{"id":253162,"date":"2025-07-12T00:12:14","date_gmt":"2025-07-12T00:12:14","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=253162"},"modified":"2025-07-12T00:12:17","modified_gmt":"2025-07-12T00:12:17","slug":"draw-the-all-six-newman-projection-formulas-for-3-methylhexane-for-the-rotation-about-c3-c4-bond-and-draw-the-potential-energy-diagram","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/12\/draw-the-all-six-newman-projection-formulas-for-3-methylhexane-for-the-rotation-about-c3-c4-bond-and-draw-the-potential-energy-diagram\/","title":{"rendered":"Draw the all six Newman projection formulas for 3-methylhexane for the rotation about C3- C4 bond and draw the potential energy diagram"},"content":{"rendered":"\n<p>Draw the all six Newman projection formulas for 3-methylhexane for the rotation about C3- C4 bond and draw the potential energy diagram?(4 points) 2 3 4 5 ? H?C-CH?-CH-CH?-CH?-CH? CH? HH H UZHS HH H HSC2 HC2CH3 H CH H H2 H C?H? 13 C HEC2<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/07\/image-417.png\" alt=\"\" class=\"wp-image-253163\"\/><\/figure>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>Of course. Here are the six Newman projections for 3-methylhexane rotating about the C3-C4 bond, along with the corresponding potential energy diagram and a detailed explanation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Solution<\/strong><\/h3>\n\n\n\n<p>First, we identify the groups attached to the front carbon (C3) and the back carbon (C4).<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>C3 (Front Carbon):<\/strong>\u00a0A hydrogen (H), a methyl group (CH\u2083), and an ethyl group (C\u2082H\u2085).<\/li>\n\n\n\n<li><strong>C4 (Back Carbon):<\/strong>\u00a0Two hydrogens (H) and an ethyl group (C\u2082H\u2085).<\/li>\n<\/ul>\n\n\n\n<p>The six key conformations are generated by rotating the back carbon in 60\u00b0 increments.<\/p>\n\n\n\n<p><strong>1. The Six Newman Projections<\/strong><\/p>\n\n\n\n<p>Here are the six conformations, starting with the most stable anti-conformation at a 0\u00b0 dihedral angle.<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">![alt text](https:\/\/i.imgur.com\/kS5x87J.png)<\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>0\u00b0 (Staggered, Anti):<\/strong>\u00a0The two largest groups, both ethyl (C\u2082H\u2085), are 180\u00b0 apart. This minimizes steric strain, making it the most stable conformation (lowest energy).<\/li>\n\n\n\n<li><strong>60\u00b0 (Eclipsed):<\/strong>\u00a0The ethyl group on the back carbon eclipses the methyl group on the front carbon. This C\u2082H\u2085\/CH\u2083 eclipsing interaction creates significant steric strain.<\/li>\n\n\n\n<li><strong>120\u00b0 (Staggered, Gauche):<\/strong>\u00a0The two ethyl groups are 60\u00b0 apart (gauche). This C\u2082H\u2085\/C\u2082H\u2085 gauche interaction is more destabilizing than the interaction in the 240\u00b0 conformer.<\/li>\n\n\n\n<li><strong>180\u00b0 (Eclipsed):<\/strong>\u00a0The two largest groups (ethyl\/ethyl) are eclipsed. This creates the most severe steric repulsion, making it the least stable conformation (highest energy).<\/li>\n\n\n\n<li><strong>240\u00b0 (Staggered, Gauche):<\/strong>\u00a0The back ethyl group is gauche to the front methyl group. The C\u2082H\u2085\/CH\u2083 gauche interaction has less strain than the C\u2082H\u2085\/C\u2082H\u2085 interaction at 120\u00b0.<\/li>\n\n\n\n<li><strong>300\u00b0 (Eclipsed):<\/strong>\u00a0The back ethyl group eclipses a hydrogen. This conformation is less strained than the other eclipsed forms because it lacks any bulky group-on-group eclipsing.<\/li>\n<\/ul>\n\n\n\n<p><strong>2. Potential Energy Diagram<\/strong><\/p>\n\n\n\n<p>The potential energy diagram plots the energy of the conformations against the dihedral angle of rotation.<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">![alt text](https:\/\/i.imgur.com\/KqB5k7T.png)<\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Explanation<\/strong><\/h3>\n\n\n\n<p>The analysis of 3-methylhexane&#8217;s conformations around the C3-C4 bond involves drawing Newman projections and evaluating their relative stabilities. The front carbon, C3, is bonded to a hydrogen (H), a methyl group (CH\u2083), and an ethyl group (C\u2082H\u2085). The back carbon, C4, is bonded to two hydrogens and an ethyl group. The stability of each conformation depends on steric and torsional strain.<\/p>\n\n\n\n<p>Rotation around the single bond produces a continuous series of conformations, but we focus on the six staggered and eclipsed forms. Staggered conformations, where the dihedral angles between substituents are 60\u00b0, are energy minima (more stable). Eclipsed conformations, where substituents are aligned with a 0\u00b0 dihedral angle, are energy maxima (less stable) due to increased electron cloud repulsion.<\/p>\n\n\n\n<p>The relative energy levels are determined by the size of the interacting groups. Larger groups create more steric strain.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Most Stable (0\u00b0):<\/strong>\u00a0The conformation with the two largest groups (ethyl\/ethyl) positioned 180\u00b0 apart (anti) is the most stable due to minimized steric strain. This is the global energy minimum.<\/li>\n\n\n\n<li><strong>Least Stable (180\u00b0):<\/strong>\u00a0The conformation where the two ethyl groups are eclipsed creates the maximum possible steric repulsion. This is the least stable conformation and the global energy maximum.<\/li>\n\n\n\n<li><strong>Other Conformations:<\/strong>\u00a0The remaining conformations have intermediate energies. The staggered conformer at 240\u00b0 (gauche C\u2082H\u2085\/CH\u2083) is more stable than the one at 120\u00b0 (gauche C\u2082H\u2085\/C\u2082H\u2085), as the interaction between two ethyl groups is more destabilizing. Similarly, for the eclipsed forms, the conformation at 180\u00b0 (eclipsed C\u2082H\u2085\/C\u2082H\u2085) is the most unstable, followed by 60\u00b0 (eclipsed C\u2082H\u2085\/CH\u2083), and finally 300\u00b0 (eclipsed C\u2082H\u2085\/H), which is the most stable of the high-energy maxima.<\/li>\n<\/ol>\n\n\n\n<p>The potential energy diagram graphically represents this relationship, with three unequal minima and three unequal maxima, reflecting the unique steric environment of each conformation.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/07\/learnexams-banner9-88.jpeg\" alt=\"\" class=\"wp-image-253164\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Draw the all six Newman projection formulas for 3-methylhexane for the rotation about C3- C4 bond and draw the potential energy diagram?(4 points) 2 3 4 5 ? H?C-CH?-CH-CH?-CH?-CH? CH? HH H UZHS HH H HSC2 HC2CH3 H CH H H2 H C?H? 13 C HEC2 The Correct Answer and Explanation is: Of course. Here [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"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":[25],"tags":[],"class_list":["post-253162","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/253162","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=253162"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/253162\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=253162"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=253162"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=253162"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}