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Diphenylbutadiyne was inserted and polymerized in porous AlPO4-54 single crystals under high temperature, high pressure conditions to form a confined, nanostructured π-conjugated polymer.

Carbon nanothreads are likely the most attracting new materials produced under high pressure conditions. Their synthesis is achieved by compressing crystals of different small aromatic molecules, while also exploiting the applied anisotropic stress to favor nontopochemical paths. The threads are nanometric hollow structures of saturated carbon atoms, reminiscent of the starting aromatic molecule, gathered in micron sized bundles. The examples collected so far suggest that their formation can be a general phenomenon, thus enabling the design of functionalities and properties by suitably choosing the starting monomer on the basis of its chemical properties and crystal arrangement. The presence of heteroatoms or unsaturation within the thread is appealing for improving the processability and tuning the electronic properties. Suitable simple chromophores can fulfill these requirements and their controlled insertion along the thread would represent a considerable step forward in tailoring the optical and electronic properties of these mechanically extraordinary materials. Here, we report the synthesis and extensive characterization of double core nanothreads linked by azo groups. This is achieved by compressing azobenzene in a diamond anvil cell, the archetype of a wide class of dyes, and represents a fundamental step in the realization of nanothreads with tailored photochemical and photophysical properties., One-step high-pressure synthesis of 2D crystalline double nanothreads linked by azo groups.

The synthesis of hydrogenated carbon nanothreads at tens of GPa from aromatic systems is one of the most brilliant recent findings in high-pressure science. C-nanothreads combine the high tensile strength of diamond with the high flexibility of polymers, and many efforts are currently being undertaken to taylor some useful physicochemical properties by smartly modifying their local structure. We present the synthesis of double core diamond-like nanothreads with the two cores being bound by a conjugated C, polyacetylene-like backbone. The two cores also form a protecting sheath for the backbone. This material exhibits an optical bandgap of 1.74 eV, similar to polyacetyelene; it is then very attractive as a potential organic semiconductor with simultaneous outstanding mechanical properties. The synthesis was achieved by reacting diphenylacetylene in diamond anvil cells, at 25-30 GPa and room temperature, and the materials were characterized by optical spectroscopy, synchrotron X-ray diffraction, and ab initio computer simulations.