic materials to nature.
Indeed, microelectronic and mechanical systems have evolved to our advantage by continually
creating complexity and miniaturization. Moreover, much of our fascination with electronically
and optically active molecular materials is inspired by the diodes, photocells, transistors,
logic gates, and memory elements created in modern semiconductor electronics.
I am well aware that writing flowery prose about these inspirational connects is the
easy part. It is the creation and manipulation of the molecular components where the
heavy lifting is needed. Hence, this cluster is focused on leading researchers creating
molecular constructions that are building brick by brick a foundation for the construction
of new generations of materials. Clearly this is going to be a long, and perhaps never-ending
process, but refining our methods to create new molecular properties and structures
with ever-improving efficiency, is necessary to empower future materials. The need
for precision in synthesis cannot be overstated and defects often limit a materials
performance. Hence, the mission of Synlett is very much aligned to highlight important
new methods for the creation of molecules that can, in turn, enable the generation
of transformative new materials. I hope you enjoy this cluster and the numerous chemical
innovations reported. As synthetic chemists, we begin with small things, but ultimately
these constituents and methods will enable new integrated materials systems.
