Design and construction of on-surface molecular nanoarchitectures: lessons and trends from trimesic acid and other small carboxlyated building blocks

Molecular self-assembly and reactions at surfaces provide a versatile and appealing approach to nanomaterials synthesis, with a tremendous potential for engineering purpose-driven nanoarchitectures. However, since the outcomes of these processes depend on the chosen substrate, molecular constituents and processing conditions, the parameter space that must be mastered to control the product is enormous. Carboxylated molecules are a useful model system for illustrating the challenges and opportunities in creating on-surface nanoassemblies. These molecular building blocks can self-assemble through hydrogen bonding, or can deprotonate to enable ionic hydrogen bonds or organometallic bonding. Decarboxylation can lead to C?C bond formation and the on-surface synthesis of conjugated polymers. By focussing on key lessons from studies of carboxylated molecules, we highlight the challenges and opportunities in using these building blocks to form complex assemblies at the vanguard of materials design.