Synthesis and properties of TTFV-hinged molecular tweezers

Switchable molecular tweezers: design and applications

Switchable molecular tweezers are a unique class of molecular switches that, like their macroscopic analogs, exhibit mechanical motion between an open and closed conformation in response to stimuli. Such systems constitute an essential component of artificial molecular machines. This review will present selected examples of switchable molecular tweezers and their potential applications. The first part will be devoted to chemically responsive tweezers, including stimuli such as pH, metal coordination, and anion binding. Then, redox-active and photochemical tweezers will be presented.

Donor/acceptor substituted dithiafulvenes and tetrathiafulvalene vinylogues: electronic absorption, crystallographic, and computational analyses

The structural, electronic, and crystallographic properties of nitrophenyl and methoxyphenyl-substituted dithiafulvenes and tetrathiafulvalene vinylogues were systematically investigated by experimental and computational approaches.

EF, Zhao Y. Redox-dependent properties of DTF-endcapped π-oligomers

Solid films of electroactive π-conjugated oligomers show distinct redox behaviour from that in solution, with interesting morphological changes accompanying oxidation.

Redox interactions of Au(iii) with carboxylated dithiafulvenes and tetrathiafulvalene analogues in polar organic media

The redox interactions between HAuCl₄ and a series of π-conjugated organic donors, namely carboxylated dithiafulvenes and tetrathiafulvalene vinylogues, were investigated. Interestingly, the dithiafulvene derivative with two carboxylic groups showed the ability to directly induce the formation of Au(0) nanoparticles in dipolar aprotic solvents such as DMF and DMSO.

A heterometallic macrocycle as a redox-controlled molecular hinge

The ability to modify the structure of nanoscopic assemblies in a controlled fashion is an important prerequisite for the creation of functional supramolecular systems. Here, we describe a heterometallic Pt2Cu2-macrocycle which behaves as a molecular hinge. A square-planar Pt(ii) complex with pendent 2-formylpyridine groups was synthesized and structurally characterized. Condensation of the complex with benzylamine followed by reaction with Cu(MeCN)4BF4 resulted in the formation of a rectangular Pt2Cu2-macrocycle. Upon chemical oxidation of the Cu centers, the macrocycle folds up to adopt a butterfly-like geometry in which the Pt centers approach each other. This process can be reversed by chemical reduction.

Synthesis of Novel Chiral Cholic Acid-Based Molecular Tweezers Containing Unsymmetrically Disubstituted Urea Units Using Microwave Irradiation

An efficient procedure has been developed for the synthesis of new chiral cholic acid molecular tweezer artificial receptors by linking an unsymmetrically disubstituted urea to methyl deoxycholate via a carbonate chain using microwave irradiation. The structures of these new receptors were confirmed by 1H NMR, IR, MS spectra and elemental analysis. Their binding properties were examined by UV-Vis spectra titration. The preliminary results indicate that these molecular tweezers not only recognised anions, but also showed good enantioselectivity for D-amino acid methyl esters.

Tetrathiafulvalene vinylogues as versatile building blocks for new organic materials

Although tetrathiafulvalene (TTF) and its derivatives have been extensively studied as important organic electronic materials over the past half century, tetrathiafulvalene vinyl-ogues (TTFVs) still remain a relatively underdeveloped branch in the family of TTF derivatives. Our recent work has investigated the synthesis and characterization of a class of diphenyl-substituted TTFVs carrying alkynyl functionality. The unique conformational and redox properties of such TTFV derivatives along with the versatile chemistry enabled by acetylenic groups (e.g., metal-catalyzed coupling and click reactions) have led us to a variety of functional molecular architectures ranging from oligoynes, polymers, and molecular tweezers, to macrocycles. Property studies of these new TTFV-based molecular materials point to appealing applications in molecular electronics and optoelectronics.

Synthesis of Novel Amide Molecular Tweezers under Solvent-Free Conditions Using Microwave Irradiation

Twelve novel amide type molecular tweezer anion receptors based on phenyl-1, 4-dioxyacetic acid have been synthesised using microwave irradiation. Their structures were established by 1H NMR, IR, MS spectra and elemental analysis. Their binding properties were examined by UV-Vis spectra titration. The preliminary results indicate that these molecular tweezers show good recognition properties for Cl-, Br-, I-, CH3COO-.