MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION
-
Upload
quinlan-carver -
Category
Documents
-
view
41 -
download
0
description
Transcript of MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION
![Page 1: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/1.jpg)
MODELING OF ENERGETICAL PROPERTIESOF BIS-AZO COMPOUNDS.
ROLE OF TAUTOMERIZATIONAlytis Gruodis, Nurija Kelminskienė
Department of General Physics and Spectroscopy, Vilnius university
![Page 2: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/2.jpg)
Material
8th decade of XX century– electrophotographic dyes1th decade of XXI century– molecular device (SC!)(in poled polymer matrix, 1MV/cm)
Bisazo π-conjugated derivative – Stable, no photochemistry
2,7-diamino-fluorenone bisazo-pigmentum
NA1 , containing [-O-Me], EE,EQ,QQ conformers (tautomers)GU3 , containing two [–Cl], EE,EQ,QQ conformers (tautomers).
![Page 3: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/3.jpg)
NA1 (R=[-C6H4-OMe])GU3 (R=[-C6H4Cl2]), where fluorenone is connected in position 2 and 7 via [-N=N-] bridge to quinine.
![Page 4: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/4.jpg)
Main task
Probable geometry of molecule in layered structures
Explanation of experimental absorption spectrum
Molecular energetics
![Page 5: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/5.jpg)
Technique of modeling• Quantum chemical methods• Gaussian09 software• 6/31G(d) basisset
Optimization of molecular geometryDensity functional B3LYP method
Calculation of electronic excitationSemiempirical ZINDO method for singlets only
Evaluation of charge redistribution Semiempirical TD method for siglets only
![Page 6: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/6.jpg)
Intramolecular proton transfer
• Enol-Quinine tautomerisation• Trans-cis transition
Proton donor Proton acceptor
![Page 7: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/7.jpg)
Second task
How many different forms? EE, EQ, QQ ?
![Page 8: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/8.jpg)
Two molecular motions• 1) proton jump in tautomerization process allows the
existence of both - hydrazone-quinine form (Q) and azo-enol form (E);
2) conformational rotation of quinine fragment allows the existence of partially ’broken’ pi-conjugated system:
Generally, three type of different tautomers (EE, EQ, QQ) for NA1 and GU3 derivatives must be analyzed
![Page 9: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/9.jpg)
Problem: EE, EQ, QQ ?
![Page 10: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/10.jpg)
1. Geometry optimization
• Gaussian09
• B3LYP/6-311G(d,p) opt
![Page 11: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/11.jpg)
NA1
![Page 12: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/12.jpg)
GU3
![Page 13: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/13.jpg)
Optimization of geometry• Three tautomiric forms: EE,EQ,QQ. Nine forms excludedEQ ir QQ – could be non-planar tautomers.
Benzene derivatives ( [-O-Me] ir [–Cl]) are oriented by angle 60 deg
![Page 14: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/14.jpg)
2. Electronic excitation
Semiempirical ZINDO methodSTO-3G basis
![Page 15: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/15.jpg)
![Page 16: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/16.jpg)
Acid solutionBasis solutionBasis solution
![Page 17: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/17.jpg)
![Page 18: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/18.jpg)
3. Charge redistribution
What about CT state in region of 2 eV?
Gaussian09, TD(singlets,nstate=6) HF/6-31G sp
Charge redistribution between quinine, fluorenone and quinine,
Derivatives R are not included ( partial skeleton redistribution)
![Page 19: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/19.jpg)
![Page 20: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/20.jpg)
![Page 21: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/21.jpg)
![Page 22: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/22.jpg)
![Page 23: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/23.jpg)
![Page 24: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/24.jpg)
![Page 25: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/25.jpg)
ConclusionsEQ form
![Page 26: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/26.jpg)
Coexixtence of both: EE and EQ forms depending of the pH of media
![Page 27: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/27.jpg)
Conclusions
1. Coexistence of both: EE and EQ forms depending of the pH of media
2. Fragmental rotation in range 30 deg (15 deg from equilibrium) like swinging. Excluding of band et 2 eV from 40 deg.
3. Partially broken pi-conjugated system 4. CT transition for EQ form
![Page 28: MODELING OF ENERGETICAL PROPERTIES OF BIS-AZO COMPOUNDS. ROLE OF TAUTOMERIZATION](https://reader035.fdocument.org/reader035/viewer/2022062217/568131a1550346895d980fcd/html5/thumbnails/28.jpg)
Thank you for attention