Novel hyperbranched polyimides from 2,6,12-triaminotriptycene

The monomer 2,6,12-triaminotriptycene was synthesized and the structure was confirmed by IR and 1H NMR spectra. Hyperbranched polyimides modified with different terminal groups were obtained from precursors, anhydride- and aminoterminated hyperbranched poly（amic acid）s from polymerization of A2 ＋ B3 system. From gel permeation chromatograrn （GPC） characterization, representative products had high molecular weight. All polymers had good solubility in CHCl3, DMF and tetrahydrofuran （THF）, and performed no detective Tgs in the range of 50-300 ℃ and high Tds above 455 ℃ when 5% weight loss.

A FACILE SYNTHESIS OF HYPERBRANCHED POLYIMIDES FROM 2,6,12-TRIAMINOTRIPTYCENE

Based on monomer 2,6,12-triaminotriptycene, hyperbranched polyimides with high molecular weight modified with different terminal functional groups were obtained by polymerization of A2 ＋ B3 system. The prepared hyperbranched polyimides had good solubility in CHCl3, DMF and THF, and performed no detective Tgs in the range of 50-330℃ and high TdS （5%） above 455℃.

Two Dimensional Triptycene End-Capping and Its Influence on the Self-Assembly of Quinoxalinophenanthrophenazines

In this report we investigated two-dimensionally triptycene end-capped QPPs in terms of their solution and solid-state behavior.For this purpose,a triphenylene based ortho-diamine decorated with two triptycenyl units as well as a phenylene diamine with two non-annulated triptycene units have been synthesized.Sequences of condensation reactions with a pyrene-based tetraketone and ortho-diamines yielded a series of QPPs and UV/Vis investigations of the corresponding compounds led to the conclusion,that the QPPs form dimers in solution,which was further supported by MALDI-TIMS-TOF-MS.Single-crystal X-ray analysis of the triply and quadruply triptycene end-capped QPPs furthermore showed shortπ-π-distances of 3.3-3.4?and a perfect shape match during the dimerization of the triply triptycenyl end-capped QPP making it possible synthon for crystal engineering.

Precise Orientational Control of Electroactive Units Using a Tripodal Triptycene Scaffold to Direct Noncovalent Pairing at the Single Molecular Level

A break junction technique has been established to explore conductive behavior at the single molecular level,and recent interest has shifted toward the evaluation of bimolecular systems interacting through noncovalent intermolecular forces.This requires precise control over the orientation of the two molecules so that they can adapt an appropriate face-to-face arrangement between two electrodes.Herein,we present an approach using a tripodal triptycene scaffold that allows for accurate positioning of electroactive subunits with an upright configuration on substrate surfaces.We incorporated electron-donating tetrathiafulvalene or electron-accepting anthraquinone into the molecular scaffold and confirmed that the resulting molecules retain the electronic properties particular to their attached subunits.Self-assembled monolayers(SAMs)of these molecules were prepared on Au(111)and characterized by XPS and STM.STM break junction techniques were applied to the SAMs,revealing two electrical conduction regimes;one arises from single-molecules sandwiched between two electrodes,and the second from intermolecularly interacting homodimers that bridge between electrodes.This observation demonstrates the validity of the approach of using tripodal triptycene scaffolds to precisely direct electroactive subunits to undergo intermolecular pairing.We believe that the present work will provide a new avenue for evaluating the heterodimers at the single molecular level.

Synthesis of Fréchet-type dendritic homotriptycenes

A rapid and efficient synthesis of novel dendrimer homotriptycenes is presented. The dendronized 9,10-dihydroanthracen-9-ols 4, having high electron densities in the benzene rings of the Fréchet-type dendrons, exhibited in the presence of acid a quantitative transannular ring closure to the corresponding dendritic homotriptycenes. The electron-donating Fréchet-type dendrons enabled the intramolecular FC alkylation by a regioselective 1,7-elimination of H2O.

Spiro-fused bicyclo[3,2,2]octatriene-cored triptycene:synthesis,molecular packing,and functional aggregates

Aggregate science has led to the existence of functional properties at the aggregate level that significantly differs from those of corresponding single-molecule species,leading to a number of novel conceptual materials with state-dependent functionality.For developing such materials,new molecular scaffolds that allow modulating the structural and functional properties of aggregates in a controlled manner could be extremely helpful.In this study,we report a class of spiro-fused bicyclo[3,2,2]octatriene triptycene derivatives with a unique 3 D molecular scaffolding structure that displays aggregation-induced emission(AIE)activity with bright solid-state blue luminescence.The core scaffold features a Y-shaped bicyclo[3,2,2]octatriene backbone and a vertical crossover arrangement of adjacent spiro-conjugated rings.Unlike classic bicyclo[2,2,2]octatrienes with high rigidity,this stereoscopic bicyclo[3,2,2]octatriene containing a seven-membered ring allows retaining certain flexibility in the molecular scaffold,which results in a weak fluorescence in dilute solutions(Φ_(F)<10%).However,the corresponding molecular aggregates emit intense fluorescence(Φ_(F)=50%-75%)and show prominent AIE activity because of the restriction of intramolecular scaffold motions.Moreover,in principle,these stereoscopic scaffold constructions with partially restricted flexibility facilitate the assembly of multiple different crystalline packing structures in both porous and nonporous forms depending on the growth conditions of crystalline aggregates.The obtained crystals with regular voids(12.85×6.89Aeach)show reversible luminescence in response to the adsorption/desorption of iodine vapor.These materials based on an unusual 3 D scaffold exhibit a high degree of structural modulation at the aggregate level and demonstrate potential applications in chemical sensing and flexible optoelectronics,which may open up the exploration of highly stereoscopic molecular building blocks for developing functional aggregates.

Microporous polymer based on hexaazatriphenylene-fused triptycene for CO2 capture and conversion

Chemical conversion of carbon dioxide(CO2)to value-added useful chemicals like cyclic carbonates represents one potential solution to climate warming.Here,a kind of porous organic polymer(HAT-TP)with large surface area and excellent carbon dioxide uptake capacity is prepared via a condensation reaction to introduce hexaazatriphenylene(HAT)units into triptycene(TP)-based microporous polymer.HAT-TP can coordinate with zinc ions,and the resulting polymer(Zn/HAT-TP)can be utilized as an efficient recyclable catalyst for chemical conversion of CO2 into cyclic carbonates with epoxides.

Solid state self-assembly of triptycene-based catechol derivatives by multiple O-H…O hydrogen bonds

Single crystals of two triptycene-based catechol derivatives 1 and 2 were obtained,and their X-ray crystal structural studies showed that the two tecton molecules had different conformations in the solid state,and they could self-assemble into interesting 3D networks with solvent molecules included inside, in which multiple O-H…O hydrogen bonds played important roles.

Microporous aromatic polyimides derived from triptycene-based dianhydride

A novel triptycene-based dianhyride as a shape-persistent building block with high internal free volume was conveniently synthesized via solvothermal method.Subsequently,three all-aromatic polyimides,Pla,PIb and PIc,were prepared by a one-step polycondensation of triptycene-2,3,6,7-tetracarboxylic dianhydride with 2,2＇-bis（trifluoromethyl）benzidine,m-tolidine and 3,3＇,5,5＇-tetramethylbenzidine,respectively.The corresponding polymers exhibit good solubility,excellent thermal stability,significant microporosity with large BET surface areas of up to 623 m^-2 g^-1 as well as an unexpected optical property with a transmittance of -85%at 450 nm as -20μm membranes.

Complexation of Triptycene-Derived Macrotricyclic Host with Bisparaquat Derivative and Self-Folding Guest： A Switchable Process Controlled by K＋ Ions

Triptycene-derived cylindrical macrotricyclic host with two dibenzo-30-crown-lO cavities could form stable 1 ： 1 complexes with not only polyether linked bisparaquat derivative but also a self-folding A-D-A guest in solu- tion and/or solid state. Moreover, it was found that switchable processes between the host and both the bisparaquat derivative and the self-folding guest could be further controlled by potassium ions.

Complexation of Triptycene-Derived Macrotricyclic Host Containing Pyridine Groups with Paraquat Derivatives: A Switchable Process Controlled by Zn^(2+) Ions

A triptycene-derived macrotricyclic host containing two pyridine groups was synthesized,and it could form 1∶1 stable host-guest complexes with paraquat derivatives in both solution and solid state.Moreover,it was also found that binding and releasing of the guest molecules in the complexes could be efficiently controlled by zinc ions.

Synthesis and structures of triptycene-derived Tr?ger's base molecular clips

A series of triptycene-derived Tr6ger＇s bases with molecular clip shaped structures have been conveniently and efficiently synthesized by one-pot condensation of corresponding amino-substituted triptycenes with paraformaldehyde in the presence of trifluoroacetic acid, and their structures have been characterized by NMR, MALDI-TOF MS spectra, elemental analyses and single-crystal X-ray diffraction. ~ 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.