Aqueous compatible supramolecular materials hold promise for applications in environmental remediation, energy harvesting and biomedicine. One remaining challenge is to actively select a target structure from a multitude of possible options, in response to chemical signals, while maintaining constant, physiological conditions. Here, we demonstrate the use of amino acids to actively decorate a self-assembling core molecule in situ, thereby controlling its amphiphilicity and consequent mode of assembly. The core molecule is the organic semiconductor naphthalene diimide, functionalized with D- and L- tyrosine methyl esters as competing reactive sites. In the presence of α-chymotrypsin and a selected encoding amino acid, kinetic competition between ester hydrolysis and amidation results in covalent or non-covalent amino acid incorporation, and variable supramolecular self-assembly pathways. Taking advantage of the semiconducting nature of the naphthalene diimide core, electronic wires could be formed and subsequently degraded, giving rise to temporally regulated electro-conductivity.

Temporal control of supramolecular assemblies to modulate the structural and transient characteristics of synthetic nanostructures is an active field of research within supramolecular chemistry. Molecular designs to attain temporal control have often taken inspiration from biological assemblies. One such assembly in Nature which has been studied extensively, for its well-defined structure and programmable self-assembly, is the ATP-driven seeded self-assembly of actin. Here we show, in a synthetic manifestation of actin self-assembly, an ATP-selective and ATP-fuelled, controlled supramolecular polymerization of a phosphate receptor functionalised monomer. It undergoes fuel-driven nucleation and seeded growth that provide length control and narrow dispersity of the resultant assemblies. Furthermore, coupling via ATP-hydrolysing enzymes yielded its transient characteristics. These results will usher investigations into synthetic analogues of important biological self-assembly motifs and will prove to be a significant advancement toward biomimetic temporally programmed materials.

Peptide-based supramolecular systems chemistry seeks to mimic the ability of life forms to use conserved sets of building blocks and chemical reactions to achieve a bewildering array of functions. Building on the design principles for short peptide-based nanomaterials with properties, such as self-assembly, recognition, catalysis, and actuation, are increasingly available. Peptide-based supramolecular systems chemistry is starting to address the far greater challenge of systems-level design to access complex functions that emerge when multiple reactions and interactions are coordinated and integrated. We discuss key features relevant to systems-level design, including regulating supramolecular order and disorder, development of active and adaptive systems by considering kinetic and thermodynamic design aspects and combinatorial dynamic covalent and noncovalent interactions. Finally, we discuss how structural and dynamic design concepts, including preorganization and induced fit, are critical to the ability to develop adaptive materials with adaptive and tunable photonic, electronic, and catalytic properties. Finally, we highlight examples where multiple features are combined, resulting in chemical systems and materials that display adaptive properties that cannot be achieved without this level of integration.

Natural systems have been an inspiration to synthetic supramolecular chemistry. Synthetic demonstrations of dissipative biological systems such as actin filaments are a formidable scientific challenge in attaining future life-like materials. Dynamic instability of such structures beckons control of self-organization in the temporal regimes. In this study, we present a fuel-dependent helical assembly of a supramolecular polymer. We further attempt the synthetic manifestation of a temporally programmable self-assembly. Additionally, the fuel-induced chiral (re)organization with the employment of various enzymes singularly and in tandem have resulted in designing a multistate transient self-assembly. These parameter modulations result in controllable lifetimes and rates. We thus report, for the first time, a temporally programmed multistate reorganization of self-assembly.

Design of artificial systems, which can respond to fluctuations in concentration of adenosine phosphates (APs), can be useful in understanding various biological processes. Helical assemblies of chromophores, which dynamically respond to such changes, can provide realtime chiroptical readout of various chemical transformations. Towards this concept, here we present a supramolecular helix of achiral chromophores, which shows chiral APs responsive tunable handedness along with dynamically switchable helicity. This system, composing of naphthalenediimides with phosphate recognition unit, shows opposite handedness on binding with ATP compared with ADP or AMP, which is comprehensively analysed with molecular dynamic simulations. Such differential signalling along with stimuli-dependent fast stereomutations have been capitalized to probe the reaction kinetics of enzymatic ATP hydrolysis. Detailed chiroptical analyses provide mechanistic insights into the enzymatic hydrolysis and various intermediate steps. Thus, a unique dynamic helical assembly to monitor the real-time reaction processes via its stimuli-responsive chiroptical signalling is conceptualized.

Naphthalene diimide (NDI) bolaamphiphilic molecules (1) self-assemble in water to form organic nanoparticles, which exhibit self-assembly induced preassociated excimer formation and hence an enhanced green fluorescence.

Supramolecular organization of π-conjugated chromophores into well defined nanostructures has gained much attention due to their promising role as active components in organic electronics. Charge-transfer (CT) nanostructures, in which aromatic donor (D) and acceptor (A) molecules are alternately arranged, (mixed stack) have emerged recently as prospective candidates in this direction, because they provide inherent, uniform doping conducive for excellent conducting properties. The present perspective highlights the importance of charge transfer (CT) based non-covalent interactions, with emphasis on supramolecular design principles, for construction of various CT nano-architectures. The whole article is divided into three parts themed on the type of interactions used for obtaining CT assemblies. Through some of our recent results, we have attempted to highlight the latent potential of this nascent field. Furthermore, we have presented our perspectives on the major challenges in this field which is expected to broaden the scope of this subject.

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