Mauveine: History, Properties and Structure

Mauveine: History, Properties and Structure Introduction One of the most important events of 1856 was the discovery of the first successful artificial dye, mauveine (aniline purple, mauve dye, Tyrian purple) by William Perkin. The discovery of mauveine led to rapidly growth of fashion trend and discovery of new synthetic dyes. Nowadays there are more than three million dyes (WordPress.com). Most dyes used back in the XIX century were derived from natural products such as animals, vegetables or minerals. The dyes made from natural products at that time were expensive and required a large amount of labour. The main disadvantage of natural dyes was their tendency to fade. The invention of mauveine was major landmark in the history of technology and science which brought great benefits to textile and synthetic dye industry. However most people do not aware of the origin of those colours, especially world’s first synthetic dye mauveine and chemical reactions beyond the mauveine dye production. This paper will discuss the historical background of mauveine invention, chemical structure of mauveine, chemical synthesis methods of mauveine and applications. Historical background In 1834, German chemist August Wilhem Hofmann was working derivatives of coal tar to produce a quinine substance for treatment of malaria. At that time, young William Perkin was one of the Hofmann’s assistants and embarked to solve this problem. In 1856, while Hofmann went back to visit Germany, Perkin conducted some experiments in the laboratory at his home to achieve Hofmann’s goal. Perkin oxidised the aniline in the presence of potassium dichromate and obtained black coloured sludge. At the end of the experiment Perkin diluted the black sludge with alcohol and gained a purple solution. Perkin patented his new discovery and established the company ‘Perkin and Sons’. In June 1857 the company ‘Perkin and Sons’ began its work producing synthetic dyes. It should be emphasized that many technical problems occurred during the operation of the company such as large scale of benzene nitration and nitrobenzene reduction. The aniline purple was obtained in poor yields, because the oxidation step required optimisation. By 1864, the company was able to trade its product as a crystalline solid. In spite of the wealth which came with successful dye production, Perkin continued his experimental works in chemistry. After his successful introduction of aniline purple in Britain, next step for Perkin was to export mauveine abroad. However, Perkin’s effort to introduce his invention in France ended unsuccessfully as his patent was invalidated. Invention of the Perkins aniline purpleencouraged other chemists to work on new synthetic dyes. For instance, in 1856 Natanson discovered magenta (triphenylmethane dye) by oxidising aniline with chloride. As it was mentioned above, developments of synthetic dye chemistry in modern times takes its background from mauveine. Taking the historical background into consideration, mauveine made our world more colorful than it was before(‘the chemistry and application of dyes’, edited by David R. Waring, and Geoffrey Hallas, Plenum Press, New York 1990, p age 4-5). Chemical structure and properties of mauveine. The structure and consist of mauveine for many years had remained mystery. First attempts establishing mauveine molecular structure was made by Perkin himself. Perkin derived similar dye when oxidised toluidine and xylidine. However, pure aniline gave dye with poorer quality than that obtained from original impure aniline. This product was called pseudomauveine which was derivative of mauveine. Perkin concluded that mauveine contains both pseudo-mauveine () and a trimethyl derivative. At that time Perkin could not determine every atom in the molecule and so he attempted to determine mauveines constitutional formula by identified properties of mauve. In 1879 Perkin came to conclusion that mauveine can be derived only from aniline and para-toluidine. It should be emphasized that Perkins work determined a molecular formula of mauveine but not a molecular structure. Other works to determine molecular structure of mauveine was done by Fischer, Hepp and Nietzki. By synthesising pseudo-mauv eine in several times they discovered pseudomauveines structure. Oxidative couplings were involved in this synthesis as shown in figure 1. Synthetic methods for pseudomauveine figure 1. However, there was little evidence to proof mauveines chemical structure (figure 2). Mauveine figure 2. Only in 1994, the structure of mauveine determined through the work of Meth-Cohn and Smith. They emphasised two compounds as a key chromophores to obtain mauveine, mauveine A with C26 structure and mauveine B with C27 structure (scheme 1). Meth-Cohn and Smith analysed seven dyed textiles and seven mauve salts from different museum such as Science museum in London (scML), Chandler Museum (Columbia University), Museum of Science and Industry in Manchester (MSIM) and Perth Museum in Scotland. Meth-Cohn and Smith analysed major components of those samples by mass spectroscopy and NMR spectrometry and found presence of different methylated homologues of pseudo-mauveine. Different chromospheres are shown in table 1 amongst the historical samples which Meth-Cohn and Smith had found. A B B2 B3+B4 C C1 ScML1 1 2 50 23 10 5 4 5 1.3 ScML2 1 3 37 26 13 6 5 8 0.8 ScML3 1 2 54 16 9 4 5 8 1.8 ScML4 1 2 37 31 12 5 5 8 0.8 MSIM1 2 39 33 12 5 4 6 0.8 MSIM2 49 41 7 3 CM 1 2 50 24 8 4 5 7 1.4 Table1. Percentage of chronophers which found from mauveine samples Meth-Cohn and Smith discovered that all mauveine samples which prepared by Perkin was mixture of about thirteen different compounds with 7-amino-5-phenyl-3-(phenylamino)-phenazin-5-ium core. The majority of the historical samples of mauve which were investigated by Meth-Cohn and Smith had both A or B mauveines. Apart from that almost all historical samples of mauveine contained mono, tetra methylated derivatives of pseudo-mauveine. Mauveine B2 (C27) and C25A, C25B were important fingerprint markers of textiles and salts amongst these. In addition, for the first time Meth-Cohn and Smith identified pseudo-mauveine in the historical sample, this was described by Perkin as a second colouring source. As it was mentioned above, the mauveine contained pseudo-mauveine, which is very soluble, uncrystallisable salt and another one is less soluble, crystalline salt obtained from para-toluidine and aniline. One of the important properties of mauveine is fastness with silk which they colour. Chemical synthesis methods of mauveine As mentioned in previous sections William Perkin did not discover the mauveine intentionally, his main aim was preparing quinine (). As chemistry were in the early stage of its development there were little known about quinines structural formula. Taking into account of the molecular formulas of quinine and allyl toluidine Perkin came to the relationship shown in equation 1 and he attempted the preparation of quinine by oxidising allyl toluidine in the presence of potassium dichromate in sulphuric acid: Equation1 In his note Perkin wrote ‘that no quinine was formed, but only a dirty reddish brown precipitate’. However, Perkin was not aware at that time structure of allyl toluidine and quinine. If he had known the structure, he would certainly choose other route for synthesising quinine: The synthesis of mauveine starting aniline also required toluidine impurities (equation 2): Application of mauveine Alcoholic extract of mauveine gives very brilliant purple colour which cannot be removed and stable during washing. Perkin quickly considered its potential as a dyestuff for textiles and fabrics. Another useful application of mauveine is food colouring dye. In United States during 1900th the mauveine was used as food colouring with different names such as violate paste, rosolan, Perkin’s violate. Conclusion This short essay has considered history of the mauveine discovery, chemical structure and properties, synthesising way of mauveine. The discovery of mauveine led to rapidly change in global fashion and chemical industry. The Perkins discovery cannot be judged by today’s knowledge and consider as a luck. There were many things which have been discovered and invented, however they were forgotten as it did not find any practical application. Perkin had the ability to combine the theoretical and practical work from his experiment. Perkin’s discovery still has not lost its significance in modern synthetic dye chemistry and contributed to development of modern fashion. Galymzhan

Teen Britain: The shocking Truth(TM) article

Bullying, drugs, alcohol and sex were a few of the issues raised in this article, published on the 27th November 2005 as facing teenagers in today's society. As one of these young adults in our civilisation, I feel that it is my duty to defend myself and others like me in the face of such criticism. Firstly some of the points mentioned in your article I fully understand and agree with. For example, I agree that there are too many teenagers in society who are taking drugs or drinking alcohol whilst roaming our streets. You state that, â€Å"72% of 14 year olds have consumed alcohol†. This growing incidence of alcohol and drug use could also be a factor in the rise of the crime rate. However, I don't think that the press or general public can put all of the blame for this on today's teenagers, their families or the area in which they live. I think that the media has had a part to play in this and so should accept some of the blame. One of the reasons I think this, is that it wasn't so long ago that many newspapers and television documentaries claimed that cannabis didn't have any side effects or create long term damage; however, we are now being told by the media that there are serious side effects to cannabis, such as, that it the effects the quickness of the brain and how well you learn in class. Cannabis is proven to affect concentration spans so therefore pupils will not be able to take as much in during lessons. This may be one of the reasons for teenagers becoming addicted to drugs as they have been given mixed messages about the use and effects of them. In my opinion, the media is to blame for some of the negative behaviour that we are seeing from the teenagers of today. The main reason for my belief is that the media publicise a lot of the bad behaviour of teenagers; for example, young teenagers getting pregnant or drunk. However, I feel that the media very rarely praise teenagers for good behaviour and the achievement of some amazing goals. For example, good exam results, helping charities or helping out at home in difficult situations. Furthermore, some negative teenage behaviour, like smoking and drinking are activities shown on many popular television programmes, such as ‘Footballers Wives' and ‘Bad Girls'. After watching such programmes, some teenagers see these activities as cool and copy what they have watched. The media may also be influencing some teenagers to behave badly, as some of them crave to be famous and they feel that the only way to achieve this ambition is to do something delinquent, as they see these sorts of things getting attention every day. However, the media plays its part in the negative behaviour of teenagers in Britain today, so do a lot of people living in our country and indeed the laws we follow. It isn't the teenagers' fault that they believe that drinking alcohol will not harm them, as this is what they have been led to believe by our new licensing laws; These allow pubs and clubs to open for much longer and therefore make alcohol more readily available. Also the companies that are selling alcohol are partly to blame as they create new drinks which appeal to a younger market by making them taste more like soft drinks. Instead of marketing alcohol to teenagers people should be making young people aware of the dangers of alcohol and binge drinking. Adolescents should be advised to drink in small amounts and not go out binge drinking like these laws may encourage. Your article is extremely negative with its facts. You suggest that a percentage of teenagers have done something disapproving rather than celebrating the percentage of teenagers who have not. For example, instead of saying that â€Å"32% of 14 year olds have had sexual intercourse†, you could have said that 68% of 14 year olds have not had sexual intercourse. By being so negative you make teenagers sound as bad as you can, rather than praising the ones who aren't like this. This makes it far easier for the people reading your article to stereotype teenagers and jump to conclusions; however we are not all like you suggest. Finally, I would like to question the facts and statistics presented in this article as I don't always fully agree. I don't think that you have taken a big enough sample of teenagers in Britain, also I don't think that you have asked teenagers to complete your surveys in enough areas of Britain. Therefore, I question how you can support some of your statements as you seem to are stereotype all teenagers in Britain to be like the few you have spoken to. Would you like someone to go and speak to one or two people in your street and say you were the same as them? No, I didn't think you would. Well, is it fair that you have done this to the teenagers of Britain?

Body Shop Proposal

Proposal Outline (4%) Proposition Statement:____________________________________________ This proposal aims to produce a 4-as campaign in Seventeen to promote The Body Shop Bath & body products to audiences aged 15 – 19. P1: Proposition (2 paras) I. The Body Shop is currently lacking in advertisement directed towards teenagers even though sales would be greatly boosted if they can manage to appeal to them. A. This is because they choose to focus on targeting working adults which is leaned towards a mature image and does not appeals to teens. B.They will lose the potential to increase their sales volume if this continues. II. There are three main possible themes that we would like to propose. A. Firstly, â€Å"Fire† will be emphasising on the strong yet feminine aspects of the product. B. Secondly, â€Å"Earth† will bring attention on the environmentally-friendly nature of the products C. And lastly, the â€Å"Air† theme showcases the comfort level of the p roducts. D. This is a proposal for an advertisement spread in Seventeen selling The Body Shop Bath & Body products. ?There is a choice of three themes for the campaign, â€Å"Fire†, â€Å"Earth†, and â€Å"Water†.The recommended products for the 4-ad campaign are to be bath & shower gel, body lotion, body butter, and body scrub. P2: Potential (3 paras) I. The Body Shop is currently lacking of advertisement directed to teenagers. A. For a cosmetics retail company, The Body Shop noticeably lacks of photographs of models with beautiful hair and perfect skin, which would attract attention of teenagers. B. Currently, The Body Shop is targeting working adults and the advertisement that they made is leaned more towards a mature image. This image does not appeal to teenagers. II.The Body Shop does not appeal to teenagers and in doing so, it loses a huge number of potential customers. A. Teenagers are not attracted to The Body Shop because of a lack of celebrity represen tation. B. With the lack of advertisement, targeted audience will not be encourage to trial purchase, brand switch and develop brand loyalty towards The Body Shop. III. Sales would be greatly boosted if The Body Shop were able to appeal to teenagers. A. The Body Shop will be able to maximise it’s profits because Singaporeans teenagers aged 15-19 are very willing to spend money on body products.B. Products such as body products could easily allow the consumer to develop brand loyalty towards the brand because they would have develop a habit for using our brand’s product. This results in repeated purchases and promotes sales in long term. P3: Possibilities (3 paras) I. The first theme, â€Å"Fire† theme will emphasize the strong yet feminine aspects of the product. A. â€Å"Fire† will pitch the products in a sexy yet elegant way, appealing to girls who want to be seen as confident and independent women. B.For example, in the Body butter advertisement, we ca n feature a model clad in only lingerie and high heels and applying body butter on her body. This would suggest that one would feel confident with their body after using our products. The main colour of this advertisement will be red, black and white to give off a Parisian feel, which represents elegance, yet at the same time emphasizes on the fiery and bold aspects of the theme. II. The second theme, â€Å"Earth† will focus attention on the environmentally friendly nature of the products.A. Products would come across as environmental and relaxing under the â€Å"Earth† theme and would appeal to both males and females because it makes them feel comfortable. B. The advertisement for bath & shower gel portray a model unwinding in a bathtub full of soapy water, implying that she had just used the product and suggest that one would feel relaxed after using the product. The background of this advertisement could be a natural setting filled with trees and plants to emphasize on the nature aspects of the theme. III.The third theme, the â€Å"Air† theme, will showcase the comfort level of the products. A. Under the â€Å"Air† theme, products would be pitch as simple yet lasting comfort, appealing to both genders because of the theme’s purity and freshness. B. One example of a body lotion advertisement under the â€Å"Air† theme is to do a compare and contrast of a model who applied the body lotion in the morning and the same model looking energetic and fresh at night to represent the lasting effects and the comfort level can be seen through the model’s cheerful appearance.The advertisement would be in pastel colours to emphasize on the theme’s purity. P4: Proposal (3 paras) I. We have decided to go with the â€Å"Earth† theme because it highlights the key feature of our product and will be effective in attracting our target audience’s interest. A. The Body Shop unique selling point is being environm entally friendly and it is also what the audience associate The Body Shop with. By going along with this theme, audience are able to identify The Body Shop because our concept will be consistent.B. B. Our target audience have a very hectic lifestyle and by portraying a product, which comes across as relaxing to them is a very feasible idea because it is what the target audience need and that is also what they are looking for. This will thus increase sales of the products. II. We have rejected the â€Å"Fire† theme because it doesn’t specifically appeals to our target audiences. A. The â€Å"Fire† theme might seem over-mature to our target audiences and they would not want to be associated with such image. B.The â€Å"Fire† theme might also be inappropriate and clashes with The Body Shop image because The Body Shop has always emphasize that beauty can be achieve even without baring a lot of skin. II. We have also rejected the â€Å"Air† theme becaus e it’s concept is very common in Body products. A. The concept of comfort in a body product is not unique and thus, would not be effective in attracting the targeted audience as it doesn’t stand out. B. Audiences are easily able to find cheaper alternatives with the same benefits. *Total number of paras: 11 (do not create any more paragraphs†¦ it’s 11, no more, no fewer)

Essay On Social Problems - 1861 Words

Ellie Caylor Miss O. Social Problems 11/1/17 Many people wonder, what is a social problem? Social problems are all over the world and affect many people. The definition of a social problem is an aspect of society that a large number of people or community are concerned about. They depend on your values or if you believe something is good or bad. There are two kinds of social problems, objective condition and subjective concern. An objective condition is a condition within society that can be measured. Subjective concern is an aspect of society that many people are concerned about. Social problems are major events that affect a lot of people. The social problem I will cover is poverty. Poverty is an extreme social problem and it means to†¦show more content†¦Everyone put their savings into the stock market in New York City on Wall Street. Then the stock market crashed and people were financially wiped out. Factories and businesses began firing people and for those who still had jobs got paid barely anything. Over 12,000 Americans were becoming unemployed every single day, this lead up to having 12 million people without jobs. Also, the drought in the middle of the country decreased the amount of farm production. Farmers couldn’t support themselves because they couldn’t grow crops. Kids couldn’t go to school because schools had to shut down due to lack of money. People couldn’t even make enough money to meet their basic needs. Then in 1932, Franklin D Roosevelt won the next election over Herbert Hoover. This was the change the country needed in order to get back on their feet. The economy continued to improve and the GDP (Gross Domestic Product) grew at an average rate of 9% per year. The Great Depression was another historical event that put many people in poverty (Great Depression Poverty). Throughout the years, the world have been living in poverty because of different events that occur. Natural disasters leave many people with nothing. Hurricanes, Earthquakes, floods and other natural disasters affect a lot of people. Every year, 26 million people are put into poverty because of a natural disaster. The tropical Storm Agatha increased the rate of poverty byShow MoreRelatedSocial Problems Essays1168 Words   |  5 PagesA way of distinguishing a realist perspective between theories of social problems within is to contrast the level of analysis on which their explanations are focused. Many theories that seek to explain social problems function at the level of the psychological or biological conditions that make some people behave badly – discovering the gene, chromosome or mental characteristic that separates the deviant from the normal. 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