Tris Research Articles

Solvothermal synthesis and enhanced electrochromic properties of coal-based reduced graphene oxide and covalent organic framework electrochromic composite films containing triphenylamine unit

Two-dimension covalent frameworks (2D COFs) with reversible redox units show the potential in the field of photo-electronic functional materials because of their rich electron transport path and reversible redox characteristic. However, the pure organic conjugated system of COF results in poor electrical conductivity and weak cyclic performance. In this work, tris (4-aminophenyl) amine and 4,4-biphenyldiformaldehyde (TABP) COF electrochromic film with triphenylamine (TPA) active unit was synthesized by a solvothermal method in Teflon-lined reactor. And then the TABP-COF/coal-based reduced graphene oxide (C-rGO) film was prepared by the one pot method. C-rGO provides the growth substrate and electron transport path for COF. Taixi anthracite with a high degree of graphitization also contributes to the preparation of GO. The electrochemical and electrochromic properties of TABP-COF and TABP-COF/C-rGO were studied and they could be switched reversibly from yellow and brown. Relative to TABP-COF, the impedance and response time of composite decrease and the contrast of composite increases. Moreover, TABP-COF/C-rGO exhibits the excellent stability, which can remain 80.1 % initial contrast after 5000 s cycle.

Repurposing Copper(II)/THPTA as A Bioorthogonal Catalyst for Thiazolidine Bond Cleavage.

Metal-mediated chemical transformations are promising approaches to manipulate and regulate proteins in fundamental biological research and therapeutic development. Nevertheless, unlike bond-forming reactions, the exploration of selective bond cleavage reactions catalyzed by metals that are fully compatible with proteins and living systems remains relatively limited. Here, it is reported that Copper(II)/tris(3-hydroxypropyltriazolylmethyl)amine (THPTA), commonly used in copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, can be repurposed as a new bioorthogonal catalyst for thiazolidine (Thz) bond cleavage. This process liberates an α-oxo-aldehyde group under physiological conditions, without requiring additional additives. To showcase the utility of this method, this simple catalyst system is coupled with genetic code expansion technology to achieve on-demand activation of genetically encoded Thz-caged α-oxo-aldehydes, enabling further functionalization of proteins. For the first time, this cell-compatible Thz uncaging reaction allows for the site-specific installation of α-oxo-aldehydes at the internal positions of proteins in phage and bacterial surface display systems, expanding the chemical space of proteins. Overall, this study expands the toolkit of bioorthogonal catalysts and paves the way for metal-promoted chemical reactions in living systems, potentially benefiting various applications in the future.

Sustainable poly(imide‐imide) vitrimer based on multiple dynamic covalent bonds

AbstractPolyimide materials with high mechanical strength are widely used in various fields, but pose certain challenges in achieving sustainable material utilization. A poly(imide‐imide) vitrimer material (ADTA) based on multiple dynamic covalent bonds (imide, imine, and disulfide bonds) was constructed by preparing vanillin difunctionalized derivatives (DVA) for aldolamine condensation reactions with bis‐amine monomers (ATFA) and tris(2‐aminoethyl) amines (TAEA) with imide structures. The ADTA material has good 5% thermal stability Td5% (278.87°C), high energy storage modulus E (2421.26 MPa), and fast relaxation time (36.39 s). The thermal stability and mechanical properties of the material are enhanced by the more stable alicyclic structure of the imide structure. The material also demonstrated excellent solvent resistance and self‐healing properties. This study provides a new option for the development of sustainable utilization of polyimide materials.

Mixed Ru(II)-Ir(III) Complexes as Photoactive Inhibitors of the Major Human Drug Metabolizing Enzyme CYP3A4.

Cytochrome P450 3A4 (CYP3A4) is a crucial enzyme in human drug metabolism. To garner photochemical control over the inhibition of CYP3A4, a potent Ir(III)-based inhibitor of CYP3A4 was complexed with two Ru(II)-based photocaging groups. Chemical, photochemical, and biological properties of the photocaged inhibitors were characterized. Importantly, mixed Ru(II)-Ir(III) complexes strongly absorb green light, which facilitates the photochemical release of the Ir(III) inhibitor from the Ru(II) caging fragment [Ru(tpy)(Me2bpy)]2+, where tpy = 2,2':6',2″-terpyridine and Me2bpy = 6,6'-dimethyl-2,2'-bipyridine. Emission turn on, type II heme binding, and more potent inhibition under light vs dark conditions were observed. The study also demonstrated that a Ru(II)-Ir(III) conjugate can be photoactivated to exert cytotoxic effects on MCF-7 breast cancer cells upon green light exposure. Additionally, a synthesized analogue with one [Ru(TPA)]2+ fragment (TPA = tris(pyridin-2-ylmethyl)amine) and two Ir(III) centers, although resistant to photochemical release, showed strong inhibition of CYP3A4 both in purified form and in CYP3A4-overexpressing HepG2 cells, with nanomolar potency. These mixed Ru(II)-Ir(III) compounds can permeate cell membranes and inhibit CYP3A4, presenting a new class of bioactive compounds.

Fabrication of an IgG-imprinted monolith micro-solid phase extraction chip for IgG extraction from human plasma

Molecular imprinted polymers (MIPs), also known as synthetic antibodies, offer a novel and promising approach for protein separation at analytical scale. In proteomics research, this approach could capture target high abundant proteins from biological fluids to reduce sample complexity. In this study, we have explored the potential to imprint human immunoglobulin G (IgG) to develop a micro-solid phase extraction chip for selective removal of IgG from human plasma. Imprinting of IgG within the polyhydroxy ethyl methacrylate monolith containing dimethyl amino ethyl methacrylate (DMAEMA) as a functional monomer was successfully achieved and characterized using FT-IR spectroscopy and protein assay kit. 0.1 M tris buffer (pH 7) and UV-polymerization were identified as the ideal buffer and polymerization strategy to imprint IgG within 30 min. Template (IgG) elution using 10 % acetic acid containing 10 % (v/v) SDS as elution buffer was moderately successful (25 % IgG-template free monolith was obtained). Protein shape has influenced its imprinting and elution from the monolith. The protocol developed to imprint one protein cannot be translated to another protein without further modifications. A 10-fold decrease of DMAEMA concentration within the monolith and a sequential elution step has resulted in >90 % IgG-template free monolith. The IgG-template free monolith has displayed an adsorption capacity of ∼ 3.7 mg per g monolith and showed good IgG selectivity as compared to other tested human proteins (human serum albumin, transferrin and fibrinogen). Translation of imprinted monolith protocol to develop a micro-solid phase extraction chip was successful. The chip can be re-used for 5 cycles with >95 % reusability and has selectively captured IgG from human plasma.

Interactions of human serum albumin with phosphate and Tris buffers: impact on paclitaxel binding and nanoparticles self-assembly

Aim To investigate the conformational changes in human serum albumin (HSA) caused by chemical (CD) and thermal denaturation (TD) at pH 7.4 and 9.9, crucial for designing controlled drug delivery systems with paclitaxel (PTX). Methods Experimental and computational methods, including differential scanning calorimetry (DSC), UV-Vis and intrinsic fluorescence spectroscopy, mean diameter, polydispersity index (PDI), ζ-potential, encapsulation efficiency (EE), in vitro release and protein docking studies were conducted to study the HSA denaturation and nanoparticles (NPs) preparation. Results TD at pH 7.4 produced smaller NPs (287.1 ± 12.9 nm) than CD at pH 7.4 with NPs (584.2 ± 47.7 nm). TD at pH 9.9 exhibited high EE (97.3 ± 0.2%w/w) with rapid PTX release (50% within 1h), whereas at pH 7.4 (96.4 ± 2.1%w/w), release only 40%. ζ-potentials were around −30 mV. Conclusion Buffer type and pH significantly influence NP properties. TD in PBS at pH 7.4, provided optimal conditions for a stable and efficient drug delivery system.

Mol-ecular structure of tris-[(6-bromo-pyridin-2-yl)meth-yl]amine.

Coordination compounds of polydentate nitro-gen ligands with metals are used extensively in research areas such as catalysis, and as models of complex active sites of enzymes in bioinorganic chemistry. Tris(2-pyridyl-meth-yl)amine (TPA) is a tripodal tetra-dentate ligand that is known to form coordination compounds with metals, including copper, iron and zinc. The related compound, tris-[(6-bromo-pyridin-2-yl)meth-yl]amine (TPABr3), C18H15Br3N4, which possesses a bromine atom on the 6-position of each of the three pyridyl moieties, is also known but has not been heavily investigated. The mol-ecular structure of TPABr3 as determined by X-ray diffraction is reported here. The TPABr3 molecule belongs to the triclinic, P space group and displays interesting intermolecular Br⋯Br interactions that provide a stabilizing influence within the molecule.

Ion-Pairing Stereodynamic Probes for Circular Dichroism Chiral Sensing of Amines.

Tris(2-pyridylmethyl)amine (TPMA) and tris(2-phenolmethyl)amine (TPA) metal complexes have been extensively used for catalysis and molecular recognition applications. In particular, due to their ability to form stereodynamic complexes through the helical arrangement of the ligand around the metal in a propeller shape, chiroptical sensing has been extensively investigated. In particular, the capability of the analyte, usually a Lewis base, to bind the metal complex has been the predominant recognition motif. Herein, we report the synthesis and application of a zinc TPA-based stereodynamic probe for the sensing of chiral amines and amino-alcohols in which an ion-pair interaction between the anionic metal complexes and the ammonium ions is responsible for the recognition.

Four-State Electrochromism in Tris(4-aminophenyl)amine- terephthalaldehyde-based Covalent Organic Framework.

Covalent organic frameworks (COFs) are of massive interest due to their potential application spanning diverse fields such as gas storage and separation, catalysis, drug delivery systems, sensing, and organic electronics. In view of their application-oriented quest, the field of electrochromism marked a significant stride with the reporting of the first electrochromic COF in 2019 [J. Am. Chem. Soc. 2019, 141, 19831-19838]. Since then, new and novel COF structures with electrochromic features (denoted as ecCOFs) have been searched continuously. Yet, only a handful of ecCOFs have been constructed to date. A closer look at these reports suggests that multielectrochromism (showing at least three redox color states) in a COF assembly has only been achieved once, manifested through three-state electrochromism [Angew. Chem. 2021, 133, 12606-1261]. Herein, we report four-state electrochromism in tris(4-aminophenyl)amine-terephthalaldehyde (TAPA-PDA)-based COF constructed through the metal-catalyst free Schiff base approach. The four-state (orange, pear, green, and cyan) electrochromism demonstrated by the TAPA-PDA ecCOF opens several futuristic avenues for ecCOF's end use in flip-flop logic gates, intelligent windows, decorative displays, and energy-saving devices.

Strong Enhancement in Cobalt(II)‐TPMA Aqueous Hydrogen Photosynthesis through Intramolecular Proton Relay

AbstractPhotosynthetic hydrogen generation by cobalt(II) tris(2‐pyridylmethyl)amine (TPMA) complexes is mainly limited by protonation kinetics and decomposition routes involving demetallation. In the present work we have explored the effects of both proton shuttles and improved rigidity on the catalytic ability of cobalt(II) TPMA complexes. Remarkably, we demonstrate that, while a small enhancement in the catalytic performance is attained in a rigid cage structure, the introduction of ammonium groups as proton transfer relays in close proximity to the cobalt center allows to reach a 4‐fold increase in the quantum efficiency of H2 formation, and a surprising 22‐fold gain in the maximum turnover number, at low catalyst concentration. The beneficial role of the ammonium relays in promoting faster intramolecular proton transfer to the reduced cobalt center is documented by transient absorption spectroscopy, showcasing the great relevance of tuning the catalyst periphery to achieve efficient catalysis of solar fuel formation.

Catalytic Appel Reaction Accessing the Mesoporous Substructure of a Robust and Heterogeneous Polyphosphamide

AbstractPolyphosphamides are normally good flame retardants. Herein a mesoporous polyphosphamide (p‐PPA) with an accessible average pore diameter of <10 nm and a surface area of 1.773 m2/g has been synthesized via condensation of 1,3‐diamino benzene (DAB) and phenyl phosphinic dichloride (PPDC). 31P, 13C CP‐MAS solid‐state NMR, Raman, and X‐ray photoelectron spectroscopic (XPS) characterizations confirm the presence of ‐{PV(O)‐NH}‐ in the repeating unit of the p‐PPA that is further used as a catalytic mediator to perform the Appel reaction i. e., conversion of alcohols to halides with a broad substrate scope and high TON (561). The heterogeneity of p‐PPA allows easy recovery of organic halides and recycling of the catalyst many times. Mesoporous p‐PPA has further given a scope to perform shape‐selective conversion of primary alcohols with linear alkyl chain (1‐dodecanol) while a low conversion for the bulky secondary (cyclo‐hexanol) and tertiary alcohol (tert‐butanol) is observed. Perhaps, the phosphamide units present inside the porous channel are non‐preferable sites for bulkier alcohols, as evident from the competitive experiments. A comparatively less catalytic conversion obtained with an analogous non‐porous n‐PPA, made of tris(2‐aminoethyl)amine (TREN) linker, highlights the role of porosity in p‐PPA to enhance the accessibility of numerous ‐{PV(O)‐NH}‐ reactive units to increase the TON.

Copper and ZnO Dual-Catalyzed Photo-Assisted Depolymerization of Poly(Methyl Methacrylate) without Deoxygenation

Despite significant advancements in thermal and photothermal depolymerizations, the success of these techniques relies on tedious deoxygenation procedures. Herein, we report the development of the depolymerization technique efficient without prior deoxygenation, which was enabled by copper/ligand complexes and the inclusion (0.25 wt% relative to solvent) of zinc oxide (ZnO) nanocrystals activated by UV light. This approach was tested for poly(methyl methacrylate) (PMMA) prepared by atom transfer radical polymerization (ATRP); the effects of solvent polarity and the activity of ligands were investigated. Unexpectedly, a low-activity Cu-complex with 2,2‘-bipyridine ligand, in combination with a low-polarity solvent, 1,2,4-trichlorobenzene, enabled relatively high depolymerization yields in less than 1 h at 150 °C. Higher activity ATRP complexes with tris(2-pyridylmethyl)amine (TPMA) and N,N,N‘,N‘‘,N‘‘-pentamethyldiethylenetriamine (PMDETA) ligands, were less efficient, which was associated with their thermal decomposition and/or the excessive formation of radicals and premature termination of the chain ends. The presented facile approach was designed to be used even in partially aerated reactors, opening new avenues for efficient depolymerization.

Efficient Removal of Mercury from Wastewater Solutions by a Nitrogen-Doped Hyper-Crosslinked Polyamine.

Mercury, a highly toxic metal and pollutant, poses a significant risk to human health and the environment. This study describes the synthesis of a new nitrogen-doped heteroaromatic hyper-crosslinked polyamine (HCPA) via the polycondensation of 2,6-diaminopyrazine and tris(4-formylphenyl)amine for the efficient removal of mercury ions from aqueous solutions. The HCPA polymer was characterized by solid-state 13C-NMR and FT-IR spectroscopy. A powder X-ray diffraction and thermogravimetric analysis showed that the polymer was semicrystalline in nature and stable up to 500 °C. Adsorption isotherms indicated that mercury adsorption occurred via mono- and multilayer adsorption by HCPA, as depicted by the Langmuir, Freundlich, and Redlich-Peterson isotherm models, with a maximum adsorption capacity of qm = 333.3 mg/g. Adsorption kinetic models suggested that the adsorption process was fast and effective, reaching equilibrium within 20 min. Thermodynamics of the adsorption process revealed that it was endothermic and spontaneous in nature due to the positive ΔH0 of 48 kJ/mol and negative ΔG0 values of -4.5 kJ/mol at 293 K. Wastewater treatment revealed 98% removal of mercury indicating the selective nature of HCPA. Finally, HCPA exhibited excellent performance and regeneration up to three cycles, demonstrating its great potential as an adsorbent for environmental remediation applications.

Role of the side chain configuration on the effective recovery of phenolic compounds using polymer inclusion membranes based on tertiary amine

Polymer inclusion membranes (PIMs) exhibit great potential in the separation and recovery of valuable materials from wastewater and secondary resources. In this work, the effect of alkyl chain configuration of the functional carriers on the physicochemical properties and permeability of PIMs was investigated. Three tertiary amine isomers with different alkyl chain configurations were selected as carriers: trioctylamine, triisooctylamine, and tris(2-ethylhexyl)amine. Operating conditions like carrier contents, feed solution pH, phenol concentration, and stripping solution properties were also investigated. The results obtained in this study indicate that tertiary amines with less branched alkyl chains perform better phenol transport efficiency. Furthermore, the transport efficiency decreased rapidly with increasing steric hindrance of the carriers. Trioctylamine-based PIM displayed optimal extraction efficiency of 92.8 % and stripping efficiency of 90.8 % due to its lower steric hindrance, higher hydrophilicity, and larger crystallinity. Phenol extraction and stripping efficiencies remained above 85.7 % and 80.8 % after 8 cycles, demonstrating excellent stability.

Glycerol as Reaction Medium for Sonogashira Couplings: A Green Approach for the Synthesis of New Triarylamine-Based Materials with Potential Application in Optoelectronics.

This study focuses on the design, eco-friendly synthesis, and characterization of several novel three-legged triphenylamine derivatives. By performing Sonogashira couplings of functionalized aryl iodides with tris(4-ethynylphenyl)amine in glycerol, a readily available bio-derived solvent, we achieved the synthesis of target products in short times and high yields, up to 94 %, with consistently lower E-factors and reduced costs compared to standard conditions using toluene as the reaction medium. The target molecules possess a D-(π-A)₃ or D-(π-D)₃ structure, where an electron-donating core connects to three electron-donating (D) or electron-accepting (A) peripheral aromatic subunits through an acetylene spacer. Their main optical and electronic properties have been determined experimentally and by DFT simulations and suggest a possible implementation in energy conversion technologies such as luminescent solar concentrators (LSCs) and perovskite solar cells (PSCs).

GFP Chromophore Integrated Conjugated Microporous Polymers toward Bioinspired Photocatalytic CO2 Reduction to CO.

The development of highly active, durable, and low-cost metal-free catalysts for the photocatalytic CO2 reduction reaction (CO2RR) is an efficient and environmentally friendly solution to address significant problems like global warming and high energy demand. In the present study, we have demonstrated the design and synthesis of a donor-acceptor based conjugated microporous polymer (CMP), TPA-GFP, by integrating an electron donor, tris(4-ethynylphenyl)amine (TPA), with a green fluorescent protein chromophore analogue (Z)-4-(2-hydroxy-3,5-diiodobenzylidene)-1-(4-iodophenyl)-2-methyl-1H-imidazol-5(4H)-one (o-HBDI-I3) (GFP). In comparison to nondonor 1,3,5-triethynylbenzene (TEB) based TEB-GFP CMP, photocatalytic CO2 reduction using donor-acceptor based TPA-GFP CMP displays a 3-fold increment of CO production yield with a maximum CO yield of 1666 μmol g-1 at 12 h. Further, the CO selectivity increases significantly from a mere 54% in TEB-GFP to an impressive 95% in TPA-GFP. The impressive CO2 reduction efficiency and selectivity for TPA-GFP can be attributed to the efficient light-harvesting capability and facile charge separation and migration through donor-acceptor building units of the CMP. The mechanistic aspect of the photocatalytic CO2 reduction process is explored using in situ DRIFTS and DFT calculation, and a plausible photocatalytic mechanism is proposed.

A double responsive ratiometric and fluorimetric chemosensor based on dual-emitting thiophene-isoxazole derivatives and position effect of hydroxy group for monitoring gallium and copper ions using a smartphone

A series of simple Schiff bases, 2n-DHTC ((E)-N’-(2,n-dihydroxybenzylidene)-5-(thiophen-2-yl)isoxazole-3-carbohydrazide (n = 3,4,5,6)), with ICT characteristic were strategically constructed by rationally introducing 2,n-dihydroxybenzaldehyde (n = 3,4,5,6) into 5-(thiophen-2-yl)isoxazole-3-carbohydrazide and altering the position of another hydroxyl group. It was found that the position of the hydroxyl group on the dihydroxybenzaldehyde influence whether the sensor exhibited a colorimetric response, prompting further investigation into this phenomenon by DFT calculation. 25-DHTC, as a dual-emission fluorescent platform, demonstrated distinctive properties compared to other sensors, exhibiting ratiometric recognition towards Ga3+ ions and reversible fluorimetric quenching of Cu2+ ions in DMSO/H2O tris buffer. Meanwhile, limits of detection of 25-DHTC for Ga3+ and Cu2+ ions were as low as 15.0 nM and 2.4 nM, respectively. In addition, the 1:3 chelation stoichiometry between 25-DHTC and Ga3+/Cu2+ ions was confirmed, utilizing Job’s Plot analysis and mass spectrometric titration. The 25-DHTC sensor was employed to identify target ions in real water samples, while separate portable paper sensors were developed successfully for detecting Ga3+ ions. Subsequent visualization and assessment of real samples were performed through RGB analysis.

Synthesis and EPR Studies of Zinc and Copper TPMA Metal Complexes Containing TEMPO Functionalities

A new family of stable radical‐containing polytopic ligands based on tris(2‐pyridylmethyl)amines TPMA architecture and their corresponding metal complexes have been synthesized. These molecular systems offered the possibility to investigate how various spin carriers, such as the metal ion and the organic radical, influence their EPR properties mainly through the empirical ratio of peak heights d1/d. Moreover, it has been possible to analyze how different conformations of TEMPO radical units in the molecular skeleton affect the metallic system.

Enzymatic Digestion of the Intervertebral Disc Alters Intradiscal Injection and Leakage Mechanics.

Intradiscal injection is required to deliver therapeutic agents to the intervertebral disc (IVD) nucleus pulposus (NP). However, injectate leakage following needle retraction may result in decreased treatment efficacy and adverse side effects. While enzymatic digestion is a common research approach for simulating degeneration in healthy animal IVDs, contributions to the leakage phenomenon are unknown. In this study, bovine caudal discs were treated with injection into the NP of either a tris buffer control, collagenase (to primarily target collagen), or trypsin (to primarily target proteoglycans), then injected with fluorescent saline using a through-puncture defect protocol. Pressure-volume records during injection were used to determine volume and pressure at leakage. Discs were then frozen, transected, and photographed to visualize injectate dispersion. Collagenase treatment resulted in a large increase in injectate dispersion, along with a decrease in injection pressure relative to control. Trypsin treatment resulted in a moderate increase in dispersion, with no associated effect on pressure. This study concludes that care should be taken when employing enzymatic digestion to simulate IVD degeneration, as NP tissue disruption may affect both retention and dispersion of subsequent therapeutic injections.

Standardized Sperm Cryofreezing Technique for Caspian Sea Sturgeons (Huso huso, Acipenser persicus, Acipenser stellatus, Acipenser nudiventris)

Sturgeons, considered `living fossils,` face extinction due to various factors, according to the International Union for Conservation of Nature's Red List. The present study describes a uniform sperm cryopreservation method for the endangered Caspian Sea sturgeon species, which are beluga (Huso huso), Persian (Acipenser persicus), stellate (Acipenser stellatus), and ship (Acipenser nudiventris) sturgeons for both artificial reproduction and ex-situ conservation attempts. For this aim, sperm samples were diluted 1:1 in extender composed of 118 mM Tris buffer (pH=8) and 23.4 mM sucrose-based extender containing 15% DMSO and equilibrated for one hour at 4°C. Then, sperm samples were placed into 0.50-ml straws and multi-stage cooling was applied to freeze with the help of a programmable freezer with an accuracy of ±0.1C/min, and finally stored in liquid nitrogen (-196C) tank. Thawing was performed at 40°C water baths for 25 s. The results indicated that storage for two years resulted in a 24.7% fertilization rate for the stellate sturgeon, while the Persian sturgeon had a remarkable rate of 58.2% after five years storage.