Tetraphenylmethane Core Research Articles

Reticular syntheses of hydrogen-bonded organic frameworks based on pyrazole tetramers with tunable electrostatic potential for enhanced C2H2/CO2 separation

Reticular chemistry has been widely used to predict and design structures of MOFs and COFs, but it still limited in HOFs due to the flexible and fragile nature of hydrogen bonding. Herein, by employing the N-H···N hydrogen-bonding tetramers to connect the pyrazole monomers, we realize the reticular syntheses of three isostructural HOFs (HOF-FJU-45, HOF-FJU-46 and HOF-FJU-47) with tunable pore environments and explore their separation performance toward C2H2/CO2 mixtures. Among these three HOFs, the electrostatic potential of pore surface in HOF-FJU-47a with tetraphenyladamantane core is complementary to C2H2, enabling it to perform better C2H2/CO2 separation performance than HOF-FJU-45a with tetraphenylmethane core and HOF-FJU-46a with tetraphenylsilane core. Dynamic breakthrough experiments also confirm that HOF-FJU-47a can achieve superior C2H2/CO2 separation performance with a balanced C2H2 working capacity (1.98 mmol g−1) and separation factor (5.5) in HOFs materials. The multiple host–guest interactions between C2H2 and the framework of HOF-FJU-47a are further revealed by theoretical calculations.

Tetraphenylmethane Derivatives Containing Nitrogen Heterocycles

AbstractWe disclose a useful approach to novel tetrahedral building blocks containing N-heterocycles. Pyrrole was introduced on to the tetraphenylmethane (TPM) core by employing the RCM strategy, Clauson–Kaas reaction, Paal–Knorr condensation, and Ullmann coupling as key steps. In addition, various heterocyclic derivatives of TPM were prepared using nickel catalysts. We also studied the photophysical properties of the synthesized TPM derivatives containing different peripheral substituents and found that they exhibit high quantum yields.

Synthesis and two-photon properties of phenothiazine-based dendrimers with tetraphenylmethane cores

We have synthesized two new two-photon active dendritic molecules with tetraphenylmethane core with four phenothiazine-based arms. They show good solubility in organic solvents, including dichloromethane, chloroform, toluene and tetrahydrofuran. It is found that the two dendrimers display strong two-photon absorption and two-photon excited up-conversion fluorescence at 800 nm. • Two new phenothiazine-based dendrimers with tetraphenylmethane cores have been synthesized. • The dendritic molecules display two-photon absorption activity. • The two-photon absorption cross section increased with the increasing of the conjugation degree.

Intrinsically Porous Dual-Responsive Polydiacetylenes Based on Tetrahedral Diacetylenes

The combinatorial functionalization in a single molecular framework by structural integration utilizing multiple functional materials to create predefined structural morphology and multistimuli-responsive smart materials has attracted intensive attention. Herein, we constructed intrinsically porous and dual-responsive supramolecule, TeDA, by introducing a photopolymerizable diacetylene template (10,12-pentacosadiynoic acid) to the sterically rigid tetrahedral tetraphenylmethane (TPM) core. The self-assembled monomeric TeDA is transformed into the covalently cross-linked blue-phase polydiacetylene (TePDA) by UV irradiation (UV 254 nm). The BET measurement and examination of SEM images confirm the mesoporous characteristic for TeDA/PDA. Very interestingly, the blue-phase TePDA produces a naked-eye detectable colorimetric response to heat and VOCs (liquid and vapor phase). Most importantly, TePDA exhibits reversible thermochromism and excellent colorimetric response to chloroform vapors. To signify the struc...

Multi‐Component Spirane Assemblies

AbstractA scaffold with a tetraphenylmethane core carrying two identical phenanthroline and two equal zinc porphyrin terminals is utilized for the clean self‐assembly of supramolecular three‐ and five‐component spiranes. The self‐assembly is guided by the orthogonality of the heteroleptic bisphenanthroline complex, heteroleptic terpyridine and phenanthroline complex, and Npy → zinc porphyrin interactions. In contrast to Newkome’s spirane assembly (Chem. Eur. J.2014, 20, 11291), the present systems are fully dynamic structures in which both rings share one common atom.

Size-Dependent Oxidation State and CO Oxidation Activity of Tin Oxide Clusters

The CO oxidation reaction is an industrially important reaction; however, the practical catalysts are limited to noble metals. In this paper, we report a systematic study of the CO oxidation ability on cheap and less noble tin oxide clusters with the aim of quantitatively understanding the active sites. We synthesized size-controlled tin oxide clusters in mesoporous silica using the dendrimer templating method, employing dendritic phenylazomethine with a tetraphenylmethane core (TPMG4) as the template molecule. The clusters had different sizes depending on the added amount of SnCl2 as a precursor to TPMG4. The synthesized tin oxide clusters contained not only stable tetravalent Sn(IV) but also metastable divalent Sn(II) due to the structural stability and had a size-dependent composition. The CO oxidation activity of the tin oxide clusters increased with decreasing cluster size depending on the Sn(II)/Sn(IV) ratio. We also found the correlation between the Sn(II) fraction and the CO oxidation activity, cl...

Tetraphenylmethane-Arylamine Hole-Transporting Materials for Perovskite Solar Cells.

A new class of hole-transporting materials (HTM) containing tetraphenylmethane (TPM) core have been developed. After thermal, charge carrier mobility, and contact angle tests, it was found that TPA-TPM (TPA: arylamine derivates side group) showed higher glass-transition temperature and larger water-contact angle than spiro-OMeTAD with comparable hole mobility. Photoluminescence and impedance spectroscopy studies indicate that TPA-TPM's hole-extraction ability is comparable to that of spiro-OMeTAD. SEM and AFM results suggest that TPA-TPM has a smooth surface. When TPA-TPM is used in mesoscopic perovskite solar cells, power conversion efficiency comparable to that of spiro-OMeTAD is achieved. Notably, the perovskite solar cells employing TPA-TPM show better long-term stability than that of spiro-OMeTAD. Moreover, TPA-TPM can be prepared from relatively inexpensive raw materials with a facile synthetic route. The results demonstrate that TPM-arylamines are a new class of HTMs for efficient and stable perovskite solar cells.

Linear Tetraphenylmethane-Based Thioether Oligomers Stabilising an Entire Gold Nanoparticle by Enwrapping.

The design and synthesis of a novel linear thioether-based ligand subunit with a tetraphenylmethane core used in the stabilisation of gold nanoparticles (AuNPs) are presented. Mono-, tri, penta- and heptamers of the ligand have been synthesised and used to stabilise AuNPs by enwrapping. With the exception of the monomer, all ligands provide reliable long-term stability and redispersibility for the coated nanoparticles in common organic solvents. Despite variation of the oligomer length, all stable particles were of the same size within error tolerance (1.16±0.32 nm for the trimer, 1.15±0.30 nm for the pentamer, 1.17±0.34 nm for the heptamer), as investigated by transmission electron microscopy (TEM). These findings suggest that not only the number of sulfur atoms in the ligand, but also its bulkiness play a crucial role in stabilising the AuNPs. These findings are supported by thermogravimetric analysis (TGA), showing that AuNPs stabilised by the penta- or heptamer are passivated by a single ligand. Thermal stability measurements suggest a correlation between ligand coverage and thermal stability, further supporting these findings.

Three-dimensional supramolecular polymers driven by rigid tetrahedral building blocks through tetrathiafulvalene radical cation dimerization

Rigid tetrahedral compounds T1 and T2 that bear four tetrathiafulvalene (TTF) units, which are connected to a tetraphenylmethane core by the ethynylene or amide linker were designed and prepared. Upon one-electron oxidation of the TTF units by Fe(ClO4)3, the resulting TTF+ radical cations stacked intermolecularly to give rise to three-dimensional supramolecular polymers, which were supported by UV–vis spectroscopy, cyclic voltammetry, dynamic light scattering, and scanning electron microscopy.

Synthesis, characterization and sorption properties of zinc(II) metal–organic framework containing methanetetrabenzoate ligand

► Complex with formula {[Zn 2 (MTB)(H 2 O) 2 ]·3H 2 O·3DMF} n was prepared by solvothermal reaction. ► Single crystal X-ray diffraction revealed non-interpenetrating PtS-like structure with interconnected 3D channels. ► A specific surface area ( S BET ) of 248 m 2 g −1 and micropore volume ( V p ) of 0.0891 cm 3 g −1 were calculated. ► Sorption capacity of carbon dioxide is 1.06 mmol g −1 at 293 K and 1.37 mmol g −1 at 273 K. Abstract Porous metal–organic framework {[Zn 2 (MTB)(H 2 O) 2 ]·3H 2 O·3DMF} n (where MTB = methanetetrabenzoate, DMF = N,N′-dimethylformamide) was prepared by solvothermal route and characterized by elemental analysis, FT-IR spectroscopy, thermal analysis coupled with mass spectrometry, single-crystal X-ray diffraction and adsorption of nitrogen and carbon dioxide. Structure of the compound is formed by the clusters of paddle-wheel secondary building units (SBUs) with composition [Zn 2 (H 2 O) 2 (COO) 4 ] (COO = carboxylate group), which are interconnected through tetraphenylmethane core of MTB 4− ligand with tetrahedral spatial arrangement. This interconnection gives rise to the final 3D porous structure of the compound with the channels propagating along a , b and c crystallographic axes. The sizes of the channel openings, after substraction of van der Waals radii of the atoms, were 21.2 × 6.0, 9.0 × 9.0 and 6.0 × 6.0 Å 2 . The accessibility of the pores for the guest molecules was revealed by the measurements of adsorption of nitrogen and carbon dioxide. The specific surface area determined from nitrogen adsorption at 77 K using BET equation was 248 m 2 g −1 , and the pore volume calculated using t -plot was 0.0891 cm 3 g −1 . Sorption of carbon dioxide was performed at two temperatures 273 and 293 K giving the sorption capacities 5.67 and 4.74 wt.%, respectively.

Synthesis of a Dendrimer Reactor for Clusters with a Magic Number

Abstract A new type of phenylazomethine dendrimer (DPA) that has one more coordination site compared to the tetraphenylmethane core DPA was synthesized for the “magic number 13” metal cluster template that has cubic or hexagonal densely packed structures. The stepwise complexation property was revealed, and this property is expected to be the “magic number 13” metal cluster template.

Patterning Carbazole–Phenylazomethine Dendrimer Films

The synthesis of double-layer-type dendrimers with carbazole and phenylazomethine as the dendron with a symmetric tetraphenylmethane core is reported. Structural modeling studies showed that the G3 dendrimer has a rigid and spherical structure. These dendrimers were thermally stable (Td10% over 500 °C) with the TGA-MS study revealing a degradation mechanism occurring first at the inner-layer phenylazomethine group. The metal (Lewis acid) complexation property of these dendrimers was also studied. Electrochemical measurements showed that these dendrimers have the appropriate HOMO level as a hole-transporting material with electropolymerizability on the peripheral carbazole groups. A photo-cross-linking property of the dendrimer film was also observed. Finally, electro-nanopatterning with conducting AFM and photopatterning of the dendrimer film were demonstrated. Thus, the new dendrimer is a potential hole-transporting material that is patternable through oxidation of the peripheral carbazole units by either photochemical or electrochemical methods.

Synthesis of Tetrahedral Shape‐Persistent Tetranuclear Metal–salphens

AbstractThe synthesis of two novel tetrakis(salicylaldehydes) based on a rigid tetraphenylmethane core is presented. These salicylaldehydes were used as precursors for the construction of three‐dimensional multimetallic salphens, as exemplified by the synthesis of rigid and shape‐persistent tetranuclearzinc–, nickel– and palladium–salphens with defined geometries and distances between the metal sites. The UV/Vis measurements of the tetranuclear metal complexes are presented.

Synthesis of Tripodal-anchor Units Having Pyridine or Amine Functional Groups and Their Adsorption Behavior on Metal Electrodes

Abstract Synthesis of new tripodal-anchor units composed of a tetraphenylmethane core with pyridine or amine as anchoring functional groups has been successfully accomplished. Cyclic voltammetry measurements of their monolayers on metal electrodes revealed the estimated surface coverage and robust adsorption of three-armed structures on the surface.

Nanoporous Polymers Containing Stereocontorted Cores for Hydrogen Storage

This paper reports synthesis of several nanoporous polymers containing stereocontorted cores for hydrogen storage. The spirobifluorene and tetraphenylmethane cores were used as the building blocks for the cross-linked polymers. Trimerizations of acetylinic compounds or oxidative coupling of thiophenyl compound were used for the polymerization. Characterizations on structures and hydrogen storage capacities of the resulting polymers were performed. It was found that the polymers thus prepared generally have a narrow pore size distribution, and specific surface areas up to 1000 m2/g were obtained. It was shown that the reaction conditions affect the size of nanopores and the surface areas. Hydrogen adsorption capacities at liquid nitrogen and ambient temperatures were measured using a Sievert isotherm apparatus.

Synthesis of tripodal anchor units bearing selenium functional groups and their adsorption behaviour on gold

The synthesis of new selenium-functionalized tripodal anchor units composed by a tetraphenylmethane core with three selenocyanate or selenol arms has been successfully accomplished and CV, XPS and UPS measurements of their monolayers on a gold surface were investigated.

Implementing a tripodal relay station in a phthalocyanine–[60]fullerene conjugate

A tripodal architecture 1—based on a tetraphenylmethane core bearing three phthalocyanine arms and a fullerene arm—has been realized en route towards a novel electron donor–acceptor conjugate that reveals long range electron transfer activity.

Fluorescence Quenching Naphthalene Diimide Multimers with Siloxane Cores

The hydrosilylation of a naphthalene diimide (NDI) to form three amorphous electron-accepting compounds with siloxane cores is presented. All three compounds successfully quench emissions from p-type polymers poly(3-hexylthiophene) (P3HT) and poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-p-phenylene vinylene] (MDMO-PPV). The work is an extension of their earlier report featuring a tetrameric NDI system with a tetrahedral tetraphenyl methane core (J. Am. Chem. Soc. 2005, 127, 14530).

Polyphenylene Dendrimers with Pentafluorophenyl Units: Synthesis and Self-Assembly

A series of polyphenylene dendrimers (PDs) incorporating additional pentafluorophenyl units have been synthesized. A key building block thereby is the tetrakis(pentafluorophenyl)cyclopentadienone, which serves as the end-capper for making the outer shells of the dendrimers. The variation of the peripheral pentafluorophenyl content was varied using desymmetrized tetraphenylmethane cores for the divergent construction of the dendrimers. The self-assembled nanostructures, prepared by drop-casting solutions of the second-generation species on highly oriented pyrolytic graphite (HOPG), have been investigated by tapping mode atomic force microscopy (AFM). Besides isotropic globular aggregates and percolated networks of nanometer size anisotropic objects, the herein presented dendrimers self-organize into micrometer long nanofibers. The formation of a certain morphology depends upon the amount of pentafluorophenyl rings at the periphery of the dendrimers. Furthermore, it has been observed that by the progressive blending of two dendrimers with different peripheral functionalities a certain control over the length of the formed nanofibers is possible.

Synthesis and Properties of a Novel Phenylazomethine Dendrimer with a Tetraphenylmethane Core

[structure: see text] A new type of phenylazomethine dendrimer with a tetraphenylmethane core was synthesized by a convergent method. The properties of the dendrimer were confirmed by thermal, rheological, TEM, and AFM measurements. A stepwise radial complexation was clearly observed with SnCl(2).