Triptycene-based diiron(II) mesocates: spin-crossover in solution

Triptycene-based diiron(II) and dizinc(II) mesocates were obtained using a novel rigid ligand with two pyridylbenzimidazole chelating units fused into the triptycene scaffold. Studies on the diiron(II) assembly in solution showed that the complex undergoes thermal-induced one-step spin-crossover with T1/2 at 243 K (Evans method).

Preparation of cage-shaped hexakis(spiroborate)s

In previous research studies, various types of prismatic cage-shaped molecular containers have been prepared and evaluated in terms of their guest inclusion properties. Basically, most of these molecular cages have a cationic or electron-deficient nature, and exhibit strong affinity mainly toward electron-rich aromatic guests. On the other hand, there is no report concerning anionic prismatic cages that are expected to recognize cationic polyaromatic guests with various structures and functions. In this manuscript, we present the preparation of hexakis(spiroborate)-type molecular cages, which was achieved by the reaction of phenylene- or biphenylenebis(dihydroxynaphthalene), hexahydroxytriphenylene, and boric acid in N,N-dimethylformamide. Their triangular prismatic hollow structures were confirmed by X-ray crystallographic analysis, and it was found that both phenylene- and biphenylene-bridged spiroborate cages have internal cavities of the corresponding size. It was also revealed that tetra(n-butylammonium) cations located inside the cavity and between the two adjacent spiroborate cages resulted in the formation of a one-dimensional columnar array. The molecular recognition behavior of the spiroborate cages was evaluated using tris(pyridinium)triazines as tricationic aromatic guests. ¹H NMR measurement implied that a discrete 1 : 1 host-guest complex was formed when 1 equiv. of guest was added to the cage, whereas infinite one-dimensional aromatic stacks were constructed by the addition of 2 equiv. of guest.

Effect of the triptycene scaffold on the photophysical, electrochemical and electroluminescence properties of the iridium(iii) complex

Complex 2 achieves obviously higher nondoped device performance (12.6 cd A⁻¹, 5.5%) than that of complex 1 (9.8 cd A⁻¹, 3.8%).

Novel phosphorescent triptycene-based Ir(iii) complexes for organic light-emitting diodes

A series of charge-neutral cyclometalated iridium(iii) complexes (1-3 and 5-7) containing triptycene-substituted ligands (tbt and tpbi) and two parent complexes (4 and 8) were synthesized and characterized. The crystal structures indicated that π-π stacking interactions existed in ligand tbtH, but not in complex 6. However, a large intramolecular repulsion was found in complex 6. These triptycene-based complexes exhibited good thermal stability, which was higher compared with that of the parent complexes. These complexes showed green to yellow emission with peaks that ranged from 503 to 563 nm. The introduction of the rigid non-conjugate triptycene skeleton caused a slight emission red shift (<25 nm), but a significant increase in the PLQYs (>47%) was observed. The electroluminescent devices employing 2 and 6 as phosphors displayed impressive performance improvements and low efficiency roll-off because of the higher PLQYs and HOMO levels of these triptycene-based complexes. The maximum current and external quantum efficiencies of the devices based on complexes 2 and 6 were 41.7 cd A^-1, 11.9% and 41.2 cd A^-1, 12.6%, respectively, which were about 31% higher than that of the devices based on the parent complexes 4 and 8. This work provides a novel approach to develop highly efficient phosphors with a triptycene skeleton.

Concentration dependent supramolecular interconversions of triptycene-based cubic, prismatic, and tetrahedral structures

New insight into the molecular fission–fusion process is obtained with the characterization of a stable intermediate prismatic cage.

Terpyridine-based metallosupramolecular constructs: tailored monomers to precise 2D-motifs and 3D-metallocages

Comprehensive summary of the recent developments in the growing field of terpyridine-based, discrete metallosupramolecular architectures.

Design of a flexible organometallic tecton: host–guest chemistry with picric acid and self-assembly of platinum macrocycles

A new “flexible” and ditopic Pt(ii) organometallic compound is a tecton for the self-assembly of neutral metallacycles. It also exhibits significant binding affinity for picric acid.

Stepwise, multicomponent assembly of a molecular trapezoid possessing three different metals

A novel terpyridine-based, trapezoidal architecture was synthesized by a coordination-driven multicomponent assembly and features three different tpy–M²⁺–tpy bonds (M²⁺ = Ru²⁺, Fe²⁺, and Zn²⁺) in the macrocyclic ring.

Pyrazine-based donor tectons: synthesis, self-assembly and characterization

Two donor tectons, each bearing a central pyrazine moiety covalently linked to two pyridine units, have been self-assembled with PtII2 acceptor units to yield ionic nanoscalar metallamacrocycles, having a convex hexagonal cavity.

Zinc-mediated diastereoselective assembly of a trinuclear circular helicate

We have designed a triptycene-based ditopic ligand H₂L, which is able to adopt an adequate topology required for optimal binding to naked Zn²⁺ leading to a neutral trinuclear circular helicate Zn₃L₃.

Size dependent effect of new organometallic triptycene tectons on the dimensions of self-assembled macrocycles

The effect of changing the dimension of triptycene-based acceptor building blocks on the shape and size of the resulting supramolecular framework is reported.

Robustness of thioamide dimer synthon, carbon bonding and thioamide–thioamide stacking in ferrocene-based thiosemicarbazones

The role of thioureas in crystal engineering as robust supramolecular synthons is now recognized, but their analogs, namely thiosemicarbazones/N-iminothioureas, have not received the attention they deserve.