THE SYNTHESIS OF THE NOVEL (N''1Z, N''6Z)- N''1, N''6-BIS(2,4-DIHYDROXYBENZYLIDENE) ADIPOHYDRAZIDE (ADHB

Abstract

The Synthesis of the novel (N”Z, N’6Z)- N’1, N,6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection of Picric acid and ammonia. The present invention introduces a novel N’*Z, N’6Z)- N’1, N’6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe .for selective detection of Picric acid and ammonia, fbiTiicd through the condensation reaction between dihydroxy benzaldehyde and dihydrazide. This AIE active fluorescent probe exhibits blue fluorescence in the solution state. It possesses remarkable chemical and optical stability and demonstrates a specific fluorescence quenching and increase in response to picric acid and ammonia. The detection limit reaches the nanomolar level and is comparable with the other reported values, unaffected by other ions, and provides a rapid response. The fluorescent probe has better selectivity to Picric acid and ammonia, and the detection limit is 22.12nM and 2.017nm.

Specification

TITLE OF INVENTION
The Synthesis of the novel (N' *Z, N '.6Z)- N ' 1, N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection of Picric
acid and ammonia.. [0100] We claim
1. J. The novel (N ' ' Z, N '6Z-)- N' 1, N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base is synthesized from a dihydroxybenzaldehyde and a dihydrazide through a simple condensation reaction which is cost-effective. 2. The novel (N^Z, N '6Z)- N " , N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base, as claimed in claim 1, where the molecule exhibited a C=N moiety. 3. The novel (N" Z, N'6Z)- N' 1, N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base, as claimed in claim 1-2, Where in the molecule exhibited solvatochromism and aggregation-induced emission property.


FIELD OF INVENTION
10001] This invention is about creating a novel NJ1Z, N'6Z)- N" , N,6-bis(2,4-
dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection of Picric acidand ammonia
BACKGROUND OF INVENTION
[0002] Given the potential of Schiff bases with A1E behavior for sensing applications, they are particularly useful in detecting hazardous substances such as nitroaromatic compounds.
Picric acid is a polynitroaromatic compound (PNAC) that is highly explosive. Il is also identified as an environmental polliiuini that is harmful and can cause chronic disorders such as cancer and cyanosis. Hence, it is very important to develop a novel probe that is highly sensitive and selective for monitoring picric acid at various, is one o f the powerful explosives in nilroaromalic explosives (NAEs) and is widely used in industry and civil use, such as chemical industries o f fireworks, leather, dyes and the like. The method causes huge pollution to soil and waler environment in the processes of production, use and transportation, and is a potential soil and water system pollutant
[0003] The traditional picric acid detection methods such as chromatography, ion transfer method, spectrometry and the like have certain defects, such as expensive instruments and equipment, complex operation process, time consumption, inapplicability to field detection and the like, although the sensili vily o f the methods is higher. Since fluorescent probes have certain advantages in terms o f rapidness, accuracy, convenience, economy and the like, designing and using fluorescent probes to detect picric acid has attracted a great deal of attention from analysts. However, some of the picric acid fluorescent probes disclosed in the prior art do'not have a good compromise between water solubility, selectivity and visibility. Therefore, the


method which is simple to operate, has high selectivity and high sensitivity and can detect TNP in the waler body environment is developed, and the method has very important significance for reducing environmental pollution and ensuring human health and safety. [0004) Ammonia is a kind of colourless hypertoxic gas, there is larger'toxicity to human body, and acute ammonia poisoning, has that cough is more than, feels suffocated Etc. symptoms, ammonia slow poisoning can cause the diseases of respiratory system such as chronic bronchitis, pulmonary emphysema, ammonia that can make one at low concentrations Body health is by prodigious harm, thus ammonia detection is much led in industry, medicine, refrigeration, agricultural,'air detection, national defence etc. Domain has very important significance.Ammonia gas sensor is the strong sensitivity having to ammonia using certain substance, small ammonia The variation of amount can cause the prodigious variation of certain physically or chemically performances o f the substance, • such as resistance, temperature, burning point, optics Performance et
|0005| The current work deals with the development o f a novel hydrazone-based ligand by condensation reaction in methanol medium, cost effective, avoids the formation o f side products and reacts rapidly. Addition of picric acid and ammonia resulted in the turn o ff and turn on fluorescence respectively o f the ligand.
[0006] The present work highfighrs the design and development of highly sensitive schiff base based optical and fluorescent chemosensors for the detection of picric acid and ammonia in environment. Further this novel sensor shows fast responsiveness, easy reversibility, reproducibility and very lower level o f picric acid and ammonia detection.
[0007] CN202010085847.XA describes the synthesis of a fluorescence schiff base compound formed by the reaction of 8-formyl-7-hydroxycoumarin and 3,3 '-diamino-4,4' -dihydroxy diphenyl sulfone for the selective sensing o f 2,4,6 trinitrophenol. CN110055058A describes . the synthesis of Schiff base in methylene chloride by 2- (2- hydroxy phenyl) benzothiazole and organic base dissolution adding 4- bromobulanoylchloride reaction as and prepare intermediate and tertiary amine salt-forming reaction, purification obtains having water-soluble probe compound for sensing picric acid in solution. CN10824627 IB describes a preparation method o f molecularly imprinted polymer microspheres for detecting 2, 4, 6-trinitrophenol.
CNI05866175B describes the invention discloses the printable flexible ammonia gas sensors o f one kind, including flexible base board, ammonia sensitive layer and interdigited electrode.



BRIEF DESCRIPTION OF THE INVENTION
10008] In accordance with one embodiment o f the present invention, the synthesis of a novel (N" Z, N '6Z )-N '1,N ,6-bis(2,4-dihydroxybenzylidene) adipohvdrazide (ADHB). schiff base fluorescent probe is provided. The synthesis involves the reaction of a Dihydroxy benzaldehyde with a dihydrazide, which are refluxed in an methanoi medium for 4 hours. The resulting product is poured into a petri dish, and the solvent is allowed to evaporate. A brown colored product is obtained, which exhibits fluorescence
100091 In accordance with another embodiment of the disclosure ,the picric acid and ammonia selectivity using the novel (N S,Z, N '6Z)~ N " , N '6-bis(2,4-dihydroxy benzylidene) adipohydrazide (ADHB) schiff base fluorescent probe is disclosed. The UV and emission spectra o f novel (N ' 'Z, N,6Z)- N ' 1, N '6-bis(2,4-dihydroxybenzyIidene) adipohydrazide (ADHB) schiff base fluorescent probe in the presence of nitro aromatic and amine compounds were recorded. The stoichiometry of the Schiff base and ammonia was determined
using a Job's plot.
[00.10| The present invention is described in detail below, including a comprehensive explanation and detailed illustrations that provide further clarification. These figures represent a typical embodiment of the current invention, but they can be studied further to explore potential extensions and applications. The appended description and illustrations aim to provide a complete understanding of the invention's features and functions, including any - variations or modifications that may be possible.
|00111 We claim,
1. The novel (N'] Z, N '6Z)- N " , N,6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base is synthesized from a dihydroxybenzaldehyde and a dihydrazide through ■ a simple condensation reaction which is cost-effective. 2. The novel (N' ' Z, N'6Z)- N ' 1, N '6-bis(2,4-di hydroxy benzylidene) adipo hydrazide (ADHB) schiff base, as claimed in claim 1, where the molecule exhibited a C=N moiety. 3. The novel (N, l Z, N'6Z)- N " , N '6-bis(2,4-di hydroxybenzylidene) adipo hydrazide (ADHB) schiff base, as claimed in claim 1-2, Where in the molecule exhibited solvatochromism and aggregation-induced emission properly.



4. The novel (N' ' Z, Nn 6 Z)- N '1, Nj6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff basewas utilized for the selective detection of Picric acid and ammonia via fluorescence sensing studies. .
5. The novel (N" Z, N'6Z)- N" , N ,6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) s ch iff base, as claimed in claim 4 wherein the lim it of detection for picric acid was obtained at 22.21 nM which is useful for picric acid sensing applications.
6. The novel (N, l Z, N 'fiZ)- N.' 1, N'6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base, as claimed in claim 4 wherein the lim it o f detection for ammonia was obtained at 2.017nm which is useful for ammonia sensing applications. 7. The novel (NH Z, N '6Z)- N' 1, N '6-bis(2,4-dihydroxybenzyIidene) adipohydrazide (ADHB) schiff base, as claimed in claim 4 and 6 wherein the binding stoichiometry o f the fluorescent probe and ammonia was found to be 1:1.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will be elucidated with additional particularity and detail with the following
figures in which:
|001 21 Figure 1 is a flow chart representing the steps involved in the synthesis (N''Z, MAZI­N ' 1, N ,6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base, fluorescent probe in accordance with an embodiment of the invention.
[0013] Figure 2 is a NMR spectrum o f the (N ^Z, N '6Z)- N ' 1, N '6-bis(2,4- dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection of Picric acid and ammonia in accordance with an embodiment o f the invention. 10014] Figure 3 is a graphical representation of FTIR analysis of the (N5lZ, N '6Z)- N ' ', N '6- bis(2,4-di hydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection o f Picric acid and ammonia in accordance with an embodiment o f the
invention

[0015] Figure 4 illustrate the UV-Vis spectra and fluorescence spectra of the (N ' 'Z, N '6Z)- N ' 1, N '67bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection o f Picric acid in accordance with an embodiment of the invention [0016] Figure 5a and 5b illustrate the linear plot and selectivity spectra of the (N ' 'Z, N '6Z)- N '1, N '6-bis(2,4-dihydroxybenzylidene) adipuhydrazide (ADHB) schiff base fluorescent probe for the selective detection of picric acid with other nitro aromatic compounds in accordance with an embodiment of the invention.
10017] Figure 6 illustrate the UV-Vis spectra and fluorescence spectra of the (N ' 'Z, N '6Z)- N 11, N 'fi-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for selective detection o f ammonia in accordance with an embodiment o f the invention [0018] Figure 7 illustrates the jobs plot o f (N ' 'Z, N '6Z)- N 1', N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe , for the selective detection o f ammonium ion in accordance with an embodiment o f the invention. [0019] Figure 8 illustrates the selectivity study o f the (N ' 'Z, N '6Z)- N ' 1, N '6-bis(2,4- dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for the selective detection of ammonium ion in accordance with an embodiment o f the invention |0020] Figure 9 illustrates the fluorescence intensities of the competitive binding studies of the N '1- (( E)- 3,5- dibromo- 2- hydroxybenzylidene) - N '6- ((Z)- 3,5- dibromo- 2- hydroxybenzylidene)adipohydrazide schiff'base fluorescent probe for the selective detection of cobalt ion with different cations in accordance with an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
|0021] In order to promote a better understanding of the features of the present disclosure, references w ill now be made to the embodiment illustrated in the figures, and specific language w ill be used to describe them. It w ill nonetheless be comprehended that no limitation o f the scope o f the disclosure is therefore purposed. Such further applications of the features o f the disclosure as would naturally occur to those skilled in the art are to be interpreted as being within the scope of the present disclosure
[0022] Appearances of the phrase " in an embodiment" , " in another embodiment," and similar language throughout this specification may, but not necessarily do, all refer to the same


embodiment. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system and methods provided herein are only illustrative and not intended to be
limiting.
10023] In the following specification and the claims, reference w ill be made to a number of terms, which shall be defined to have the following meanings. The singular forms " a" , " an" , and " the" include plural references unless the context clearly dictates otherwise.
[0024] Embodiments o f the present invention provide details of cobalt ion fluorescent probe . .[00251 Figure I is a How chart representing the steps involved in tho synthesis (N11/ , N '67,)- N '1, N '6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base. [0026] Figure 2 is a NMR spectrum o f the (N J1Z, N '6Z)- N '1, N '6-bis(2,4- dihydroxybenzylidene) adipohydrazide (ADHB) schiffbase fluorescent probe for the selective detection of picric acid and ammonia .
[00271 Figure 3 represents Fourier transform infrared spectroscopy o f the (N51Z, N i6Z)- N ' 1, N ,6-bis(2,4-dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for the selective detection of Picric acid and ammonia exhibited the characteristic bands at 3200- 3000, 1200-1500 , 3400-3200, 1500-2000 cm'1 corresponding to v(-NH), v(HC=N), v(-OH),
v(C=O) vibrations
[0028] Figure 4a represents the UV -Vis spectra o f the (N ' 'Z, N ,6Z)- N ' 1, N '6-bis(2,4- dihydroxybenzylidene) adipohydrazide (ADHB) schiff base fluorescent probe for the selective detection o f Picric acid with incremental addition of Picric acid solution of (20 pM). Figure 4b represents the fluorescence spectra of the fluorescent probe with incremental additions of the picric acid solution (20 uM), showing a quenching in fluorescence intensity with each addition. The initial intensity of the fluorescent molecule was measured at 240 (a.u), and with the incremental addition of the picric acid solution (IO"6 M), the intensity was recorded at 60 (a.u), and it nearly reached the isosbestic point.

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