Volatile Organic Amines Research Articles

Sulfato‐β‐cyclodextrin induced multivalent supramolecular directional aggregation of cyanovinylene derivatives for achieving reversible near‐infrared fluorescence

AbstractMolecular aggregation or supramolecular aggregation‐induced emission is one of the research hotspots in chemistry, biology, and materials. Herein, we report negatively charged sulfato‐β‐cyclodextrin (SCD) induced cyanovinylene derivatives (DPy‐6C) directional aggregation to form regular nanorods (DPy‐6C@SCD) through supramolecular multivalent interactions, not only achieves ultraviolet‐visible absorption redshifted from 453 to 521 nm but also displays near‐infrared (NIR) aggregation‐induced emission with a large spectral redshift of 135 nm. The DPy‐6C monomer presents random nanosheets with weak fluorescence but obtains regular aggregates after assembly with SCD through electrostatic interactions. In the presence of H+, the DPy‐6C@SCD can further aggregate into elliptical nanosheets without fluorescence changes due to the protonation of secondary amines. In contrast, the morphology of DPy‐6C@SCD becomes flexible and sticks together upon the addition of OH− with an emission blue shift of 72 nm and a 90‐fold intensity increase because of disrupting the stacking mode of aggregates, thereby achieving acid‐base regulated reversible fluorescence behaviors that cannot be realized by DPy‐6C monomer. The DPy‐6C@SCD can efficiently select the detection of volatile organic amines both in liquid and gas phases within 5 s at the nanomolar level. Taking advantage of RGB analysis and calculation formula application, the DPy‐6C@SCD has been successfully used to monitor various organic amines on a smartphone, accompanied by naked‐eye visible photoluminescence. Therefore, the present research provides an efficient directional aggregation method through supramolecular multivalent interactions, which not only realizes topological morphology transformation but also achieves reversible NIR luminescent molecular switch and high sensitivity organic amines fluorescent sensing devices.

N-aryl-4-amino-1,8-naphthalimide Tröger's bases-based internal charge transfer (ICT) fluorescence ‘turn-on’ chemosensors for volatile organic amines

The design of reliable sensor systems for quick sensing and monitoring the trace concentrations of volatile organic compounds (VOCs) has been a topical area of research in recent years due to their serious menace to living systems and environmental hazardousness. In this article, we report two unique ‘cleft-shaped’ N-aryl-4-amino-1,8-naphthalimide derived Tröger's bases (TBNap-Ph and TBNap-Es) as efficient, fast fluorescence sensors for discriminative sensing of volatile organic amines (VOAs). The fluorescence titration studies using TBNap-Ph and TBNap-Es demonstrated discriminative fluorescence sensing responses for VOAs with high selectivity for benzylamine detection. The initial emission intensity of TBNap-Ph and TBNap-Es was enhanced drastically upon the addition of benzylamine. However, similar titration studies using other VOAs such as n-propylamine, n-butylamine, diethylamine, isopropylamine, 3-dimethylamino-1-propylamine, triethylamine, and ethanolamine elicited poor to negligible changes in the fluorescence emission intensity. The selective ‘turn-on’ fluorescence sensing of benzylamine was also reflected by sharp color changes and these sensors can be used to detect benzylamine at the parts-per-millions (ppm) level of sensitivity. Furthermore, the experimentally observed discriminative fluorescence sensing property of TBNap-Ph and TBNap-Es towards VOAs was supported by computational calculations.

Recent advances in fluorescent and colorimetric sensing for volatile organic amines and biogenic amines in food

Volatile organic amines and biogenic amines produced by the amino acid degradation can undeniably affect the food quality and safety, and thus causes serious health problems. It is of great urgency to exploit reliable and sensitive detection methods for amines to ensure food safety and public health. The fluorescent and colorimetric sensors offer simple and robust means to monitor amines with high sensitivity and selectivity, quick response, facile operation and low cost. Herein, we briefly review the past five years’ progress in fluorescent and colorimetric sensing for monitoring organic and biogenic amines in food. The architectures of sensing materials ranging from small molecules to frameworks to polymers or self-assembly materials have been highlighted. Moreover, the main challenges and perspective of various sensing materials are presented to inspire further research and development. In the end, the development trend of new sensing materials and devices for real-time monitoring of food quality is also forecasted. This review is expected spur more research interest in design of novel amine sensing materials for future application transformation research.

Tunable Luminescence of Silver Nanoclusters Confined in SOD/FAU Zeolites and Selective Sensing for Organic Amine

A series of Ag-zeolite luminescent composites are prepared based on SOD and FAUY zeolites, and the effect of zeolite host particle size on their dynamic luminescent emission properties was discussed for the first time. The relationship between zeolite particle size and the nucleation of silver nanoclusters (AgNCs) is revealed. With the increase of zeolite particle size from nanometers to microns, the luminescent color of both Ag-SOD and Ag-Y composites shows significant blue shift. The observed tunable luminescence can be accounted for the slower nucleation rate of AgNCs in micron-scale zeolites with longer channels, resulting in smaller nuclearity of AgNCs within large-size zeolites, through the characterization of extended X-ray absorption fine structure, implying the important roles played by the zeolite themselves in determining the luminescence properties. Moreover, the composites prepared by us feature simple signal transduction, fast response (30 s), and excellent selectivity and sensitivity for discriminative luminescence detection of triethylamine and ethylamine, and they have good reversible luminescence response after sensing HAc gas, which might imply the potential applications in the volatile organic amine detection and information encryption field.

High-quality all-inorganic CsPbI2Br thin films derived from phase-pure intermediate for efficient wide-bandgap perovskite solar cells

Mixed-halide alloying inorganic perovskite CsPbI2Br with prominent thermal stability has been considered as a promising candidate for wide-bandgap solar cells. However, the thermally driving coordination configuration evolution and phase transition during the crystallization of the perovskite CsPbI2Br were still not understood in depth, which was not conducive to the controllable preparation of high-quality CsPbI2Br thin films and the enhancement of photovoltaic performance. In this study, the phase segregation and unfavorable phase transition during the crystallization of CsPbI2Br that lead to the low quality of the perovskite thin films were investigated systematically. Moreover, the existing issue was overcome through intermediate engineering by introducing volatile organic amine acetates. Specially, the introduction of 0.5 equiv. of formamidine acetate (FAAc) in the precursor of CsPbI2Br generated a phase-pure intermediate, which facilitated the crystallization of high-quality CsPbI2Br perovskite thin films, and thus improved the device performance. As a result, the champion device achieved a power conversion efficiency (PCE) of 16.36%.

Rationally Engineering a CuO/Pd@SiO2 Core-Shell Catalyst with Isolated Bifunctional Pd and Cu Active Sites for n-Butylamine Controllable Decomposition.

Volatile organic amines are a category of typical volatile organic compounds (VOCs) extensively presented in industrial exhausts causing serious harm to the atmospheric environment and human health. Monometallic Pd and Cu-based catalysts are commonly adopted for catalytic destruction of hazardous organic amines, but their applications are greatly limited by the inevitable production of toxic amide and NOx byproducts and inferior low-temperature activity. Here, a CuO/Pd@SiO2 core-shell-structured catalyst with diverse functionalized active sites was creatively developed, which realized the total decomposition of n-butylamine at 260 °C with a CO2 yield and N2 selectivity reaching up to 100% and 98.3%, respectively (obviously better than those of Pd@SiO2 and CuO/SiO2), owing to the synergy of isolated Pd and Cu sites in independent mineralization of n-butylamine and generation of N2, respectively. The formation of amide and short-chain aliphatic hydrocarbon intermediates via C-C bond cleavage tended to occur over Pd sites, while the C-N bond was prone to breakage over Cu sites, generating NH2· species and long free-N chain intermediates at low temperatures, avoiding the production of hazardous amide and NOx. The SiO2 channel collapse and H+ site production resulted in the formation of N2O via suppressing NH2· diffusion. This work provides critical guidance for a rational fabrication of catalysts with high activity and N2 selectivity for environmentally friendly destruction of nitrogen-containing VOCs.

Dithienylethenes functionalized by triphenylethene and difluoroboron β-diketonate fragments: Synthesis, optical switching behavior and fluorescent turn-on sensing for volatile organic amines

Two novel dithienylethenes were obtained by appending triphenylethene and BF2bdk moieties at the termini of dithienylethene unit (TDBB and TDTB), in which BF2bdk group not only functions as electron acceptor (A) but also responds to volatile organic amines. Only TDBB displayed excellent visible light-triggered photochromism and fluorescent switching behavior in toluene and in the PMMA film upon alternating irradiation with blue light (460–470 nm) and near-infrared light (760–770 nm). More importantly, they displayed a distinct fluorescent turn-on and colorimetric sensing performance for volatile n-propylamine in THF. Specially, the addition of excessive n-propylamine can effectively modulate their photochromic properties in THF. And their PMMA films showed the fluorescent turn-off and colorimetric sensory behavior towards n-propylamine vapor. Consequently, they would be utilized as novel dual sensory materials for volatile primary or secondary amine vapors in the environment and biological systems.

Pyrazine-based hollow spherical self-assemblies: A portable tool for detection of volatile organic amines

Development of easy and efficient sensing tool for instant detection of various organic amines in aqueous media has prime significance. In this context, hollow spherical H-aggregates of pyrazine derivative bearing terminal acetyl groups were demonstrated as a reaction-based vapor phase sensing tool for organic amines. The aggregates displayed ratiometric fluorescence behavior toward aliphatic amines with a detection limit at nanomolar concentrations with concomitant self-assembly modulation from spherical H-aggregates to rod-shaped J-aggregates. Surprisingly, in the presence of p-nitroaniline remarkable quenching response was observed among various aromatic amines, which is attributed to the inner filter effect and energy transfer. Furthermore, a portable efficient tool for sensing various organic amines was constructed using the aggregates, demonstrating the practical applicability of this approach. This work will provide straightforward way for designing multifunctional self-assemblies for efficient selective behavior toward various organic amines in the ground water bodies.

In vitro toxic synergistic effects of exogenous pollutants-trimethylamine and its metabolites on human respiratory tract cells

The wide presence of volatile organic amines in atmosphere has been clarified to relate to adverse effects on human respiratory health. However, toxic effects of them on human respiratory tract and their metabiotic mechanism of in vivo transformation have not been elucidated yet. Herein, cell viability and production of reactive oxygen species (ROSs) were first investigated during acute exposure of trimethylamine (TMA) to bronchial epithelial cells (16HBE), along with identification of toxic metabolites and metabolic mechanisms of TMA from headspace atmosphere and cell culture. Results showed that cell activity decreased and ROS production increased with raising exposure TMA concentration. Toxic effects may be induced not only by TMA itself, but also more likely by its cellular metabolites. Increased dimethylamine identified in headspace atmosphere and cell solution was the main metabolite of TMA, and methylamine was also confirmed to be a further metabolite. In addition, TMA can also be oxygenated to generate N,N-dimethylformamide and N,N′-Bis(2-hydroxyethyl)-1,2-ethanediaminium by N-formylation or hydroxylation, which was considered to be the participation of cytochrome P450 (CYP) enzymes. Overall, we can conclude that respiratory tract cells may produce more toxic metabolites during exposure of toxic organic amines, which together further induce cellular oxidative stress and necrosis. Hence, the environment and health impact of metabolites as well as original parent atmospheric organic amines should be paid more attention in further researches and disease risk assessments.

Tri(pyridinyl)pyridine Viologen-Based Kagome Dual Coordination Polymer with Selective Chromic Response to Soft X-ray and Volatile Organic Amines.

The development of new responsive smart materials has been highly desirable in the recent decade due to growing demand in our daily life, and extended viologen-based coordination polymers are regarded as proper and promising candidates for stimuli-responsive study. A tri(pyridinyl)pyridine viologen-based Kagome dual (kgd) topological coordination polymer, [Mn3Cl4(tpptb)2]·Cl2·(H2O)2, (tpptb = N,N',N″-tri(3-carboxybenzyl)-2,4,6-tri(pyridinium-4-yl)pyridine; 1) has been solvothermally synthesized, which can selectively respond to soft X-ray Al-Kα (λ = 8.357 Å) irradiation but not to UV light and hard X-rays of λ < 1.5418 Å at room temperature. Appealingly, 1 is very sensitive and convenient for the visual detection of various volatile amine vapors, especially ethylamine vapors at a low concentration of 100 ppm, and the vapochromic sample can be recovered after exposure in the air at room temperature. The sequence of amines in vapochromism could be rationalized by combined consideration of vapor pressure, the molecular size, and electron-donor ability of various amine molecules as well as the void spaces of 1. In addition, 1 exhibits an obvious hydrochromic transformation upon heating in the air and an anhydrous atmosphere. Combined XPS and EPR confirmed that these physical and chemical stimuli can cause electron transfer from electron-rich groups to quaternary nitrogen atoms of the ligand to generate charge-separated radicals, leading to soft X-ray-induced photochromic and selective vapochromic behavior of 1. Such behavior indicates that it will become a convenient, recyclable, and practical multifunctional material for chemical and environmental sensing. These results provide an effective avenue for the rational design and synthesis of multifunctional chromic materials for potential use in sensing devices.

A reaction-based sensing scheme for volatile organic amine reagents with the chromophoric-fluorogenic dual mode.

In this study, we present the classical Michael's addition reaction-based sensing scheme for volatile organic amine reagents such as ethylenediamine, N, N-dimethylethylenediamine and diethylenetriamine using a near-infrared fluorescent dye TCF1. Obvious spectral changes in the UV-vis absorption and fluorescence spectra of TCF1 were observed upon addition of these amine reagents with an effective catalyst DBU, resulting in significant and fast color changes detectable by the naked-eye. TCF1 showed an efficient response to these amine reagents with a low detection limit, especially for diethylenetriamine. NMR and MS spectral analysis proved that the mechanism of the detection was based on the classical Michael addition, which was also verified by the theoretical calculations. In addition, a portable test paper incorporated with TCF1 had also successfully realized the detection of a low concentration of these amine reagents.

Correction to Au-TiO2-Loaded Cubic g-C3N4 Nanohybrids for Photocatalytic and Volatile Organic Amine Sensing Applications.

Correction to Au-TiO2-Loaded Cubic g-C3N4 Nanohybrids for Photocatalytic and Volatile Organic Amine Sensing Applications.

Properties of aqueous amine based protic ionic liquids and its application for CO2 quick capture

Three kind of pure amines which have high solubility of CO2 were used as absorbents hardly to be recovered. A series of aqueous ethoxyacetate anion-based protic ionic liquids (PILs) with three different amine cations were designed, and physical properties including measured density and viscosity were measured. Solubility of CO2 in the three PILs solution, 90% [DMAPAH][EOAc], 90% [DEEDAH][EOAc] and 90% [DMEDAH][EOAc], were systematic determined at the range of 303.2–333.2 K under the pressure of 1.2 bar. Impressively, the solubility of CO2 in 90% [DMAPAH][EOAc] reached up to 2.44 mol/kg, which showed more advantage than some traditional or functional ILs. The 90% [DMAPAH][EOAc] could be reused four times. Besides, the proposed mechanism was advised. Considering the advantages of high absorption capacity, low cost, easy regeneration including fast absorption rate, we believe the three PILs solution can be recommended as alternatives to some volatile organic amines to be applied in CO2 capture.

Design of large π-conjugated α-cyanostilbene derivatives as colorimetric sensors for volatile acids and organic amine gases

Two large π-conjugated α-cyanostilbene derivative isomers (M-PDC and P-PDC) could sensitively and continuously detect volatile acids and organic amine gases.

Multifunctional supramolecular self-assembly system for colorimetric detection of Hg2+, Fe3+, Cu2+ and continuous sensing of volatile acids and organic amine gases.

A novel multifunctional gelator (1) based on an azobenzene derivative was designed and characterized. This compound could gelate some solvents including hexane, petroleum ether, DMSO, acetonitrile and ethanol through a heating-cooling procedure. The self-assembly process in different solvents was studied by means of UV-vis absorption and Fourier transform infrared (FTIR) spectra, field emission scanning electron microscopy (FESEM), rheological measurements, X-ray powder diffraction and water contact angle experiments. Interestingly, compound 1 had a high-contrast colorimetric detection ability towards Hg2+, Cu2+, Fe3+ and volatile acids and further organic amine gases in solution through its color change. At the same time, organogel 1 in acetonitrile also exhibited detection performance through a color or gel state change. In the response process, the self-assembly structures were changed from a nanofiber into a microsphere under induction by analytes. More significantly, film 1 could continuously detect volatile acids and organic amine gases. The number of cycles of film 1 for the detection of volatile acids and organic amine gases was at least seven times. The limit of detection (LOD) of film 1 towards TFA was calculated to be 0.0848 ppb. The sensing mechanisms were studied using 1HNMR, FESEM, UV-vis absorption spectra and HRMS. The intramolecular cyclization occurred on molecule 1 and a H2S molecule was lost during the detection process of Hg2+. It was proposed that the -N[double bond, length as m-dash]N- bonding could be coordinated by Fe3+ and Cu2+ and this further induced the absorption spectra and color change. For a volatile acid, it was possible that the volatile acid was combined with the N,N-dimethyl amine group of molecule 1. This research opens up a novel pathway to the fabrication of supramolecular self-assembly gels to detect polymetallic ions and trace volatile acids in the environment.

Continuous multi-channel sensing of volatile acid and organic amine gases using a fluorescent self-assembly system

A new gelator was designed and synthesized which could detect volatile acid and organic amine in multi-channel.

Amperometric responses of volatile organic amines in air by using 5-sulpho-salicylic acid modified narrow-gap electrochemical cell

In this article, different kinds of volatile basic organic compounds (n-butylamine, morpholine, ethanolamine, triethylamine, pyridine) were investigated by using amperometric techniques with a narrow-gap cell. In case of bare electrode continuous current increase could be observed from beginning of exposure to the saturated vapour of all chemicals during the repetitive amperometric recording at 2 V working potential. The cell did not respond to triethylamine. When the cell was modified with 5-sulpho-salicylic acid the cell responded quickly and it showed high sensitivity to the investigated compounds. Repeatability was investigated which was satisfactory for all compounds except for ethanolamine and morpholine.

A gas–liquid interface synthesis in polyoxometalate chemistry: potential bag filter for volatile organic amines

Diffusion of piperidine and pyridine into an acidified aqueous solution of $$\hbox {Na}_{2}\hbox {MoO}_{4}$$ , yield compounds $$[(\hbox {pipH})_{4}][\hbox {Mo}_{8}\hbox {O}_{26}]\cdot 4\hbox {H}_{2}\hbox {O}$$ $$(\hbox {pip} = \hbox {piperidine} = \hbox {C}_{5}\hbox {H}_{11}\hbox {N})$$ (1) and $$[(\hbox {pyH})_{4}][\hbox {Mo}_{8}\hbox {O}_{26}]$$ $$(\hbox {py} = \hbox {pyridine} = \hbox {C}_{5}\hbox {H}_{5}\hbox {N})$$ (2), respectively. Compound 1 possesses supramolecular 3-D network and the relevant connectivity pattern generates channels of approximate dimensions of $$10.76 \times 11.57 \acute{{\AA }}^{2}$$ , in which the piperidinium cations are located as guests. Multidimensional supramolecular frameworks (3-D in compound 1 and 2-D layer type of network in compound 2) have been made possible, as the organic cations and polyoxometalate (POM) anions are glued together by significant hydrogen bonding interactions. The synthesis of compounds 1 and 2 provides a unique ‘gas–liquid’ synthetic route in POM chemistry that result in organic–inorganic hybrid materials with structural diversities. This synthetic approach, first time in POM chemistry, can be described as a potential bag filter for volatile organic amines. Synopsis: Diffusion of piperidine and pyridine vapours into acidified aqueous molybdate solution leads to the formation of ion pair compounds having supramolecular framework structures. These organic amines are trapped as guest or as part of the framework making the present system a potential bag filter for the volatile organic amines.

A supramolecular self-assembly material based on a quinoline derivative and its sensitive response toward volatile acid and organic amine vapors

A new gelator 1, containing a quinoline group, was designed, synthesized, and fully characterized.

Hybrid N-Butylamine-Based Ligands for Switching the Colloidal Solubility and Regimentation of Inorganic-Capped Nanocrystals.

We report on a simple and effective technique of tuning the colloidal solubility of inorganic-capped CdSe and CdSe/CdS core/shell nanocrystals (NCs) from highly polar to nonpolar media using n-butylamine molecules. The introduction of the short and volatile organic amine mainly results in a modification of the labile diffusion region of the inorganic-capped NCs, enabling a significant extension of their dispersibility and improving the ability to form long-range assemblies. Moreover, the hybrid n-butylamine/inorganic capping can be thermally decomposed under mild heat treatment, making this approach of surface functionalization well-compatible with a low-temperature, solution-processed device fabrication. Particularly, a field-effect transistor-based on n-butylamine/Ga-I-complex-capped 4.5 nm CdSe NC solids shows excellent transport characteristics with electron mobilities up to 2 cm2/(V·s) and a high current modulation value (>104) at a low operation voltage (<2 V).