1. Spectroscopic Analysis of Molybdenum Model Compounds by: 1.Infrared 2. 1 H NMR 3.Electronic (UV/vis) 4.ESI-MS Why? What did I make? How do molecules differ?

2. UV/vis Spectroscopy = Electronic Spectroscopy What does it monitor / probe? What information about molecule can one obtain? What if 350 nm has  = 8,000 M -1 cm -1 and 550 nm has  = 80 M -1 cm -1 ?

3. IR Spectroscopy What does it tell us? What more information about molecule can one obtain? Mo O O O O O

4. 1 H NMR: what do you expect to see?

7. a b c a b c Expected: 3 resonances, 2 -CH 3 (a & c with 6H) and 1 H (b) ( B-H not visible due to broadening) … plus H’s on cation TEA = [N(CH 2 CH 3 ) 4 ]+

8. [Tp*Mo(S)(S 4 )] — 1 H NMR: what do you expect to see?

10. a a a e e b b b d d Mo=S Mo=O TEA + -CH 2 - TEA + -CH 3 c c c f f

11. a b c d e f a b c a b c d ef Mo=S Mo=O TEA + -CH 2 - TEA + -CH 3

12. R1 ≠ R2: How many H’s expected in NMR from pyrazole rings? All -methyl and ring H’s will be unique: see 6 -Me and 3 ring H

13. How many H’s expected in NMR from detc liagnds?

14. Mass Spectometry Facility Dr. Arpad Somogyi

15. Electrospray Ionization Mass Spectrometry ESI-MS black box mass detector magnetic field separates light and heavy mass ions Molecules in gas phase as ions + or -

17. Electron impact ionization

18. Electrospray ionization method makes tiny droplets Vacuum removes solvent Electric potential creates + and - ions

19. All Mo molecules are identified by a characteristic series of lines: Mo isotopes: 92 Mo, 94 Mo, 95 Mo, 96 Mo, 97 Mo, 98 Mo,

20. YELLOW (calculated mass spectrum) MassRelative abundance 474.000 6.12 476.000 8.84 477.000 7.34 478.000 11.91 479.000 10.57 480.000 17.08 482.000 14.14 481.000 7.06 484.000 6.00 483.000 3.06 486.000 1.29 485.000 0.94 488.000 0.14 475.000 0.88 487.000 0.18 489.000 0.02 490.000 0.01

21. RED (calculated mass spectrum) MassRelative abundance 404.000 11.48 406.000 8.72 407.000 12.64 408.000 15.04 409.000 10.98 410.000 20.73 412.000 10.58 411.000 4.24 414.000 1.58 405.000 1.66 413.000 1.55 415.000 0.21 416.000 0.10 417.000 0.01 418.000 0.00

22. BLUE (calculated mass spectrum) MassRelative abundance 468.000 10.36 470.000 8.81 471.000 11.67 472.000 14.47 473.000 11.15 474.000 20.10 476.000 11.30 475.000 5.04 478.000 2.33 469.000 1.66 477.000 1.93 479.000 0.35 480.000 0.24 481.000 0.03 482.000 0.01 483.000 0.00

23. PURPLE (calculated mass spectrum) MassRelative abundance 824.000 1.32 826.000 2.03 827.000 3.18 828.000 4.63 829.000 5.22 830.000 9.33 832.000 11.22 831.000 7.37 834.000 10.77 833.000 9.98 835.000 8.87 836.000 9.11 837.000 5.00 838.000 5.46 840.000 1.99 839.000 1.99 842.000 0.43 841.000 0.58 844.000 0.06

24. Y B P R All have one Mo atom More lines, more Mo atoms

25. RED mass spectrum 409.6

26. YELLOW mass spectrum 444.6

27. BLUE full mass spectrum

28. YELLOW (high mass species)

29. Accurate mass : 540.019287 for Modetc3 MassRelative abundance 536.000 9.82 538.000 8.43 539.000 11.53 540.000 14.33 541.000 11.33 542.000 19.63 544.000 10.96 537.000 2.13 543.000 5.83 545.000 2.42 546.000 2.30 547.000 0.45 548.000 0.25 549.000 0.04 550.000 0.02 551.000 0.00 Accurate mass : 556.014160 for MoOdetc3 MassRelative abundance 552.000 9.80 554.000 8.44 555.000 11.51 556.000 14.32 557.000 11.33 558.000 19.62 560.000 10.98 559.000 5.85 562.000 2.32 553.000 2.12 561.000 2.43 563.000 0.46 564.000 0.25 565.000 0.04 566.000 0.02 567.000 0.00

30. MoOdetc 2 : Mo1S4O1N2C10H20mass: 408.48 g/mol MoOdetc 2. NCCH 3 : Mo1S4O1N3C12H23mass: 449.53 g/mol MoOCl 2 detc 2 : MoCl2S4O1N2C10H20mass: 479.38 g/mol Mo 2 O 3 detc 4 : Mo2S8O3N4C20H40mass: 832.96 g/mol MoOS 2 detc 2 : MoS6ON2C10H20mass: 472.61 g/mol

31. MoOCl 2 detc 2 : MoCl2S4O1N2C10H20 Accurate mass : 478.893738 MassRelative abundance 474.000 6.12 476.000 8.84 477.000 7.34 478.000 11.91 479.000 10.57 480.000 17.08 482.000 14.14 481.000 7.06 484.000 6.00 483.000 3.06 486.000 1.29 485.000 0.94 488.000 0.14 475.000 0.88 487.000 0.18 489.000 0.02 490.000 0.01

32. MoOdetc 2 : Mo1S4O1N2C10H20 Accurate mass : 407.987732 MassRelative abundance 404.000 11.48 406.000 8.72 407.000 12.64 408.000 15.04 409.000 10.98 410.000 20.73 412.000 10.58 411.000 4.24 414.000 1.58 405.000 1.66 413.000 1.55 415.000 0.21 416.000 0.10 417.000 0.01 418.000 0.00

33. Mo 2 O 3 detc 4 : Mo2S8O3N4C20H40 Accurate mass : 831.970276 MassRelative abundance 824.000 1.32 826.000 2.03 827.000 3.18 828.000 4.63 829.000 5.22 830.000 9.33 832.000 11.22 831.000 7.37 834.000 10.77 833.000 9.98 835.000 8.87 836.000 9.11 837.000 5.00 838.000 5.46 840.000 1.99 839.000 1.99 842.000 0.43 841.000 0.58 844.000 0.06

34. MoOS 2 detc 2 : MoS6ON2C10H20 Accurate mass : 471.931763 MassRelative abundance 468.000 10.36 470.000 8.81 471.000 11.67 472.000 14.47 473.000 11.15 474.000 20.10 476.000 11.30 475.000 5.04 478.000 2.33 469.000 1.66 477.000 1.93 479.000 0.35 480.000 0.24 481.000 0.03 482.000 0.01 483.000 0.00