{"id":112,"date":"2012-10-12T14:50:34","date_gmt":"2012-10-12T14:50:34","guid":{"rendered":"http:\/\/www.studyorgo.com\/blog\/?p=112"},"modified":"2014-02-21T03:22:24","modified_gmt":"2014-02-21T03:22:24","slug":"chirality-stereoisomers-enantiomers","status":"publish","type":"post","link":"https:\/\/www.studyorgo.com\/blog\/chirality-stereoisomers-enantiomers\/","title":{"rendered":"Chirality, Stereoisomers, Enantiomers"},"content":{"rendered":"<p>Hello Orgo Students!<\/p>\n<p>Here at <a title=\"Organic Chemistry Help\" href=\"\/\">StudyOrgo.com<\/a> we like to simplify things. You know that whole big chapter in your textbook on Chirality, Stereoisomers and Enantiomers that&#8217;s so confusing that you&#8217;re just lost?! Well, let&#8217;s see if we can simplify things.<\/p>\n<p>Here is our summary on the topic:<\/p>\n<p>This is some of the information presented in Part 9 of our Study Guide: one of the many resources available to <a href=\"studyorgo.com\">StudyOrgo.com<\/a> members. Learn more about it here:\u00a0<a href=\"http:\/\/www.studyorgo.com\/how-it-works.php\">http:\/\/www.studyorgo.com\/how-it-works.php<\/a><\/p>\n<p>&nbsp;<\/p>\n<ol>\n<li>Chiral\n<ol>\n<li><span style=\"text-decoration: underline;\">Definition<\/span>: a plane of symmetry does NOT exist in a given structure<\/li>\n<li>Two objects are chiral if they are NOT superimposable on one another<\/li>\n<\/ol>\n<\/li>\n<li>Achiral\n<ol>\n<li><span style=\"text-decoration: underline;\">Definition<\/span>: a plane of symmetry DOES exitst in a given structure<\/li>\n<li>Two objects are achiral if they are superimposable on one another<\/li>\n<\/ol>\n<\/li>\n<li>Enantiomers\n<ol>\n<li><span style=\"text-decoration: underline;\">Definition<\/span>: Two isomers that are mirror images of one another<\/li>\n<li>Enantiomers are chiral and they are NOT superimposable on one another<\/li>\n<li>Properties of Enantiomers\n<ol>\n<li>A pair of enantiomers almost have identical properties. They differ in one aspect:\n<ol>\n<li>Two enantiomers rotate plane-polarized light in opposite directions\n<ol>\n<li>Plane polarized light are light waves that travel only in one plane<\/li>\n<li>This is referred to as optical activity<\/li>\n<li>Clockwise rotations are abbreviated by a (+) or the letter &#8220;d&#8221;<\/li>\n<li>Counterclockwise rotations are abbreviated by a (-) or the letter &#8220;l&#8221;<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<li>Racemic mixture\n<ol>\n<li>Definition: When equal amounts of each enantiomer of a pair are mixed together<\/li>\n<li>While each individual enantiomer on its own is optically active, when the two equal amounts are mixed together, the mixture is NOT optically active<\/li>\n<\/ol>\n<\/li>\n<li>Meso compound\n<ol>\n<li>Definition: A structure that possesses both a plane of symmetry and at least one asymmetric carbon. Meso compounds are achiral.<\/li>\n<\/ol>\n<\/li>\n<li>Chiral carbons\n<ol>\n<li>A chiral carbon has four different items attached to it.<\/li>\n<li>A chiral carbon is also known as asymmetric carbon<\/li>\n<li>The chiral carbon is the chirality center of the molecule<\/li>\n<li>Enantiomers possess chiral carbons.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<li>R and S nomenclature\n<ol>\n<li>Used to assign an identifying label to each chiral carbon in a given enantiomer<\/li>\n<li>How to determine R and S nomenclature\n<ol>\n<li><span style=\"text-decoration: underline;\">Step 1: Find the chiral carbon<\/span><\/li>\n<li><span style=\"text-decoration: underline;\">Step 2: Assign the numbers 1 through 4 to each item attached to that carbon.<\/span>\n<ol>\n<li>Assign 1 to the item that is of highest priority through 4 to the item of lowest priority<\/li>\n<li>Hierarchy of priority (in order from most important to least important)\n<ol>\n<li>a. Halogens (I&gt;Br&gt;Cl&gt;F)<\/li>\n<li>O<\/li>\n<li>N<\/li>\n<li>C<\/li>\n<li>H<\/li>\n<\/ol>\n<\/li>\n<li>Some important notes:\n<ol>\n<li>a. Often you will have a tie. In that case, go to the next item after that atom to break the tie and determine the priority.<\/li>\n<li>b. When encountering double or triple bonds, pretend they are single bonds and duplicate the items attached to that bond. Duplicate twice for triple bonds.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<li><span style=\"text-decoration: underline;\">Step 3: Draw a circle from 1 to 2 to 3 to 4. <\/span>\n<ol>\n<li>Before starting, look and see where item #4 is. If item #4 is within the plane of the screen or paper: redraw the image to have item #4 going into the plane of the screen or paper before continuing.\n<ol>\n<li>If item #4 is going into the screen or paper or coming out of the screen or paper, continue as follows.<\/li>\n<\/ol>\n<\/li>\n<li>Determine if the circle was drawn clockwise or counterclockwise.<\/li>\n<li>If the circle was drawn clockwise: assign the letter &#8220;R&#8221;<\/li>\n<li>If the circle was drawn counterclockwise: assign the letter &#8220;S&#8221;<\/li>\n<\/ol>\n<\/li>\n<li><span style=\"text-decoration: underline;\">Step 4: Check and see where the item #4 is<\/span>\n<ol style=\"text-align: left;\">\n<li>Usually this item is a hydrogen. If item #4 is in the plane positioned behind you or is going into the plane of the screen or paper then leave the assigned letter as is. However, if item #4 is positioned in front or is coming out of the plane of the screen or paper, then assign the opposite letter from what you assigned in Step 3.<\/li>\n<li>If item #4 is coming out of the plane of the screen or paper? assign the opposite letter\n<ol>\n<li>If R was chosen: new assignment is S<\/li>\n<li>If S was chosen: new assignment is R<\/li>\n<\/ol>\n<\/li>\n<li>Remember, if item #4 is within the plane of the screen or paper: redraw the image to have item #4 going into the plane of the screen or paper before determining clockwise or counterclockwise (see step 3 above).<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":"<p>Hello Orgo Students! Here at StudyOrgo.com we like to simplify things. You know that whole big chapter in your textbook on Chirality, Stereoisomers and Enantiomers that&#8217;s so confusing that you&#8217;re just lost?! Well, let&#8217;s see if we can simplify things. Here is our summary on the topic: This is some of the information presented in [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[1],"tags":[],"class_list":["post-112","post","type-post","status-publish","format-standard","hentry","category-organic-chemistry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/posts\/112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/comments?post=112"}],"version-history":[{"count":6,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/posts\/112\/revisions"}],"predecessor-version":[{"id":388,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/posts\/112\/revisions\/388"}],"wp:attachment":[{"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/media?parent=112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/categories?post=112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.studyorgo.com\/blog\/wp-json\/wp\/v2\/tags?post=112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}