A caged tris(2-pyridylmethyl)amine ligand equipped with a Ctriazole-H hydrogen bonding cavity.

A capped bioinspired ligand built from a tris(2-pyridyl-methyl)amine (TPA) unit and surmounted by a triazole-based intramolecular H-bonding secondary sphere was prepared. The resulting cage provides a well-defined cavity combining the hydrophobic nature with H-bonding properties. Its coordinating properties were explored using Zn(II) and Cu(II) metal ions.

A tris(benzyltriazolemethyl)amine-based cage as a CuAAC ligand tolerant to exogeneous bulky nucleophiles.

The archetypal tris(benzyltriazolemethyl)amine (TBTA) ligand was equipped with a bowl-shaped cap in the cage Hm-TBTA. Hm-TBTA accelerates CuAAC reactions without suffering from product inhibition. Furthermore, this shielded ligand efficiently protects the copper center from deactivation by the CuI-chelator glutathione, opening the way to novel approaches for efficient CuAAC reactions in complex media.

Rationalization of chirality transfer and fast conformational changes in a tris(2-pyridylmethyl)amine-based cage.

The key features that govern the chirality transfer in a structurally contracted covalent cage, consisting of a northern chiral cyclotriveratrylene (CTV) connected to a southern tris(2-pyridyl-methyl)amine (TPA) unit by three methyl bridges, are described. The preferential orientation of the propeller arrangement of TPA is dictated by its compact structure, with an arm of the TPA unit pointing inside the cage, together with the relative positioning of the three pyridines regarding the chiral CTV cap. The diastereomers with P/P (or M/M) configurations for the CTV and TPA units adopt eclipsed structures and were found to be more stable by 40 kJ mol-1 than the P/M (or M/P) diastereomer which displays a staggered arrangement. The existence of isomerization pathways between isomers of the cage with low energy barriers (38 kJ mol-1) accounts for the 1H-NMR signal, which is consistent with an averaged C 3 structure.

Control and Transfer of Chirality Within Well-Defined Tripodal Supramolecular Cages.

The development of new strategies to turn achiral artificial hosts into highly desirable chiral receptors is a crucial challenge in order to advance the fields of asymmetric transformations and enantioselective sensing. Over the past few years, C 3 symmetrical cages have emerged as interesting class of supramolecular hosts that have been reported as efficient scaffolds for chirality dynamics (such as generation, control, and transfer). On this basis, this mini review, which summarizes the existing examples of chirality control and propagation in tripodal supramolecular cages, aims at discussing the benefits and perspectives of this approach.

Chirality transfer in a cage controls the clockwise/anticlockwise propeller arrangement of the tris(2-pyridylmethyl)amine ligand.

Predictable control of the propeller arrangement of the tris(2-pyridyl-methyl)amine (TPA) ligand was achieved through the preparation of the smallest hemicryptophane 1. This newly designed cage displays a chirality transfer from its northern unit to the TPA ligand. 1 can coordinate Cu(i), yielding a rare T-shaped complex with controlled helicity of the TPA-Cu(i) core.

An Asymmetric Furan/Thieno[3,2-b]Thiophene Diketopyrrolopyrrole Building Block for Annealing-Free Green-Solvent Processable Organic Thin-Film Transistors.

A new asymmetric furan and thieno[3,2-b]thiophene flanked diketopyrrolopyrrole (TTFDPP) building block for conjugated polymers is designed and used to generate a donor-acceptor semiconducting polymer, poly[3-(furan-2-yl)-2,5-bis(2-octyldodecyl)-6-(thieno[3,2-b]thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-thieno[3,2-b]thiophene] (abbreviated to PTTFDPP-TT), consisting of TTFDPP unit copolymerized with thieno[3,2-b]thiophene comonomer (TT), which is further synthesized. Results demonstrate that PTTFDPP-TT-based thin-film transistors in a bottom-gate bottom-contact device configuration exhibit typical hole-transporting property, with weak temperature dependence for charge carrier mobility from room temperature to 200 °C. In addition, the good solubility of PTTFDPP-TT due to the incorporation of a polar furan unit and an asymmetric conjugated structure makes it able to be solution processed with a less toxic nonchlorinated solvent such as toluene, demonstrating comparable performance with that prepared from chlorinated solution. These results suggest PTTFDPP-TT as a promising organic semiconductor candidate for annealing-free, environmentally benign, and less energy-consuming applications in large-area flexible organic electronic devices.