Ch 13 - Nuclear Magnetic Resonance Spectroscopy

Ch 13 - Nuclear Magnetic Resonance Spectroscopy - 13 N...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
13 Nuclear Magnetic REso±A±CE SpECT²osCopy Nuclear magnetic resonance spectroscopy (NMR) is the most powerful tooL avai±able For organic sTrucTuRe deterMInation. ²ike ³´ specTroscopy, Nµ´ can be used wiTh a very sma±l samp±e, and it does noT ha¶m The samp±e. ·he Nµ´ specT¶Um pRovides a greaT deal oF inFoRmation abouT The stRucTure oF The compound, and some sTrucTures can be deTer- mined us¸ng on±y the Nµ´ spectrum¹ µore commonlyº however, The Nµ´ specT¶um is used in conjuncTion with otHer Forms oF specTroscopy and chemica± ana±ysis to deTerMine The sTructures oF comp±icaTed organic mo±ecu±es» Nµ´ is used To sTudy a wide varieTy oF nucLei, inc±uding ¼ ½, l3C, 15 N, ¾9 ¿, and ±1p. O¶ganic chemisÀs FÁnd proton (IH) and carbon-13 ±l3e² NMR To be most use Ful because hydrogen and carbon aRe majoR components oF organic compounds» ½isà toricaL±yÄ Nµ´ was FÅRst used To study proTons (the nucLei oF hydrogen aToms), and proTon magneTic resonance ³i ½ Nµ´Æ specTRomeTeRs are The most comÇon» "NucLear magnetic ResonanceÈ is assUmed to mean "proton magneTic resonanceÈ unless a diÉÊerË ent nuc±eus is speciÌed» We begin our study oF Nµ´ wiTh proTon magnetic resonance and concLude wiTh a discussion oF l±C Nµ´. A nuc±eus wiTh an odd aTomic numbeR or an odd mass number has a nuclear spin ThaT can be observed by The Nµ´ specTRomeTeR. A pRoTon is The simpLesT nucleus, and iTs odd atomic number oF 1 imp±ies iT has a spin» We can visualize a spinning proTon as a ¶oTaTing sphere oF positive chaRge (¿igure Í3ÎÍÏÐ ·his movement oF charge is ±ike an eLectric cu¶renT in a Loop oF wiRe¹ Ñt generaTes a magneTic ÉÁeld (symboLiZed by B ), called the magnetic moment, ThaT ±ooks Like The F¸e±d oF a small bar magneT» spinnjng proton looP of cuRent bar magNet circulation ( ± \ ½ ½ ² J ± induced magnetic FieLd 13-1 Introduction 13-2 Theory of Nuclear Magnetic Resonance .± Figure 13-1 The MagnetIC MoMent. A spInnIng p±oton gene²ates a MagnetIc fIeld, called Jts MagnetIc MoMen³. ´Hjs MagnetIc fIelD (8) ²eseMBles µ¶at of a sMall loop oF CU²²ent Ò¶ Bar Magnet. 559
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon