NMRcalculation2022
NMR calculation 2022
NMRcalculationCompute NMR for TMS using the same modelchemistry!Steps:1. Geometry optimization (TMS/Test molecule)2.NMR @ opted geom (TMS/Test molecule)G1:M1:V1-Gaussian Calculation Setup+ritle:B3LIP/6-31g(a)mmrKeywords:tp nmr=giaob3lyp/6-31g(d)nosynn geon=connectivityCharge/Mult.:01Job TypeMethodTitleLinkoGeneralNBOPBCAdd.InpGuessSolvation网NMRGIAO MethodVComputespin-spin couplings(forallatoms)NR-mixedAdditionalKeywords:Update(Unnamed Schene)Scheme:Quick LaunchCancelEdit..DefaultsHelpSubmit.Betain
NMR calculation Steps: 1. Geometry optimization (TMS/Test molecule) 2. NMR @ opted geom (TMS/Test molecule) Compute NMR for TMS using the same model chemistry!
In the log file, find "isotropic"189.6467Isotropic7.08822CAnisotropy188.0842YX=-1.9057XX=1:1170ZX=XY=1.1233YY=-2.7603188.8404ZY=-1.8910YZ=-2.7311192.0155XZ=ZZ=TMSdataobtained187.2496187.3183194.3721Eigenvalues:using the same model3HIsotropic32.17829.3882Anisotropy =29.0254-0.3421XX=YX--1.7738ZX=chemistryXY=YY=ZY=-1.877237.4413-2.286230.0679XZ=-0.2768YZ=-2.4656ZZ=28.188229.9093Eigenvalues:38.4370In GV6, TMS HF/6-31G(d);Results-NMRTMS B3LYP/6-311+G(2d,p);CH4HF/6-31G(d) GIAOG1:M1:V1-NMRSpectraG1:M1:V1-NMRSpectraPlotsPlots1SCF GIAo Magnetic shieldingSCF GIAO Magnetic sh6.0-6.010-H05.05.04.0--7H4.0SH3.013C谱1H谱3.012-H802.09H.1. 0-1.00.0ReTTTT0.07.06.04.08. 05.03.0TTTTTTTTTTUTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTShift(ppm)140120806040201001BefererefElement:CMMShiel3ng189.6467Element:HVReference:refShift(ppm)=7.2063,Degeneracy=6Shift(ppm)=120.983,Degeneracy=6
13C谱 1H谱 1 2 3 Results-NMR TMS data obtained using the same model chemistry In the log file, find “isotropic” In GV6, TMS HF/6-31G(d); TMS B3LYP/6-311+G(2d,p); CH4 HF/6-31G(d) GIAO
Exercises1. Compute the NMR spectrum for urea moleculeusing the model chemistry of HF/6-31G(d).H2NNH2. Compute the NMR spectrum for pyridinemolecule using the model chemistry ofB3LYP/6-311+G(2d,p)
Exercises 1. Compute the NMR spectrum for urea molecule using the model chemistry of HF/6-31G(d). 2. Compute the NMR spectrum for pyridine molecule using the model chemistry of B3LYP/6-311+G(2d,p)
Singlepointcalculation:NMR#TRHF/6-31G(d)NMR1. Shielding constants reported in experimental studies areusually shifts relativeto a standard compound, oftentetramethylsilane (TMS);2. In order to compare predicted values to experimentalresults, we also need to compute the absolute shieldingvalue;3. for TMS, using exactly the same model chemistry. Here isthe relevant output for TMS:GlAOMagneticshieldingtensor(ppm):1Clsotropic=195.1196Anisotropy17.52144. To obtain the predicted shift for the carbon atom inmethane, we subtract its absolute value from that of thereferencemolecule5
Single point calculation : NMR 5 #T RHF/6-31G(d) NMR 1. Shielding constants reported in experimental studies are usually shifts relative to a standard compound, often tetramethylsilane (TMS); 2. In order to compare predicted values to experimental results, we also need to compute the absolute shielding value; 3. for TMS, using exactly the same model chemistry. Here is the relevant output for TMS: GIAO Magnetic shielding tensor (ppm): 1 C Isotropic = 195.1196 Anisotropy 17.5214 4. To obtain the predicted shift for the carbon atom in methane, we subtract its absolute value from that of the reference molecule