Additional Office Hour Time • Every Thursday, 2-3pm in Mol Sci 4100 (the person leading this office hours will be different each week) • BEGINS TOMORROW and will go to the end of the quarter NMR practice problems Sources: Web Spectra: http://www.chem.ucla.edu/~webspectra/ Spectral Database of Organic Compounds (SDBS) http://riodb01.ibase.aist.go.jp/sdbs/cgibin/cre_index.cgi LEGEND: -1H means an integration value of “1”, while 2H means an intergration value of “2” etc. - s = singlet - d = doublet - t = triplet - m = multiplet Ch14C, Spring 2012 Prof. Dong Rough 1H-NMR guidelines • • • • • • • • Aldehyde Aromatic Vinylic -OCH3 Ketone (α position) H-C≡C-R -CH3 TMS Si(CH3)4 10 ppm 7-9 5-7 3-4 2 2 0-1 0 (we use this as reference) For next several slides, the chemical structure and its 1H-NMR spectra is given to you. Please try to assign as many of the protons to the peaks shown. Confirm the following 4 features: 1. Number of equivalent protons 2. Chemical shift 3. Integration 4. Splitting Also, using the molecular formula, calculate the DBE and confirm that it matches the structure shown Position of peak on 1H-NMR depends on the “chemical” environment around the proton • Each of the molecules below give 1 peak on 1H-NMR because all the protons experience the same chemical environment H H2 C H2C CH2 H2C C H2 H H H H O H 2 PPM 1 8 7 0 6 3 5 4 PPM 2 3 PPM 2 1 1 0 Beginner #7, C14H14 H H H H H H H H H H H H H H 4H,s 10H,m (overlap) Beginner #10, C10H10O2 O H H OCH3 H H 3H, s H H H 1H,m 1H,m 1H,m 1H,m 1H,m 1H,m 1H,m Beginner #12 C6H12O2 O H3C O H2 C C H2 H2 C CH3 3H,s 2H, t 2H,pentet 3H,t 2H,sextet Beginner #27, C3H7OCl Cl H2 C C H2 H2 C OH 2H, t 1H, s 2H, t 2H, pentet Beginner #25, C4H8O O H3C C H2 CH3 3H, s 3H, t 2H, q Int1 #1, C3H4O H H H H O 3H (overlapping peaks) 1H,d Int2 #13, C10H15N H3C H2 C N H H H 6H,t 2H,m 3H,m CH3 H H 4H,q H2 C Int#12, C7H9NO NH2 H O H H H 3H,s 4H,m 2H,s CH3