{"id":17710,"date":"2017-03-16T17:22:19","date_gmt":"2017-03-16T17:22:19","guid":{"rendered":"http:\/\/www.ch.imperial.ac.uk\/rzepa\/blog\/?p=17710"},"modified":"2017-03-16T17:22:19","modified_gmt":"2017-03-16T17:22:19","slug":"how-does-silane-invert-its-configuration","status":"publish","type":"post","link":"https:\/\/www.rzepa.net\/blog\/?p=17710","title":{"rendered":"How does silane invert (its configuration)?"},"content":{"rendered":"
\n

In the previous post<\/a>, I found intriguing the mechanism by which methane (CH4<\/sub>) inverts by transposing two of its hydrogens. Here I take a look at silane, SiH4<\/sub>.<\/p>\n

It appears it is a three-stage process! Firstly, silane eliminates molecular hydrogen to form a molecular complex between H2\u00a0<\/sub>and SiH2<\/sub> (DOI:\u00a010.14469\/hpc\/2290<\/a>). The barrier (~60 kcal\/mol) is very much lower than with methane.<\/p>\n

\"\"\"\"<\/a>\"\"<\/a><\/p>\n

The H2<\/sub> component of this complex then rotates (DOI: 10.14469\/hpc\/2289<\/a>) transposing atoms 1 and 2. The barrier for this process is tiny (~4 kcal\/mol).<\/p>\n

\"\"\"\"<\/p>\n

Finally, the rotated H2<\/sub>\/SiH2<\/sub> complex goes back to silane by the first route, but now with the two hydrogens transposed.<\/p>\n

So this inversion is a stepwise process<\/span><\/strong> in contrast to methane which was concerted<\/span><\/strong>, albeit with “frustrated” elimination of hydrogen. Again a little molecule can show us so much chemistry, in this case also illustrating the avoidance of a Woodward-Hoffmann forbidden cheletropic elimination<\/a> by desymmetrisation.<\/p>\n\n<\/div> ","protected":false},"excerpt":{"rendered":"

In the previous post, I found intriguing the mechanism by which methane (CH4) inverts by transposing two of its hydrogens. Here I take a look at silane, SiH4. It appears it is a three-stage process! Firstly, silane eliminates molecular hydrogen to form a molecular complex between H2\u00a0and SiH2 (DOI:\u00a010.14469\/hpc\/2290). The barrier (~60 kcal\/mol) is very […]<\/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":true,"_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":[1085],"tags":[1416,2072,2078,2088,2089],"class_list":["post-17710","post","type-post","status-publish","format-standard","hentry","category-reaction-mechanism-2","tag-chemistry","tag-industrial-gases","tag-methane","tag-sih2-complex","tag-silanes"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p1gPyz-4BE","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/17710","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=17710"}],"version-history":[{"count":0,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=\/wp\/v2\/posts\/17710\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=17710"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17710"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rzepa.net\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17710"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}