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MC LC1. S LC PH CNG HNG T PROTON (1H NMR)31. SPIN HT NHN V TN HIU HP TH41. Spin ht nhn v iu kin cng hng40. Spin ht nhn40. iu kin cng hng51. Ph k cng hng t proton51. Ph k cng hng t ht nhn sng lin tc51. Ph k cng hng t proton bin i Flourier61. S CHN V GIM CHN71. Cac yeu to anh hng en o dch chuyen hoa hoc70. Cc yu t ni phn t nh hng n dch chuyn ho hc71. S chn ti ch71. S chn t xa90. Cc yu t ngoi phn t nh hng n dch chuyn ha hc101. Lin kt Hidro101. S trao i proton101. nh hng ca dung mi101. nh hng ca nhit 111. Ht nhn tng ng v dch chuyn ha hc111. nh ngha111. dch chuyn ho hc131. Hng s chn v t trng hiu dng131. chuyn dch ho hc141. Phng php qut trng: thay i B0201. NG CONG TCH PHN221. PROTON TNG NG V KHNG TNG NG231. Cc proton tng ng v dch chuyn ho hc ( ph 1H NMR)231.1. Cc proton tng ng231.2. Cc proton khng tng ng242. Cng phn tch ca mi cng hng241. TNG TC SPIN SPIN241. Bn cht tng tc spin-spin241. Hng s tng tc spin-spin251. Tng tc spin spin trong ph 1H NMR252. L thuyt tch spin spin 252. Quy tc (n+1)262. Gii hn s ghp t262. S ghp spin271. PH 1H NMR V TIN TRNH TC 281. Phng php phn tch ph cng hng t ht nhn 1H280. K hiu ca ph280. Ph bc 1280. Ph bc cao AB, A2B v ABX322. Ph AB322. Ph A2B ph l thuyt ca A2B342. Ph ABX360. Ghp xa 371. Cng vn ph cng hng t proton371. KHO ST PH 1H NMR CA MT S LOI HP CHT HU C381. CCH GII PH421. NG DNG481. ng dng lm sng ca cng hng t ph (1H- NMR) trong chn on u no trong trc ngi ln481. X tr bng proton chng t hiu qu tt hn so vi tia X thng thng trong vic cha tr mt s loi bnh ung th nht nh nh ung th u v c, ung th phi, ung th tuyn tin lit50

I. S LC PH CNG HNG T PROTON (1H NMR)Ph proton c th xem l ph c nhy cao nht trong k thut 1D-NMR v hm lng 1H trong t nhin chim n 99.98% ( trong khi hm lng C-13 trong t nhin ch chim 1.108% ). V th y l mt ph rt quan trng v c th cung cp nhiu thng tin qu gi v cu trc ca hp cht.Ph 1H-NMR l mt k thut s dng xc nh cu trc ha hc ca hp cht hu c. Ph proton cho ta bit c s loi proton c trong phn t (khng phi l s proton, m ch l s loi proton ). Mi loi proton s c tnh cht khc nhau (nh proton lin kt vi vng benzen s khc vi proton lin kt vi Csp3) v th s c dch chuyn khc nhau trn ph proton. Ngi ta s dng TMS (tetra methyl silan) lm cht chun trong ph proton v dch chuyn ca proton trong TMS c chn l 0 pmm .Mt im c bit ca ph proton l ngoi cho bit loi proton trong phn t, ph cn cho bit mi quan h gia cc proton gn nhau thng qua s ghp spin v hng s ghp. Hai proton lin kt vi hai carbon k nhau s tng tc vi nhau thng thng qua 3 lin kt H-C-C-H v dng mi ghp spin s theo nguyn tc (n + 1) ( v d CH3-CH2- th proton CH3- s c dng mi 3 v proton CH2- s c dng mi 4 do cnh l ba proton ) v s c cng hng s ghp ( coupling constant ).

Hnh dng cc mi ghp spin n gin ( H AX )

II. SPIN HT NHN V TN HIU HP TH1. Spin ht nhn v iu kin cng hng1.1. Spin ht nhnHt nhn nguyn t gm cc proton v ntron. S lng t spin ca proton cng nh ca ntron u bng . Tu thuc vo cc nucleon c cp i hay khng m ht nhn nguyn t c th c c trng bi mt s lng t spin ht nhn I bng khng hoc khc khng. Nu spin ca tt c cc nucleon u cp i th s lng t spin ht nhn bng khng (I=0). Nu ht nhn c mt spin khng cp i th I = , nu c nhiu spin khng cp i th I 1. C mt s quy tc kinh nghim phng on s lng t spin ht nhn: I = 0 i vi cc ht nhn cha s proton chn v s ntron chn (16O, 12C, 32S) I = s nguyn (1, 2, 3, ) i vi cc ht nhn cha s proton l, s ntron cng l (14N, 10B, 2H (D)) I = na s nguyn (1/2, 3/2, 5/2,) i vi cc ht nhn c s proton chn, s ntron l hoc ngc li (1H, 19F, 31P,)Nhng ht nhn khng c spin I = 0 th khng gy ra momen t ( = 0) tc l khng c t tnh. Ngi ta ni ht nhn khng c t tnh v khng c cng hng t ht nhn. Nhng ht nhn c I 0 gy ra mt momen t 0. Ht nhn c hot ng t v c cng hng t ht nhn.Khi t ht nhn c I 0 vo trong mt t trng B0 th vect momen t ht nhn c nh hng trong trng B0 theo s lng t, momen gc ca spin ht nhn mI. S lng t momen gc ca spin ht nhn s nhn mt trong (2I + 1) gi tr, l mt trong cc s I, I 1, , -I + 1, -I.V d: I = th mI = v -1/2I = 1 th mI = -1, 0, 1Hiu s gia hai mc nng lng ht nhn tng ng vi hm sng ht nhn c tnh bng cng thc:

(1): T s t hi chuyn, c trng cho mi loi ht B0 : cng t trng h : hng s PlankBiu thc trn cho thy E ph thuc vo bn than ht nhn v vo cng ca t trng p t cho ht nhn. V E= h ( theo Borh ) nn suy ra

vi l tn s (Hz)(2)H phng ny l php o c bn ca php o ph cng hng t ht nhn1.2. iu kin cng hng c c ph cng hng t ht nhn ta cn t mu nghin cu vo mt t trng mnh, c cng B0 v tc dng ln mu mt tn s tha mn phng trnh (2). Trong cc iu kin ny s xy ra cc hin tng l c s chuyn cc ht nhn t mc nng lng ny ln mt mt mc nng lng cao hn lc ny xy ra cng hng t ht nhn.2. Ph k cng hng t proton2.1. Ph k cng hng t ht nhn sng lin tcB phn chnh ca ph k ny l mt nam chm in hay nam chm siu dn c t trng B0 ng nht, mt b phn pht t trng v tuyn to tn s B1 v mt cun t cm nhn tn hiu. mu c t trong ng thy tinh di 20cm c ng knh 5mm v quay lin tc t trng tc ng ng nht vo mi ch ca mu. T trng B1 c pht hin lin tc nn c gi l ph k cng hng t ht nhn sng lin tc. Ph k nhn c l ng cong a hm s ph thuc tn s f().My ch ghi dng dung dch. Dung mi thng dng l nhng cht khng cha ht nhn t proton nh CCl4, CDCl3, ...thng dng TMS lm cht chun.2.2. Ph k cng hng t proton bin i FlourierPh k loi ny c t trng B1 tc ng khng lin tc ln ht nhn nguyn t c t trong t trng B0. Tn hiu cao tn c iu phc bng cc xung vung v hp. Sau cc xung /2 v nhn c tn hiu cm ng t do (FID). Ph k nhn c di dng ng cong ca hm s ph thuc thi gian f(t). Trn ph o c thi gian phc hi ngang T2v thi gian phc hi dc T1.u im ca ph k bin i Flourier l c nhy cao v c t s tn hiu/nhiu ln v c th tu c nhiu thng s t ph k.1- My pht tn hiu cao tn2- To dy xung theo cc chng trnh nh sn3- iu phc bin cao tn theo xung vung4- u o to t trng khng lin tc5- Thu tn hiu tch lu ghi cc im ph ca cm ng t do6- Bin i Flourier7- Ghi ph f()8- My tnh iu hnh chng trnh xung, tch ly s liu, bin i Flourier, x l, ghi ph.

III. S CHN V GIM CHN1. Cc yu t nh hng n dch chuyn ho 1.1. Cc yu t ni phn t nh hng n dch chuyn ho a. S chn ti chTrc ht ta xt trng hp proton. Trong phn t proton t nhiu u c bao quanh bi electron. Di tc dng ca t trng B0, electron s chuyn ng thnh mt dng in vng quanh proton. Dng in ny lm pht sinh mt t trng cm ng m ng sc ca n v bng cc nt t. vng gn ht nhn, t trng cm ng ny ngc chiu vi t trng B0, n chng li t trng sinh ra n v lm cho t trng hiu dng Hhd quanh proton gim i so vi B0 ( Bhd < B0 ). Nh th elelctron che chn cho proton. Ngi ta gi n l s chn mn electron ti ch hay s chn ti ch. V s chn ti ch lm gim cng t trng tc ng ti ht nhn, do nu ht nhn c chn mn nhiu th cho n i vo cng hng cn phi tng cng t trng.S chn ny ph thuc mt elelectron xung quanh ht nhn ang xt nn n c lin quan trc tip n m in ca cc nguyn t hoc nhm nguyn t nh vi ht nhn . Ngoi s ph thuc vo mt electron s chn cn ph thuc hnh dang v kch thc elelctron.Trn thc t cc proton trong hp cht hu c khng tr tri m chng c bao quanh bi cc in t, cc in t ny che chn 1 phn no nh hng ca t trng bn ngoi ln proton. Cc in t di chuyn v to nn t trng cm ng c cng nh, ngc chiu vi t trng bn ngoi dn n t trng hiu dng Tc dng ln proton thc t s nh hn khi t trng p t ln proton, trn thc t ngi ta ni ht nhn b chn bi cc in t bao quanh n. Do mi ht nhn trong phn t hu c c boa quanh bi nhng m my in t khc nhau nn mi loi ht nhn b chn khc nhau My cng hng t ht nhn nhanh nhn bit c tng s khc bit nh ny ghi thnh nhng tn hiu cng hng nh hng ca hiu ng cm ng m ca nhm k

Nhm k c th gm 1 nguyn t hay nhm nguyn t, gy nh hng n nhm cn li. Cc loi ht nhn khc nhau trong 1 phn t c dch chuyn ho hc khc nhau l do mi loi ht nhn c che chn khc nhau bi cc m my in t xung quanh. Ht nhn no c che chn cng nhiu th cng cn t trng mnh hn cng hng, h qu l cc ht nhn ny hp thu vng trng cao. Ht nhn no c cc in t che chn t th ch cn tc dng bi 1 t trng yu l c th cng hng, h qu l cc ht nhn ny hp thu vng trng thp. Khi proton gn vo cacbon i vi nguyn t c m in mnh, cc nguyn t ny s ht i in t ni ho tr v vi n, lm gim s chn ca in trng bn ngoi vo proton kho st v th proton cng c gim chn nn c dch chuyn ho hc vng trng thp.S che chn ny gim dn theo khong cch sau 4 ni ho tr s gim chn ht tc dng.CH3XCH3FCH3OHCH3ClCH3BrCH3ICH4

XXFOClBrIH

m in4,03,53,12,82,52,1

4,263,403,052,682,160,23

b. S chn t xaKhng phi lc no trt t v dch chuyn ha hc cng tng ng vi trt t v m in. Chng hn, proton ca benzen cho tnh hiu trng yu hn proton ca etilen v proton ca acetilen mc d m in ca Csp2 nh hn ca csp. Thm na tn hiu ca proton benzene th hin trng yu hn CH2Cl2 v H2O mc d mt electron xung quanh ht nhn ny khng tng ng vi s thay i v dch chuyn ha hc nh th. Nhng nguyn t hoc nhm nguyn t bn cnh proton, c bit l nhng nhm khng no, nhm vng thm, hoc cc nguyn t c cha cp electron khng lin kt c th l ngun gc ca nhng dng in vng mnh hn v to ra xung quanh proton cc t trng c hiu sut ln hn t trng ca cc electron ha tr ca chnh proton . Chnh v th nhng nhm nguyn t bn cnh proton cng c tc dng che chn i vi proton. l s chn t xa hay cn gi l s chn bt ng hng bi v hng ny th b chn cn hng kia th b phn chn.1.2. Cc yu t ngoi phn t nh hng n dch chuyn ha hca. Lin kt HidroLin kt hiro gy ra s thay i ng k dch chuyn ha hc ca proton cc nhm OH, NH, v i khi c nhm SH. Nh bit, lin kt hiro ph thuc nhiu vo bn cht dung mi, nng v nhit . Chnh v vy, chuyn dch ha hc ca cc proton axit bin i trong mt khong rng. Do tm tn hiu ca cc proton axit chng cn xt xem chng c to lin kt hidro hay khng, mc lin kt hidro nh th no.b. S trao i protonProton lin kt vi cc d t nh O, N,...khng nhng c kh nng to lin kt hiro m cn c kh nng trao i vi proton ca cc tiu phn xung quanh. S trao i proton cng th hin r trn ph NMR.Th d: Khi o ph ca CH3COOH trong nc ngi ta khng nhn c tn hiu ca proton COOH v proton ca nc mt cch ring r m nhn c tn hiu chung cho chng. l do tc ion ha nhanh n mc m s trao i xy ra khi proton vo trng thi cng hng.CH3COOH + H2O CH3COO- + H3O+c. nh hng ca dung miKhi thay dung mi CCl4 bng CDCl3, chuyn dch ha hc ca proton lin kt vi cacbon ch thay i 0.1ppm. Cn khi chuyn sang cc dung mi phn cc hn nh CD3OD, CD3COCD3... th