Conjugation of Carboxylic Acid to Gold Nano Tip - Lab Report Example

Esterification; conjugation of carboxylic acid to gold nano tip The mechanical and electronic transport properties of the underlying 4-(methylthio) benzoic acid junctions are used density functional theory. The prevailing mathematical outcomes depicts that the rupturing force of the 4-(methylthio) benzoic acid is approximately 0.6±0.1 nN0.6±0.1 nN as described within the experiment since they are extremely smaller as compared to the corresponding force required in breaking the COO−– bond. The prevailing COO− group strongly affect the -(methylthio) benzoic acid molecular junction thus further strengthening the bond at the other terminal of the underlying junction. The carboxylic acid is less steady since the CH3 group connected to the COO group that is destroyed by the mechanical steadiness of COO–linking. The conductance of the junction is relatively older as compared to the -(methylthio) benzoic acid junction as depicted in the experiment. The final Esters 03” and the final Esster04” both show multiple products eluting, and several show typical fragmentation for an alkyl chain containing the group. However, the alkyl chains are too long. The alcohol mixes with the acid to undergo esterification, which entails a unimolecular two-step procedure of conversion via conjugation mechanism. The product results in the structure subsequent to the experimentation are the regular confirmation via the Refractive Index, FTIR, and HNMR analysis. The experiment aims at attaching carboxylic acid mainly 11-Mercaptoundecanoic acid employed to connect to conjugate the useful molecule to the nano tip. It entails two parts of coating the 11-Mercaptoundecanoic acid onto the nano tip and attaching the alcohol to the 11Mercaptoundecanoic acid. Introduction Comprehending the charge transport of the single metal- molecule junctions is significant in the determination of the prospect molecular electronic devices (Hassner, Namboothiri & Hassner, 2012). Ideally, the conductance of the single molecule junctions is frequently influenced by the underlying intrinsic nature of the molecular structure and corresponding molecule electrode contact. The intrinsic nature of the prevailing molecular structure includes either conjugated or unconjugated backbone of the molecule, molecular confirmation and similar substitution group apart from the backbone. Conversely, molecule electrode contact is influenced by the anchoring groups, electrodes and contact configuration of the electronic that coupling amidst the metal and molecule. The influence of the insertion of the unconjugated bond to the pie delocalization system on the single molecule conductance via replacing the saturated bond with the conjugated bond within the saturated system. Experimental Methodology or Theoretical Analysis The chemical reagents for the experiment include 2M hydrochloric acid, alcohol, Carboxylic Acid, Iodine, phosphine. Crystal structure was too poor, trying on 6C-ms. Moreover, attempting to the region within DCM 3.0mmol of iodine was added to 40mL dry DCM. Then 3.0mmol of phosphine was added to the resultant mixture of iodine and dry DCM. On addition of phosphine, the color changed to brown yellow. 6.6mmol of ionidazole was then added to the resultant mixture thus making the color to change to light yellow. It was followed by addition of 2mmol carboxylic acid and stirring at room temperature for 5 minutes. After stirring the mixture, add 3.0mmol of alcohol and check the reaction for completeness by TLC or suitable test for a period ranging from 12 hours to 24 hours. To the resultant solution add approximately 50mL of DCM and wash organic layer with 2M HCL and dH2O then dry it with sodium sulphate ( Na2SO4). Remove the solvent using rot cap and then run it through the flash column to purity of the final product with hexanes. For lab 3 experiment of the Esterification of 1st alcohol-ph3P and Benzyl Alcohol regarding the “Conjugation of 11-MUA to a Nano tips the 1mm 11-Mercaptoundecanoic acid solution was created within three separate 10mL beakers. Then the tape tips were carefully within immersed in the solution and removed after four, 8 and 12 hours respectively. The tip was rinse in the EtOH and dried in nitrogen. 30mL of 1mm 11-MUA is equivalent to 6.55g of 11-MUA in 30Ml thus 2.183mg per 10mL was placed into the beaker. After immersion and drying, SEM mainly to determine rate of conjugation carried out analysis of the tips. The method for identification of 4-mercapto-4- methylpentan-2-one from the Box tree and Bcoom for 6C-ms. The parameters entail starting temperature and end temperature, which were 35oC and 230 oC respectively. The ramping was 10oC /min. The final Esters 03” and the final Esster04” both show multiple products eluting, and several show typical fragmentation for an alkyl chain containing the group. However, the alkyl chains seem too long in some cases. Preparation MALDI samples need approximately 250μg/ml concentration. The Weight 27.3mg was then diluting 100x within CHCI3 resulting to Ester 1. Moreover, Ester 2 sis made by weighing 26.9mg and then diluting 100x within CHCI3.MALDI data depicts that the final step did not occur. CDI-Activated PEG Coupling method entails activation and coupling. Activation involves dissolving alcohol in the dioxane at a concentration of 50mm by heating at 37 degrees. Subsequently, add solid CDI to make a final concentration 0.5M then the reaction was stirred for two hours at 37 degrees (Schmid, 2011). Excess CDI were removed and by-products, precipitated with diethyl thus re-dissolving in acetone and precipitating again with the diethyl ether. The product is dried through rotary evaporation. Coupling entails dissolving amine to be pegylated in 10mm sodium borate with the PH of 8.5 at the concentration of 1-10mg/Ml. This can also be done by 0.1M sodium carbonate having a PH ranging from 9 to 10. Then add CDT- activated intermediate to the solution with stirring for 48 hours. Results 1: Esterification of 1st alcohol-ph3P and Glucose Creation of approximately 2M HCL solution entails dilution of 5ml fuming 38% HCL to 30ml with dH2O. Mass of Erlenmeyer= 38.1119g Mass of RBF= 56.5669g Very low solubility DCM addition improves solubility. After prolonged exposure to air both the aqueous phase and the drying agent have turned dark orange I2 theoretical value is 0.7614g and actual value is 0.7612g Phosphine theoretical value is 0.7869g and actual values 0.7869g. Carboxylic Acid theoretical value is 0.4367g and actual value is 0.4369g. Alcohol theoretical value is 0.5405g and actual value is 0.5407g. Imidazole theoretical value is 0.4493g and actual value is 0.4498g. Iodine turned DCM deep red-purple phosphine turns thus turning yellow. Iodine needs to be stirred to dissolve. Ionidazole changed color to yellow and precipitate was observed. It 2. Esterification of 1st alcohol-ph3P and Glucose (without using dry glassware) I2 theoretical value is 0.7619g and actual value is 0.7603g. Phosphine theoretical value is 0.7869g and actual values 0.7862g. Carboxylic Acid theoretical value is 0.4367g and actual value is 0.4364g. Alcohol theoretical value is 0.5405g and actual value is 0.5396g. Imidazole theoretical value is 0.4493g and actual value is 0.4493g. Iodine turned DCM deep red-purple. Iodine needs to stir to dissolve. Phosphine changed color to yellow. Upon the addition of ionidazole. Yellow color remained and precipitate is observed color is quite light. Carboxylic acid changed color to white while the precipitate remains. 3: Esterification of 1st alcohol-ph3P and Benzyl Alcohol I2 theoretical value is 0.7614g and actual value is 0.7617g. Phosphine theoretical value is 0.7869g and actual values 0.7878g. Carboxylic Acid theoretical value is 0.4367g and actual value is 0.4375g. Alcohol theoretical value is 0.3107g. Imidazole theoretical value is 0.4493g and actual value is 0.4499g. Iodine turned DCM deep red-purple. Iodine needs to stir to dissolve. Phosphine turned color to yellow. Ionidazole changed the color to yellow and precipitate is observed. Carboxylic acid changed color to white while the precipitate remains. “Conjugation of 11-MUA to a Nanotips” entails SEM images that show spotted surface after 8 to 12 hours for the tip to get lost. Discussion Performed DECA run on the PEG (HS-PEG-NH2 *HCI) within ACN mainly to determine degradation. The addition of 1.305g maltodextrin to 10mL of the 1,4-dioxane followed by the 0.73g CDI. The white precipitation was visible but gradually dissolving due to the substitution of butyl phenyl ether for the diethyl ether. The solid GC-MS Esterification product had the peak at 82.69 and 207.00. The peaks were 131.05, 145.07nm, 159.09nm, 178.03nm, 187.10nm and 202.08nm. The product major peaks were 87.00nm, 101.02nm, 115.02nm, 129.07nm, 143.08nm, 157.10nm, 171.11nm, 185.09nm, 199.10nm and 213.14nm. The formula weight of 11-MUA side product fragments is 418.69708 while the 11-MUA product fragments had a formula weight of 380.49678. The 11-MUA major peaks were 92.91nm, 121.00nm, 138.00nm, 149.02nm, 166.01nm and 193.98nm. The visible spectrum of the peak depicts symmetrical peak possessing a maximum at 213nm, which is used in the computation of the mean diameter of the particles within the solution with a result of 207nm. The carbodiimide chemistry enabled prevailing covalent immobilization of the molecule to the PEGylated gold nanoparticles. Covalent immobilization offered relatively stronger bond and a steadier conjugate (Hassner, Namboothiri & Hassner, 2012). Nevertheless, the PEGylated as a linker layer ultimately placed the conjugate further from the underlying particle. Since the width of the PEG layer was unknown, the range for the prevailing mental enhancing impact was unknown. PEGylated particles were characterized utilizing visible spectroscopy, and the peak was 82.69nm and 207.00nm (Schmid, 2011). The particle size granted by the Nano parts was 213.14nm as compared to the conjugate stabilized particles the corresponding PEG layer thus producing a 6nm shift. As depicted for the conjugate particles the correlation amidst the peak and the underlying excitation coupled with the emission maximum employed of the used nano tip was not perfect even though MEF could be possible. Esterification reaction of the alcohol and unimolecular conjugation reaction entails loss of the hydroxyl group (OH‑) from the adjacent carbon. The entire impact is the loss of the water molecule resulting in the formation of the ∏-bond alkyl The carboxylic acid and corresponding hydroxyl of the oxidized nanotubes can be utilized to link covalently other small and polymeric molecules via reactions specific of the –COOH and –OH functionalities. Long alkyl chains are chemically attached i=onto the prevailing oxidized nanotubes via amidation reaction (Hassner, Namboothiri & Hassner, 2012). They are attached covalently onto the oxidized nanotubes via a relatively simpler reaction amidst the carboxylic acid and the amine groups. A carboxylate-ammonium salt enhances the solubility of the nanotubes. The etherification reaction is utilized to attach covalently alkyl groups onto the oxidized carbon nanotubes. The formation of the acid-oxidized compound via esterification amidst carboxylic acid and corresponding hydroxyl end groups at the nanotube tips within the existence of the condensation agent The nanotube hetero-junction possessing the carbons nanotubes joined at either end to side or end-to-end configuration is constructed via the biofunctionalized amine linkage. Oxidative treatment of the aligned carbon nanotubes within the solution aids in generating carboxylic and hydroxyl for further modification thus resulting in the total collapse of the underlying aligned nanotubes (Hassner, Namboothiri & Hassner, 2012). Protection of the prevailing, the alignment structure takes place while filling the gaps amidst the aligned nanotubes with the spin-on glass before oxidative reaction. The functionalization of the aligned carbon nanotubes with the carboxylic groups occur via chemical coupling of the nucleic acids to the corresponding aligned nanotube array utilizing the standard water soluble coupling reagents namely EDC. The existence of the conducting polymer layer was distinctly within the TEM images and through much sturdier redox responses of the underlying piloting polymer layer when coated on the nanotube surface than that of the identical polymer on the conservative flat electrode under the identical situations (Schmid, 2011). The big interfacial surface area for every unit mass attained for the nanotube reinforced conducting polymer layer potentially fundamental within numerous optoelectronic applications. The SEM images depict that the particles solution contained particles of numerous diverse sizes. Gold nanoparticles utilize extinction coefficient at the existing Peaks. The peak shift was mainly observed after conjugation resulting to the alteration of refractive index of the nearby media thus changing the extinction coefficient for the peak value. From the measurement undertaken and the mean curve, it is evident that the stock solution produced a relatively higher signal as compared to the conjugated gold nanoparticles. The computed standard deviation depict high gold nanoparticle chips thus making it cumbersome to make conclusion on an enhancement impact. SEM analysis allows accurate analysis of the true surface coverage of the tip. Moreover, SEM images depict partial aggression resulting to a problem for utilization of the effect of gold nanoparticles. The PEG layer stabilizing the prevailing PEGylated gold nanoparticles offered steric stabilization and thus the salt trials offer information during the fundamental stage of the conjugation process for the citrate stabilized particles. Moreover, diverse conjugation steps undertaken could not be observed within the visible spectroscopy, as there was very small shift within the position of the peak. Conclusion and Summary Based on the underlying data formulated from the experiment, the group successfully prepared gold nano tip attached on the conjugation. The spectroscopy graphs depict same readings as anticipated of the conjugation. Depending on the underlying diameter and helicity of the arrangement of the graphitic rings within the walls, carbon nanotubes can exhibit fascinating electronic properties. Even though the identity of the product is verified, the percentage yield of 23.43% is relatively lower than anticipated. Crystal structure was too poor, trying on 6C-ms. Method taken from identification of 4-mercapto-4- methylpentan-2-one from the Box tree and parameters entail starting temperature and end temperatures, The ramping shows multiple products eluting, and several show typical fragmentation for an alkyl chain containing the group. However, the alkyl chains seem too long in some cases. CDI-Activated PEG Coupling method entails activation and coupling. Excess CDI were removed and by-products, precipitated with diethyl thus re-dissolving in acetone and precipitating again with the diethyl ether. Coupling involves dissolving amine to be pegylated in 10mm sodium borate with the PH of 8.5 at the concentration of 1-10mg/Ml. This can also be done by 0.1M sodium carbonate having a PH ranging from 9 to 10. Then add CDT- activated intermediate to the solution with stirring for 48 hours. References Hassner, A., Namboothiri, I., & Hassner, A. (2012). Organic syntheses based on name reactions: A practical guide to 750 transformations. Amsterdam: Elsevier. Schmid, G. (2011). Nanoparticles: From Theory to Application. Weinheim: Wiley-VCH. Read More