![\"\"](\"http:\/\/box5250.temp.domains\/~aceorgan\/blog\/resonance1.jpg\" "\\"resonance")
<\/p>\nHi Everybody–Resonance is one of those issues that you will have to deal with for both semester I & II organic chemistry.\u00a0 It is much better to have a solid understanding of it now, rather than have to worry about it later.\u00a0 The basic goal of resonance structures is to show that molecules can move electrons and charges\u00a0onto different atoms on the molecule.\u00a0 This makes the molecule generally more stable because the charge is now delocalized and not “forced” on an atom that does not want it.<\/p>\n
\u00a0<\/p>\n
Below\u00a0are some handy rules of\u00a0resonance.\u00a0 If you learn these and think about them when tackling different resonance problems, you will be able to handle whatever is thrown at you.<\/p>\n
\u00a0<\/p>\n
1) Know each atom’s “natural state”.\u00a0 You need to recognize what each atom generally looks like, in an uncharged state.\u00a0 This will help you to construct the\u00a0Lewis Dot structure on which you will base your resonance structures.\u00a0 In most uncharged cases:<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – C has four bonds and no lone pairs<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – N has three bonds and one lone pair<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – Halogens (F, Cl, Br, I) have one bond and three lone pairs.\u00a0<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – O has two bonds and two lone pairs<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – H has one bond and no lone pairs<\/p>\n
\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 – With the exception of H, everyone in group I & group II are only counterions (+1 or +2 and not involved in resonance).<\/p>\n
Remember that halogens and hydrogens are always terminal, meaning that are at the end of the molecule and only have one bond, and therefore, they will not participate in resonance.<\/p>\n
2) Atom positions will not change.\u00a0 Once you have determined that an atom is bonded to another atom, that will not change in a resonance structure.\u00a0 If they do change, it is no longer a resonance strucutre, but is now a constitutional isomer.<\/p>\n
\u00a0<\/p>\n
3) Check the structure you have created to make sure that it follows the octet rule.\u00a0 This will become much easier once you have a better handle on the “natural state” of atoms.<\/p>\n
\u00a0<\/p>\n
4) When two or more resonance structures can be drawn, the one with the fewest total\u00a0charges is the most stable.\u00a0 In the example below, A is more stable than B.<\/p>\n
\u00a0<\/p>\n
\u00a0<\/p>\n
5) When two or more resonance structures can be drawn, the more stable has the negative charge on the more electronegative atom.\u00a0 In the example below, A is more stable than B.<\/p>\n
\u00a0![\"\"](\"http:\/\/box5250.temp.domains\/~aceorgan\/blog\/resonance2.jpg\" "\\"resonance2\\"")
<\/p>\n
6) In the end, each resonance structure should have the same overall charge and total number of electrons (bonds + lone pairs) as when you started.<\/p>\n","protected":false},"excerpt":{"rendered":"
Hi Everybody–Resonance is one of those issues that you will have to deal with for both semester I & II organic chemistry.\u00a0 It is much better to have a solid understanding of it now, rather than have to worry about it later.\u00a0 The basic goal of resonance structures is to show that molecules can move […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[4,8,9],"tags":[44,46],"class_list":["post-73","post","type-post","status-publish","format-standard","hentry","category-chemistry","category-o-chem-help","category-organic-chemistry","tag-chemistry","tag-organic-chemistry"],"yoast_head":"\n