Lecture 14-NMR [核磁共振计算]

1、计算化学及其应用计算化学及其应用Computational Chemistry and Its ApplicationpyppDalian Universityof TechnologyComputational Chemistry, Lecture 142011 Autumn本资料来自于大工人论坛（）大工人（）是大连理工大学由学生自主成立的新兴论坛，正式成立于2011年6月8日。秉着团结进取，求实创新的大工精神，初步形成了一个创新合作优势互补的团队。旨在为大工的每一位学子提供一个一起学习，一起进步，一起娱乐的网上交流平台，真正的做到属于大工每个人的论坛。你们的支持就是我们前进的动力大工人社区

2、|家园|群组|游戏大工校园校内校外|交友广场|校务通知|新生专区|失物招领|大工知道一起进步课业资料|考研交流 |电脑技术|创意交流|职来职往|热点聚焦校园集市跳蚤市场|家教兼职休闲娱乐开心灌水|趣味测试|精彩应用站务专区事务所|公告区Lecture 14NMRCalculationNMR CalculationDalian Universityof TechnologyComputational Chemistry, Lecture 142011 AutumnMethaneNMRShieldingConstantsMethane NMR Shielding Constants(1)(1) C

3、reating methane moleculeCreatingmethanemolecule(2) Structure optimization# B3LYP/6-31G(d) opt(3) NMR calculation(3)NMRcalculation# B3LYP/6-31G(d) NMR(4) follow (1)(3) to calculate the NMR shieldingconstantsofstandardcompoundshielding constants of standard compound, often tetramethylsilane (TMS)Dalia

4、n Universityof TechnologyComputational Chemistry, Lecture 142011 AutumnPart of an output file of NMR calculationCalculating GIAO nuclear magnetic shielding tensors.SCF GIAO Magnetic shielding tensor (ppm):1CIsotropic=1929900Anisotropy=000001 C Isotropic = 192.9900 Anisotropy = 0.0000XX= 192.9900 YX=

5、 0.0000 ZX= 0.0000XY= 0.0000 YY= 192.9900 ZY= 0.0000XZ=00000YZ=00000ZZ=1929900XZ= 0.0000 YZ= 0.0000 ZZ= 192.9900Eigenvalues: 192.9900 192.9900 192.99002 H Isotropic = 31.8854 Anisotropy = 8.5975XX= 31.8854 YXXX318854YX= 2.8658 ZX28658ZX= 2.865828658XY= 2.8658 YY= 31.8854 ZY= 2.8658XZ= 2.8658 YZ= 2.8

6、658 ZZ= 31.8854Eigenvalues: 29.0196 29.0196 37.6170g3 H Isotropic = 31.8854 Anisotropy = 8.5975XX= 31.8854 YX= 2.8658 ZX= -2.8658XY= 2.8658 YY= 31.8854 ZY= -2.8658XZ= -2.8658 YZ= -2.8658 ZZ= 31.8854Eigenvalues: 29.0196 29.0196 37.6170Dalian Universityof TechnologyComputational Chemistry, Lecture 142

7、011 AutumnResultsAbsolute Shielding value for C atomgCH4: 193.0 ppmppSiMe4: 189.7ppm189.7193.0 = 3.3The relative value ( 3.3 ppmpp) is comparable pto the experimental value (-7.0 ppm)A negative number indicates more shielding, and a positive number indicates less shielding. Dalian Universityof Techn

8、ologyComputational Chemistry, Lecture 142011 AutumnNMR properties of Alkanes, NMRpropertiesofAlkanes,Alkenes an Alkynes(1) butane(2）2-butene (trans)(3)2-butynebutyne (3) 2Model chemistry: Optimization at B3LYP/6-31G(d);NMRlltiNMR calculation at B3LYP/6-31G(d)tB3LYP/631G(d)Taking the value for the ce

9、ntral carbons in butane as reference value (176.3 ppm)Dalian Universityof TechnologyComputational Chemistry, Lecture 142011 AutumnResultsCCompounddbutane2-butene2-butyneC1 (outer)C1(t)Calc. Expt.-11.8-7.6C2 (inner)C2(i)Calc. Expt.0.00.0100.848.4Dalian Universityof TechnologyComputational Chemistry, Lecture 142011 AutumnFurther TrainingPleasetrytocomputethemagneticgofnitrog