Multi-stimuli responsive organogels based on low-molecular-weight gelators (LMWGs) have attracted much attention due to their potential applications. Herein, the synthesis and the self-assembly behavior of a novel molecular gelator based on a tetrapeptide-dithienylcyclopentene conjugate is described. This gelator forms stable gels in THF, acetone and acetonitrile, in which the formation of anti-parallel b-sheets of the biomimetic tetrapeptides is the key driving force. Further studies suggest that the organogel is multi-responsive to various external stimuli including temperature, light, chemicals, and mechanical force. Moreover, in the presence of catechol, this gelator forms a more robust organogel, accompanied by a dramatic change of the assembly manner and rheological properties. These prominent features of this conjugate make it an excellent smart soft material with potential applications in areas such as drug encapsulation and release systems.

Biomolecule-directed self-assembly of p-conjugated oligomers has attracted great attention in the past decade. In this contribution, two conjugates composed of quaterthiophene and tetrapeptide (Gly-Val-Gly-Val) were synthesised, namely peptide-thiophene -peptide (PTP) and thiophene -peptide -thiophene (TPT), to investigate the influence of peptide content ratio and its location in the molecular structures on the nanostructures and properties of the assemblies. Both conjugates formed organogels consisting of left-handed twisted nanostructures; however, anti-parallel b-sheets were observed in PTP while parallel b-sheets were obtained for TPT, although in both cases oligothiophenes adopted an H-like stacking mode. Obvious solvent-induced supramolecular chirality inversion from the oligothiophene segment was observed for PTP while such phenomenon was not clear for TPT. PTP and TPT gels also showed different stabilities towards temperature increase, as evidenced by variable-temperature circular dichroism study. From the data, it is suggested that the rational design of the location and ratio of peptide plays a key role in constructing materials with determined properties based on peptidethiophene conjugates.

Alternating copolymers of an oligopeptide (N3‐GVGV‐N3, where G: glycine; V: valine) and an oligothiophene (5,5′‐bis(ethynyl)‐3,3'‐dioctyltetrathiophene) are prepared by click chemistry. The experimental results discover that these copolymers exhibit strong molecular‐weight‐dependent self‐assembly behaviors. The copolymer P1 with the lowest weight‐average molecular weight (trueM¯normalw = 7400 g mol−1), assembles into well‐ordered fibrous nanostructures. P3 (trueM¯normalw = 16 980 g mol−1) assembles into nano­balls. P2, which has the medium trueM¯normalw between P1 and P3, (trueM¯normalw = 14 800 g mol−1), exhibits more‐complicated self‐assembly behaviors, more like a transition state between the other two. All of the results suggest the self‐assembly ability of these oligopeptide segments might be the major reason for the nano‐structure evolution.