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29 papers of Perkin Transactions1 (year 2000) -31% chlorinated solvents -35% dipolar aprotic solvents such as D/MF -24% noxios solvents such as benzene and pyridine - one paper water as the solvent. • Transportation – production of gasoline and diesel from petroleum,
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29 papers of Perkin Transactions1 (year 2000) -31% chlorinated solvents -35% dipolar aprotic solvents such as D/MF -24% noxios solvents such as benzene and pyridine -one paper water as the solvent
•Transportation–production of gasoline and diesel from petroleum, fuel additives for greater efficiency and reduced emissions, catalytic converters, plastics to reduce vehicle weight and improve energy efficiency. •Clothing–man-made fibres such as rayon and nylon, dyes, water-proofing and other surface finishing chemicals. •Sport–advanced composite materials for tennis and squash rackets, all-weather surfaces. •Transportation–production of gasoline and diesel from petroleum, fuel additives for greater efficiency and reduced emissions, catalytic converters, plastics to reduce vehicle weight and improve energy efficiency. •Clothing–man-made fibres such as rayon and nylon, dyes, water-proofing and other surface finishing chemicals. •Sport–advanced composite materials for tennis and squash rackets, all-weather surfaces.
•Safety–lightweight polycarbonate cycle helmets, fire-retardant furniture. •Food–refrigerants, packaging, containers and wraps, food Processing aids, preservatives. •Medical–artificial joints, ‘blood bags’, anaesthetics, disinfectants, anti-cancer drugs, vaccines, dental fillings, contact lenses, contra-ceptives. •Office–photocopying toner, inks, printed circuit boards, liquid-crystal displays. •Home–material and dyes for carpets, plastics for TVs and mobile phones, CDs, video and audio tapes, paints, detergents. •Farming–fertilizers, pesticides. •Safety–lightweight polycarbonate cycle helmets, fire-retardant furniture. •Food–refrigerants, packaging, containers and wraps, food processing aids, preservatives. •Medical–artificial joints, ‘blood bags’, anaesthetics, disinfectants, anti-cancer drugs, vaccines, dental fillings, contact lenses, contra-ceptives. •Office–photocopying toner, inks, printed circuit boards, liquid-crystal displays. •Home–material and dyes for carpets, plastics for TVs and mobile phones, CDs, video and audio tapes, paints, detergents. •Farming–fertilizers, pesticides.
THE TWELVE PRINCIPLES OF GREEN CHEMISTRY
1. It is better to prevent waste than to treat or clean up waste after it is formed Chromare & Nitrite corrosion inhibitor Cerium corrosion inhibitor Common fertilizer(P+N) Soya base fertilizer(N 7% )
-Because of low polarity of dioxins and furans, like many other organochlorine compounds, are far more soluble in the fatty tissues of animals than they are in water. -When these compounds enter the animal they are not readily exerted and tend to accumulate in fatty tissues that we call it bioaccumulation. -So can result in an animal having significantly higher concentrations of the organochlorine compound in its body than in the surronding environment . -At each higher level of the food chain there is an increasing concentration of the contaminant.This is known as biomagnification. -The combined effects of bioaccumulation and biomagnification can make the contaminant levels in fish up to 100000 times greater than that of their suuronding environment.
2. Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product. The classic evaluation of effectiveness and efficiency of a synthesis is yield. Yield also totally ignores the use or generation of any undesirable products that are an intrinsic part of synthesis.. It is possible and very often the case that a synthetic pathways, or even a synthetic step can achieve 100% and generate waste that is greater in mass and volume than that of the desired product.
The standard synthetic transformation types can be evaluated generically to determine the intrinsic atom economy of each type. 1) Rearrangement 2) Addition 3) Substitution 4) Elimination
Efficiency of a Reaction Percentage yield= (actual yield/theoretical yield) X 100
Topic: Atom Economy • A Measure of the Efficiency of a Reaction and isan assessment in which one looks at all of reactants to measure the degree to which each of them is incorporated into the final product.
ATOM ECONOMY“Because an Atom is a Terrible Thing to Waste” • How many of the atoms of the reactant are incorporated into the final product and how many are wasted? Infusing green chemistry into organic.
Atom Economy in a Substitution Reaction Equation 1b
Equation 1a 0.08g 1.33 2.0 1.48 g (theoretical yield) 0.0108mole 0.0129 0.0200 0.0108 mole (theoretical yield) Compound 1 is the limiting reagent Suppose the actual yield is 1.20 g of compound 4. Percentage yield= (actual yield/theoretical yield) X 100 = (1.20 g/1.48 g) X 100 = 81%
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100 = (137/275) X 100 = 50%
Table 4 Experimental Atom Economy of Equation 1: Based on Actual Quantities of Reagents Used % Experimental Atom Economy= (mass of reactants utilized in the desired product/total mass of all reactants) X 100 = (theoretical yield/total mass of all reactants) X 100 = (1.48 g/4.13 g) X 100 = 36%
% Yield X Experimental Atom Economy % Yield X Experimental Atom Economy = (actual yield/theoretical yield) X (mass of reactants utilized in the desiredproduct/total mass of all reactants) X 100 %PE .EAE= (actual yield/theoretical yield) X (theoretical yield/total mass of all reactants)X 100= (actual yield/total mass of all the reactants) X100 = (1.20 g/4.13 g) X 100= 29%
Percentage yield= (actual yield/theoretical yield) X 100 = (1.20 g/1.48 g) X 100 = 81 % Atom Economy = (FW of atoms utilized/FW of all reactants) X 100= (137/275) X 100 = 50% % Experimental Atom Economy = (mass of reactants utilized in the desired product/total mass of all reactants) X 100 = (theoretical yield/total mass of all reactants) X 100= (1.48 g/4.13 g) X 100 = 36% %PE .EAE= (actual yield/theoretical yield) X (theoretical yield/total mass of all reactants)X 100= (actual yield/total mass of all the reactants) X100 = (1.20 g/4.13 g) X 100 = 29
GREEN CHEMISTRY • The Synthesis of Ibuprofen • Advil, Motrin, Medipren • 28-35 million pounds of ibuprofen are produced each year (37-46 million pounds of waste)
Since about 15 million kg of ibuprofen are produced each year, this translates into more than 17.5 million kg of waste generated each year from the synthesis of ibuprofen!
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100 = (206/514.5) X 100 = 40%
% Atom Economy = (FW of atoms utilized/FW of all reactants) X 100 = (206/266) X 100 = 77%
3. Wherever practicable, synthetic methodologies should be designed to use and generate substances that possess little or no toxicity to human health and the environment
LD50 &LC50. LD and LC stand for lethal dose and lethal concentration respectively. LD50 is the dose of a chemical at which 50% of a group of animals (usually rats or mice) are killed, whilst LC50 is the concentration in air or water of the chemical which kills 50% of test animals. These tests are the most common ways of measuring the acute toxicity of chemicals. LD50 tests are done by injecting, applying to the skin or giving orally a known dose of pure chemical. The result is usually expressed in terms of milligrams of chemical per kilogram of animal, e.g. LD50 (oral, rat) – 10 mg kg 1 means that when given orally at the rate of 10 mg kg 1 animal weight the chemical will kill 50% of rats tested. Similarly LC50 tests are usually carried out by allowing the animal to breathe a known concentra-tion of the chemical in air, results being expressed in parts per million (ppm) or milligrams per cubic metre (mg m 3 ). LD50 &LC50. LD and LC stand for lethal dose and lethal concentration respectively. LD50 is the dose of a chemical at which 50% of a group of animals (usually rats or mice) are killed, whilst LC50 is the concentration in air or water of the chemical which kills 50% of test animals. These tests are the most common ways of measuring the acute toxicity of chemicals. LD50 tests are done by injecting, applying to the skin or giving orally a known dose of pure chemical. The result is usually expressed in terms of milligrams of chemical per kilogram of animal, e.g. LD50 (oral, rat) – 10 mg kg 1 means that when given orally at the rate of 10 mg kg 1 animal weight the chemical will kill 50% of rats tested. Similarly LC50 tests are usually carried out by allowing the animal to breathe a known concentra-tion of the chemical in air, results being expressed in parts per million (ppm) or milligrams per cubic metre (mg m 3 ). LD50 &LC50. LD and LC stand for lethal dose and lethal concentration respectively. LD50 is the dose of a chemical at which 50% of a group of animals (usually rats or mice) are killed, whilst LC50 is the concentration in air or water of the chemical which kills 50% of test animals. These tests are the most common ways of measuring the acute toxicity of chemicals. LD50 tests are done by injecting, applying to the skin or giving orally a known dose of pure chemical. The result is usually expressed in terms of milligrams of chemical per kilogram of animal, e.g. LD50 (oral, rat) –10 mg kg –1 means that when given orally at the rate of 10 mg kg -1animal weight the chemical will kill 50% of rats tested. Similarly LC50 tests are usually carried out by allowing the animal to breathe a known concentration of the chemical in air, results being expressed in parts per million(ppm) or milligrams per cubic metre (mg m3).
4. Chemical products should be designed to preserve efficacy of function while reducing toxicity. The balance btwn maximizing the desired performance and function of chemical product while ensuring that the toxicity and hazard is reduced to its lowest possible level is the goal of designing safer chemicals
Mechanism of action analysis: Direct toxicity: Chemical substance itself that is reacting to cause the end effect of concern Indirect toxicity: it is metabolite or derivative of the original substance that is responsible for harmful interaction with the body
SAR(structure activity relationships): SAR are based on a correlation btwn the molecular architecture of a compond and its activity Avoid the use of functional group that posses some toxicity: Isocyanate base adhesive Acetoacetate esters Mask the functional group that posses some toxicity Vinyl solfone base dye Vinyl solfone sulfatebase dye
Minimizing bioavailability: The ability to enter the various biological systems and organs is called bioavailability Minimizing auxiliary substances: Innocuous coating need to be dissolved in hazardous solvent Coating with the same properties but can be used in aqueous systems