Synthesis and preferred all-syn conformation of C3-symmetrical N-(hetero)arylmethyl triindoles

From truxenes to heterotruxenes: playing with heteroatoms and the symmetry of molecules

As a result of the modification of truxene, we can change the electronic structure or create multidimensional materials. Thus, the use of truxenes is very wide.

Triazatruxene-Rhodamine-Based Ratiometric Fluorescent Chemosensor for the Sensitive, Rapid Detection of Trivalent Metal Ions: Aluminium (III), Iron (III) and Chromium (III)

We investigated the ability of a novel triazatruxene-rhodamine-based (TAT-ROD) chemosensor to detect the trivalent metal ions aluminium (Al³⁺), iron (Fe³⁺) and chromium (Cr³⁺). Operating via the through-bond energy transfer (TBET) pathway, the chemosensor exhibited low detection limits of 23.0, 25.0 and 170.0 nM for Al³⁺, Fe³⁺ and Cr³⁺, respectively, along with high sensitivity and selectivity during a brief period (<15 s). The binding ratio of the chemosensor and trivalent metal ions achieved by Job's method was 3:1, and when we added ethylenediaminetetraacetic acid (EDTA), the sensing process reversed. Altogether, our TAT-ROD chemosensor marks the first triazatruxene-based colorimetric and fluorometric metal ion sensor reported in the literature.

Chiral Self-Sorting in Truxene-Based Metallacages

Two chiral face-rotating metalla-assembled polyhedra were constructed upon self-assembling achiral components, i.e., a tritopic ligand based on a truxene core (10,15-dihydro-5H-diindeno[1,2-a;1′,2′-c]fluorene) and two different hydroxyquinonato–bridged diruthenium complexes. Both polyhedra were characterized in solution as well as in the solid state by X-ray crystallography. In both cases, the self-sorting process leading to only two homo-chiral enantiomers was governed by non-covalent interactions between both truxene units that faced each other.

Synthesis and Characterization of Zn-Carboxylate Metal–Organic Frameworks Containing Triazatruxene Ligands

Reactions between triazatruxene-based tricarboxylate ligands, H3tat-R, and zinc nitrate under solvothermal conditions afforded new metal–organic frameworks (MOFs) with the general formula [Zn3(tat-R)2(H2O)2], MUF-tat-R (R=a hydrocarbon substituent on the triazatruxene nitrogen atoms). Single-crystal X-ray diffraction analysis revealed that these frameworks are 3D networks with a (10,3)-a topology. Linear trinuclear zinc clusters are connected to tat ligands to form chiral channels that accommodate the substituents on the tat ligands. MUF-tat and MUF-tat-benzyl crystallize in a cubic crystal system whereas MUF-tat-butyl and MUF-tat-hexyl are tetragonal. MUF-tat-benzyl retains its porosity on activation, which was confirmed by gas adsorption studies.

Palladium-catalysed decarboxylative nitrile insertion via C–H activation or self-coupling of indole-2-carboxylic acids: a new route to indolocarbolines and triindoles

Palladium catalysed decarboxylative nitrile insertion/dual C–H activation of indole carboxylic acids afforded indolocarbolines or triindoles in the absence of nitriles.

Structure of 1,5-benzodiazepinones in the solid state and in solution: Effect of the fluorination in the six-membered ring

Two novel tetrafluorinated 1,5-benzodiazepinones were synthesized and their X-ray structures determined. 6,7,8,9-Tetrafluoro-4-methyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one crystallizes in the monoclinic P2₁/c space group and 6,7,8,9-tetrafluoro-1,4-dimethyl-1,3-dihydro-2H-1,5-benzodiazepin-2-one in the triclinic P−1 space group. Density functional theory studies at the B3LYP/6-311++G(d,p) level were carried out on these compounds and on four non-fluorinated derivatives, allowing to calculate geometries, tautomeric energies and ring-inversion barriers, that were compared with the experimental results obtained by static and dynamic NMR in solution and in solid state.

Prototropic tautomerism of 5-aryloxy-1(2)H-tetrazoles

The structure of 5-(2,6-dimethylphenoxy)-1H- and 2H-tetrazoles together with those of 5-(2,6-diisopropyl-phenoxy)-1H and 2H-tetrazoles have been theoretically studied including absolute shieldings and energies. The conclusion of these studies is that a slow tautomerism between 1H- and 2H-tetrazoles cannot explain the experimental observations reported recently in the literature.

Self-assembly of C3-symmetrical hexaaryltriindoles driven by solvophobic and CH-pi interactions

The synthesis and aggregation properties of a series of differently substituted star-shaped hexaaryltriindoles both in solution and in the solid state are being reported. While these molecules do not show any significant intermolecular aggregation in CDCl(3), it has been possible to induce aggregation by increasing the polarity of the solvent and therefore facilitating the occurrence of solvophobic forces. A study of the influence of the electronic character of peripheral substituents on the self-association behavior in solution has shown that increasing the electron-donor character of the substituents facilitates self-association while derivatives substituted with electron-acceptor substituents do not self-assemble. The electronic nature of the substituents also has an influence in the geometry of the stacking of these derivatives observed in the solid state. While unsubstituted hexaphenyl triindole self-assemble in a staggered face-to-face arrangement, attaching six cyano functional groups results in an offset stacking. The influence of the substituents in the strength and geometry of the stacking tendency contrasts with the trend expected for an aggregation induced solely by pi-pi interactions, but can be explained considering an important contribution of multiple cooperative CH-pi interactions.