{"id":9119,"date":"2013-01-13T09:15:37","date_gmt":"2013-01-13T09:15:37","guid":{"rendered":"http:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=9119"},"modified":"2013-01-13T09:15:37","modified_gmt":"2013-01-13T09:15:37","slug":"the-strangely-attractive-conformation-of-c17h36","status":"publish","type":"post","link":"https:\/\/www.rzepa.net\/blog\/?p=9119","title":{"rendered":"The strangely attractive conformation of C17H36."},"content":{"rendered":"<div class=\"kcite-section\" kcite-section-id=\"9119\">\n<p>We tend to think of simple hydrocarbons as relatively inert and un-interesting molecules. However, a recent article<span id=\"cite_ITEM-9119-0\" name=\"citation\"><a href=\"#ITEM-9119-0\">[1]<\/a><\/span>, which was in fact <a href=\"http:\/\/comporgchem.com\/blog\/?p=2366\" target=\"_blank\">highlighted<\/a> by Steve Bachrach on his blog , asks what &#8220;<em>The Last Globally Stable Extended Alkane<\/em>&#8221; might be. In other words, at what stage does a straight-chain hydrocarbon fold back upon itself, and no significant population of the linear form remain? The answer was suggested to be C<sub>17<\/sub>H<sub>36<\/sub>. I thought I might subject this conformation to an NCI (non-covalent-interaction) analysis.<\/p>\n<div id=\"attachment_9120\" style=\"width: 413px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-9120\" data-attachment-id=\"9120\" data-permalink=\"https:\/\/www.rzepa.net\/blog\/?attachment_id=9120\" data-orig-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?fit=672%2C376&amp;ssl=1\" data-orig-size=\"672,376\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"C17\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;NCI analysis. Click for  3D.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?fit=300%2C167&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?fit=450%2C252&amp;ssl=1\" class=\" wp-image-9120 \" onclick=\"jmolInitialize('..\/Jmol\/');jmolSetAppletColor('black');jmolApplet([500,500],'load wp-content\/uploads\/2013\/01\/C17_den.cub.xyz;isosurface wp-content\/uploads\/2013\/01\/C17_den.cub.jvxl;zoom 130;measure 27 20;measure 20 34;measure 34 32;measure 43 50;measure 22 29;measure 32 22;measure 45 47;');\" alt=\"NCI analysis. Click for  3D.\" src=\"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?resize=403%2C226\" width=\"403\" height=\"226\" srcset=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?w=672&amp;ssl=1 672w, https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C17.jpg?resize=300%2C167&amp;ssl=1 300w\" sizes=\"auto, (max-width: 403px) 100vw, 403px\" \/><p id=\"caption-attachment-9120\" class=\"wp-caption-text\">NCI analysis. Click for 3D.<\/p><\/div>\n<p>The colour coding for the <a href=\"http:\/\/hdl.handle.net\/10.6084\/m9.figshare.106658\" target=\"_blank\">NCI surface<\/a> is such that towards blue is attractive, with green being mildly attractive and yellow mildly repulsive. Both blue and yellow can be seen at the point where the molecule bends round, and attractive green dominates the region where the two chains are parallel. Much in the manner of a Gekko&#8217;s feet<span id=\"cite_ITEM-9119-1\" name=\"citation\"><a href=\"#ITEM-9119-1\">[2]<\/a><\/span>, the <a href=\"https:\/\/wiki.ch.ic.ac.uk\/wiki\/index.php?title=Coursework#Coursework_not_to_be_attempted_at_any_time:_Antimodelling_Molecules\" target=\"_blank\">strangely attractive van der Waals<\/a> terms in a hydrocarbon are surprisingly cumulative! \u00a0You can generate an NCI surface for your favourite molecule <a href=\"http:\/\/www.ch.ic.ac.uk\/rzepa\/cub2nci\/\" target=\"_blank\">here<\/a>.<\/p>\n<p><strong>Addendum:<\/strong> \u00a0To show that NCI interactions are pretty additive, here is \u00a0<a href=\"http:\/\/hdl.handle.net\/10.6084\/m9.figshare.106718\" target=\"_blank\">C<sub>28<\/sub>H<sub>58<\/sub><\/a>:<\/p>\n<div id=\"attachment_9131\" style=\"width: 384px\" class=\"wp-caption aligncenter\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-9131\" data-attachment-id=\"9131\" data-permalink=\"https:\/\/www.rzepa.net\/blog\/?attachment_id=9131\" data-orig-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?fit=624%2C528&amp;ssl=1\" data-orig-size=\"624,528\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"C28\" data-image-description=\"\" data-image-caption=\"&lt;p&gt;C28 double hairpin. Click for  3D.&lt;\/p&gt;\n\" data-medium-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?fit=300%2C253&amp;ssl=1\" data-large-file=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?fit=450%2C381&amp;ssl=1\" class=\" wp-image-9131 \" onclick=\"jmolInitialize('..\/Jmol\/');jmolSetAppletColor('red');jmolApplet([500,500],'load wp-content\/uploads\/2013\/01\/C28_den.cub.xyz;isosurface wp-content\/uploads\/2013\/01\/C28_den.cub.jvxl;zoom 130;');\" alt=\"C28 double hairpin. Click for  3D.\" src=\"https:\/\/i0.wp.com\/www.ch.imperial.ac.uk\/rzepa\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?resize=374%2C317\" width=\"374\" height=\"317\" srcset=\"https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?w=624&amp;ssl=1 624w, https:\/\/i0.wp.com\/www.rzepa.net\/blog\/wp-content\/uploads\/2013\/01\/C28.jpg?resize=300%2C253&amp;ssl=1 300w\" sizes=\"auto, (max-width: 374px) 100vw, 374px\" \/><p id=\"caption-attachment-9131\" class=\"wp-caption-text\">C28 double hairpin. Click for 3D.<\/p><\/div>\n<h2>References<\/h2>\n    <ol class=\"kcite-bibliography csl-bib-body\"><li id=\"ITEM-9119-0\">N.O.B. L\u00fcttschwager, T.N. Wassermann, R.A. Mata, and M.A. Suhm, \"The Last Globally Stable Extended Alkane\", <i>Angewandte Chemie International Edition<\/i>, vol. 52, pp. 463-466, 2012. <a href=\"https:\/\/doi.org\/10.1002\/anie.201202894\">https:\/\/doi.org\/10.1002\/anie.201202894<\/a>\n\n<\/li>\n<li id=\"ITEM-9119-1\">J. Yu, S. Chary, S. Das, J. Tamelier, N.S. Pesika, K.L. Turner, and J.N. Israelachvili, \"Gecko\u2010Inspired Dry Adhesive for Robotic Applications\", <i>Advanced Functional Materials<\/i>, vol. 21, pp. 3010-3018, 2011. <a href=\"https:\/\/doi.org\/10.1002\/adfm.201100493\">https:\/\/doi.org\/10.1002\/adfm.201100493<\/a>\n\n<\/li>\n<\/ol>\n\n<\/div> <!-- kcite-section 9119 -->","protected":false},"excerpt":{"rendered":"<p>We tend to think of simple hydrocarbons as relatively inert and un-interesting molecules. However, a recent article, which was in fact highlighted by Steve Bachrach on his blog , asks what &#8220;The Last Globally Stable Extended Alkane&#8221; might be. In other words, at what stage does a straight-chain hydrocarbon fold back upon itself, and no [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[1],"tags":[108,348,1527],"class_list":["post-9119","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-conformational-analysis","tag-steve-bachrach","tag-tutorial-material"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1gPyz-2n5","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/9119","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=9119"}],"version-history":[{"count":0,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/9119\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=9119"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=9119"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=9119"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}