分子模拟实验实验报告甲酸的故事

1、分子模拟实验作业甲酸的故事一、实验部分1.用GAMESS程序优化甲酸分子、一氧化碳分子和水分子的结构（HF/6-31G(d)）H2O:GAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy = -47705.498936 kcal/mol (-76.023615 Hartrees)HCOOHGAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy =-118455.220427 kcal/mol (-188.770566 Hartrees)C

2、OGAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy = -70744.027355 kcal/mol (-112.737877 Hartrees)E(H2O)= -47705.5kcal/molE(HCOOH)= -118455.2kcal/molE(CO)= -70744.0kcal/molE(反应物)= -118455.2kcal/molE(生成物)=- -47705.5kcal/mol -70744.0kcal/mol=-118449.5kcal/mol2.一个H2O催化的五元环络合物络合物结构图1. 一

3、个H2O催化甲酸解离的五元环络合物结构图络合物能量- GAMESS Interface -GAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy = -166164.064457 kcal/mol (-264.799511 Hartrees)E1=-166164.1kcal/mol3.一个H2O催化的六元环络合物络合物结构图2.一个H2O催化甲酸解离 的六元环过渡态结构图络合物能量- GAMESS Interface -GAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(

4、d,p)Finish energy = -166171.296248 kcal/mol (-264.811036 Hartrees)E2= -166171.3kcal/mol4.两个H2O催化的七元环络合物络合物结构图3.两个H2O催化甲酸解离 的七元环过渡态结构图络合物能量- GAMESS Interface -GAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy = -213877.508674 kcal/mol (-340.835787 Hartrees)E3= -213877.5kcal/mol5.两个H2

5、O催化的八元环络合物络合物结构图4.两个H2O催化甲酸解离 的八元环过渡态结构图络合物能量- GAMESS Interface -GAMESS Job: Minimize (Energy/Geometry) RHF/6-31G(d,p)Finish energy = -213887.311389 kcal/mol (-340.851409 Hartrees)E4= -213887.3kcal/mol6.甲酸自催化的七元环络合物络合物结构图5.两个H2O催化甲酸解离 的八元环络合物结构图络合物能量- GAMESS Interface -GAMESS Job: Minimize (Energy/G

6、eometry) RHF/6-31G(d,p)Finish energy = -236916.531395 kcal/mol (-377.550837 Hartrees)E5= -236916.5kcal/mol7.甲酸无催化的结构及能量拉长C-H和C-O键，减小H-O-C键角- GAMESS Interface -GAMESS Job: Optimize to Transition State RHF/6-31G(d,p)Finish energy = -118363.726456 kcal/mol (-188.624761 Hartrees)E6= -118363.7 kcal/mol图6

7、.无催化甲酸解离结构图7.各种条件催化甲酸解离的过程模拟图数据表格（以甲酸为能量基准）E (kcal/mol)E (kcal/mol)HCOOH（反应物）-118455.20H2O-47705.5CO-70744.0H2O+CO（产物）-118449.55.7HCOOH+H2O(五元环)-166164.1-3.4HCOOH+H2O(六元环)-166171.3-10.6HCOOH+2H2O（七元环）-213877.5-11.3HCOOH+2H2O（八元环）-213887.3-21.1HCOOH自催化-236916.5-6.1HCOOH无催化-118363.791.5甲酸解离的过程模拟图图6.甲酸催化解离过程图（图中能量为相对值，单位：kcal/mol）8.针对几种催化方式对甲酸解离能量影响的分析由甲酸解离过程的模拟图可知，催化甲酸解离条件按照甲酸解离由难到易依次为：无催化、一个水五元环催化、甲酸自催化、一个水六元环催化、两个水七元环催化、两个水八元环催化。本实验中，两个水八元环催化时活化能最小，为最佳催化条件，无催化势垒很高，可见在无催化条件下，甲酸很难解离。一个水六元环催化与两个水七元环催化的效果相近。二、实验心得与体会通过本次实验，我清楚地了解到了“甲酸的故事”。通过对不同条件下催化甲酸解离的结构和能量的计算，我找到了最优催化方式，本次实验，使我更加熟悉了建模的操作，对甲酸