Describing and predicting molecular properties via vibrational spectroscopy in combination with electron density analysis [Elektronische Ressource] / von Martin Presselt

Sujets

• Physik

Informations

• Publié par: friedrich-schiller-universitat_jena
• Publié le: 01 janvier 2009
• Nombre de lectures: 21
• Langue: English
• Poids de l'ouvrage: 22 Mo

Extrait

Describing and predicting molecular
properties via vibrational
spectroscopy in combination with
electron density analysis
Dissertation
zur Erlangung des akademischen Grades
doctor rerum naturalium (Dr. rer. nat.)
vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakult˜at
der Friedrich-Schiller-Universit˜at Jena
von
Diplomchemiker Martin Presselt
geboren am 19.12.1979 in Jena
Jena 2009Gutachter:
1. Prof. Dr. Jurgen˜ Popp
2. Prof. Dr. Gerd Buntkowsky
3. Prof. Dr. Wolfgang Kiefer
Tag der ˜ofientlichen Verteidigung: 10. 06. 2009Fur˜ KatjaContents
List of Figures iii
List of Tables vii
List of Abbreviations ix
1 Introduction 1
2 Theoretical details 7
2.1 Concepts to describe atomic properties, bonds and reactivities . . . . . . . 7
2.2 Calculation and analysis of the electron density distribution . . . . . . . . 9
2.2.1 Quantum mechanical calculations . . . . . . . . . . . . . . . . . . . 9
2.2.2 The quantum theory of atoms in molecules . . . . . . . . . . . . . . 13
2.3 Vibrational spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.3.1 Normal modes and vibrational transition energies . . . . . . . . . . 17
2.3.2 IR and Raman intensities . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Resonance Raman spectroscopy . . . . . . . . . . . . . . . . . . . . 23
2.4 Relations between reactivities and spectroscopic properties . . . . . . . . . 24
3 Experimental details 27
3.1 UV-vis absorption and remission spectroscopy . . . . . . . . . . . . . . . . 27
3.2 Fluorescence spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.3 Raman spectroscopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.4 Processing of Raman spectra . . . . . . . . . . . . . . . . . . . . . . . . . . 28
4 Characterizing molecules in the electronic ground state 29
4.1 Electron density studies in life sciences . . . . . . . . . . . . . . . . . . . . 29
4.2 Prediction of electron density features . . . . . . . . . . . . . . . . . . . . . 37
4.2.1 Electron density properties . . . . . . . . . . . . . . . . . . . . . . . 37
4.2.2 Vibrational and NMR data . . . . . . . . . . . . . . . . . . . . . . 41
4.2.3 Prediction of ‰(r)-features utilizing spectroscopic data . . . . . . . . 42
iContents
4.3 The …-conjugation in tpy-ph derivatives and their metal complexes. . . . . 62
2+4.3.1 The in uence of Zn . . . . . . . . . . . . . . . . . . . . . . . . . . 62
4.3.2 The of substituents at the 4-phenyl position . . . . . . . . 76
2+ 2+4.3.3 Comparison of Zn and Ru complexes and derivation of new
molecular structure with improved properties . . . . . . . . . . . . 85
5 Characterizing the initial step of photoexcitation 101
1 2+5.1 Substructures involved in the MLCT of [(tbut-tpy)Ru(tpy-ph-R)] . . . . 101
1 2+5.2 Charge localization at the MLCT of [(tbut-bpy) Ru(tpphz)PdCl ] . . . 1052 2
5.2.1 AssignmentofRamanandresonanceRamanbandstosubstructures
2+in [(tbut-bpy) Ru(tpphz)PdCl ] . . . . . . . . . . . . . . . . . . . 1062 2
1 2+5.2.2 Estimation of MLCT energies in [(tbut-bpy) Ru(tpphz)PdCl ] . 1072 2
6 Summary - Zusammenfassung 113
6.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
6.2 Zusammenfassung . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
A Supporting vibrational data 121
2+A.1 Vibrational assignment of the Raman spectrum of [Zn(L4) ] . . . . . . . 1212
2+ 2+A.2 Ramanspectraof[(tbut-bpy) Ru(tpphz)PdCl ] ,[(tbut-bpy) Ru(tpphz)]2 2 2
2+and [(tbut-bpy) Ru(dppz)(Br) ] . . . . . . . . . . . . . . . . . . . . . . . 1262 2
Bibliography 127
Selbstst˜andigkeitserkl˜arung 143
Acknowledgement - Danksagung 145
Vita 147
iiList of Figures
DFT4.1 Structureand‰ -mapofdimethyl-3((4-nitro)phenyl)aziridine-2,2-dicarb-
oxylate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
4.2 Crystal section of a dimethyl-3((4-nitro)phenyl)aziridine-2,2-dicarboxylate
single crystal (16 molecules) . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4.3 Dimersofdimethyl-3((4-nitro)phenyl)aziridine-2,2-dicarboxylateextracted
DFTfromthecrystalstructureandrespective¢‰ -mapsoftheaziridinering
DFTreferring to the isolated molecule. The aziridines referring to the ¢‰ -
maps are labelled with an asterisk. . . . . . . . . . . . . . . . . . . . . . . 33
DFT4.4 ¢‰ -map of dimethyl-3((4-nitro)phenyl)aziridine-2,2-dicarboxylatein a
simulated aqueous environment. . . . . . . . . . . . . . . . . . . . . . . . . 36
4.5 Comparison of DFT and MP2 calculated ‰-values. . . . . . . . . . . . . . . 38
4.6 of the lowest-‰- and the cis-convention. . . . . . . . . . . . . . 39
4.7 Electron densities (left), respective laplacians (middle) and ellipticities
(right) in the BCPs of the CH-bonds in phenyl. . . . . . . . . . . . . . . . 41
4.8 Comparison of calculated ‰(ph-CH-BCP) values with the transition ener-
gies of corresponding CD-stretching vibrations.. . . . . . . . . . . . . . . . 45
1H4.9 Data related to the ‰(WN,? ) flt at the meta2-position . . . . . . . . . 50C6H6
1H4.10 Data related to the ‰(RA,? ) flt at the ortho1-position . . . . . . . . . 51C6H6
4.11 DFT-calculated, fltted and validated ‰-values of the best flts for CH-BCPs
on all ph-positions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
24.12 fltted and validated r ‰-values of the best flts for CH-
BCPs on all ph-positions. . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
4.13 DFT-calculated, fltted and validated "-values of the best flts for CH-BCPs
on all ph-positions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
24.14 DFT-calculated and validated ‰(r)-target values (‰,r ‰, ") of the best flts
for CH-BCPs on all ph-positions applying rel. variables. . . . . . . . . . . 61
2+4.15 UV-vis spectra of L4 and Zn(L4) . . . . . . . . . . . . . . . . . . . . . . 642
4.16 Raman spectra of L4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.17 Bond lengths in L4 and [Zn(L4) ](PF ) . . . . . . . . . . . . . . . . . . . 682 6 2
iiiList of Figures
4.18 Experimental (top) and DFT-calculated (bottom; BP86/RI/def2-TZVP)
2+Raman spectra of [Zn(L4) ] . . . . . . . . . . . . . . . . . . . . . . . . . . 702
2+4.19 Top: DFT-calculated structure of [Zn(L4) ] with atomic labels. Middle2
DFTand bottom: Trig. ring breathing modes – (trig. ring br.) (”~ =ip
¡1 DFT ¡11010 cm ) and ”(ph-py(trig))(”~ = 1351 cm .) . . . . . . . . . . . . . 71
4.20 Sketch of the correlation between Raman shift of ”(ph-py(trig)) and bond
shortening of the ph-py bond upon complexation. . . . . . . . . . . . . . . 72
2+4.21 Inter-¢‰-plot: ‰(trans-L4)-‰([Zn(L4) ] ) . . . . . . . . . . . . . . . . . . 742
2+ 2+ 2+4.22 Inter-¢‰-plots of [Zn(L2) ] , [Zn(L3) ] and [Zn(L4) ] , referring to2 2 2
2+[Zn(L1) ] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782
2+ 2+4.23 Experimental Raman spectra of Zn(L1) -Zn(L4) . . . . . . . . . . . . . 792 2
4.24 Correlation between ", geometrical and Raman characteristics. . . . . . . . 80
4.25 Raman spectra of [Zn(L) ](PF ) containing vinyl groups (top: L = L3,2 6 2
L5, L7) or ethynyl (down: L = L4, L6, L9) groups at phenylene . . . . . 82
2+4.26 HOMO (bottom) and LUMO (top) of Zn(L3) . . . . . . . . . . . . . . . . 842
4.27 Valenceformulaoftpy-ph,thehomolepticZn(II)complexes,theheterolep-
tic Ru(II) as well as substituents at phenylene. . . . . . . . . . . . . . . . . 86
4.28 Correlations between " and r and fi of the py-ph bond in tpy-ph-R and
related Zn(II) and Ru(II) complexes . . . . . . . . . . . . . . . . . . . . . . 88
4.29 Vectors deflning the plane studied in the inter-¢‰-plots. . . . . . . . . . . 90
4.30 Inter-¢‰-plots to visualize the in uences of the cation and substitution on
‰(r) in the ph-py bond. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
4.31 HOMO-, LUMO- and gap-energies of Ru(II) and Zn(II) complexes of tpy-
ph-R dependent on "(py-ph-BCP). . . . . . . . . . . . . . . . . . . . . . . 93
2+4.32 Structuralrepresentationsofcomplexes[Zn(tpy-ph-R) ] withthephmoi-2
eties substituted with NH - and vinyl-groups. . . . . . . . . . . . . . . . . 972
2+5.1 Normalizedabsorptionspectraof[Ru(tbut-tpy) ] and[(tbut-tpy)Ru(tpy-2
2+ph-R)] dissolved in CH CN. . . . . . . . . . . . . . . . . . . . . . . . . . 1023
2+5.2 RRS of [(tbut-tpy)Ru(tpy-ph-R)] (from top: R=Br, NH , NO ) and2 2
2+[Ru(tbut-tpy) ] (bottom), dissolved in CH CN (*). . . . . . . . . . . . . 1032 3
2+5.3 Resonance Raman spectrum of [(tbut-tpy)Ru(tpy-ph-CN)] dissolved in
dichloromethane (RR-bands labelled with asterisks). . . . . . . . . . . . . . 105
2+ 2+5.4 Valence structure of [(tbut-bpy) Ru(tpphz)PdCl ] ([RuPd] , left) and2 2
2+[(tbut-bpy) Ru(dppz)(Br) ] (right). . . . . . . . . . . . . . . . . . . . . . 1062 2
2+5.5 ComparisonoftheresonanceRamanspectraof[RuPd] (uppergraph,dif-
ferentRRSarecorrespondingtodifierentexcitationwavelength,seelegend)
2+and [Ru(tbut-bpy) ] (‚ =458 nm). . . . . . . . . . . . . . . . . . . . . . 1073 ex
ivList of Figures
2+5.6 Deconvolution of experimental resonance Raman spectra of [RuPd] dis-
solved in acetonitrile, excited at 515, 488, 477, 458, 413 nm. . . . . . . . . 109
2+ 45.7 MLCT-absorptionbandof[RuPd] ;dots: normalizedsumsof” -corrected
RR-intensities, star-shaped dots: tpphz