ESPECTROMETRIA NO INFRAVERMELHO UMA PARTE DO ESPECTRO ELETROMAGNÉTICO, Esquemas de Química Orgânica

Baixe ESPECTROMETRIA NO INFRAVERMELHO UMA PARTE DO ESPECTRO ELETROMAGNÉTICO e outras Esquemas em PDF para Química Orgânica, somente na Docsity! ESPECTROMETRIA NO INFRAVERMELHO UMA PARTE DO ESPECTRO ELETROMAGNÉTICO alta Frequência (v) baixa alta Energia baixa RAIOS X ULTRAVIOLETA Ultravioleta Visível iraviraRio vibracional nuclear I | É 25um €—> 15 um 1 mé— 280 nm €— 3400 nm €——s 800 nm AZUL VERMELHA curto — — Comprimento de onda (N) ———— s longo VIBRAÇÕES DE ABSORÇÃO DE UM ÁLCOOL / Remains ot molecuje 7 4/// 7 77 (3) C—O stretching (2) C-O0-—H bending (in-plane) 1200-1000em= “es 1500 1200em”: S (4) C-0-H bending (out-of-plane) | 650 250em N N (1) 0-H stretching 3700-3000 cm =! Fig. 1.2 Vibrations and absorptions of the alcoholic hydroxyl group. FIGURA ESQUEMÁTICA DE UM ESPECTRÔMETRO DE INFRAVERMELHO FOTÔMETRO TERMOPAR MONOCROMADOR (REDE) ÁREA DA AMOSTRA Sistema óptico de um espectrofotômetro de infravermelho de feixe duplo. O ESPECTRO DE INFRAVERMELHO evcronexanont costa cu ' , WAVELENGTH dm 28 21 i 6 7 18 o ho 12 15 20 dos 000 ; Le Lual, a Ls ' 1 | , + 1 ] al i | 1 8 é í t ' E É I ' i ! E I I t 14 ê ' t ] Vo < 1 ' | ! ! 1 1 i | 19 | I 1 | ' I l à ! E | Eme sa 4600 1400 1 1200 foco 800 800 400 | cama nesta onjrmes nd enquency cu | a Darci d - WEcSÕ=E à 1 o-u Ee, “gu 4 Peace | <u i 1=CH 1=05€ 1 cem | Il Neo! 1 EA ea 1 nd ! i 1 -C | =uu 1 i 1 puma | j LN Je x ! Vibrações de estiramento (V) Vibr. de Estiramento e Deformação Vibr. de Deformação Fora do Plano Região da Impressão Digital 200 - VIBRAÇÕES FUNDAMENTAIS DE INFRAVERMELHO DO GRUPO CH; Nx MM A É a SS Estiramento simétrico (2853 cm”) A A c o x s ” EE H SN Estiramento assimétrico (-2926 em") VIBRAÇÕES DE ESTIRAMENTO Scissoring Wagging (-1450 em") (-1250 em”) 3 | sela | | n| 1H J | Rocking Twisting (-720 em) (1250 em) NO PLANO FORA DO PLANO VIBRAÇÕES DE DOBRAMENTO VIBRAÇÕES FUNDAMENTAIS DE INFRAVERMELHO DO GRUPO CH, Deformação axial simétrica (vs CH) -2853 cm! Deformação angular simétrica fora do plano (balanço) (wCH,) 1350-1150 em”! Deformação axial assimétrica (vas CHs) -2926 em! Deformação angular assimétrica fora do plano (meneio) (7CH,) 1350-1150 cm! Deformação angular simétrica no plano (6, CH,) -1465 em! Deformação angular assimétrica no plano (torcedura) (p CH;) -120 em! CÁLCULO DAS VIBRAÇÕES DE ESTIRAMENTO Eq. DE HOoOkE vp= An sm aa 21C) Ny My Mytr My D= freç. vibracioma| c= Veloc. da luz $= const. de gorça de ligação (dimas/Cara) My, My = massas dos átomos X «xy Cum gramas m= 3Ib f = 5x4 dimas/cm -> ligação simples =40x 409 “ o —s n duplas 18x 49º ” “ —» “ tri plo. s Me = 19,2 x 1 = 464 x 1% 200] d dpi A jus dit dd dio i NA 1 mah “4009 E 3000 2 qua 2000 “im 1800 a) 1900 ao eo «09 2 seriam mestanom ramomaromes, me. TRaDUaREy que? sean cm remeter 17 mecaDeumos Da mude ut Figure 8. A. CH itretch: 2962 em! (3.38 um) vas CHs, 2872 em! (3.48 jm) ve CHy, 2926 em! (3.43 um) vas Ch 2853.em'! (3.51 um) v, CHy. B. C-H bend: 1465 cm? (6.83 um) 8, CHs, 1450 em! (6.90 um) Sos CF 1375 em” (7.28 um) 6 CH. C.CH; rock: 722 em? (13.9 um) p CH. ae = omenenpertam tumor o WAVELENGTH pm ia 25 3 4 5 8 ? so os nm na ml 1 1 rsss sital dasanlanaitass! ata ssa cad La rasa 0.05] 0] = 020] - om» o e 040] ne 0%) 080 - om - 190 = E ti dd ss tuts si pis ts io "ao — 38 300 E 200 emo 160 Tao 10 JO MO RO «o 2% D moruem emeance LABORATORIES 1 PREQUENCY ICu-t) Denento om remo mmem say Com mmmacerraa oa. teto usa, Seca Mm fere Coeary fartensto, ram Figure 9. A. C-H stretch (see Figare 8). B. C-H bend fsee Figure 8). There is an unresolved gem-dimethy! band fo, 1388-1395 em!. Compare the weak methylene rocking band(s) (800-1000 em!) to that for Figure 8. (Ai ee abrorption C in Figure 16.) CH stretching frequencies TABLE 2 ALKENES (Non-diagnostic bands in italics) (e* in parentheses) 1) =CH, 3080, m (30) | vas CH, 2975 band overlaps with alkane absorption. 2975,m v.CH Bands higher than 3000 suggest presence x sa ofunsaturated =CH- (alkenes, aromatics). 2) =CH- 3020, m vCH, Substitution type (c* in parentheses) ALCENOS (Continuação) dubstitution type (e“ in parentheses) Overtone of scH E Ty 8'cH vC=C ' & CH (out-of-plane) Figs. E (out-of-plane) (in-plane) : 3) R/CH=CH, 1860-1800 | 1645,m (40)| 1420, | 990 s(50), and 910s(110); |(5)(3) (term. vinyl) m (30) RUE) sui nº Sameregion | 990 = asin Table 1, mr nm? 14-16. o 910 NM 1300, mw eco 9R 1800-1750 | 1655, m (35) | 1415, 890 s (100-150) (69) >cecH, m (80) m (10-20) He R E ES LM Same region C=C. o (term. methylenc) asin Table 1, í H 14-16. 5) R R 1660, m (10) | 1415, 730-675 m (40), ambigu- >eecf m (1020) | cus and varable. OO H H N 4 (cis) C=C Og “ sHº 6) R H 1675, w (2) 965 s (100) ScscZ o HZ NR N M pe=cf (trans) Pg NR Rº 1670, w=m 840-800 s (40). Vibration ) ç E: of single H; not as useful OM Rº *H as others. (tri-subs.) BRR 1670, w No outof-plane bending = SR” Intensified tm aboetA]; Dus ; À ifbonded C=C-CH,- may be de- tetra-subs. irectly to ' OorN. trai ny Fi bending ALCENOS (Continuação) Conjugated double bonds Group vC=C & CH (out-of-plane) Figs. 9) Diene 1650 and 1600 Position not affected much by conjugation. The trans 965 band is sometimes shifted to 990. The cis band is usually found at 720, occasionally as a group of bands. 10) Triene 1650 and 1600;sometimes only one band; sometimes addi- tional shoulder on 1650 band. trans-cistrans and cis-trans-trans systems have bands at 990 s, 960 m, and 720. 11) Polyene 12) Enones Broad band at 1650-1580. see Table 8 (p. 16). 990970 if trans-double band present. PADRÃO DE SUBSTITUIÇÃO BENZENOS SUBSTITUÍDOS Setistotuted IR Spectrum Qrmiene Sina ne ras o ad se. “a - ás “ all st é [ Mem vara é tida [ o MU IN NM Ss | — Juma ajoe ., 1MUimtaá pa ' | e me nal UA NV 1) A E Mi uam - Cs) , | EM Dimtatd ERRA; U E Ee TRF + F e O + «+ 4 DN ; EAD oenteaia i : : i ii o A 4 Eh E e DON Ii . v ie AEsideto 1 i | . TR AMI | a sr -— uy y 7 —i— “ ua | 135 Primabaatá ii e PADRÃO DE SUBSTITUIÇÃO BENZENOS SUBSTITUÍDOS qem, IR Spectrum err E CE E pa t | | k E FRA ri i Z]L- ; Fido . e = = Es cú 1 + ' ias trata] 3 E + um + Axe E a 12545 Prenda ! Pulo Espectral de benzenos substituídos E | Eos CHg | É «o - | o do estiramento | À THsp? estiramento = Che monossubstituido : torado o estiramento O2G aromático Plane Soco asao Caboa O UUcaão 7 ao PC DR ao sm “ao núniERO ce ONDA vem =; Espectro infravermelho de tolueno (ilquido puro, placas de KBn. aitsons » mr ortossubermo o | N em Em HoCHa - E CH>CHa É * = estiramento e ss a Hd =... " .. fulo Sstramento ortossubetituido Ro estiramento “EEE aromático torrdepiano cHsp? : - so "amo em amo temo domo 4400 q) 30 E mo Do No NÚMERO DE ONDA (ov= Espectro infravermelho co orto-dietilbenzeno (líquido puro, placas de KBr). songs . tê PES 7 o popa Am : em apo N rop «» metassapsmtuído |À go CHsCHa * wo . estiramento . | no G-Hsp2 CHoCHg A estiramento estiramento 1 * CHspê C=C aromático metassubstituído fora do plano Caco asso UU indo Pos aco somo tese ro Cio amo amo ado oo “o NEMERO 03 ONDA et) Espectro infravermelho do meta-die:ilbenzeno (líquido puro, placas de KBn. rirgao 109 4 º . : : » pura = o TT ss, hr .o él CHaCH3 agrassubstiuído ya Êo - sao Í, - mo estiramento CHzCHa “ aressubsttuído 2 Csp Wc asitansonia Caramento TT fora do plano ceHsp? G=6 araniafiéa Como oo Co Jeso amo eo osdo têoo o quarta” “am em] ao MÓMERO DE ONDA (CH Espectro infravermelho do para-dietilbenzeno (líquido puro, placas de KBn). TABLE 4 X=Y, XºY=Z GROUPS 2) Nítrile, -CaN 2260-2210 Variable, | The lower wavenumber re] 2 [ (3) | 10-150 glon indicated is observed] 3 . when conjugated to other unsaid. groups or when Alkali meta) salts show very | 18 2050. Position varies with aé counter ton and physical state. WAV EEENETH em a 1 a Lp Pri iii lina FREQUENCY (CM TABLE 4 Key, XaY=Z GROUPS 6) lrocyanate, 2275-2250 1500-2000] Extremely strong, position] 8,9 O a] E: not affected by conj. + 1350 No practical value became of : weak intensity and ouer lapping with CH, peak. miceons ' 3 a s 8 7 o 2 ORM E Y 3 = monassubstituido perante (re |-N=C=0 fora do plano 1 1 ' 1 pai emo se cm Sm re cu e ” - - Espectro infravermelho de isocianato de benazilalliquido puro, placas de KBr). TABLE 4 X=Y, X=Y=Z GROUPS s ua Rana, aliphatic: 2140 Tor ed intensky has been! 12, [puedes 2175-2160/ age assado E) & ane a aliphatic: 2140-1990] than Somewhat broad, frequency 14. -NeGoS acomatie: 2130-2040] SOSVaNte | Cori or accompanied by) 1! Molde” Gus Bando: 1090 (5), arom. 1250 (w) and 930 em”! (5). [12] TABLE 4 X=Y, X=Y=Z GROUPS 8) Azíide,-N, 2160-2095 vas roogseromatics usualy no 6) split duc to Fermi reso- a mance with C-N, 40-60 em", .* 1340-1180 Pg weak. TABLE 5 ALCOHOLS AND PHENOLS Table Sa O-H Stretching vibration State of OH eo pra Shape Remarks Free (monometric) 3640-3610 [30--100| sharp | Data measured in socalled non- polar (CCI,, CHCI,, etc.”) dilute p-OH 3640 70 solutions. 168) 9 s-0H 3630 60-50 Water absorptionat 3710 cm”! when | (26) +-0H 3620 45 solution is damp. phenolic OH 3610 2) -0-0-H, hydro- 3560--8580f1 peroxide E Intermol H-bond Urca RD in polymeric band O é ; . vide infra) unless: polymer for- 3) diminnio, 8600-5500 rates mation is hindered by steric hio- drançe, Absorptions arising from H-bond with polar solvents such as ethers, ketones, and amines also appear in this region. 4) polyméric 3400-3200 | strong With solids and liquids, this broad | (13) (E broad absorption is the only one ob- served; in dilute solutions, ac- companied by monomer band. Free and assoc. » NH of amines and amides also appcar at 3500-8200 cm”), First overtone of vC=O (ca. 1720 cm”! also appears at 3500 3400 cm”?, but can be differenti- ated because Of low. intensity, «a<10. Water of crystallization: also at 3600-3100 cm!, but not so strong and somewhat narrower; also weak band at 1640-1615 em”! (H-O-H bending vibration). TABLE 6 . ETHERS AND RELATED GROUPS e? of vC-O bands are usually greater than 200. ——— — Group Band (cm"!) Remarks Figs. 1) Ethees, ditpã ata nos 1150-1070 | C-O-C antisym. stretching. Common with other | (29º gencral (3) . C-O bands. Effect of a-branching uncicar. arom. and vinyl | 1275-1200 | Antisym. stretching. Common with other «G-O. f =C-0-C Socalicd *1250 cm"! Bando VOC. ot vinyi DO ethers intensificd. 1075-1020 | Sym. stretching. Weaker than 1250 cm”! band. Methoxyl group has following bands in addition. aliph. 2830-2815 | CH, sym. stretchi Lacks in -OC,H,. The -ocH,p) (eº 50) ay sietching Seat 2990-2970 (pecicol ve -0C,H,) but position is non-characteristic. arom, 2850 CH, sym. stretching. Following bands 6) -OCH, E] Pose my ition non-characteristic: 000, s 5 (he MecpRCa), 1460 and 1840) Gan. so fee E C antisym. stretch- 180 and 1125 (methyl rocking and arom?), 1040-1020 (=C-0-C sym. stretchine). 4) Spiroketal of steroidal 1350-- 650 | Many characterístic sharp bands. * sapogenins(1,6] 5) Epoxy (17912) | 3000 (<* 40) | Epoxy methine group of chain compounds and Daa< 3040 («º 20) | Epóxy methine group of straincd rings. * 3050 («* 30) | Methylene group of terminal epoxy rings. 1250 So-calicd “8 uy band”; syra, stretching of ring. 950- 810 | Socalled “11 u band"; asym: stretching of ring. 840- 750 | So-called “12 yu band.” Espectro IV de ÉTERES 1425 5 « E e se no gr gap 18 o - - My Êo | cH(CH5)-O-(CHa)CHs | É Ê dobrámenids ” = dobramentos CHo CHa |) ie oo Hs? e we estiramento estiramento C-O o A Lada Ea ooo amo axo oáiê amo essa ss? acco eoó sop ão 1600 2409 NÚMERO DE ONDA 1H; Espectro infravermelho de éter dibutílico (líquido puro, placas de KBr). 2s 3 e 5 5 2. o - . A 7 eos a , ada | | am EO estratos À a! É CHsp2 | ES estiramento T 5 8 ti CoHispêoe A A . “o E a estiramento CO" amy . e ae o monessubstituição fora-do-plano o C=C aromático" Vo eu P 4000 emo ooo dao amo 2000 s00 100 “090 “seo sao som . 14057" iza NÚMERO DE CNDA (CM 1) Espectro infravermelho de anisol (líquido puro, placas de KBr). TABLE 8 CARBONYL GROUPS (Bold figures denote vC=0) Group Band (cm!) Remarks Figs. Ketone 1715 e* 300600. Values of CHCI, solutions 6) -CO- and solids, lower by 10-20 cm”?, Values of gases, +20 cm"*, Occasionally over- tone at ca. 3400 em”?. 1100 be) Je”. e% 50-150, Caused by C-C-C bending ' 1300 (arom.)4 several | and C-C stretching of -C-(CO)-C-. sã 1 a) a, prunsatd. 1675 vC=C shows clearly at 1650-1600 cm"; E in scis forms, may be shifted below 1600 cin"? and intensity becomes com- parable to that of vC=0. 1 b) Ar-CO- 1690 Affected by 1, M, and steric effects of substituents. DO 1 c) a, 8%, ô-unsatd. 1 d) a, Ba, B-unsatd. 1665 1 e) Ar-CO-Ar 1 f) -CO-R 1695 Conj. with cyclopropane lowers by ca. 20 O) 1 ) 7 memb. and larger 1705 en". 1 h) 6-membered 1715 Same as standard value. Shift caused by 6) conj. with unsatd. groups is same with aliph. ketones. 1 à) 5-membered 1745 Shift caused by conj. with unsatd. groups is same with aliph, ketones, 1 5) 4membered 1780 1 k) 3-membered 1850 1 1) cchalo- shiftofO-+25 | Shift to higher freg. is larger the smaller | (53) gi the angle between C=O0 and C-X. No ç - shift when angle excceds 90º. Following xo values apply to satd. aliph. and cyclic (X:halogen) ketones: -CI, 0-+25; -Br, 0-+20; =1, 0-+10 cm! Im) -CX,-CO- and shift of 0-+45 Effect of single halogen substitution ap- =CX-CO-CX (X:halogen) pears additively. Shift of +45 cm”! results when Cl on both sides of C=O are in same plane with C=0. Co-existence of several conformers give rise to each corresp. band, the relative intensities of which are dependent upon state of measurement. “e VEANSMITÂNCIA SA TRANSMITÁNCIA = reanstarrâncIA Espectros IV de ALDEIDOS nicroxs n américa "| banda-de em C=0 N o cadeia longa. a E | O HiitHocHacH a io CH . õ e = | estiramento 1. ira nn : 1 C-Hsp? o no estiramento C=0 E too amo amo Cabo 00 2 nto No rio É vioo em aó ax 1800 00 1 NUMERO DE ONDA (OH 1) Espectro infravermelho de nonanal (líquido puro, placas de KBr). rtcaons £ «o estiramento CHspê CH ó “e aldeído conjugação * + estiramênto .... e D=c o. C-Hép conjugação-do “5 16 e => estiramento c-0 trans fora-do- plano o Lai o 14 iii dog 3800 amo ad 2doo 2060 480 “00 HED iodo são do sx nMÉRO DE ONDA tou) Espectro infravermelho de crotonaldeiído (líquido puro, placas de KBr). - Co sm estiramento - H co. E-Hsp? aldeido CH conjugação do o 2 erre estiramento co arorriático...... menossubstituição fora do plano a ora aa 4 Dto ooo eso cao 2800 | cúto 200 180 1500 Casa 1600 s00 Soo amo NÚMERO DE ONDA (E Espectro infravermelho de benzaldeído (líquido puro, placas de KBr). Acid -COOH 3 a) C=C-COOH and ÁCIDOS CARBOXÍLICOS 3000-2500 1760 (monomer) 1710 (dimer) 1420 1300-1200 920 1720 (monomer) Data are mostly for dimers because H- BE bonding power is unusually strong, and they exist also in gas state. Very characteristic. Group of small bands. Band at highest freg. is due to vOH, and others are combinations. 3550 cm”! in monomers. Considerably stronger than ketonic vC=0. e? up to 1500. Two bands may be ob- served with gases or solutions. Both due to coupling betwcen in-plane O-H bending and C-O stretching of dimer. O --H—O Dia Broad, medium intensity. O-H out-of-planc bending of dimer. Ar-COOH 1690 (dimer) 3 b) a-halo- Shift of Values for «-Br and a-CI. Larger fora-F +10-20 cm”! ca. +50 Eme, º pera Carboxylate 1610-1550 and C-O antisym. and sym. stretching, resp., 6,69) -CO0- 1400 o of -c< k - o When an acid is converted into its inor- ganic salt, the five characteristic freq. are replaced by these two. Instead of being converted to inorganic salts, they can be changed to ammonium salts by adding few drops of Et,N to CHCI, solution; carboxylate ions are not formed in CCl,, while addition of NH, or p-amines gives confusing N*H, and N*H, bands that overlap with -COO” band. WAVELENGTH sm 38 3 « 5 5 7 o dmofa ca as Dia sp tara ado as tasas ra a ra Paga Lasaa Ass a psi tips sis tis ss Ls ss tasas Liss 4 a 3000 zt00 200 IO 80 10 120 “00 O GW 40 20 FREQUENCY (CM!) LACTONAS Band (cm"!) Remarks 1770 1840 1750 when a-H is present: 1785 and 1755 (doublet) 1770 1790 1735 1720 1760 Table 10-4 In non-polar solvents (CCl,, CS,), the higher band is stronger, while in polar solvents (CHCI,, CH,CN, CH,0H) or liquids and solids, the lower band is stronger[2] . vC=C is weak. Around 1780 in non-polar solvents, and ca. 1760 in polar solvents; affected by polarity of solvents. Influenced by M and other effects of substitucnts on arom. ring. The band is not split, contrary to a, 6- unsatd.-y-lactones. vC=C at 1660 cm” (s). Same as with aliph. esters. Same as with aliph. esters. Samc as with aliph. esters. vC=C at 1685 em! (s). ePyroncs. See Table 10-a for ypyrones. ANIDRIDOS Acid anhydride -CO-O-CO 6-membered «, B-unsatd. 6-membered 5-membered maleic phthalic acrylic- or benzoic: * 1820 and 1760 1300-1050 1785 and 1725 1800 and 1750 1780 and 1735 1865 and 1785 1850 and 1790 1850 and 1770 Relative intensity of two bands variable. Band separation usually ca. 60 cm”, but this may differ from 35 to 90 cm”! according to type); lower band absorbs near vC=0 of corresp. ester or lactone. Higher and lower band, resp., is stronger in acyclic and cyclic anhydrides[4). 1-2 strong bands arising from C-O-C portion. AC=0, 50-70 cm"). AC=0, 45 cm”! when double bond is endo (75 cm”! when exo) 3). AC=0, 80 cm" "[3]. AC=0, 60 cm!. 1790 cm”! band is split and bchaves similarly to 5 m(3). 1770 em”! band is split and behaves simi- larly to 5 m(2). O 00 AMIDAS Group Band (cm"!) Remarks Figs. 10 Amide -CO-N primary -CONH, secondary -CO-NHR- tertiary -CO-NÇ Free Assoc. two at: 3500,3400 1690 1600 3440 1680 1530 1260 several: 3350-3200 1650 1640 3300 3070 1655 1550 1300 Complicated but extensively studied. [11] Influenced by state of measurement as with -COOH. Data for both free and assoc. states are given. vNH vC=0, “Amide I band.” Mainly 5NH, “Amide II band.” Shifted higher upon association. Solid spectra of -CONH, show two strong bands at 1650-1640, but “I band” is stronger. In concentrated solutions, all four bands arising from free and assoc. states may appear. vNH, 3300 cm”? band considered to be due to trans assoc. form (structure I in figure shown). Band at 3070 is due to first overtone of N-H in plane bend. In cyclic lactams, 3440 when free, and 3175 (dimeric, structure II) and 3070 cm”! when assoc. (3300 lacking). “Amide I band” Mainly 5NH, mixed with vC-N, “Amide H band.” Present only in trans amides; in cis amides (e.g., small ring lactams) it is weak and shifted to 1440 cm”. Mainly »C-N, mixed with 8NH, “Amide HI band.” Shift in positions of free and assoc. vNH and “Amide I-III bands” is consistent with assignment. Thus contribution of limiting structure Ib is enhanced upon association. R H R e: C-N e C=N ? Sã -0 > da (Ia) (Ib) Nega: ré primo, dimeric lactam (II) Solid IR of amides are, however, especially sensitive to crystal orientation. Effect of substituents may thus not be exerted correctly, and a slight complication in structure may prevent the shift of “TI” and “II” bands to lower frequencies in the solid state. In concentratéd solutions the assoc. and free absorptions both appear. Since H-bonding with NH is absent, posi- tion is only slightly higher in the free imilar to other C=O groups).