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Theoretical Calculation of UV-Vis Spectral Band Locations of PAHs with Unknown Syntheses Procedures and Prospective Carc

This research paper discusses the theoretical calculation of the UV-Vis spectral band locations of Polycyclic Aromatic Hydrocarbons (PAHs) with unknown synthesis procedures and potential carcinogenic activity. The study utilizes Annellation Theory and reference PAHs to predict these locations.

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Theoretical Calculation of UV-Vis Spectral Band Locations of PAHs with Unknown Syntheses Procedures and Prospective Carc

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  1. THEORETICAL CALCULATION OF THE UV-VIS SPECTRAL BAND LOCATIONS OF PAHs WITH UNKNOWN SYNTHESES PROCEDURES AND PROSPECTIVE CARCINOGENIC ACTIVITY Jorge Oña-Ruales, Ph.D., MRSC Nazarbayev University, Astana Kazakhstan jorge.onaruales@nu.edu.kz Yosadara Ruiz-Morales, Ph.D. Instituto Mexicano del Petróleo, Mexico City, Mexico June 2017

  2. Introduction Polycyclic Aromatic Hydrocarbons • Polycyclic Aromatic Hydrocarbons (PAHs) are organic compounds composed of C/H forming multiple aromatic rings that are released from burning coal, oil, gasoline, trash, tobacco, or other organic substances. PAHs have potential carcinogenic behavior. Coal Oil Gasoline Trash Tobacco Burning 2

  3. Introduction Polycyclic Aromatic Hydrocarbons • Polycyclic Aromatic Hydrocarbons (PAHs) are organic compounds composed of C/H forming multiple aromatic rings that are released from burning coal, oil, gasoline, trash, tobacco, or other organic substances. PAHs have potential carcinogenic behavior. • Aromatic Sextets are areas in PAHs with high electron density. The electrons in these areas are capable of resist disruption. Coal Oil Gasoline Trash Tobacco Aromatic Sextets Burning 3

  4. Introduction Polycyclic Aromatic Hydrocarbons • Polycyclic Aromatic Hydrocarbons (PAHs) are organic compounds composed of C/H forming multiple aromatic rings that are released from burning coal, oil, gasoline, trash, tobacco, or other organic substances. PAHs have potential carcinogenic behavior. • Aromatic Sextets are areas in PAHs with high electron density. The electrons in these areas are capable of resist disruption. • Peri-condensed PAHs have some of the carbon atoms situated in more than two molecular constitutive rings • Cata-condensed PAHs have all of their carbon atoms situated in one or maximum of two molecular constitutive rings Coal Oil Gasoline Trash Tobacco Aromatic Sextets Aromatic Sextets Burning peri-condensed cata-condensed 4

  5. PAH Groups Analyzed Peri-condensed UV-Vis spectra not reported C26H14 (326 Da) 4 9 isomers ALTERNANT C32H16 (400 Da) 39 46 isomers C34H16 (424 Da) 31 34 isomers 5

  6. PAH Groups Analyzed Cata-condensed Peri-condensed UV-Vis spectra not reported C26H16 (328 Da) 37 isomers C26H14 (326 Da) 4 9 isomers UV-Vis spectra not reported 8 ALTERNANT C32H16 (400 Da) 39 46 isomers C34H16 (424 Da) 31 34 isomers 6 6

  7. PAH Groups Analyzed Cata-condensed Peri-condensed UV-Vis spectra not reported C26H16 (328 Da) 37 isomers C26H14 (326 Da) 4 9 isomers UV-Vis spectra not reported 8 ALTERNANT C32H16 (400 Da) 39 46 isomers C34H16 (424 Da) 31 34 isomers UV-Vis spectra not reported C24H14 (302 Da) N/ALTERNANT 9 21 isomers 7

  8. PAH Groups Analyzed Cata-condensed Peri-condensed UV-Vis not reported C26H16 (328 Da) C26H14 (326 Da) 37 isomers 4 9 isomers UV-Vis not reported 8 OBJECTIVE: Predict the locations of the UV-Vis spectral bands of PAHs with unknown synthesis procedures using Annellation Theory ALTERNANT C32H16 (400 Da) 39 46 isomers C34H16 (424 Da) 31 34 isomers UV-Vis not reported C24H14 (302 Da) 9 N/ALTERNANT 21 isomers 8

  9. Ultraviolet – Visible (UV-Vis) Spectrum and Absorbance Bands The UV-Vis spectrum is the representation of the electron density distribution inside of a PAH molecule Absorbance 8H-dibenzo[a,jk]pyrene published UV-Vis spectrum 250 300 350 400 Wavelength (nm) 9

  10. Ultraviolet – Visible (UV-Vis) Spectrum and Absorbance Bands The UV-Vis spectrum is the representation of the electron density distribution inside of a PAH molecule β bands p bands α bands Absorbance 8H-dibenzo[a,jk]pyrene published UV-Vis spectrum 250 300 350 400 Wavelength (nm) • The p bands appear at intermediate wavelengths. Indicate an electron transition from HOMO to LUMO. Intermediate Absorbance. • The β bands appear at low wavelengths. Indicate an electron transition from HOMO to s-LUMO. Highest absorbance. • The α bands appear at high wavelengths. Indicate an electron transition from s-HOMO to LUMO. Lowest Absorbance. 10

  11. Ultraviolet – Visible (UV-Vis) Spectrum and Absorbance Bands The UV-Vis spectrum is the representation of the electron density distribution inside of a PAH molecule β bands p bands α bands Absorbance 8H-dibenzo[a,jk]pyrene published UV-Vis spectrum 250 300 350 400 Wavelength (nm) • The p bands appear at intermediate wavelengths. Indicate an electron transition from HOMO to LUMO. Intermediate Absorbance. • The β bands appear at low wavelengths. Indicate an electron transition from HOMO to s-LUMO. Highest absorbance. • The α bands appear at high wavelengths. Indicate an electron transition from s-HOMO to LUMO. Lowest Absorbance. 11

  12. Annellation Theory Erich Clar 12

  13. Annellation Theory Erich Clar 13

  14. Annellation Theory Erich Clar 14

  15. Theoretical Methods Annellation Theory Method for the prediction of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs not yet synthesized using the UV-Vis spectra of reference PAHs already synthesized. Requires no more than pen a paper. Black line denotes structural and aromatic relationship Red line denotes structural and aromatic enclosure 15

  16. Example Annellation Theory ? ? λp, nm λβ, nm λp, nm λβ, nm dibenzo[c,k]- tetraphene ? λp, nm λβ, nm λp, nm λβ, nm ? 16

  17. Example Annellation Theory ? ? λp, nm λβ, nm λp, nm λβ, nm λp, nm 458 431 406 λβ, nm 335 320 λp, nm 450 435 423 λβ, nm 337 322 310 dibenzo[c,k]- tetraphene ? λp, nm λβ, nm λp, nm λβ, nm λp, nm 365 347 331 λβ, nm 305 288 280 λp, nm 357 351 348 λβ, nm 307 290 ? 17

  18. Theoretical Methods ZINDO/S method to calculate the UV-Vis spectra COMPASS(Condensed-Phase Optimized Molecular Potentials for Atomistic Simulation Studies) force field is an ab initio force-field that enables accurate and simultaneous prediction of gas-phase properties (structural, conformational, vibrational, etc.) PAH structure optimization using the COMPASS force field (FF) ZINDO(Zerner´s Intermediate Neglect of Differential Overlap) is a Semi-Empirical Hartree-Fock electronic structure method that has been parameterized for spectroscopic properties of molecules. Calculation of the UV-Vis spectrausingtheZINDO method Optimized geometry PAH structure • This method has provided satisfactory agreement with experimental values for the calculation of optical properties of PAHs. 18

  19. Procedure • Validation Comparison of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs predicted using the Annellation Theory and the locations of maximum absorbance of the p and β bands reported for already synthesized PAHs. 19

  20. Procedure • Validation Comparison of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs predicted using the Annellation Theory and the locations of maximum absorbance of the p and β bands reported for already synthesized PAHs. • Elucidation Prediction of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs with unknown synthesis procedures using the Annellation Theory. 20

  21. Procedure • Validation Comparison of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs predicted using the Annellation Theory and the locations of maximum absorbance of the p and β bands reported for already synthesized PAHs. • Elucidation Prediction of the locations of maximum absorbance of the p and β bands in the UV−vis spectra of PAHs with unknown synthesis procedures using the Annellation Theory. • Substantiation Comparison between the Annellation Theory predictions and the ZINDO/S calculations for the locations of the p bands in the UV−vis spectra of PAHs with unknown synthesis procedures. 21

  22. Validation Comparison between locations of the spectral bands predicted by the Annellation Theory and locations reported from synthesis procedures 326 Da 328 Da 400 Da 424 Da 302 Da PAH group PAH with UV-Vis reported 12 5 29 7 3 22

  23. Validation Comparison between locations of the spectral bands predicted by the Annellation Theory and locations reported from synthesis procedures 326 Da 328 Da 400 Da 424 Da 302 Da PAH group PAH with UV-Vis reported 12 5 29 7 3 Annellation Theory approach ? ? PAH 1 PAH 2 λβ, nm λp, nm λβ, nm λp, nm ? PAH 3 PAH 4 424 Da λp, nm λβ, nm λβ, nm λp, nm ? 23

  24. Validation Comparison between locations of the spectral bands predicted by the Annellation Theory and locations reported from synthesis procedures 326 Da 328 Da 400 Da 424 Da 302 Da PAH group PAH with UV-Vis reported 12 5 29 7 3 Annellation Theory approach PAH 1 PAH 2 λβ, nm λp, nm λβ, nm λp, nm 300 288 302 288 374 354 338 440 414 392 PAH 3 PAH 4 424 Da λp, nm λβ, nm λβ, nm λp, nm 341 328 343 328 302 454 422 396 520 482 450 24

  25. Validation Comparison between locations of the spectral bands predicted by the Annellation Theory and locations reported from synthesis procedures 326 Da 328 Da 400 Da 424 Da 302 Da PAH group PAH with UV-Vis reported 12 5 29 7 3 Less than 5% 4.7 4.1 3.5 3.4 3.4 Predicted versus reported deviation, % 2.8 2.7 1.8 1.6 1.6 p bands β bands 25

  26. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 326 Da 328 Da 400 Da 424 Da 302 Da PAH group PAH with UV-Vis not reported 9 4 8 39 31 26

  27. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 302 Da PAH group PAH with UV-Vis not reported 9 Annellation Theory approach λβ, nm λp, nm λβ, nm λp, nm PAH 1 PAH 2 301 293 289 287 282 276 369 350 338 359 342 323 * PAH 3 PAH 4 λp, nm λβ, nm λβ, nm λp, nm 332 319 318 308 393 384 380 383 376 365 27

  28. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 326 Da PAH group PAH with UV-Vis not reported 4 Annellation Theory approach λβ, nm λp, nm λβ, nm λp, nm 286 277 PAH 1 PAH 2 257 249 334 321 308 284 273 * PAH 3 PAH 4 λp, nm λβ, nm λβ, nm λp, nm 332 320 303 292 438 415 388 367 348 28

  29. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 328 Da PAH group PAH with UV-Vis not reported 8 Annellation Theory approach λβ, nm λp, nm λβ, nm λp, nm 267 259 PAH 1 PAH 2 251 242 319 306 295 293 281 274 * PAH 3 PAH 4 λp, nm λβ, nm λβ, nm λp, nm 293 281 261 347 331 321 306 309 298 29

  30. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 400 Da PAH group PAH with UV-Vis not reported 39 Annellation Theory approach λβ, nm λp, nm λβ, nm λp, nm 315 302 PAH 1 PAH 2 311 298 272 458 430 406 418 394 373 * PAH 3 PAH 4 λp, nm λβ, nm λβ, nm λp, nm 330 316 326 312 300 500 466 440 460 430 307 30

  31. Elucidation Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures 424 Da PAH group PAH with UV-Vis not reported 31 Annellation Theory approach λβ, nm λp, nm λβ, nm λp, nm PAH 1 PAH 2 267 259 251 242 319 306 295 293 281 274 * PAH 3 PAH 4 λp, nm λβ, nm λβ, nm λp, nm 414 392 369 388 367 348 319 309 303 292 31

  32. Substantiation Comparison between the Annellation Theory predictions and the ZINDO/S calculations for the locations of the p bands Semi-empirical approach Aromatic approach Less than 7% 6.2 Predicted versus ZINDO/S deviation, % 4.2 4.1 4.0 1.2 326 Da 328 Da 400 Da 424 Da 302 Da PAH group 32

  33. Carcinogenic potential of PAHs benzo[a]pyrene benzo[c]phenanthrene bay fjord open side open side 33

  34. Carcinogenic potential of PAHs benzo[a]pyrene benzo[c]phenanthrene bay fjord open side open side metabolic activation carcinogens (+)-anti-benzo[a]pyrene-diol-epoxide (-)-anti-benzo[c]phenanthrene-diol-epoxide 34

  35. Carcinogenic Potential of PAHs Carcinogenic potential of C34H16 (424 Da) PAHs bay open side Five isomers with a bay region, open side, and sextet distribution similar to benzo[a]pyrene. Phenanthro[10,1,2-abc]coronene Benzo[p]naphtho[8,1,2-abc]coronene Naphtho[3,2,1,8,7-defgh]pyranthrene Benzo[j]naphtho[8,1,2-abc]coronene Tribenzo[a,hi,kl] coronene 35

  36. Carcinogenic Potential of PAHs Carcinogenic potential of C34H16 (424 Da) PAHs bay fjord open side open side Five isomers with a bay region, open side, and sextet distribution similar to benzo[a]pyrene. One isomer with a bay region, open side, and sextet distribution similar to benzo[c]phenanthrene Phenanthro[10,1,2-abc]coronene Benzo[p]naphtho[8,1,2-abc]coronene Naphtho[3,2,1,8,7-defgh]pyranthrene anthra[9,1,2-abc] coronene Benzo[j]naphtho[8,1,2-abc]coronene Tribenzo[a,hi,kl] coronene 36

  37. Summary • A theoretical methodology based on the Annellation Theory has been proposed and applied for the first time to predict the locations of the spectral bands of PAHs. 37

  38. Summary • A theoretical methodology based on the Annellation Theory has been proposed and applied for the first time to predict the locations of the spectral bands of PAHs. • A three-step procedure composed of validation, elucidation, and substantiation has been applied to predict the locations of the spectral bands of PAHs C24H14 (302 Da), C26H14 (326 Da), C28H14 (328 Da), C32H16 (400 Da), and C34H16 (424 Da). • Validation: • Comparison of Annellation Theory locations and literaturelocations for PAHs synthesized. The difference is less than 5%. • Elucidation: • Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures. • Substantiation: • Comparison of Annellation Theory p bands locations and ZINDO/S methodology locations for PAHs with unknown synthesis procedures. The difference is less than 7%. 38

  39. Summary • A theoretical methodology based on the Annellation Theory has been proposed and applied for the first time to predict the locations of the spectral bands of PAHs. • A three-step procedure composed of validation, elucidation, and substantiation has been applied to predict the locations of the spectral bands of PAHs C24H14 (302 Da), C26H14 (326 Da), C28H14 (328 Da), C32H16 (400 Da), and C34H16 (424 Da). • Validation: • Comparison of Annellation Theory locations and literaturelocations for PAHs synthesized. The difference is less than 5%. • Elucidation: • Prediction of the locations of the bands using the Annellation Theory for PAHs with unknown synthesis procedures. • Substantiation: • Comparison of Annellation Theory p bands locations and ZINDO/S methodology locations for PAHs with unknown synthesis procedures. The difference is less than 7%. • The carcinogenic behavior of six C34H16 (424 Da) PAHs has been potentially established using benzo[a]pyrene and benzo[c]phenanthrene as model carcinogens. 39

  40. Thank you…. Questions? 40

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