- •Англійська мова для професійного спілкування
- •Передмова
- •Brief contents
- •Unit 1 structure and bonding
- •1. You are going to read three texts which are all connected with chemistry. Read the texts and be able to make intelligent guesses about:
- •2. Decide what books the texts come from. What helped you to make up your mind? Choose from the following:
- •3. Which sentence could be the opening sentence of the text?
- •4. Think about the first sentences above and decide which you think are likely to introduce a paragraph with:
- •6. Give the definitions of the following terms:
- •2. Look at Appendix 3 and Render the following text.
- •3. Read the following text. Discuss the point with your colleagues. What do you know about the methods of scientific investigation? The Scientific Method
- •The Scientific Method
- •1. Culture clips: London life
- •2.What museums are there in your city/town? Have you ever visited any?
- •3.Have you ever visited science museum of the “kpi”? Are there any in your university? Imagine that you are a guide at such museum, tell about the most interesting museum piece.
- •2. What was said in the text about:
- •3. Render the following text.
- •1. Imagine that you are starting a presentation. What phrases might you use?
- •2. Listen totwowaysofopeningpresentationsandseeifyoucanhearsomeofthephrasesabove.
- •3. Read some advices on delivering effective presentations in the Appendix 7 and write your own opening for the topic “Stereochemistry”.
- •Imagine that you are a major distributor of the following product. Look at Business English section and write a letter asking more information about the product presented below.
- •Unit 3 molecular symetry
- •2. Find five things in the texts to finish the sentence: “It reminds me of…”
- •2. Read the flowcharts given in the figure 1 and 2.
- •3. Read some information about creation of the flow charts in the Appendix 4-6 and create your own describing any experiment you made in the laboratory.
- •4. Create a list of rules related to the theme of the text given in the exercise 1. Share and compare the rules with your partners and think how they might be improved, choose the best ones.
- •5. Render the text given in the exercise 1.
- •2. Listen to two ways of giving presentations and see if you can hear some of the phrases above.
- •3. Read some advices on delivering effective presentations in the Appendix 7 and write your own presentation for the topic “Molecular symmetry”.
- •You ordered: Beckman du64 uv/VisSpectrophotometer
- •Unit 4 stereochemistry of reactions
- •Chiral Drug
- •1.Presentation: questions.
- •Unit 5 resolution of enantiomers
- •Resolution of enantiomers
- •1. Method of resolution is the title of the text in this section. What is the likely content of the article? Predict the methods which might be described.
- •3. Mark and talk about five things from the text you are glad to find out about. Talk in pairs about these things and why you chose them.
- •5.Render the text.
- •4. Think of three reasons you liked the text and three reasons you didn’t like it. Share and compare your reasons with other students. Find out how many other students share your opinion.
- •1.Presentation: useful tips.
- •3.Complete the sentence with the correct phrase.
- •Principles of Stereochemistry
- •Enantiomeric Relationships
- •Diastereomeric Relationships
- •Methods of determining configuration
- •The Cause of Optical Activity
- •Molecules With More Than One Chiral (Stereogenic) Center
- •Asymmetric Synthesis
- •Business english
- •Formal letter
- •1.Titles and addresses
- •2Covering the issues
- •3 Beginning your letter
- •4 Ordering ideas
- •5 Range
- •6 Ending the letter
- •Sample formal letter
- •Informal letter or email
- •1 Titles and addresses
- •2 Openings
- •3 Covering all the issues
- •4 Using informal language
- •5 Range
- •6 Connectors
- •7 Closing statements
- •Writing a tactful advice letter
- •How to write a request letter
- •Complaint letter
- •If necessary, add any further information:
- •Writing claim letter
- •Inquiry letter
- •Establish Your Objective
- •Determine Your Scope
- •Organize Your Letter
- •Draft Your Letter
- •Close Your Letter
- •Review and Revise Your Inquiry Letter
- •Sample Inquiry Letter __________Better Widget Makers, Inc.__________
- •5555 Widget Avenue
- •Appendices appendix 1 exclamations
- •Appendix 2 general conversation gambits
- •Appendix 3 the scheme of rendering the text
- •Appendix 4 flow charts
- •Appendix 5 graph
- •Appendix 6 reading and interpreting graphs
- •Types of Graphs
- •Appendix 7 presentations
- •Typescripts
- •Bbc Learning English. Talking Business
- •(Bbclearningenglish. Com)
- •Bibliography 1
- •Bibliography 2
The Cause of Optical Activity
The question may be asked: Just why does a chiral molecule rotate the plane of polarized light? Theoretically, the answer to this question is known and in a greatly simplified form may be explained as follows.
Whenever any light hits any molecule in a transparent material, the light is slowed because of interaction with the molecule. This phenomenon on a gross scale is responsible for the refraction of light and the decrease in velocity is proportional to the refractive index of the material. The extent of interaction depends on the polarizability of the molecule. Plane-polarized light may be regarded as being made up of two kinds of circularly polarized light. Circularly polarized light has the appearance (or would have, if one could see the wave) of a helix propagating around the axis of light motion, and one kind is a left-handed and the other a right-handed helix. As long as the plane-polarized light is passing through a symmetrical region, the two circularly polarized components travel at the same speed. However, a chiral molecule has a different polarizability depending on whether it is approached from the left or the right. One circularly polarized component approaches the molecule, so to speak, from the left and sees a different polarizability (hence, on a gross scale, a different refractive index) than the other and is slowed to a different extent. This would seem to mean that the left- and right-handed circularly polarized components travel at different velocities, since each has been slowed to a different extent. However, it is not possible for two components of the same light to be traveling at different velocities. What actually takes place, therefore, is that the faster component "pulls" the other toward it, resulting in rotation of the plane. Empirical methods for the prediction of the sign and amount of rotation based on bond refractions and polarizabilities of groups in a molecule have been devised, and have given fairly good results in many cases.
In liquids and gases, the molecules are randomly oriented. A molecule that is optically inactive because it has a plane of symmetry will very seldom be oriented so that the plane of the polarized light coincides with the plane of symmetry. When it is so oriented, that particular molecule does not rotate the plane but all others not oriented in that manner do rotate the plane, even though the molecules are achiral. There is no net rotation because, the molecules being present in large number and randomly oriented, there will always be another molecule later on in the path of the light that is oriented exactly opposite and will rotate the plane back again. Even though nearly all molecules rotate the plane individually, the total rotation is zero. For chiral molecules, however (if there is no racemic mixture), no opposite orientation is present and there is a net rotation.
An interesting phenomenon was observed when the CD of chiral molecules was measured in achiral solvents. The chiral solvent contributed as much as 10-20% to the CD intensity in some cases. Apparently, the chiral compound can induce a solvation structure that is chiral, even when the solvent molecules themselves are achiral.