Jet-FTIR-spectroscopy of pyrrole clusters

Transcription

1 , Corey A. Rice and Martin A. Suhm Institute of Physical Chemistry, University Göttingen Tammannstr. 6, Göttingen, Germany 61 st Ohio State University International Symposium on Molecular Spectroscopy June 19 23, 2006 TB10 - Infrared / Raman

2 Outline Introduction 1 Introduction Motivation Experimental setup Theory Overview 2 Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion 3 Structure Filet-Jet spectra Structure of the dimer Frequency calculations

3 Motivation Introduction Motivation Experimental setup Theory Overview N H Pyrrole

4 Motivation Introduction Motivation Experimental setup Theory Overview N H Properties of pyrrole: heterocyclic aromatic ring electron rich aromatic (lone pair of N delocalized in aromatic ring) N H functionality H-bond donor π-electrons H-bond acceptor (unconventional) self clustering (N H π)

5 Motivation Introduction Motivation Experimental setup Theory Overview N H Properties of pyrrole: heterocyclic aromatic ring electron rich aromatic (lone pair of N delocalized in aromatic ring) N H functionality H-bond donor π-electrons H-bond acceptor (unconventional) self clustering (N H π)

6 Motivation Introduction Motivation Experimental setup Theory Overview N H Properties of pyrrole: heterocyclic aromatic ring electron rich aromatic (lone pair of N delocalized in aromatic ring) N H functionality H-bond donor π-electrons H-bond acceptor (unconventional) self clustering (N H π)

7 Motivation Introduction Motivation Experimental setup Theory Overview N H Properties of pyrrole: heterocyclic aromatic ring electron rich aromatic (lone pair of N delocalized in aromatic ring) N H functionality H-bond donor π-electrons H-bond acceptor (unconventional) self clustering (N H π)

8 Motivation Introduction Motivation Experimental setup Theory Overview N H Properties of pyrrole: heterocyclic aromatic ring electron rich aromatic (lone pair of N delocalized in aromatic ring) N H functionality H-bond donor π-electrons H-bond acceptor (unconventional) self clustering (N H π)

9 Motivation Introduction Motivation Experimental setup Theory Overview Schematic structure of the pyrrole dimer:

10 Motivation Introduction Motivation Experimental setup Theory Overview N H Porphyrin

11 Experimental setup Introduction Motivation Experimental setup Theory Overview Filet-Jet (fine but lengthy) Slit nozzle mm 2 C. A. Rice, N. Borho and M. A. Suhm, Z. Phys. Chem., 219, 2005,

12 Introduction Motivation Experimental setup Theory Overview Vibrational spectroscopy of clusters

13 Introduction Motivation Experimental setup Theory Overview Vibrational spectroscopy of clusters

14 Introduction Overview of the measured systems Motivation Experimental setup Theory Overview H-bond donors N CH3 N CH3 H Pyrrole H 2,5-Dimethylpyrrole Pure H-bond acceptors N H3C N CH3 CH3 Benzene N-Methylpyrrole 1,2,5-Trimethylpyrrole CH3

15 Outline Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion 1 Introduction Motivation Experimental setup Theory Overview 2 Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion 3 Structure Filet-Jet spectra Structure of the dimer Frequency calculations

16 Pyrrole Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion º P P N ln(i0/i)/10 3 ¾º ¾ ½º P 2 P 3 P 4? H ½º¼ Ö ¾¼¼ Ò µ ν N H ν N H / cm 1 / cm 1 P 3533 P P P ½ ¼º Ö ¾¼¼ Ò µ ¼º ¼º Ö ¾¼¼ Ò µ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¾ ¼ ¾¼¼ ν/cm 1

17 Introduction Pyrrole - structures of the clusters Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion P 2 P 3 P 4 Dimer Trimer Tetramer B3LYP / G** A. Gómez-Zavaglia and R. Fausto, J. Phys. Chem. A, 108, 2004,

18 Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion Comparison - experiment and DFT calculations this work Gómez-Zavaglia et al. in Helium Calculation a ν N H ν N H b ν N H ν N H / cm 1 / cm 1 / cm 1 / cm 1 P P P P a B3LYP / G** b Scaling factor of A. Gómez-Zavaglia and R. Fausto, J. Phys. Chem. A, 108, 2004,

19 Introduction Expansion in Helium vs. Argon Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

20 Introduction Expansion in Helium vs. Argon Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

21 Introduction Pyrrole in Helium and Argon Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

22 Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion Comparision - Argon nanomatrix and Argon matrix this work Gómez-Zavaglia et al. in Argon Argon matrix ν N H ν N H ν N H ν N H / cm 1 / cm 1 / cm 1 / cm 1 P@Ar P P P A. Gómez-Zavaglia and R. Fausto, J. Phys. Chem. A, 108, 2004,

23 Pyrrole / Benzene Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion º P P N + B º P 2 P 3 H ln(i0/i)/10 3 ¾º ¾ ½º ½ ¼º P+B P 4? ½º¼ Ö ¾¼¼ Ò µ ¼º Ö ¾¼¼ Ò µ ν N H ν N H / cm 1 / cm 1 P 3533 P+B P P P ¼º Ö ¾¼¼ Ò µ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¾ ¼ ¾¼¼ ν/cm 1

24 Pyrrole as donor - overview

25 Pyrrole as donor - overview

26 Pyrrole as donor - overview

27 Pyrrole as donor - overview

28 Pyrrole as donor - overview

29 Pyrrole as donor - overview

30 2,5-Dimethylpyrrole Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion ½º ½º¾ D D CH3 N D 2 H D 3 CH3 ½ ln(i0/i)/10 3 ¼º ¼º ¼º ¼º¾ ½º¼ Ö ¼¼ Ò µ ¼º Ö ¾¼¼ Ò µ ν N H ν N H / cm 1 / cm 1 D D D ¼ ¼º Ö ¾¼¼ Ò µ ¼¼ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¾ ¼ ¾¼¼ ν/cm 1

31 2,5-Dimethylpyrrole as donor - overview

32 2,5-Dimethylpyrrole as donor - overview

33 2,5-Dimethylpyrrole as donor - overview

34 Introduction Red-shift of the donor bands Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

35 Introduction Red-shift of the donor bands Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

36 Introduction Red-shift of the donor bands Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion

37 Introduction Red-shift of the donor bands Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion universal order

38 Introduction Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion Electron densities of the aromatic H-bond acceptors

39 Outline Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations 1 Introduction Motivation Experimental setup Theory Overview 2 Pyrrole as H-bond donor 2,5-Dimethylpyrrole as H-bond donor Conclusion 3 Structure Filet-Jet spectra Structure of the dimer Frequency calculations

40 Structure Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations

41 Structure Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations H O N N H O H H cis trans

42 Structure Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations E »ÑÓÐ ¼ ¾ ¼ ¾ ¾ ¾ ¾¼ ½ ½¾ ¼ O N H H H H N N O O H H ¼ ¼ ½¾¼ ½ ¼ ¾ ¼ ¼¼ ¼ ÌÓÖ ÓÒ Ò Ð τ NC CO MP2 / G**

43 Introduction Comparision with a peptide Structure Filet-Jet spectra Structure of the dimer Frequency calculations

44 Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations Filet-Jet spectrum of the N H stretching vibration ¼º ¼º ¼º PCA (PCA) 2 N H O H PCA ¼º ½º¼ Ö ¾½ Ò µ ln(i0/i)/10 3 ¼º ¼º ¼º¾ ¼º½ ¼º Ö ¾¼ Ò µ ν N H ν N H / cm 1 / cm 1 PCA 3493 (PCA) ¼ ¼º Ö ½ Ò µ ¹¼º½ ¼ ¼¼ ¼ ¼¼ ¼ ¼¼ ¾ ¼ ¾¼¼ ½ ¼ ½¼¼ ν/cm 1

45 Introduction Structure Filet-Jet spectra Structure of the dimer Frequency calculations Filet-Jet spectrum of the C=O stretching vibration ½º¾ PCA H ln(i0/i)/10 3 ½ ¼º ¼º ¼º ¼º¾ (PCA) 2 N O H PCA ½º¼ Ö ¼¼ Ò µ ν N H ν N H / cm 1 / cm 1 PCA 1687 (PCA) ¼ ½ ¾¼ ½ ¼¼ ½ ¼ ½ ¼ ½ ¼ ½ ¾¼ ν/cm 1

46 Introduction Structure of the dimer (top view) Structure Filet-Jet spectra Structure of the dimer Frequency calculations B3LYP / G**

47 Introduction Structure of the dimer (side view) Structure Filet-Jet spectra Structure of the dimer Frequency calculations B3LYP / G**

48 Frequency calculations N H stretching vibration

49 Frequency calculations N H stretching vibration

50 Frequency calculations N H stretching vibration

51 Frequency calculations N H stretching vibration C=O stretching vibration

52 Frequency calculations N H stretching vibration C=O stretching vibration

53 Frequency calculations N H stretching vibration C=O stretching vibration

54 Frequency calculations N H stretching vibration C=O stretching vibration

55 Introduction

56 Introduction

57 Introduction

58 Introduction

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