From owner-chemistry@ccl.net Tue Sep 25 05:07:01 2012 From: "Nguyen Minh Ly nguyenminhly2209*|*yahoo.com" To: CCL Subject: CCL:G: SN1 reaction Message-Id: <-47657-120925050542-28343-MQwEw5E67ds5F8ifYeK1aA|server.ccl.net> X-Original-From: "Nguyen Minh Ly" Date: Tue, 25 Sep 2012 05:05:39 -0400 Sent to CCL by: "Nguyen Minh Ly" [nguyenminhly2209,yahoo.com] I have a problem to discuss. I survey the SN1 reaction of tert-butyl chloride and OH- by: 1 / Optimization of structures with Gaussian 2 / Optimize to find the transition state in the first stage of the SN1 reaction (using QST2 keyword) As we all know, this reaction depends on the concentration of OH-. If concentration of OH- is low (dilute solution), the reaction will occur SN1. If concentration of OH- is high (special solution), the reaction will occur E1. But in GaussView, when I optimized to find the transition state in the first stage of the SN1 reaction, I can only draw a molecule C4H9Cl and a OH- in Reactants window, a molecule C4H9OH and a Cl- in products window. This means that the rate of C4H9Cl and OH- concentration in the solution was 1:1 (corresponding to the high concentration of OH-). So E1 reaction will occur! But I want to find the transition state in the first stage of the SN1 reaction. How can do this ? Please help me Thank you