Chemical Shift J-Coupling化学位移和J耦合 英文版.ppt

按一下以編輯母片標題樣式,按一下以編輯母片,第二層,第三層,第四層,第五層,*,Chemical Shift and J-Coupling,Chemical Shift,The surrounding electrons cause a,shielding magnetic field at the nucleus,Different environments cause different,shieldings,(Representing different local chemical environments,Proctor and Yu,1951,),Shielding Anisotropy(CSA),B,0,B,0,Chemical shift anisotropy,(CSA)tensor,In liquids,CSA is averaged out by rapid molecular tumbling;in solids,CSA is kept.,Electron clouds are seldom,spherically symmetrical.They,are anisotropic in almost,all molecules.,Oriented Molecules,B,0,Oriented Single Crystals,B,0,Powder(Polycrystalline Solid),B,0,Chemical Shift Tensor,Anti-shielding Is Possible,Some proton chemical shifts,Reference shift,Most shielded,Least shielded,CHARACTERISTIC PROTON CHEMICAL SHIFTS,Type of Proton,Structure,Chemical Shift,ppm,Cyclopropane,C,3,H,6,0.2,Primary,R-C,H,3,0.9,Secondary,R,2,-C,H,2,1.3,Tertiary,R,3,-C-,H,1.5,Vinylic,C=C-,H,4.6-5.9,Acetylenic,triple,bond,CC,-,H,2-3,Aromatic,Ar,-,H,6-8.5,Benzylic,Ar,-C-,H,2.2-3,Allylic,C=C-C,H,3,1.7,Fluorides,H,-C-F,4-4.5,Chlorides,H,-C-,Cl,3-4,Bromides,H,-C-Br,2.5-4,Iodides,H,-C-I,2-4,Alcohols,H,-C-OH,3.4-4,Ethers,H,-C-OR,3.3-4,Esters,RCOO-C-,H,3.7-4.1,Esters,H,-C-COOR,2-2.2,Acids,H,-C-COOH,2-2.6,Carbonyl Compounds,H,-C-C=O,2-2.7,Aldehydic,R-(,H,-)C=O,9-10,Hydroxylic,R-C-O,H,1-5.5,Phenolic,Ar,-O,H,4-12,Enolic,C=C-O,H,15-17,Carboxylic,RCOO,H,10.5-12,Amino,RN,H,2,1-5,Carbon-13 Chemical Shifts,Carbon-13*Environment,Chemical ShiftRange(,ppm,),(CH,3,),2,C*O,-12,CS,2,0,CH,3,C*OOH,16,C,6,H,6,65,CHCl,=,CHCl,(,cis,),71,CH,3,C*N,73,CCl,4,97,dioxane,126,C*H,3,CN,196,CHI,3,332,Phosphorous-31 Chemical Shifts,Phosphorous-31 Environment,Chemical ShiftRange(,ppm,),PBr,3,-228,(C,2,H,5,O),3,P,-137,PF,3,-97,85%phosphoric acid,0,PCl,5,80,PH,3,238,P,4,450,Compound,Chemical Shift(,ppm,)Relative to 85%H3PO4,PMe3,-62,PEt3,-20,PPr(n)3,-33,PPr(i)3,+19.4,PBu(n)3,-32.5,PBu(i)3,-45.3,PBu(s)3,+7.9,PBu(t)3,+63,PMeF2,245,PMeH2,-163.5,PMeCl2,+192,PMeBr2,+184,PMe2F,+186,PMe2H,-99,PMe2Cl,-96.5,PMe2Br,-90.5,Phosphorous(III)Chemical Shift Table,(from,Bruker,Almanac 1991),Phosphorous(V)Chemical Shift Table(from,Bruker,Almanac 1991),Compound,Chemical Shift(,ppm,)Relative to 85%H3PO4,Me3PO,+36.2,Et3PO,+48.3,Me4P+1,+24.4,PO4-3,+6.0,PF5,-80.3,PCl5,-80,MePF4,-29.9,Me3PF2,-158,Me3PS,+59.1,Et3PS,+54.5,Et4p+1,+40.1,PS4-3,+87,PF6-1,-145,PCl4+1,+86,PCl6-1,-295,Me2PF3,+8.0,Fluorine-19 Chemical Shifts,Fluorine-19 Environment,Chemical ShiftRange(,ppm,),UF,6,-540,FNO,-269,F,2,-210,bare nucleus,0,C(CF,3,),4,284,CF,3,(COOH),297,fluorobenzene,333,F-,338,BF,3,345,HF,415,Nitrogen-14 Chemical Shifts,Nitrogen-14*Environment,Chemical ShiftRange(,ppm,),NO,2,Na,-355,NO,3,-(aqueous),-115,N,2,(liquid),-101,pyridine,-93,bare nucleus,0,CH,3,CN,25,CH,3,CONH,2,(aqueous),152,NH,4,+(aqueous),245,NH,3,(liquid),266,B-11 Chemical Shift,Factors Affecting Chemical Shift,Temperature,Solvents(pH,concentration),Pressure,Major Contributions To CS,Applications of Chemical Shift,Applications of Chemical Shift,,www.bmrb.wisc.edu/data_access/outlier_selection_grid.html,Applications of Chemical Shift,Applications of Chemical Shift,Relaxation,dynamics,Solid state NMR,CS Imaging,Story Goes On,Indirect Dipolar Interaction,(J-Coupling),N,S,N,S,Interaction between spins mediated by electrons around them.,J-coupling is usually much smaller than direct dipolar coupling.,J-Coupling,NMR/I,Homonuclear,system,A,Heteronuclear,System,AX,System,X,X,A,X,Spin A:,Spin B:,00000000,10000000,11111101,11111111,11111110,01000000,00100000,11000000,01100000,00110000,1=“up”,0=“down”,General Cases of Two-Site,Homonuclear,Systems,00000,10000,11101,11111,11110,01000,00100,11000,01100,0011.00,Spin B,Spin A,Exercise:Who are They?,ABC System,Equivalent Spins,Coupled with,Quadrupolar,Spins,Strong Coupling and Quantum Mechanical Treatment,Example,Ha,Hb,Ha,（）,Karplus,Equation,Karplus,Equation showing the relationship between the observed coupling,constant and the,(=,-135,o,)angle.Note that unique solutions are obtained only for J 8 Hz and J 5 Hz.,Karplus,Equations,Karplus,Equations,3,J,H-C-C-H,=10 cos,2,q,for 0,q,90,0,and,3,J,H-C-C-H,=12 cos,2,q,for 90,q,180,0,Typical J-coupling constants,3,J,COCH,Mulloy,et al.,Carbohydr,.Res.,184,(1988)39-46,Tvaroska,et al.,Carbohydr,.Res.,189,(1989)359-362,Anderson et al.,J.Chem.Soc.,Perkin 2,(1994)1965-1967,3,J,COCC,B.Bose et al.,J.Am.Chem.Soc.,120,(1998)11158-11173,Q.,Xu,and A.Bush,Carbohydr,.Res.,306,(1998)335-339,M.J.Milton et al.,Glycobiology,8,(1998)147-153,3,J,CCCH,R.,Aydin,&H.,Gnther,Mag.,Reson,.Chem.,28,(1990)448-457,A.de Marco et al.,Biochemistry,18,(1979)3847-,3,J,POCH,Lankhorst,et al.,J.,Biomol,.,Struct,.,Dyn,.,1,(1984)1387-1405,3,J,CCOP,Lankhorst,et al.,J.,Biomol,.,Struct,.,Dyn,.,1,(1984)1387-1405,3,J,HNCH,S.,Ludvigsen,et al.,J.Mol.Biol.,217,(1991)731-A.,Pardi,et al.,J.Mol.Biol.,180,(1985)741-,V.F.,Bystrov,，,Prog,.NMR,Spectrosc,.,10,(1976)41-,3,J,CNCH,L.-F.Kao et al.,J.Am.Chem.Soc.,107,(1985)2323-,3,J,CNCC,L.-F.Kao et al.,J.Am.Chem.Soc.,107,(1985)2323-,3,J,HCOH,R.R.Fraser et al.,Can.J.Chem.,47,(1969)403-409,Applying the,Karplus,Equation,Applying the,Karplus,Equation,Long Range Coupling,Amino Acids,Amino Acid,Name,Abbr.,R=,Alanine,ala,A,CH,3,-,Arginine,arg,R,H,2,N-C(=NH,2,+,)-,NH-(CH,2,),3,-,Asparagines,asn,N,H,2,NC(O)CH,2,-,Aspartic acid,asp,D,HOOC-CH,2,-,Cysteine,cys,C,HS-CH,2,-,Glutamic,acid,glu,E,HOOC-(CH,2,),2,-,Glutamine,gln,Q,H,2,NC(O)CH,2,-,CH,2,-,Glycine,gly,G,H-,Histidine,his,H,Isoleucine,ile,I,CH,3,CH,2,-CH(CH,3,)-,Leucine,leu,L,(CH,3,),2,CHCH,2,-,Lysine,lys,K,+H,3,N(CH,2,),4,-,Methionine,met,M,CH,3,SCH,2,CH,2,-,Phenylalanine,phe,F,Ph-CH,2,-,Praline,pro,P,Serine,ser,S,HOCH,2,-,Threonine,thr,T,CH,3,CH(OH)-,Tryptophan,trp,W,Tyrosine,tyr,Y,HO-Ph-CH,2,-,Valine,val,V,(CH,3,),2,CH-,Summary of one-bond,heteronuclear,couplings along the polypeptide chain utilized in 3D and 4D NMR experiments,Structure of an A-U(top)and a C-G,(bottom)Watson-Crick base pair.Notice that in each,case,there is a single N-H.N hydrogen bond.Scalar,coupling across this bond was determined to be,approximately 6.3 Hz for the GC,bp,and 6.7 Hz for the,AU,bp,.Non-Watson Crick,bp,schemes(such as,Hoogsteen,)contain different hydrogen bonds that can be,distinguished from traditional Watson-Crick.,(CH,3,),2,CH,(CH,3,),2,CH,Coupled,Decoupled,Varian parameters:,dn,dm,dmm,dpwr,C-H Coupling and,13,C Broadband Decoupling,13,C-,1,H Coupling and,13,C Broadband Decoupling,Selective Decoupling of,1,H-,1,H,Selective Decoupling of,1,H-,1,H,