Synthesis Method of Napthoyl-thiourea Derivatives

Synthesis Method of Napthoyl-thiourea Derivatives CHAPTER 3 METHODOLOGY This chapter explains briefly on the synthesis method of napthoyl-thiourea derivatives, experimental characterization techniques (CHNS, FTIR, UV-Vis, UV-F, 1H and 13C NMR, Single Crystal X-Ray Crystallography Analysis, XRD, TGA, SEM, CV), electrodeposition of napthoyl-thiourea derivatives on ITO substrate, electrical conductivity measurement, IV curve characteristic, performance of organic diode and theoretical calculation via Gaussion 09 software package functions. 3.1  Reagents, Chemicals and Solvent All chemicals used in this study were commercially available and used as received without any purification step taken. Chemicals namely 1-napthanoyl chloride (C10H7COCl), ammonium thiocyanate (NH4SCN), 2-aminopyridine (C5H6N2), 2-amino-5-chloro-pyridine (C5H5N2Cl) and 3-amino-4-methylpyridine (C6H8N2) were purchased from Sigma-Aldrich. In addition, 2-amino-5-picoline (C6H8N2) and 2-amino-3-picoline (C6H8N2) were supplied from Merck. Solvents such as methanol (CH3OH), dichloromethane (CH2Cl2) and dimethylsulphoxide were supplied by Merck. Other solvents used in this study namely chloroform (CHCl3), ethyl acetate (CH3COOCH2CH3) and hexane (C6H14) were purchased from Sigma-Aldrich. Acetonitrile (C2H3N) and diethyl ether (C4H10O) were supplied by R M chemicals. Whilst, acetone (CH3COCH3) was obtained from Fisher scientific. 3.2  Instrumentation and Characterization Techniques The infrared (IR) spectra of the synthesized compounds were recorded on a Fourier Transform-Infrared Spectrophotometer, Perkin Elmer Spectrum 100 in the range of 4000-400 cm-1 using potassium bromide (KBr) pellets. Electronic absorption spectra of the samples were recorded in the range of 200-400 nm using Shimadzu UV-Visible Spectrophotometer 1601 series in 1cm3 cuvette while the electronic emission spectra were recorded in the same range by using Shimadzu UV-Fluorescence Spectrophotometer. For Single X-Ray Crystallography, the diffraction data were collected at 296.15K. The structure was solved and refined by using Olex2 solution program and refinement package using Gauss-Newton Minimization. The 1H (400.11 MHz) and 13C (100.61 MHz) NMR spectra were recorded using Bruker Avance III 400 Spectrometer in CDCl3 as solvent and internal standard at room temperature in the range between ÃŽ ´H 0–15ppm and ÃŽ ´C 0–200ppm, respectively. Besides, CHNS-O Analyzer Flashea 1112 series was used to determine the experimental percentage of C, H, N and S elements of the synthesized compounds. Thermogravimetric analysis was performed using Perkin–Elmer TGA Analyzer from 0oC to 700oC at a heating rate of 10oC/min under nitrogen atmosphere. Analytical thin-layer chromatography (TLC) was carried out on precoated plate of TLC Silica Gel 60 F254 (Merck) and spots were visualized with ultraviolet light. The X-ray Diffraction (XRD) analysis was performed using Rigaku MiniFlexll from 3à ¯Ã‚ Ã‚ ±-80à ¯Ã‚ Ã‚ ±. The technique cyclic voltammetry was performed using Electrochemical Impedence Spectroscopy (EIS) PGSTAT302 with three-electrode cell consisting of a polished Pt rod working electrode, Pt disc counter electrode and AgCl reference electrode. The solutions were ~10-3 M in electroactive material and 0.1 M supporting electrolyte, sulphuric acid. Electrochemical Impedance Spectroscopy (EIS) PGSTAT302 was used to coat the synthesized compounds on the ITO thin film by using electrochemistry method. EIS was used to study the oxidation and reduction state of the element of the synthesized compounds. The surface morphology of the final synthesised compounds in the form of powder and thin films were scanned by JSM 6360 Joel Scanning Electron Microscopy (SEM) with accelerated voltage 20 kV and magnification from 2000Ãâ€" until 10000Ãâ€" The electrical conductivity of the thin film was measured in the dark conditions by using Four-Point Probe and LI-200 Pyranometer Sensor with LI-1400 Data Logg er while Keithley 4200 SCS Semiconductor Characterization System and Probe Station were used for efficiency determination and OLED parameters were evaluated from IV curve. The performance as Diode was performed by using D2 Power Supply GP-430D. Last but not least, the experimental result were proven by using ab initio quantum mechanical evaluation at the theoretical level of DFT B3LYP/6-31G (d,p). The physical parameters such as dipole moment, energy band gap (HOMO and LUMO) and Mulliken Charges Bond length were calculated using Natural Bond Orbital Theory at the same theoretical level. 3.3  General Research Design In this study, the methodology is divided into four parts. Firstly, this research started with the synthesis napthoyl substructure of thiourea derivative. Secondly, all the synthesized compounds were characterized by using elemental analysis, typical spectroscopic and analytical techniques and electrochemical analysis. Next, the synthesized compounds were deposited on the ITO substrate as a thin film by using electrochemical deposition method. The conductivity and performance of the synthesized compounds as OLED were evaluated. Lastly, the experimental data were compared with the theoretical calculation by using Gaussion 09 software package. Figure 3.1 shows the schematic diagram of the experimental flow chart. 3.4  Synthetic Approach The synthetic approach to obtain the compounds of interest is shown in Scheme 3.2. Thiourea derivatives (15) were prepared by using 1-naphthoyl chloride as starting material. The mixture of 1-napthhoyl chloride, an equimolar amount of ammonium thiocyanate and designated amines (3-methylpyridin-2-amine, 6-methylpyridin-3-amine, 5-methylpyridin-2-amine, pyridine-2-amine and 5-chloropyridin-2-amine) in acetone was put at reflux with constant stirring for around ca. 10 hours. After completion, the reaction mixture was cooled to room temperature before it was then filtered. The off-white precipitate was removed and the filtrate was added to some ice blocks. The precipitate was crystallised from hot acetone to afford crystals of the title compounds (15). Scheme 3.2The general overview of the synthetic pathway applied in this study 3.5  Experimental Section 3.5.1  Synthesis of N-((3-methylpyridin-2-yl)carbamothioyl)-1-naphthamide (1) A solution of 1-napthanoyl chloride (1.5ml, 1mol) with the equimolar amount of ammonium thiocyanate (0.76g, 1mol) in ca. 50ml acetone in 100ml two-necked round-bottom flask. The reaction mixture was put at reflux with continuous stirring for ca. 5 hours. Then, a solution of 6-methylpyridin-3-amine (1.07g, 1mol) in ca. 50ml acetone was added to the reaction mixture and was put at reflux with continuous stirring for ca. 7 hours. The progress of the reaction was monitored with TLC (Hexane: DCM; 3:2). Once the reaction completed the reaction mixture was cooled to room temperature and filtered into a beaker containing some ice cubes. The resulting light brown precipitate obtained, recrystallized from hot acetone to afford the title compound (1). 3.5.2  Synthesis of N-((5-metylpyridin-2-yl)carbamothioyl)-1-naphtamide (2) The title compound 2, (2.33g, 96%) obtained as light yellow crystalline solid was prepared from 1-napthanoyl chloride (1.5ml, 1mol), ammonium thiocyanate (0.76g, 1mol) and 3-methylpyridin-2-amine (1.07g, 1mol) in the manner as describe above. 3.5.3  Synthesis of N-((3-metylpyridin-2-yl)carbamothioyl)-1-naphtamide (3) The title compound 3, (2.66g, 98%) obtained as light yellow crystalline solid was prepared from 1-napthanoyl chloride (1.5ml, 1mol), ammonium thiocyanate (0.76g, 1mol) and 5-methylpyridin-2-amine (1.07, 1mol) in the manner as describe above. 3.5.4  Synthesis of N-(pyridin-2-ylcarbamothioyl)-1-naphthamide(4) In a manner similar to that described above 3, the title compound 4, (0.88g, 45%) obtained as light yellow crystalline solid was prepared from 1-napthanoyl chloride (1.5ml, 1mol), ammonium thiocyanate (0.76g, 1mol) and pyridin-2-amine (0.94g, 1mol). 3.5.5  Synthesis of N-((5-chloropyridin-2-yl)carbamothioyl)-1-naphthamide(5) The title compound 5, (1.97g, 87%) obtained as light yellow crystalline solid was prepared from 1-napthanoyl chloride (3ml, 1mol), ammonium thiocyanate (0.76g, 9.95mmol) and 5-chloropyridin-2-amine (1.28, 1mol) in the manner as describe above. 3.6Electrodeposition of Naptoyl-Thiourea Derivatives on ITO substrate The ITO substrates were used as working electrode was firstly cleaned with distilled water, detergent and acetone by using ultrasonic cleaner. All the synthesized compounds (15) were deposited on the ITO substrates by electrochemistry method by using Electrochemical Impendance Spectroscopy (EIS) PGSTAT302. By using the GPES method software, cyclic voltammetry (staircase) method was set to be in normal procedure. The depositions of the compounds were done in a mixture of compound dissolved in 45ml acetonitrile (10-3 M) and 5ml sulphuric acid (10-3 M) which act as supporting electrolyte .The cyclic of the process were set in Table 3.1 below. Figure 3.1 represent the arrangement layers of ITO/napthoyl-thiourea thin film. While, scheme 3.3 shows the overall methodology for organic light emitting diode (OLED) formation and characterization. Table 3.1 Procedure set for electrodeposition process No of scan 5 Start potential (V) 0 First Vertex Potential (V) 0 Second Vertex Potential (V) 3 Step Potential (V) 0.01 Scan Rate (Vs-1) 0.05 Figure 3.1The arrangement layers of ITO/napthoyl-thiourea thin film (1a5a) 3.7  Electrical Conductivity Measurement Four point probe was used to determine the conductivity of the thin film. The sheet resistivity of the films was measured with complete four probing system that consists of the Jandel Universal Probe combined with a Jandel RM3 Test Unit (Figure 3.2). In this study, the electrical conductivity of thin film was measured in dark condition to see its tendency to be applied as organic diode. Four probes were aligned and lowered onto the sample. The two outer probes supplied a voltage difference that drives a current through the film while the two inner probes pick up a voltage difference. Figure 3.2Jandel Universal Probe and RM3 Test Unit The sheet resistances (resistivity) for the thin films are shown in Equation 3.1 below. The unit of sheet resistance is ohms per square (à ¯Ã‚ -/sq): Rs = 4.532 x V / I (Equation3.1) Where: Rs = sheet resistance 4.532 = correction factor V = voltage measured I = current applied The electrical conductivity can be determined which it is the reciprocal (inverse) of the electrical resistivity, à ¯Ã‚ Ã‚ ³ as shown in Equation 3.2. The unit of electrical conductivity is ohm-1 m-1 (à ¯Ã‚ --1 m-1) = Siemens m-1 (Sm-1). à ¯Ã‚ Ã‚ ³ = 1 / Rs(Equation 3.2) Where, à ¯Ã‚ Ã‚ ³ = electrical conductivity Rs = sheet resistivity 3.8  IV Curve Characteristic The IV curves of the 1a5a were measured by using Keithley 4200 SCS Semiconductor Characterization System and Probe Station (Figure 3.3). In this study, ITO substrate act as hole collecting layer (anode) while napthoyl-thiourea derivatives act as hole and electron carriers. The coated ITO substrates were mask with low work function metal which is aluminuim which act as cathode. Figure 3.3Semiconductor Characterization System and Probe Station The I-V curve shows the relationship between the currents and voltages gradient associated with the different current terminal (anode and cathode) of the diode. The obtained curve displays the forward current, reverse current, knee voltage and breakdown voltage of the diode. 3.9  Performance as Diode The performances of 1a5a as organic diode were tested by using D2 Power Supply GP-430D (Figure 3.4) under dark condition with difference voltagesin the range 15V to 30V. Figure 3.4D2 Power Supply GP-430D

Ralphs Leadership in William Golding’s Lord of the Flies Essay

Ralph's Leadership in William Golding’s Lord of the Flies Ralph, the elected leader of the group of British boys in William Golding’s Lord of the Flies, strives to take the civilized society to which he is accustomed and apply it to society on the island on which he and the other boys are stranded. As leader, this task seems simple – tell the other boys what they each need to do and expect them to do it. Ralph fails to realize the difference between the rest of the boys and himself. The world is in the middle of a massive war, a war in which the threat of the atomic bomb looms prominently. In fear of losing all its future fighting force, Britain sends a group of its schoolboys on an airplane to safety. Before reaching its destination, though, an enemy fighter plane shoots down the boys’ plane. The plane crashes into a forest on a remote island and, as a result, the pilots die. This group of schoolboys jumps from a society in which adults direct them to act properly to one in which there is no authoritative figure to give them orders. Back in Britain, adults train the boys to obey them and follow their lead. They act appropriately because of the threat of punishment for disobedience. Even later in the novel, once things begin to fall apart, Golding writes, â€Å"Here, invisible yet strong, was the taboo of the old life. Round the squatting child was the protection of parents and school and policemen and the law† (62). As the story progresses, though the boys go so far as to participate in savage acts such as killing each other, in the end, they realize that they conducted themselves immorally. Stranded on the island with a bunch of boys and no adults, Ralph quickly takes charge and demands the election of a leader of the bo... ...ings a type of closure to the ordeal, and it also shows a realization he had about society, about mankind in general. He has witnessed with his own eyes the evil that comes about as a result of the lack of civilization and the inborn nature to do evil. Golding describes Ralph’s profound crying simply: â€Å"Ralph wept for the end of innocence, the darkness of man’s heart, and the fall through the air of the true, wise friend called Piggy† (202). While nearly all the boys on the island ignore those standards British society has taught them, Ralph does not, and, as leader, tries to apply them to society on the island. Even when everyone else reverts to his inborn evil nature, Ralph sticks with that which is good, that which he learned from British society – civility. Ralph is different than the other boys, and because of that difference, it is only fitting that he cry.

Ill Mind of Hopsin

Brandon Williams Ms. Hildebrandt English 1100-0022 October 8, 2012 Ill Mind of Hopsin 5 â€Å"Ill Mind of Hopsin,† is a song that a lot of people will probably never hear in their lifetime, kind of like some classical music. For the most part, classical music is all instrumental, but it can still tell a story or have an idea behind it. In the â€Å"I’ll Mind of Hopsin,† Hopsin is trying to convey that the younger population of today’s society is pretty much the most messed up and corrupt group of people ever with very complicated lyrics and a repetitive beat. His lyrics might sound like they’re just words, but in fact they actually have a meaning.Even though it is a rap song it actually is very complex, not just some idiot talking about nothing important over a crappy beat. First off, the beat of the song is very important to the way Hopsin expresses his ideas. For a rap song, it is pretty fast paced. He needs to be able to fit a lot of words into a 5 minute song. The beat is very repetitive to allow for the same pace. Most raps nowadays have a chorus while Hopsin’s songs do not. Actually nothing in the song is ever repeated. To me, that is a way of showing intelligence. Most modern rap artists include a chorus because they can’t think of anything else to say in their song.Sometimes, just by hearing the beat of a song you can determine what the outcome will be. When I hear the beginning of â€Å"Ill Mind of Hopsin 5,† I think, â€Å"Wow, this is going to be serious and a very meaningful song. † Also, when I hear a fast beat song, I know that it is going to have more to say as a song than the slower, less intelligent sounding songs. Hopsin expresses in the first few lines of the song that he can’t believe and is embarrassed that he played a part in this game, the ‘game’ being society and all of its ideas about how life is and should be.Hopsin felt like he had no common sense. It w as taken away from him by all of his surroundings such as friends, media, and school. He wants to let people know, that is not the way that life is supposed to be lived. People just don’t care about what they do anymore. If it is fun to do at the moment, people automatically do it without thinking ahead about what the consequences could be. For example, Hopsin tells a girl in his song, â€Å"One of these niggas got you pregnant and you can’t raise it, but you caused it, your actions made a fat statement. His telling her that she royally messed up and that she has to deal with a problem she could have avoided. He also says, â€Å"Do you even have any goals? † He is talking about the lazy kids and young adults that just don’t care what they do for the rest of their life. Hopsin wants to know what the point of living is, if someone doesn’t have a plan in life. This seems to be a problem that is very prevalent in today’s society and Hopsin is c alling everyone out on this issue. He is not just rapping about some pointless argument. There are a lot a lot of people that could care less about rap.Most rap songs these days are meaningless, but Hopsin proves otherwise. It takes care of a lot of stereotypes and points them out clearly. Any artist that makes a song as clear as this one has to be a genius. It is hard to make a complex song like this with so many different stereotypes that is easy to understand and without confusing the audience. Hopsin is African American but that doesn’t stop him from calling out his own race. He states, â€Å"Cause you in the streets actin like a Neanderthal. † Hopsin doesn’t even want to be associated with his own race because of the stereotype they have put on themselves.He is trying to say that there is more to life than fighting, basketball, and rapping. He can’t believe that there are people out there that are prideful that they have been shot and stabbed, like t hat is something to be proud of. If that is what it takes to become famous than is someone really a musical artist. Hopsin wants people to know that these new age rappers are full of themselves and nothing else. They don’t care about their listeners. Hopsin is angry at the music industry too. Obviously, it is hard to be a fake classical artist, but it is easy to be a fake rapper or singer these days.He is mad at the industry for putting this idea that all you need to be successful in life is money, girls, and a large persona. He states songs whose sole purpose is to fulfill these ideas are a disgrace to the Hip Hop community and to all of the people who are trying to make rap a more complex genre of music. Most rappers are in the â€Å"game† for all the money instead of the satisfaction of making good music whether the public thinks it is good or not. It is all about making yourself feel like you have accomplished what you wanted to accomplish. It was the same case wit h classical writers like Bach, Beethoven, and Mozart.They made their music because they were interested in the art of making music. These artists stayed fairly humble during their careers. Hopsin also shows these qualities. He is successful enough to be making a lot of money, but he isn’t treating it like the majority of rappers are today. He doesn’t flaunt his cash around in his music videos or at his concerts. This is why I respect him as an artist and not a fake person whose job in life is to be a puppet for the music industry. Hopsin’s song is the perfect example of how someone can express their feelings toward society and its problems.He makes it pretty easy for the listener to understand what he, the artist, is saying. The words are very clear as well as the ideas in the song. He wants people to see the messed up society that everybody lives in today. The whole entire song is one huge call out towards the world. Hopsin took it into his own hands to admit t he obvious problems that people see every day. Hopsin isn’t afraid to let people know that they are stuck in this never ending loop of insanity that is the media and what it does to corrupt people’s minds.

An Exploration of British Injustice in Shooting an...

. By the type of language and the choice of words that the author used to write his essay, it is very likely that it was written for the British people, to make them aware of the injustice and cruelty of Imperialism in the colonies. The author’s aim is to make the reader feel disturbed and uneasy by describing in detail his negative experiences in India. This rhetorical analysis explores the success of the author in portraying the negative impact that Imperialism had on those being governed under it, but also on the impact on those in power. The way Orwell used the words for describing the scene of shooting the elephant, his aim was to get the reader’s mind to understand the injustice of Britain’s rule over the natives. While Shooting an†¦show more content†¦With the use of the words ‘white man’ and ‘tyrant,’ it is obvious Orwell was referring to one of the sides of Imperialism, the side that has the power. They are becoming t he puppets of the natives: â€Å"A sahib has got to act like a sahib† (Orwell, 410). With the use of this phrase Orwell uses the word â€Å"sahib† as a symbol of tyrant or master. This phrase shows not only how the people oppressed by the Imperialism suffer, but the tyrant itself by giving up his freedom. Through the way Orwell arrange this paragraph the audience can now truly understand Orwell’s argument about how Imperialism has negative effects on those in the power, and how ironically it is for Orwell to gain power and dominance over others, just to lose freedom and dominance over yourself. Through the essay, with the use of particular emotional words and sentences, the audience can perceive Orwell’s feelings and emotions, by the memorable amount of pathos over his essay. Orwell goes on describing the cruel reality the Burmese people lived in by describing, with the use of dramatic and lively words, the terrible situations, and consequences of Imperialism. Giving more reasons for his logos, Orwell at the same time uses pathos to emotionally involve