Chemistry 211 Laboratory Fall 2013 Paper Unknown Final Reports Complete pp. 1-4 of the attached report form for each of your Group Paper Unknowns and submit the report to your laboratory instructor by the end of your laboratory period during the week of December 3 - 6. See Model Report pp. 5-8. This report form is available on the Experiment 7 page of the course website. The report may be completed by hand or by word processor using the electronic copy from the website. While your reports must be clearly and neatly presented, wordprocessed text and electronically produced figures are not required. Remove this cover page before submitting your report. CHEM 211-13 Final Group Paper Unknown Report Group Name Group Members: Unknown # Append your Group Paper Unknown data handout sheets. Summary of Results Fill in the tables below with data from group paper unknown spectra (See attached model report) Molecular Mass: Melting Point: ˚C Boiling Point: MS Molecular ion Data: M+ mass M+ Intensity M+1 Intensity M+2 Intensity Does the compound contain chlorine or bromine? How do you know? Cite data. Does the compound contain a nitrogen atom? How do you know? Cite data. Approximate number of carbon atoms in the molecule. From MS M+1 peak: Solubility tests: Water: 1 M HCl 1 M NaOH Is your compound acidic, basic or neutral? How do you know? Cite data. Interpretable IR Data (List useful peaks, you need not list all peaks in each region) Region Structural (cm-1 -1 (cm ) Feature Region 1:3600-3200 Region 2:3100-2500 Region 3:2300-2000 Region 4:1750-1630 Region 5:1630-1400 Region 6:1350-1000 ˚C CHEM 211-13 Final Group Paper Unknown Report 2 Interpretable Mass Spectral Data (List the largest peaks from the mass table and any others that suggest recognizable structures) m/e Ion M+ - Ion Structural Information* M+ M+ * Provide a structure rather than a molecular formula (e.g. CH3CH2CH2+ rather than C3H7+) 1H Chemical Shift ( Multiplicity NMR Relative Areas 13C Chemical Shift ( Interpretation* NMR Interpretation* CHEM 211-13 Final Group Paper Unknown Report 3 Discussion of the Process for Determining the Unknown’s Structure Proposed Compound Name Proposed Compound Structure Discussion Your discussion must explain the sequence by which the structure was devised from the data. Indicate how parts of the structure were identified and the logic used to finally “put the pieces together” to create a complete structure. The order in which your data is introduced will depend upon the logic used in devising your structure. Your discussion should be thorough but concise, 300 words or less. (See model, p. 7) CHEM 211-13 Final Group Paper Unknown Report 4 Spectral Assignment Diagrams Use spectral assignment diagrams similar to those provided in the attached model report (p. 8) to illustrate how your structure accounts for the IR, MS and NMR data summarized in your data tables. Be sure to note any significant data that cannot be explained from your structure. IR MS 1H-NMR 13C-NMR CHEM 211-13 Final Group Paper Unknown Report 5 Model Report for a Final Group Paper Unknown Summary of Results: Molecular Mass: 163 Melting Point: ˚C Boiling Point: 222 ˚C MS Molecular ion Data: M+ mass 163 M+ Intensity 34.1 M+1 Intensity 4.4 M+2 Intensity 0 Does the compound contain chlorine or bromine? How do you know? Cite data. Molecule does not contain chlorine or bromine => There is no significant M + 2+ peak in MS. Does the compound contain a nitrogen atom? How do you know? Cite data. Molecule contains an odd number of nitrogen atoms => M+ is odd Approximate number of carbon atoms in the molecule. From MS M+1 peak: ~12 Solubility tests: Water: Insoluble 1 M HCl Soluble 1 M NaOH Insoluble Is your compound acidic, basic or neutral? How do you know? Cite data. Molecule is basic – more soluble in H-Cl than in water indicates that it reacts with acid => basic IR Data Region Structural (cm-1 (cm-1) Interpretation 3600-3200 No absorption NO N-H or O-H 3100 Aromatic C-H 3100-2500 2950 Sat’d C-H 2300-2000 No absorption No triple bonds 1750-1630 No absorption No C=O 1610 Aromatic C-C 1630-1400 1530 Aromatic C-C 1210 C-N or C-O 1350-1000 1170 C-N or C-O CHEM 211-13 Final Group Paper Unknown Report 6 Mass Spectral Data (List the largest peaks from the mass table and any others that suggest recognizable structures) m/e Ion M+ - Ion 163 M+ Structural Interpretation* M+ 148 M-15 Loss of CH3 119 M-44 ? 91 M-72 77 M-86 CH2 * Provide a structure rather than a molecular formula (e.g. CH3 CH2 CH2+ rather than C3H7+) 1H Chemical Shift ( 1.2 2.2 2.6 3.3 7.2 NMR Multiplicity Relative Areas Interpretation doublet singlet doublet multiplet multiplet 3 6 2 1 5 CH3 next to CH 2 equivalent CH3's attached to N CH2 adjacent to C=O or aromatic ring and C-H CH attached to O or to N & other func. group C-H Aromatic w/5 H’s – singly substitute aromatic ring 13C Chemical Shift ( 20 32 41 48 112 114 121 145 NMR Interpretation sp3 C sp3 C sp3 C sp3 C attached to N or O aromatic C aromatic C aromatic C aromatic C, most sub’d. CHEM 211-13 Final Group Paper Unknown Report 7 Proposed Compound Name N,N-dimethyl-1-phenyl-2-propanamine Proposed Compound Structure CH3 CH2 CH3 C N CH3 H Discussion Your discussion must explain the sequence by which the structure was devised from the data. Indicate how parts of the structure were identified and the logic used to finally “put the pieces together” to create a complete structure .The order in which your data is introduced will depend upon the logic used in devising your structure. H-NMR (7.2 A=5) & 13C-NMR (112,114,121 &145 ) suggest phenyl group (C6H5). This structure is supported by IR 3100 (aromatic C-H), & 1610->1470 cm-1 (aromatic C-C) and MS-77 m/e. MS 91 & 92 m/e suggest that phenyl has an adjacent CH2. That leaves 163 – 91 = 72 mass. Odd M+ indicates a nitrogen atom. That leaves 72-14= 58 mass. 1H-NMR (2.2 A=6, sing.) suggests 2 equivalent CH3 groups attached to an atom with no H’s. 1H-NMR (2.2 A=3, doublet => CH3 next to C-H, 1.2 A=2, doublet => CH2 next to C-H and 3.3 A=1, multiplet => CH next to the CH3 & CH2 gives a CH3CHCH2 structure. IR: no 3300 cm-1 for NH, so N doesn’t have any attached H’s. So pieces seem to be: 1 CH3 CH2 ? ? CH2 C ? N ? CH3 ? H Mass = 42 Mass = 91 CH3 ? ? Mass = 30 Mass = 14 Total mass = 177 Comparison of the total mass above (177) with the M+ mass (163) indicates that there must be some overlap among the pieces identified (excess mass 177-163 = 14). All carbon atoms have at least 1 H attached, so the two methyls with NMR singlets must be attached to the nitrogen and the chemical shifts of the methyls (2.2 ) support that attachment. That change leaves three pieces. CH3 CH2 Mass = 91 ? ? CH2 C CH3 ? N ? CH3 H Mass = 42 Mass = 44 Total mass = 177 The Mass 91 and Mass 44 pieces have only one available attachment site (bond) and the mass 42 piece has two bonding sites. So the mass 91 and 44 pieces must be attached to the mass 42 piece. The mass overlap of 14 can be removed if the two CH2 groups are the same. (mass 14 each) The result of these changes gives the final structure. CH3 CH2 C H CH3 N CH3 CHEM 211-13 Final Group Paper Unknown Report 8 Spectral Assignment Diagrams (See data in tables on the previous pages) Use spectral assignment diagrams similar to those provided in the attached model report to illustrate how your structure accounts for the IR, MS and NMR data summarized in your data tables. Be sure to note any significant data that cannot be explained from your structure. IR C-H aromatic 3100 cm-1 CH3 CH2 C CH3 N C-N 1210 & 1170 cm-1 CH3 H C-C aromatic 1610->1470 cm-1 sat'd C-H 2950 cm-1 MS m/e CH3 CH3 CH2 77 C H N 148 CH3 (M-15) 91 119 (M-44) 1H 2.6 A=2 doublet H H H 13C NMR 121 1.2 A=3 doublet CH3 CH3 CH2 C N CH3 H H H 3.3 A=1 Mult. 7.2 A=5 sing. 114 2.2 A=6 sing. 41 145 121 32 20 48 112 114 NMR N 32