Synthesis of Polyfunctional Organic Systems Containing 1- Acyl / Aroyl-anilido-butadienes and their uses as Photochemical Probes and Chelating Agents for Removal of Bismuth (III) from Industrial Wastewater

Polyfunctionalally substituted oxo anilides e.g. azoloazines have received considerable interest in recent years (Hussein et al., 2009). Such class of compounds has diverse physiological activities e.g. acting as central nervous systems depressants and calcium sensitizing agents and possess hypnotic, diuretic, antihistaminic, anti inflammatory, antimicrobial and hypoglycecemic activities (Fathalla et al., 2001).The synthesis and spectroscopic characterization of bdiketones as potential ligands have been reported by Funk et al., 1993; Zheng and Swager, 1994. In this class of compounds, complex formation is conceived by replacement of the enolic proton by chelation with metal ions in a bidentate fashion (Sievers et al., 1993; Knoevenagel and Arnot, 1904).


Introduction
Polyfunctionalally substituted oxo anilides e.g. azoloazines have received considerable interest in recent years (Hussein et al., 2009). Such class of compounds has diverse physiological activities e.g. acting as central nervous systems depressants and calcium sensitizing agents and possess hypnotic, diuretic, antihistaminic, anti inflammatory, antimicrobial and hypoglycecemic activities (Fathalla et al., 2001).The synthesis and spectroscopic characterization of bdiketones as potential ligands have been reported by Funk et al., 1993;Zheng and Swager, 1994. In this class of compounds, complex formation is conceived by replacement of the enolic proton by chelation with metal ions in a bidentate fashion (Sievers et al., 1993;Knoevenagel and Arnot, 1904).
A series of benzoyl -acetanildes and their physico organic properties have been reported by (Abdel-Rahman, 1988; Abdel-Rahman et al., 1991). The starting material prepared has been used for building a series of novel bio-active pyrazoline derivatives. The thermodynamic characteristics and spectroscopic characterization of a series of hydrazono -1,3-bi carbonyl derivatives and their lanthanide complexes have been investigated (Abdel-Rahman et al., 1991; Ramadan et al., 1993).The dimerized species of 2-diazo-3methyl-1-phenyl-5-pyrazolone have produced 4-(5-hydoxy-4pyrazolxlimino-2-pyrazolin-5-one. Recent literature survey has indicated that, no work on the Knoevenagel condensate bketoanilide and its metal chelates. Therefore, in continuation to our previous work (Bashammakh et Zaki et al.1995), the present study is focused on the synthesis and characterization of a series of some bdiketone derivatives bearing anilido moieties and their unsaturated bdiketone derivatives. In view of their properties, some of the compounds were tested as antimicrobial and photochemical agents. Moreover, one of the prepared compounds for the pre-concentration/ separation of bismuth (III) from aqueous as a highly toxic metal ions the industrial waste water. The cyclic voltammetry of two selected compounds were also investigated.

Experimental Apparatus & measurements
A Perkin Elmer (Lambda EZ-210) double beam spectrophotometer (190-1100 nm) with 1cm (path width) was used for recording the electronic spectra of the prepared solutions. A Perkin-Elmer (Analyst TM 800, USA) atomic absorption spectrometer (AAS) was used for measuring the concentration of bismuth (III) ions before and after extraction at the optimum operational parameters of the instrument. A Perkins Elmer model RXI-FT-IR system 55529 was used for recording the IR spectra of the prepared compounds. A Brucker advance DPX 400 MHz model using TMS as an internal standard was used for recording the 1 HNMR spectra of the compounds on deuterated DMSO. A GC-MS-QP 1000-Ex model was used for recording the mass spectra of the compounds. A Metrohm 797 VA trace analyzer and 797 VA stand were used for recording the cyclic voltammetric (CV) experiments. In the CV experiments, a three-compartment (Metrohm) voltammetric cell (10 mL) incorporating Pt wire as working, doublejunction Ag/AgCl, (3M KCl), as reference and Pt wire (BAS model MW-1032) as counter electrodes, respectively. The surface area of the counter electrode was 100 times larger than the area of the working electrode. Digital pH-meter (model MP220, Metter Toledo) was used for pH measurements. Melting points were determined with an electro thermal Bibbly Stuart Scientific Melting Point SMPI (US). Molecular weights and elemental analysis of the compounds were preformed on Micro analytical center, Cairo University, Egypt. Microanalysis of nitrogen and sulfur (%) was performed in Microanalytical Center, Ain-Shams University, Cairo, Egypt.

Organic preparation
Preparation of acyl/benzoyl acetanilide derivatives I and III: To preheated ethyl acetoacetate and/or ethylbenzylacetate (0.01mol) a selective hetero primary amines and/or sulfa drugs (0.01mol) were added in dry system then warmed for 10-15 min at 100-110°C, cooled and finally washed with diethyl ether. The resultant solid was dried and crystallized to give I and III respectively ( Table 1).

Preparation of 1-acyl/benzoyl-1-anilido-4-methyl/aryl-1,3butadiene (II and IV):
Equimolar mixture of compounds I and/ or III and unsaturated aldehydes as crotonaldehyde and/or 4-dimethylaminocinnamaldehyde in absolute ethanol (100 mL), piperidine (0.5 mL) was heated under reflux for 8 h, cooled. The solvent was removed and the obtained solid was crystallized to give II and IV respectively ( Table 1).

Preparation of the reagent IVa immobilized PUFs packed column
Polyurethane foam (PUFs) cubes immobilized with the reagent IVa were prepared by mixing the dried foam cubes with the required weight of the reagent (0.05% w/v) in ethanol with efficient stirring for 10 min. The reagent immobilized PUF cubes were then dried to remove the excess reagent with filter papers as reported earlier

Pre concentration and/ or separation of bismuth (III) by reagent IVa treated PUFs
An accurate weight (0.1±0.01g) of the reagent IVa treated foam cubes was equilibrated with 50 mL of an aqueous solution containing bismuth (III) ions at concentration of 10 µg mL -1 . The solutions were then adjusted to the required pH with B-R buffer (pH 2-10). The test solutions were then shaken for 2 h on a mechanical shaker. The aqueous phase was then separated out by decantation and the amount of bismuth (III) remained in the aqueous phase was determined with atomic absorption spectrometry at the optimum wavelength. The amount of bismuth (III) retained on the PUFs cubes was determined from the difference between the concentration of bismuth (III) solution before (C o) and after (C a ) shaking with the foam cubes.

Journal of Bioanalysis & Biomedicine -Open Access
some sulfa drugs as sulfanilamide and sulfadiazine with preheated ethyl acetoacetate and/or ethyl/benzoyl acetate at 100-110°C for 10-15 min in dry condition led to the formation of acyl/bezoyl acetanilide derivatives I and III (Scheme I, II). Knoevenagel condensation of compounds I and III with unsaturated aldehydes such as crotonaldehyde and/or 4-dimethylcinnamaldehyde in boiling ethanol with few drops of piperidine as catalyst afforded 1-acyl/benzoyl -1-anilido-4-methyl-1,3-butadiene (II) and 1-acyl/benzoyl -1-anilido-4-(4`-dimethylaminophenyl)-1,3-butadiene (IV), respectively. The compounds prepared are summarized in schemes 1-III. Both carbonyl compounds I-IV having a second carbonyl at b -position, are termed as b diketones. In general hydrogen bonding is possible only in syn form and not in anti form, where the orientation of enolization is towards the aryl or phenyl groups (Mishra et al., 1991) indicating the high enolic content of 4-aryl-1,3-diketones and not in 4-methyl-1,3diketones.
UV -Visible spectra of compounds II and IV have two strong bands around 360 and 260 nm which characteristics bands of carbonyl chromophore and the conjugated C=C of butadiene (n → π * and π→ π * transitions) while that of compounds I and III recorded a low bands at 330 and 240 nm due to a bathochromic shift, indicating the involvement of the two carbonyl groups isolated by methylene group, assigned to the intramolecular charge transfer interaction involving the whole molecule (Sawyer et al., 1984).
IR spectra of compounds I and III show no characteristic C=O absorption band at ν 1725-1710 cm -1 which is present in the spectrum of acetylacetone ~ 1680 cm -1 while that of II and IV recorded of strong absorption bands at v 1650 cm -1 of true C=O group. Also, intarmolecular as well as intermolecular hydrogen bonding are observed in the regions 2700-2500 and 3000-2900 cm -1 respectively. The presence of absorption bands at 1610-1480 cm -1 (C=C) and 960-900 cm -1 confirm the presence of trans -CH=CH-moiety of compounds II and IV, respectively. These vibrations indicate that the transformation of the electronic effect is quite apparent through the part comprising the NH, OH and CO groups. 1 HMNR spectra of compounds I and III showed a one proton signal at δ~15 ppm confirming the presence of strong intramolecular hydrogen bonded enol proton, in addition, a signal appeared at δ 6.5-6.8 (methine) 6.9-7.9 ppm (aryl)protons. In such systems, the maximum enolization is two especially if containing aryl moieties. On the other hand, 1 HMNR spectra of compounds II and IV, showed a resonance signals at 8.0-8.5 ppm (olefinic), 2.5 ppm (methyl protons (due to an allylic coupling between HC=CH and methyl group), in addition of aromatic protons at δ 6.7-7.7 ppm. The tautomeric forms of compounds I and III were confirmed via 1 HMNR where, one resonated singlet for proton linked to sp 3 -carbon at δ 4.66 ppm was noticed. The structures of the compounds Id and IIId were deduced from 13  Mass spectra of compounds I-IV confirmed the degree of stability as indicated from the equilibrium between ketonic and enolic forms. Fragmentation also revealed the loss of Me-CO and Ar-CO from their chemical structures. A good physico chemical evidence for the presence of enolic and or ketonic tautomers of compounds I and III was deduced from free solubility of their Ar-NHCO derivatives in aqueous NaOH which confirm that the enolization forms take place towards aryl and or phenyl groups (Mishra et al., 1991).

Applications of the prepared compounds
Biocidal activity: Some of the synthesized compounds were tested in-vitro against microorganisms such as bacteria Escherichia. Coli and the fungi Aspergillums fumigates in DMF using the agar diffusion disk method (Barry et al., 1981;Winker et al., 1962). The results are compared with pipercillin and mycostatine as standard antibiotic. The antimicrobial potentialities of the tested compounds were evaluated by placing pre sterilized filter paper disks (11 mm diameter) impregnated with 50 mg/disk using DMSO as solvent which revealed no zone (IZ) after 5 days incubation at 28°C for fungi ( Table 2). Photochemical probe effects of these compounds were determined before and after using UV light at 366 nm as a second test ( Table 2). The compounds IIIe,d,f and IVe,d,f showed a highly biocidal effect and only compounds IIIe,d,f were found characterized by photo chemical probe action lower than other prepared compounds. This behavior is most likely attributed to the rich oxygen atoms in their structures with multi excitation states.

Pre concentration and / or separation of bismuth (III) onto reagent IVa immobilized PUFs
In preliminary experiments the use of the reagent IVa immobilized The effect of contact time and shaking time on the retention of bismuth by the treated AMP-PUFs of bismuth (III) from the aqueous solution containing high excess of KI (5-7% w/v) by AMP-loaded foam was carried out at pH 2.0. The bismuth (II) uptake was fast and reached maximum within ~ 10-15 min contact time. The half-life time (t ½ ) of the equilibrium sorption of bismuth (III) as calculated from the plot of -log (C b -C a )/C b versus time onto the reagent immobilized PUFs from the aqueous media to reach 50% saturation of the sorption capacity was in the range 1-1.5 min (Figure 1). The uptake of bismuth (III) ions was fast within the first 10 min and increased up to a constant value in less than 60 min shaking time. Thus, a shaking time of 60 min was adopted in subsequent experiments.
The analytical utility of the reagent IVa treated PUFs solid sorbent was successful assessed using the reagent IVa immobilized PUFs in packed column for complete retention of different concentrations (100 mL, 5-1000 µgL -1 ) of bismuth (III) in de ionized water. The sample solutions were percolated through the PUFs packed column    The removal of bismuth (III) from industrial wastewater was also carried out following the same procedures. The water samples of industrial wastewater (0.1 L) of electroplating industry after acidified with phosphoric acid was spiked with various concentrations (1 and 5 µgmL -1 ) of bismuth (III), acidified with phosphoric acid and filtered through a 0.45 µm cellulose membrane filter. The test water samples were percolated through the reagent packed column at 5 mL min -1 flow rate. The analysis of bismuth in the effluent solution by FAAS revealed complete retention of cadmium from the test solution.
The results are summarized in Table 3. Bismuth was quantitatively recovered with acidified solution of nitric acid (10 mL, 3.0 M) and analyzed by FAAS. A satisfactory recovery percentage of total cadmium was achieved in the range 94 -96 .0±2.7.

Voltammetric study
The cyclic voltammograms (CVs) of the compounds 1-acyl-1anilido-4-methyl-1,3-butadiene, IIa and 1-benzoyl-1-anilido-4methyl-1,3-butadiene, IVa in DMF -TMA + . Clat Pt working electrode versus Ag/AgCl reference electrode at various scan rate were investigated. The results are shown in Figure 2 and Figure 3. The CV of compound IIa (Figure 2) at 100 mVs -1 revealed two well-defined cathodic peaks at 0.1 and -0.75 V versus Ag/AgCl electrode. One well defined anodic peak at -0.15 V was observed on the reverse scan suggesting the irreversible nature of the observed electrochemical process in the employed potential range (-2.0 -2.0 V). On raising the scan rate (>100 mV s -1 ), the potential of the two cathodic peaks were shifted cathodically, while the anodic peak shifted anodically confirming the irreversible nature of the observed electrochemical processes (Bashammakh et al., 2009;Bard and Fulkner, 1980). The observed cathodic peaks are most likely assigned to the reduction of the carbonyl group via 2H + /2e in two successive one electron / one proton reduction steps (Bard and Fulkner, 1980). Continuous scan of the CV significantly decreased the peak current height indicating passivity of the surface of the Pt electrode via formation of polymeric oxidation product or fouling of the Pt electrode by the produced reduction products suggesting prior adsorption on the surface of the electrode in the potential range (Bard and Fulkner, 1980).
In DMF-TMA + .Clthe CVs of the compound IVa (Figure 3) at the Pt working electrode showed two reduction peaks at 0.1 -0.15 and -0.65--0.8 V coupled with one broad anodic peak in the potential range 0.3-0.4 V at scan rates of 50-1000 mVs -1 versus Ag/AgCl electrode. The cathodic peaks are safely assigned to the reduction of the carbonyl group in two successive H + /e redox steps (Bashammakh et al., 2009). The peak -peak potential difference (∆E p = (E p,a -E p,c ) between the cathodic (E p,c ) and anodic peaks (E p,a ) indicated that, the observed redox processes are irreversible. On raising the scan rate both cathodic and anodic peaks are shifted to more negative and positive potential, respectively confirming the irreversible nature of the observed redox process (Bard and Fulkner, 1980). The plot of the the cathodic peak current (i p,c ) versus the square root of the scan rate was linear indicating that the electrochemical processes is diffusion controlled processes ( Bard and Fulkner, 1980). The plot of E p,c versus log scan rate was found linear at Ag/AgCl. Thus, it can be concluded that, the first reduction processes of the compound precede according to the well known electrode-coupled (EC) chemical reaction mechanism (Bard and Fulkner, 1980). The overall results suggest the possible use of the two compounds as complexing agent in cathodic stripping voltammetry for determination of bismuth (III) ions (II) in water.

Conclusion
The redox behavior of the tested compounds suggest the possible application of the compounds as chelating agent for the determination of ultra trace concentration of heavy metal ions employing differential pulse -adsorptive stripping voltammetry. Moreover, immobilization of one of the prepared compounds on polyurethane foam solid sorbent as trapping agent for minimization and / or separation of bismuth (III) from industrial wastewater was achieved. Work is still continuing for application of the compound in cathodic stripping voltammetric procedures for trace metal analysis in different matrices.