Pseudorotaxanes are the simplest prototypes for the construction of molecular machines based on threaded species. Investigation on molecular motions in these model systems is a necessary action for an efficient design of working molecular machines and motors. Herein we report on photoactive pseudorotaxanes based on the interaction between bipyridinium and cucurbit[7]uril (CB7). The molecular axle is composed of a central bipyridinium unit and two azobenzene moieties at the extremities. CB7 can form two different complexes with this molecule: a [2]pseudorotaxane, in which the macrocycle shuttles fast along the length of the axle, and a [3]pseudorotaxane, in which two CB7 s are confined at the extremities of the axle. Upon trans to cis isomerization of the azobenzene moieties, the [3]pseudorotaxane is destabilized, and only one CB7 resides on the axle, surrounding the bipyridinium unit. The system was successfully inserted into the core of liposomes, and preliminary investigations confirmed that it maintains its switching ability.
Clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR‐associated 9 (Cas‐9) technology holds tremendous potential as a gene editing tool. Different strategies have been adopted for in vitro and in vivo delivery of CRISPR/Cas9, including both viral and non‐viral. The possibility of tailoring properties of nanosized systems makes the molecular design of self‐assembled non‐viral delivery systems based on organic (lipids and polymers) and hybrid (zeolitic imidazolate frameworks, ZIF and gold nanoparticles) materials of a great interest in CRISPR/Cas9 delivery. This review highlights the progress and challenges of organic and hybrid CRISPR/Cas9 delivery vehicles.
Compounds that emit blue light are of interest for applications that include optoelectronic devices and chemo/biosensing and imaging. The design and synthesis of small organic molecules that can act as high‐efficiency deep‐blue‐light emitters in the solid state and can be easily processed from solutions represents a significant challenge. Herein we present the preparation and photophysical, photochemical and electrochemical properties of a series of triazolopyridinium and triazoloquinolinium compounds. The compounds are soluble in water or polar organic solvents and exhibit photoluminescence in the blue region of the spectrum in fluid solution, in the solid state and in a frozen matrix.
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