No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Synthesis of Highly Symmetrical Triptycene Tetra- and Hexacarboxylates
Abstract
Two alternative procedures, both starting from easily accessible tetramethylanthracenes and employing the Diels-Alder addition as the key reaction step(s), have been examined in the synthesis of the title compounds.
... A similar procedure was reported in the literature during this work. [20][21]. ...
... ESi-MS experiments were performed on a Agilent ESI-IonTrap instrument by direct flow injection using methanol as mobile phase. Compound 5 was synthesised according to [21]. ...
A new D3h symmetric triptycene derivative has been synthesized with the aim of
obtaining molecules that are able to assemble into porous structures, and can be used in the development of new ligands. The synthesis involves a Diels-Alder reaction as the key step, followed by an oxidation and the formation of a maleimide ring. Triptycene trimaleimide furnished single crystals which have been analyzed by means of X-ray diffraction
... The stepwise formation of the third aromatic ring in the triptycene skeleton in place of the aryne addition has already been reported to afford good yields of the product, albeit that the synthesis is relatively laborious, i.e., it requires six reaction steps from tetramethylanthracene to 4 (total yield: 26%). 17 Colorless single crystals of TrpHOF were grown by slow evaporation of solvent from a solution of 4 in acetone/CHCl 3 . The crystal structure of TrpHOF was determined by a single-crystal X-ray diffraction analysis (Table S1). ...
Triptycene-2,3,6,7,14,15-hexacarboxylic acid (4) was synthesized via a new and efficient route. A single-component, porous hydrogen-bonded organic framework (TrpHOF) was constructed by recrystallization of 4. Although TrpHOF shows almost no N2 uptake, not even at 1 atm and 77 K, the maximum CO2 adsorption at 1 atm and 273 K is 8.2 cm3/g, showing a type-I isotherm, which is characteristic of microporous materials.
... 3,6,7,14, The schematic illustration for the synthesis of the THC was showed in Scheme 1 . The intermediate product, triptycene-2,3,6,7,14,15-hexacarboxylic acid (THA), was prepared following the procedure given in the literature [36] . Briefly, the synthesis of THC mainly comprised of three steps as follow. ...
A novel triptycene based polyamide (TPA)thin film composite (TFC)nanofiltration (NF)membrane was successfully synthesized via interfacial reaction between piperazine (PIP)and mixed acyl chloride on porous support film. Specifically, the mixed acyl chloride was made up of a rigid 3D-symmetric contorted monomer, triptycene-2,3,6,7,14,15-hexaacyl chloride (THC)and a conventional non-contorted planar monomer, trimesoyl chloride (TMC). Based on the contorted structure and low reactivity, the THC could enhance microporosity, hydrophilicity and surface negative charge of prepared membrane. When the mass ratio of THC equaled to 40%, an excellent NF membrane was acquired, the water permeance was 21.4 L m ⁻² h ⁻¹ bar ⁻¹ as well as the Na 2 SO 4 rejection was above 95%. Moreover, the TPA-40 also showed high divalent to monovalent ions selectivity and long-term operating stability. The TPA TFC NF membrane had potential application in seawater reverse osmosis (SWRO)pretreatment.
... Isopentyl nitrite and 2aminobenzoic acid were synthesized as the Organic Chemistry Experiment of Wang Qinglian published by Higher Education Press of China in 1994. Both 2,3,6,7-tetramethyltriptycene (2) and triptycene-2,3,6,7-tetracarboxylic acid (3) were prepared as described in the literature [13]. All other solvents and reagents were obtained from various commercial sources and used as the AR grade level as received. ...
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, PIa, 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 m2 g−1, as well as an unexpected optical property with a transmittance of ∼85% at 450 nm as ∼20 μm membranes.
Triptycene is an aromatic compound with D3h symmetry, where three benzene rings are fused to a bicyclo[2.2.2]octatriene skeleton. 1,8,13-Substituted triptycenes exhibit interesting structural features: the C-1,8,13 substituents and the bridgehead C-9 position are located in the same plane. Three faces of the molecule are open for interesting interactions and applications. This paper summarizes the syntheses of 1,8,13-substituted triptycenes.
In this study, triptycene-based carboxylic acid (triptycene-2,3,6,7-tetracarboxylic acid) was synthesized for polycondensation with two amino compounds to ultimately form linear polyamides with different backbone structures. Characterizations, including nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy, were performed to confirm the polycondensation, and the structural properties were determined. Solubility of the synthesized polyamides was also measured. Subsequently, these polyamides were fabricated into membranes to investigate the separation of N2 over the VOCs, and their stability and separation performance under different operating conditions were determined. Good separation performance, such as a rejection rate above 95%, was obtained during the studied separation range for the N2/VOC mixture, indicating that a linear polymer can also be used for the separation of a condensable gas/vapor mixture and only the rotation of polymer chains can be restricted to a certain extent by the side groups.
In order to verify if the triptycyl (the analog of triphenylmethyl in which the three phenyl groups were united to a CH) free radical 1a should be more instable than the triphenylmethyl radical itself, Bartlett et al. (J Am Chem Soc 64:2649–2653, 1942) first synthesized triptycene 1 in a low total yield by a multistep route starting from the Diels–Alder addition reaction of anthracene and benzoquinone in 1942. Several years later, Bartlett et al. (J Am Chem Soc 72 (2):1003–1004, 1950) also reported the synthesis of 9-bromotriptycene (2) from the 9-bromoanthracene and benzoquinone according to the similar synthetic strategy. However, it was noted that the target compound 2 could be immediately afforded by the deamination of the diamine with NaNO2 in the presence of 50 % H3PO2 at − 3 °C.
Iptycenes are a class of aromatic compounds that contain several arene units fused to a bicyclo[2.2.2]octatriene bridgehead system. This unique, rigid, three-dimensional molecular structure provides several open electron-rich cavities with an abundance of reactive positions, and makes them useful for a wide range of applications. There is no doubt that the synthesis and reactions of iptycene derivatives with different functional groups form the fundamental basis of iptycene development. In this account, the synthesis of substituted iptycenes is described. In particular, the different synthetic strategies toward substituted triptycenes and pentiptycenes are the main focus.
1 Introduction
2 Synthesis of Substituted Triptycenes
2.1 Direct Diels–Alder Addition Reactions
2.2 Selective Substitution of the Triptycene Skeleton
2.2.1 Acetylation
2.2.2 Nitration
2.2.3 Halogenation
3 Synthesis of Substituted Pentiptycenes
4 Synthesis of Other Substituted Iptycenes
5 Conclusion and Outlook
Four Organic Molecules
of Intrinsic Microporosity (OMIMs) were
prepared by fusing triptycene-based components to a biphenyl core.
Due to their rigid molecular structures that cannot pack space efficiently,
these OMIMs form amorphous materials with significant microporosity
as demonstrated by apparent BET surface areas in the range of 515–702
m2 g–1. Bulky cyclic 1′,2′,3′,4′-tetrahydro-1′,1′,4′,4′-tetramethylbenzo
units placed on the triptycene termini are especially efficient at
enhancing microporosity.
The family of triptycene derivatives have special structures, unique electrochemical and photochemical properties and have been found versatile for materials chemistry, in host-guest interactions and as molecular rotors. This present review summarizes the synthesis of triptycene and derivatives and their use in synthesis and as ligands.
Extended triptycenes 5a,b and 7a-c have been designed to serve as convenient building blocks for a stepwise ramification of, the parent triptycene structure by Diels-Alder oligomerization.
A large selection of triptycenes functionalized with tetrathiafulvalene (TTF) units as well as triptycenes containing extended TTFs as a part of the triptycene core have been synthesized utilizing new triptycene di- and tetraaldehydes as well as bis-, tetrakis- and hexakis(bromomethyl) derivatives. The largest scaffold contains a total of 12 TTFs around the central triptycene core. From spectroelectrochemical and chemical oxidation studies, we have elucidated the extent to which an increasing number of electrostatic interactions among oxidized TTF units exert an influence on the absorption characteristics.
We report a novel luminescent Al-based metal-organic gel G1 comprising 1,4,5,8-triptycenetetracarboxylic acid, which exhibits highly sensitive detection towards nitro aromatic compounds particularly picric acid. Furthermore, under identical reaction conditions, using a Co(ii) salt instead, a novel 3D framework material, trip-MOF-1, was isolated and its sensitivity towards picric acid was also evaluated.
1,5- and 1,8-bis(bifluorenyl)anthracene were synthesized and converted to their corresponding bis(bifluorenyl)triptycenes and bis(bifluorenyl)-9,10-dihydroanthracenes. Analysis of their optical properties shows no feature of extended conjugation in the triptycene pair. The electronic spectra of the triptycene and dihydroanthracene pairs are in fact superimposable. There is definite evidence that triptycene displays zero homoconjugation effect.
The title tetrasubstituted spirobifluorenes 3a , 3b have been designed to serve as convenient achiral tectons for self-assembly of 2D layers with large chiral pores. The underlying stereochemical concept has been confirmed by the results of crystallographic analysis of tetraacid 3a . Self-assembly of isosteric tetraamide 3b led to markedly different results.
A stable derivative of cyclooctatrienyne (1), namely 1,4,7,10-tetramethyl-5,6-didehydrodibenzo-[a,e]cyclooctene (3), has been synthesized and fully characterized. X-Ray crystallographic analyses indicate that 3 adopts a “butterfly” conformation intermediate between those of virtually planar 5,6-didehydrodibenzo-[a,e]cyclooctene (2) and tub-shaped 1,4,7,10-tetramethyldibenzo[a,e]cyclooctene(16). The methyl substituents effectively shield the otherwise rather exposed strained triple bond of 3 and kinetically stabilize it against dimerization and/or air oxidation.
Crystallographic analysis of the title binaphthyl tetracid 2 revealed unique propensity to polycatenation upon crystallization of both the enantiomerically homogeneous as well as the racemic form of the axially chiral tecton. Stereochemical aspects of the polycatenation have been analyzed in three conceptual steps, (i) formation of infinite 2D grids set up from hydrogen-bonded tecton cyclotetramers, (ii) stacking of the 2D grids, and (iii) interpenetration of the resulting stacks. In the crystal self-assembly of the enantiomerically uniform tecton, all three steps are homochiral. Conversely, in the crystal of the racemic tecton the homochiral self-assembling algorithm operates only in the steps (i) and (ii), giving rise to separate, antipodal, stacks of homochiral 2D layers. In the final step (iii), the antipodal stacks mutually interpenetrate, yielding racemic 3D polycatenated architecture within a single crystal.
A simple two-step synthesis of triptycene di- and tetracarboxylic acids is reported. Diels-Alder reaction between dimethylanthracenes and appropriate arynes, generated in Situ from anthranilic or dimethylanthranilic acid, afforded di- or tetrainethyl-triptycenes in 41-69% yields. Subsequent oxidation of the methyl groups with potassium permanganate provided the corresponding triptycene carboxylic acids in 86-96% yields.
2,2′,5,5′-Tetracarboxy- and 2,2′,5,5′-tetracarbamoyl-substituted biphenyls and also the 2,2′,3,3′,6,6′-hexacarboxy-substituted analogue behave as Siamese twins of terephthalic tectons in the single crystal self-assembly, giving rise to chiral 2D grid layers. A comparison has been made with the corresponding 2,2′,6,6′-tetrasubstituted biphenyls which mimic isophthalic twins in their self-assembly.
The syntheses of fourteen derivatives of the dl-form of the Hydrangea alkaloid containing two identical substituents on the benzene ring are described, all of which are active antimalarials.
The synthesis and properties of the "antiaromatic" hydrocarbon dicycloocta[1,2,3,4-def:1′,2′,3′,4′-jkl]biphenylene (1) are described. The observed electronic and 1H NMR spectra of 1 agree well with previous predictions. The series of polycycles consisting of biphenylene (3), cycloocta[def]biphenylene (2), and dicycloocta[def:jkl]biphenylene (1) is examined in terms of resonance energy and qualitative aromaticity models.
[reaction: see text] A concept for modifying the photochemical properties of a dibenzobarrelene derivative by the combination of supramolecular assembly and solid-state photochemistry is presented. The irradiation of dibenzobarrelene 1b and alkali metal complexes thereof (1:1) in acetonitrile or benzene solution leads preferentially to the dibenzocyclooctatetraene 4b as the photoproduct. In contrast, the dibenzosemibullvalene 5b is formed as the main photoproduct in the solid state because of a strong cation effect.