Chapter Three Experimental
3 Experimental
Anhydrous tetrahydrofuran ( Aldrich, 99 % ) was refluxed with Na metal and distilled. Dimethyl Formamide ( Aldrich, 99 % ) was made anhydrous utilizing activated molecular screens. 2, 3 dimercapto-1-propanol ( Fluka ) , Sodium methoxide ( sodium metal was reacted with methyl alcohol ) , sodium metal ( 99 % , Riedel-de-Ha & A ; euml ; n ) , methanol ( distilled ) , Ethylene ethanediol ( 99 % , BDH ) , triethylenetetramine ( Aldrich, 97 % ) , Silver nitrate ( Aldrich, 95 % ) , Copper sulfate ( Aldrich, 97 % ) , p-toluene sulphonyl chloride was recrystallised with tetrahydrofuran since it had drosss and wet ( Aldrich ) and ammonium hydroxide ( Aldrich, 25 % ) .
3.1 SYNTHESIS OF PER-6-IODO & A ; beta ; -CYCLODEXTRIN
3.1.1 Synthesis of per-6-iodo & A ; beta ; -Cyclodextrin
To three-necked unit of ammunition underside flask ( 250ml ) triphenyl phosphine ( 7.02g, 26.6mmol ) and I ( 7.04g, 26.4mmol ) were added and dissolved in anhydrous dimethyl formamide ( 150ml ) with uninterrupted flushing of N gas and stirring at room temperature for 15
mins. Cyclodextrin ( 2g, 1.8mmol ) was so added and the reaction was heated nightlong ( 18 hours ) under N ambiance at 70 & A ; deg ; C in an oil bath. The reaction mixture was cooled to 0 & A ; deg ; C and Na methoxide ( 8ml ) was added bead wise. The mixture was so poured in cold methyl alcohol ( 500ml ) . The precipitate formed was filtered under vacuity in a burchner funnel. A xanthous pulverization was obtained ( 2.54g, 1.5mmol )
% output: 73.9
1H-NMR: ( DMSO ) & A ; delta ; ( ppm ) : 1.1005 ( T, 1H ) , 2.409 ( s, 1H ) , 2.800 ( s, 1H ) , 3.07 ( Q, 1H ) , 3.516 ( m, 54H ) , 5.873 ( s, 4H )
3.1.2 Synthesis of per-6-Ethylenediamine & A ; beta ; -Cyclodextrin
In a double-necked unit of ammunition underside flask ( 100ml ) per-6-Ethylenediamine & A ; beta ; -Cyclodextrin ( 2g, 1.05mmol ) and ethylene diamine were reacted under N ambiance and uninterrupted stirring. The reaction flask was heated under reflux in an oil bath at 50 & A ; deg ; C for 72 hours. The dissolver was reduced to half its volume and DMF ( 150ml ) was added. A white precipitate ( 4.15g, 2.7mmol ) was obtained.
% output: 44.6
1H-NMR ( D2O ) & A ; delta ; ( ppm ) : 2.10 ( s, 2H ) , 2.91 ( T, 49H ) , 3.575 ( vitamin D, 23H ) , 3.880 ( s, 25H ) , 5.04 ( s, 13H )
Prior to synthesis of per-6-ethylene diamine & A ; beta ; -cyclodextrin, Cu ( II ) ions were chelated with ethylene diamine and the complexation was monitored under UV/Visible spectrophotometer.
3.2.1 Introductory surveies on complexation of Cu ( II ) ions and ethylenediamine as ligand.
Ethylene diamine being non-miscible in H2O was diluted in THF. Copper ( II ) sulfate was diluted in distilled H2O. In the titration cell, 3cm3 of the ligand ( clean ) was pipetted and optical density was measured over a scope of 400 to 900 nanometers. Then with a micropipette ( 10 – 100 & A ; micro ; L ) , 10 & A ; micro ; L, ( 1 equality of the ligand ) , of the Cu sulfate solution was added followed by stirring with a magnetic stirred. The optical density was measured after add-on and stirring of each 10 & A ; micro ; L Cu sulfate solution in the cell. This experiment was carried out with different concentration of the ligand and Cu ( II ) sulfate solution.
Table below shows the different concentration used:
|
Concentration of ligand ( mol dm-3 ) |
Concentration of Cu2+ ( mol dm-3 ) |
Volume of Cu2+ ( & A ; micro ; L ) added each clip |
|
0.01 |
0.4 |
10 |
|
0.4 |
0.01 |
10 |
After the synthesis of per-6-ethylene diamine & A ; beta ; -cyclodextrin, the cyclodextrin based ligand was complexed with Cu ( II ) ions utilizing UV/Visible spectrophotometer to supervise the titration and binding.
3.2.2 Chelation of per-6-ethylene diamine & A ; beta ; -cyclodextrin with Cu ( II ) ions
Per-6-ethylene diamine & A ; beta ; -cyclodextrin ( 0.0714g ) placed in a volumetric flask ( 5ml ) was diluted with distilled H2O to give a solution ( 0.004M ) . Copper ( II ) sulfate ( 1.2g ) was diluted in a similar manner to give a solution ( 1.5 M ) . The ligand ( 3 cm3 ) was pipetted in a titration cell ( clean ) and optical density was measured over a scope of 400 to 900 nanometers. The ligand was so titrated each clip with Cu ( II ) sulphate solution utilizing a micropipette ( 10 – 100 & A ; micro ; L ) and maximal optical density was recorded after add-on of each 10 & A ; micro ; L of Cu2+ ions. Titration was continued until complexation was completed.
3.3 SYNTHESIS OF 2, 3 DIMERCAPTO-IODO-PROPANE
3.3.1 Synthesis of 2, 3 Dimercapto- iodo- propane
To a three-necked unit of ammunition underside flask ( 250ml ) , nitrogen gas was flushed followed by the add-on of I ( 10.155g, 0.2mmol ) and triphenyl phosphine ( 10.507g, 0.2mmol ) . Anhydrous THF ( 100ml ) was added and the mixture was stirred for 15mins anterior to add-on of 2, 3 dimercapto-1- propyl alcohol ( 2ml, 0.10mmol ) . The reaction mixture was stirred and refluxed overnight at 70 & A ; deg ; C in an oil bath. Then maximal volume of the dissolver was removed through rotary evaporator. The merchandise was purified utilizing column chromatography technique. Silica was the stationary stage and a mixture of THF and Ether in a ratio of 1:1 was used as the eluent. The purification was successful and the dissolver was once more removed via rotary evaporator to give the merchandise ( 1.895g ) .
% output: 76.5
1H-NMR ( DMSO ) & A ; delta ; ( ppm ) : 0.624 ( s, 2H ) , 1.832 ( s, 3H ) , 2.479 ( s, 1H )
3.3.2 Synthesis of calix-4-arene based ligand
In a two-necked unit of ammunition underside flask ( 100ml ) continuously flushed with N gas, Na hydride ( 0.7075g, 2.95mmol ) , anhydrous THF ( 5ml ) , calix-4-arene ( 0.125g, 0.295mmol ) were added and stirred for 15mins. The 2, 3 dimercapto-1-propanol ( 1.035g, 2.12mmol ) was added and the mixture was stirred at room temperature for 16 hours. The mixture was so cooled to 0 & A ; deg ; C and methanol ( 1.5ml ) was added. After 10mins, the reaction mixture was poured in a separating funnel ( 100ml ) followed by the add-on of H2O ( 12.5ml ) and ether ( 12.5ml ) . The organic bed was washed with H2O ( 3 & A ; times ; 6.5ml ) . The combined organic infusions were dried over Na sulfate anhydrous. The solution was so filtered and dissolver was removed via rotary evaporator.
1HNMR DMSO & A ; delta ; ( ppm ) : 1.16 ( vitamin D, 1H ) , 1.236 ( s, 1H ) , 2.494 ( s, 2H ) , 3.370 ( s, 3H ) , 7.621 ( m, 1H )
3.3.3 Complexation of Copper ( II ) ions and ligands
Complexation reaction of the ligands with Cu ( II ) ions was carried out to demo the binding of Cu ( II ) ions with the ligands and besides the permutation of these ligands by H2O molecules of add-on of certain equality of Cu ( II ) ions.
3.2.3.1 Conductimetric titration of Copper ( II ) sulfate with 2, 3 dimercapto-1-propanol.
Copper ( II ) sulfate ( 0.0156g, 2.0 & A ; times ; 10-6 mmol ) was prepared in a volumetric flask ( 100 milliliter ) and diluted with distilled H2O. 2, 3 dimercapto-1-propanol ( 0.01ml, 2.0 & A ; times ; 10-6 m mol ) was prepared in THF. The metal was titrated with the ligand maintaining the volume of the reaction mixture invariable at 10ml. Different volume of ligand and Cu ( II ) sulfate were used but the entire volume was ever 10ml. Each clip the conductance was measured and noted in each solution.
|
Solution figure |
Volume of 0.002M, Cu 2+ ions in milliliter |
Volume of 0.002M, 2,3 dimercapto-1-propanol in milliliter |
|
1 |
9 |
1 |
|
2 |
8 |
2 |
|
3 |
7 |
3 |
|
4 |
6 |
4 |
|
5 |
5 |
5 |
|
6 |
4 |
6 |
|
7 |
3 |
7 |
|
8 |
2 |
8 |
|
9 |
1 |
9 |
3.4 Stoichiometric finding of Ag composites
3.4.1Silver complexation with ethylene diamine
Silver nitrate ( 3.40g, 0.2M ) was diluted with distilled H2O in a volumetric flask ( 100ml ) while ethylene diamine ( 13.5ml, 2.0M ) was diluted with THF. Silver nitrate solution ( 50ml ) was placed in a beaker ( 100ml ) good wrapped with aluminum foil to forestall photolysis. Besides, a Ag electrode and a mercurous chloride electrode ( connected to an ion analyser ) were placed in the beaker. Ethylene diamine was placed in a burette and activity of Ag ions was noted after add-on of each 0.2ml of the ligand.
The above experiment was carried out with ammonium hydroxide as ligand prior to ethylene diamine.
3.4.2 Silver complexation with ammonium hydroxide
Silver nitrate ( 0.170g, 2.0M ) was diluted with distilled H2O in a volumetric flask ( 100ml ) and ammonium hydroxide ( 14.97 milliliter, 0.01M ) was diluted with distilled H2O in a volumetric flask ( 100ml ) . The Ag nitrate solution ( 50 milliliter ) was placed in a beaker ( 100ml ) good wrapped with aluminum foil to forestall interaction with visible radiation. Besides, a mercurous chloride electrode and a Ag electrode ( connected to an ion analyser ) were placed in a beaker. Ammonia solution was placed in a burette ( 50ml ) and after add-on of each 0.1ml of ammonium hydroxide with uninterrupted stirring. The ion activity was noted.
3.4.3 Silver complexation with 2, 3 dimercapto-1-propanol
Silver nitrate solution ( 1.698, 0.01M ) was prepared in a volumetric flask ( 100 milliliter ) with distilled H2O while 2, 3 dimercapto-1-propanol ( 0.31 milliliter, 0.03 M ) was prepared in tetrahydrofuran utilizing a volumetric flask ( 100 milliliter ) . The Ag nitrate solution was ( 50ml ) was placed in a beaker ( 100ml ) wrapped with aluminum foil. Calomel and silver electrodes were placed in the beaker. The ligand ( 2, 3 dimercapto-1-propanol ) was placed in a burette ( 50ml ) and after add-on of each 1.0 milliliter of ligand ( with uninterrupted stirring ) , the ion activity was measured.
3.5 SYNTHESIS OF CYCLEN
3.5.1 Synthesis of 1, 2 Bi ( p-toluenesulfonato ) C2H6
Sodium hydrated oxide ( 8g, 0.2mmol ) were dissolved in distilled H2O ( 40ml ) and ethylene ethanediol ( 7.4ml, 0.07mmol ) in THF ( 40ml ) were placed in a flask and the mixture was cooled in an ice bath with magnetic stirring and bead wise add-on of p-toluene sulfonyl chloride ( 24.3g, 0.13mmol ) in THF ( 40ml ) for over 4 hours. The solution was so poured into ice-water ( 100ml ) and organic bed was extracted with methylene chloride ( 2 & A ; times ; 15ml ) . The combined organic infusion was so washed twice with H2O ( 15ml ) and one time with concentrated Na chloride solution. The infusion was so dried over Magnesium sulfate. The mixture was filtered and upon vaporization, white glistening crystals ( 2.32g, mmol ) appeared.
Military policeman: 124-127 & A ; deg ; C
% output: 65
1H-NMR in CDCl3 & A ; delta ; ( ppm ) : 1.67 ( s, 2H ) , 2.18 ( vitamin D, 2H ) , 7.36 ( M, 5H )
3.4.2 Synthesis of acyclic tetratosylamide
A double-necked unit of ammunition underside flask ( 100ml ) was charged with K carbonate ( 1.46g, 30.8mmol ) , triethylene tetramine ( 1g, 6.84mmol ) and H2O ( 40ml ) . The mixture was refluxed at 80 & A ; deg ; C in an oil bath with uninterrupted and vigorous stirring. Para-toluenesulfonyl chloride was added in little parts as solid over a period of 4 hours. The mixture was refluxed and stirred overnight and so allowed to chill until a colorless precipitate was apparent. The mixture was filtered on a sintered filter funnel and washed in bend with H2O ( 3 & A ; times ; 5ml ) , methanol ( 3 & A ; times ; 5ml ) and eventually with diethyl quintessence ( 3 & A ; times ; 5ml ) . The solid was dried under high vacuity to give acyclic tetratosylamide ( 2.58g )
Military policeman: 263 & A ; deg ; C
% output: 56.6
1H-NMR in CDCl3, & A ; delta ; ( ppm ) : 3.128 ( s, 5H ) , 3.336 ( T, 2H ) , 4.309 ( s, 4H ) , 4.113 ( s, 4H ) , 8.867 ( s, 1H ) , 8.513 ( T, 5H )
3.4.3 Synthesis of cyclic tetratosylamide
To a double-necked unit of ammunition underside flask ( 100ml ) , nitrogen gas was flushed followed by add-on of anhydrous K carbonate ( 0.835g, 6.05mmol ) and acyclic tetratosylamide ( 2.22g, 2.91mmol ) dissolved in THF anhydrous ( 35ml ) . Besides a solution of 1,2 Bi ( p-toluenesulfonato ) C2H6 ( 1.09g, 2.965mmol ) in THF ( 5ml ) was prepared in a force per unit area equalising add-on funnel. The mixture was stirred smartly at room temperature. The content of the add-on funnel was easy added over a period of 3-4 hours. The concluding mixture was stirred smartly nightlong. The mixture was so heated at 70 & A ; deg ; C in an oil bath for 3 hours and the THF was distilled off via a rotary evaporator. The residue was taken up in methylene chloride ( 5ml ) and H2O ( 5ml ) and transferred into a separating funnel ( 50ml ) . The organic bed was extracted with methylene chloride ( 2 & A ; times ; 25ml ) . The organic infusion was dried over K carbonate. The mixture was filtered and solvent removed on rotary evaporator. The residue was recrystallised in hot methylbenzene ( 15ml ) . On chilling, a white precipitate was deposited. The solid was collected on a sintered filter funnel. Cyclic tetratosylamide ( 1.39g ) was obtained.
Mp: & A ; lt ; 263 & A ; deg ; C
% output: 61
1H-NMR in CDCl3 & A ; delta ; ( ppm ) : 1.395 ( vitamin D, 1H ) , 2.47 ( s, 3H ) , 7.20 ( M, 2H ) , 7.763 ( vitamin D, 2H )
3.4.4 Synthesis of Cyclen
A dry single-necked unit of ammunition underside flask ( 50ml ) was charged with the cyclic tetratosylamide ( 0.78g, 0.99mmol ) and concentrated sulfuric acid ( 2ml ) . The mixture was heated under N for 40 hours at 110 & A ; deg ; C. The mixture was poured in a conelike flask and cooled in ice-bath. Slowly H2O ( 20ml ) was added followed by add-on of K hydrated oxide pellets, while twirling the flask. Sufficient pellets were added to do the pH greater than 13. Ethanol was added ( 7.5ml ) and mixture was filtered under decreased force per unit area in a sintered filter funnel. The residue was washed with ethyl alcohol ( 3ml ) and the xanthous solid obtained was taken up in hydrochloric acid ( 0.1 M, 5ml ) . The solution was transferred in a separating funnel and washed with methylene chloride ( 2 & A ; times ; 3ml ) . The aqueous bed was separated and washed twice more with methylene chloride ( 2 & A ; times ; 30ml ) . The pH is once more raised to 13 by add-on of more K hydrated oxide pellets. The aqueous bed was extracted with trichloromethane ( 5 & A ; times ; 2ml ) . The organic infusions was combined and dried over anhydrous K carbonate. The mixture was filtered and solvent removed on rotary evaporator to give a colourless solid ( 0.121g ) .
Military policeman: 113-114 & A ; deg ; C
% output: 70.5
