Theoretical analysis of the porphyrin-porphyrin exciton interaction in circular dichroism spectra of dimeric tetraarylporphyrins

Journal of the American Chemical Society

Volumn 125, Issue 25, 2003, Pages 7613-7628

  Pescitelli, Gennaro ^a,d   Gabriel, Sven ^b   Wang, Yuekui ^b   Fleischhauer, Jörg ^b   Woody, Robert W ^c   Berova, Nina ^a  

^a Och Spine at New York Presbyterian Hospitals   (United States)

^b RWTH AACHEN UNIVERSITY   (Germany)

^c Department of Environmental and Radiological Health Sciences   (United States)

^d UNIVERSITY OF PISA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

CHEMICAL BONDS; EXCITONS; ISOMERS; STEREOCHEMISTRY;

CHIRAL RECEPTORS;

PORPHYRINS;

5 (4' CARBOXYPHENYL) 10,15,20 TRIPHENYLPORPHIN; 5ALPHA CHOLESTANE 3,17 DIOL; CHOLESTANE DERIVATIVE; DIMER; ESTER DERIVATIVE; PHENYL GROUP; PORPHYRIN; PORPHYRIN DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CALCULATION; CHEMICAL ANALYSIS; CHEMICAL BOND; CHEMICAL STRUCTURE; CHIRALITY; CIRCULAR DICHROISM; CONFORMATIONAL TRANSITION; DYNAMICS; ENERGY; HYBRID; HYPOTHESIS; ISOMER; MATHEMATICAL MODEL; MOLECULAR INTERACTION; MOLECULAR MODEL; MOLECULAR PROBE; OSCILLATION; POLARIZATION; QUANTUM MECHANICS; STEREOCHEMISTRY; STRUCTURE ANALYSIS; TECHNIQUE; ULTRAVIOLET SPECTROSCOPY;

CIRCULAR DICHROISM; CYCLOHEXANES; MAGNETIC RESONANCE SPECTROSCOPY; MODELS, CHEMICAL; MOLECULAR CONFORMATION; MONTE CARLO METHOD; PORPHYRINS; SPECTROPHOTOMETRY, ULTRAVIOLET;

EID: 0037868251     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja030047v     Document Type: Article

References (170)

1. The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: San Diego, 2000; Vols. 4 and 6.
2. (a) Ogoshi, H.; Mizutani, T. Acc. Chem. Res. 1998, 31, 81-89.
3. (b) Ogoshi, H.; Mizutani, T.; Hayashi, T.; Kuroda, Y. In The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: San Diego, 2000; Vol. 6, pp 280-340.
4. (c) Weiss, J. J. Inclusion Phenom. Macrocyclic Chem. 2001, 40, 1-22.
5. Huang, X.; Nakanishi, K.; Berova, N. Chirality 2000, 12, 237-255.
6. (a) Ghosh, A. In The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: San Diego, 2000; Vol. 7, pp 1-38.
7. (b) Gouterman, M. In The Porphyrins; Dolphin, D., Ed.; Academic Press: New York, 1978; Vol. III, pp 1-165.
8. Tinoco, I., Jr. Adv. Chem. Phys. 1962, 4, 113-160.
9. (a) Mason, S. F. Molecular Optical Activity and the Chiral Discrimination; Cambridge University Press: Cambridge, 1982.
10. (b) Rodger, A.; Nordén, B. Circular Dichroism & Linear Dichroism; Oxford University Press: Oxford, 1997.
11. (c) Circular Dichroism: Principles and Applications, 2nd ed.; Berova, N., Nakanishi, K., Woody, R. W., Eds.; Wiley-VCH: New York, 2000.
12. The term coupled-dipole or exciton model refers to a theoretical mechanism of optical activity that involves the Coulombic coupling between electric transition dipoles. This dipole - dipole coupling is often referred to as exciton coupling or interaction. UV - vis and CD spectra dominated by the coupled- dipole mechanism are often called exciton-coupled. The analysis of optical spectra according to the coupled-dipole mechanism (also referred to as exciton analysis or approach) may be qualitative or quantitative. In a qualitative way, the exciton chirality method (or simply exciton method) relates the sign of CD spectrum with the absolute configuration. In a quantitative way, full CD spectra may be evaluated through coupled-dipole calculations; these can be accomplished within a quantum-mechanics (exciton) or classical physics (coupled-oscillator) frame. One example of a coupled-oscillator method is DeVoe's polarizability theory.
13. Harada, N.; Nakanishi, K. Circular Dichroic Spectroscopy - Exciton Coupling in Organic Stereochemistry; University Science Books: Mill Valley, CA, 1983.
14. Berova, N.; Nakanishi, K. In Circular Dichroism: Principles and Applications, 2nd ed.; Berova, N., Nakanishi, K., Woody, R. W., Eds.; Wiley-VCH: New York, 2000; pp 337-382.
15. Koslowski, A.; Sreerama, N.; Woody, R. W. In Circular Dichroism: Principles and Applications; Berova, N., Nakanishi, K., Harada, N., Eds.; Wiley-VCH: New York, 2000; pp 55-95.
16. (a) DeVoe, H. J. Chem. Phys. 1964, 41, 393-400.
17. (b) DeVoe. H. J. Chem. Phys. 1965, 43, 3199-3208.
18. Matile, S.; Berova, N.; Nakanishi, K.; Novkova, S.; Philipova, I.; Blagoev, B. J. Am. Chem. Soc. 1995, 117, 7021-7022.
19. Matile, S.; Berova, N.; Nakanishi, K.; Fleischhauer, J.; Woody, R. W. J. Am. Chem. Soc. 1996, 118, 5198-5206.
20. (a) Matile, S.; Berova, N.; Nakanishi, K. Enantiomer 1996, 1, 1-12.
21. (b) Rickman, B. H.; Matile, S.; Nakanishi, K.; Berova, N. Tetrahedron 1998, 54, 5041-5064.
22. (c) Jiang, H.; Huang, X.; Nakanishi, K.; Berova, N. Tetrahedron Lett. 1999, 40, 645-7649.
23. (a) Huang, X.; Rickman, B. H.; Borhan, B.; Berova, N.; Nakanishi, K. J. Am. Chem. Soc. 1998, 120, 6185-6186.
24. (b) Huang, X.; Borhan, B.; Rickman, B. H.; Nakanishi, K.; Berova, N. Chem. Eur. J. 2000, 6, 216-224.
25. (c) Kurtan, T.; Nesnas, N.; Li, Y.-Q.; Huang, X.; Nakanishi, K.; Berova, N. J. Am. Chem. Soc. 2001, 123, 5962-5973.
26. Kurtan, T.; Nesnas, N.; Koehn, F. E.; Li, Y.-Q.; Nakanishi, K.; Berova, N. J. Am. Chem. Soc. 2001, 123, 5974-5982.
27. Huang, X.; Fujioka, N.; Pescitelli, G.; Koehn, F. E.; Williamson, T. R.; Nakanishi, K.; Berova, N. J. Am. Chem. Soc. 2002, 124, 10320-10335.
28. Proni, G.; Pescitelli, G.; Huang, X.; Quraishi, N. Q.; Nakanishi, K.; Berova, N. Chem. Commun. 2002, 1590-1591.
29. Yang, Q.; Olmsted, C.; Borhan, B. Org. Lett. 2002, 4, 3423-3426.
30. Gouterman, M.; Holten, D.; Lieberman, E. Chem. Phys. 1977, 25, 139-153.
31. (a) Selensky, R.; Holten, D.; Windsor, M. W.; Paine, J. B., III; Dolphin, D.; Gouterman, M.; Thomas, J. C. Chem. Phys. 1981, 60, 33-46.
32. (b) Von Maltzan, B. Z. Naturforsch. A 1985, 40A, 389-420.
33. (c) Osuka, A.; Maruyama, K. J. Am. Chem. Soc. 1988, 110, 4454-4456.
34. (d) Ohno, O.; Ishikawa, N.; Matsuzawa, H.; Kaizu, Y.; Kobayashi, H. J. Phys. Chem. 1989, 93, 1713-1718.
35. (e) Eriksson, S.; Kaellebring, B.; Larsson, S.; Maartensson, J.; Wennerstroem, O. Chem. Phys. 1990, 146, 165-177.
36. (f) Tran-Thi, T. H.; Lipskier, J. F.; Maillard, P.; Momenteau, M.; Lopez-Castillo, J. M.; Jay-Gerin, J. P. J. Phys. Chem. 1992, 96. 1073-1082.
37. (g) Munro, O. Q.; Marques, H. M. Inorg. Chem. 1996, 35, 3768-3779.
38. (h) Ribo, J. M.; Bofill, J. M.; Crusats, J.; Rubires, R. Chem. Eur. J. 2001, 7, 2733-2737.
39. Hunter, C. A.; Sanders, J. K. M.; Stone, A. J. Chem. Phys. 1989, 133, 395-404.
40. Stomphorst, R. G.; Koehorst, R. B. M.; Van Der Zwan, G.; Benthem, B.; Schaafsma, T. J. J. Porphyrins Phthalocyanines 1999, 3, 346-354.
41. Bayley, P. M.; Nielsen, E. B.; Schellman, J. A. J. Phys. Chem. 1969, 73, 228-243.
42. (a) Parusel, A. B. J.; Ghosh, A. J. Phys. Chem. A 2000, 104, 2504-2507.
43. (b) Nguyen, K. A.; Pachter, R. J. Chem. Phys. 2001, 114, 10757-10767.
44. (c) Parusel, A. B. J.; Grimme, S. J. Porphyrins Phthalocyanines 2001, 5, 225-232.
45. (d) Baerends, E. J.; Ricciardi, G.; Rosa, A.; van Gisbergen, S. J. A. Coord. Chem. Rev. 2002, 230, 5-27.
46. (e) Liao, M.-S.; Scheiner, S. J. Chem. Phys. 2002, 117, 205-219.
47. (f) Nguyen, K. A.; Day, P. N.; Pachter, R.; Tretiak, S.; Chernyak, V.; Mukamel, S. J. Phys. Chem. A 2002, 106, 10285-10293.
48. (g) Parac, M.; Grimme, S. J. Phys. Chem. A 2002, 106, 6844-6850.
49. Platt, J. R. In Radiation Biology; Hollaender, A., Ed.; McGraw-Hill: New York, 1956; Vol. 3, pp 71-123.
50. Simpson, W. T.; Peterson, D. L. J. Chem. Phys. 1957, 38, 588-589.
51. (a) Fulton, R. L.; Gouterman, M. J. Chem. Phys. 1961, 35, 1059-1071.
52. (b) Fulton, R. L.; Gouterman, M. J. Chem. Phys. 1964, 41, 2280-2286.
53. London, F. J. Phys. Chem. 1942, 46, 305-316.
54. Hsu, M.-C. Optical Activity of Heme Proteins; Ph.D. Thesis, University of Illinois Urbana - Champaign, 1970; pp 99-105.
55. Shingu, K.; Imajo, S.; Kuritani, H.; Hagishita, S.; Kuriyama, K. J. Am. Chem. Soc. 1983, 105, 6966-6967.
56. (a) Hsu, M.-C.; Woody, R. W. J. Am. Chem. Soc. 1969, 91, 3679-3681.
57. (b) Hsu, M. C.; Woody, R. W. J. Am. Chem. Soc. 1971, 93, 3515-3525.
58. Dong, J. G.; Akritopoulou-Zanze, I.; Guo, J.; Berova, N.; Nakanishi, K.; Harada, N. Enantiomer 1997, 2, 397-409.
59. (a) Applequist, J.; Carl, J. R.; Fung, K.-K. J. Am. Chem. Soc. 1972, 94, 2952-2960.
60. (b) Applequist, J. J. Chem. Phys. 1973, 58, 4251-4259.
61. Kasha, M. Radiat. Res. 1963, 20, 55-70.
62. Huang, X.; Borhan, B.; Berova, N.; Nakanishi, K. J. Ind. Chem. Soc. 1998, 75, 725-728.
63. When the exciton-coupling potential is small compared to the bandwidth (as in the case of bis-porphyrin derivatives discussed here), the two components of the exciton couplet cancel each other to a large extent, and the apparent exciton splitting is dominated by the bandwidth: this makes the extraction of the two parameters nontrivial: (a) Wellman, K. M.; Djerassi, C. J. Am. Chem. Soc. 1965, 87, 60-66. (b) Bayley, P. M. Prog. Bioph. Mol. Biol. 1973, 27, 1-76. However, a simple deconvolution of the experimental CD spectrum into two Gaussian or Lorentzian functions usually affords the true CD components with very good accuracy (see for example ref 48c).
64. When the exciton-coupling potential is small compared to the bandwidth (as in the case of bis-porphyrin derivatives discussed here), the two components of the exciton couplet cancel each other to a large extent, and the apparent exciton splitting is dominated by the bandwidth: this makes the extraction of the two parameters nontrivial: (a) Wellman, K. M.; Djerassi, C. J. Am. Chem. Soc. 1965, 87, 60-66. (b) Bayley, P. M. Prog. Bioph. Mol. Biol. 1973, 27, 1-76. However, a simple deconvolution of the experimental CD spectrum into two Gaussian or Lorentzian functions usually affords the true CD components with very good accuracy (see for example ref 48c).
65. Woody, R. W. In Optical Properties and Structure of Tetrapyrroles; Sund, H., Blauer, G., Eds.; Walter de Gruyter: Berlin, 1985; pp 239-259.
66. Blauer, G.; Sreerama, N.; Woody, R. W. Biochemistry 1993, 32, 6674-6679.
67. (a) Borovkov, V. V.; Lintuluoto, J. M.; Inoue, Y. J. Phys. Chem. A 2000, 104, 9213-9219.
68. (b) Borovkov, V. V.; Lintuluoto, J. M.; Inoue, Y. Org. Lett. 2000, 2, 1565-1568.
69. (c) Borovkov, V. V.; Lintuluoto, J. M.; Fujiki, M.; Inoue, Y. J. Am. Chem. Soc. 2000, 122, 4403-4407.
70. (d) Borovkov, V. V.; Yamamoto, N.; Lintuluoto, J. M.; Tanaka, T.; Inoue, Y. Chirality 2001, 13, 329-335.
71. (e) Borovkov, V. V.; Lintuluoto, J. M.; Inoue, Y. J. Am. Chem. Soc. 2001, 123, 2979-2989.
72. (f) Borovkov, V. V.; Lintuluoto, J. M.; Sugeta, H.; Fujiki, M.; Arakawa, R.; Inoue, Y. J. Am. Chem. Soc. 2002, 124, 2993-3006.
73. (g) Borovkov, V. V.; Lintuluoto, J. M.; Inoue, Y. Org. Lett. 2002, 4, 169-171.
74. (h) Borovkov, V. V.; Harada, T.; Inoue, Y.; Kuroda, R. Angew. Chem., Int. Ed. 2002, 41, 1378-1381.
75. (i) Lintuluoto, J. M.; Borovkov, V. V.; Inoue, Y. J. Am. Chem. Soc. 2002, 124, 13676-13677.
76. Hayashi, T.; Aya, T.; Nonoguchi, M.; Mizutani, T.; Hisaeda, Y.; Kitagawa, S.; Ogoshi, H. Tetrahedron 2002, 58, 2803-2811.
77. Crossley, M. J.; Mackay, L. G.; Try, A. C. J. Chem. Soc., Chem. Commun. 1995, 1925-1927.
78. (a) Takeuchi, M.; Chin, Y.; Imada, T.; Shinkai, S. Chem. Commun. 1996, 1867-1868.
79. (b) Kessinger, R.; Thilgen, C.; Mordasini, T.; Diederich, F. Helv. Chim. Acta 2000, 83, 3069-3096.
80. Redl, F. X.; Lutz, M.; Daub, J. Chem. Eur. J. 2001, 7, 5350-5358.
81. Ayabe, M.; Yamashita, K.; Sada, K.; Shinkai, S.; Ikeda, A.; Sakamoto, S.; Yamaguchi, K. J. Org. Chem. 2003, 68, 1059-1066.
82. Ema, T.; Nemugaki, S.; Tsuboi, S.; Utaka, M. Tetrahedron Lett. 1995, 36, 5905-5908.
83. Hayashi, T.; Nonoguchi, M.; Arya, T.; Ogoshi, H. Tetrahedron Lett. 1997, 38, 1603-1606.
84. (a) Rosini, C.; Zandomeneghi, M.; Salvadori, P. Tetrahedron: Asymmetry 1993, 4, 545-554.
85. (b) Rosini, C.; Ruzziconi, R.; Superchi, S.; Fringuelli, F.; Piermatti, O. Tetrahedron: Asymmetry 1998, 9, 55-62.
86. (c) Di Bari, L.; Pescitelli, G.; Salvadori, P. J. Am. Chem. Soc. 1999, 121, 7998-8004.
87. (d) Clericuzio, M.; Toma, L.; Vidari, G. Eur. J. Org. Chem. 1999, 2059-2065.
88. (e) Iuliano, A.; Voir, I.; Salvadori, P. Eur. J. Org. Chem. 2000, 1767-1772.
89. (f) Rosini, C.; Superchi, S.; Peerlings, H. W. I.; Meijer, E. W. Eur. J. Org. Chem. 2000, 61-71.
90. (g) Rosini, C.; Donnoli, M. I.; Superchi, S. Chem. Eur. J. 2001, 7, 72-79.
91. (h) Castronovo, F.; Clericuzio, M.; Toma, L.; Vidari, G. Tetrahedron 2001, 57, 2791-2798.
92. (i) Di Bari, L.; Pescitelli, G.; Reginato, G.; Salvadori, P. Chirality 2001, 13, 548-555.
93. (j) Solladié-Cavallo, A.; Marsol, C.; Pescitelli, G.; Di Bari, L.; Salvadori, P.; Huang, X.; Fujioka, N.; Berova, N.; Cao, X.; Freedman, T. B.; Nafie, L. A. Eur. J. Org. Chem. 2002, 1788-1796.
94. (k) Pescitelli, G.; Berova, N.; Xiao, T. L.; Rozhkov, R. V.; Larock, R. C.; Armstrong, D. W. Org. Biomol. Chem. 2003, 1, 186-190.
95. (l) Di Bari, L.; Lelli, M.; Pintacuda, G.; Pescitelli, G.; Marchetti, F.; Salvadori, P. J. Am. Chem. Soc. 2003, 125, 5549-5558.
96. Cech, C. L.; Hug, W.; Tinoco, I., Jr. Biopolymers 1976, 15, 131-152.
97. (a) Bode, K. A.; Applequist, J. J. Phys. Chem. 1996, 100, 17825-17834.
98. (b) Bode, K. A.; Applequist, J. Macromolecules 1997, 30, 2144-2150.
99. The DeVoe method is equivalent to the time-dependent Hartree method [(a) McLachlan, A. D.; Ball, M. A. Mol. Phys. 1964, 8, 581-595. (b) Harris, R. A. J. Chem. Phys. 1965, 43, 959-970. (c) Rhodes, W.; Chase, M. W. Rev. Mod. Phys. 1967, 39, 348-361], which also considers interactions to all orders and takes the monomer band shape into account. Recent studies of photosynthetic reaction centers [(d) Won Y.; Friesner, R. A. J. Phys. Chem. 1988, 92, 2208-2214. (e) Jordanides, X. J.; Scholes, G. D.; Fleming, G. R. J. Phys. Chem. B 2001, 105, 1652-1669] have treated the vibronic contributions to exciton band shapes without introducing arbitrary band shapes and bandwidths.
100. The DeVoe method is equivalent to the time-dependent Hartree method [(a) McLachlan, A. D.; Ball, M. A. Mol. Phys. 1964, 8, 581-595. (b) Harris, R. A. J. Chem. Phys. 1965, 43, 959-970. (c) Rhodes, W.; Chase, M. W. Rev. Mod. Phys. 1967, 39, 348-361], which also considers interactions to all orders and takes the monomer band shape into account. Recent studies of photosynthetic reaction centers [(d) Won Y.; Friesner, R. A. J. Phys. Chem. 1988, 92, 2208-2214. (e) Jordanides, X. J.; Scholes, G. D.; Fleming, G. R. J. Phys. Chem. B 2001, 105, 1652-1669] have treated the vibronic contributions to exciton band shapes without introducing arbitrary band shapes and bandwidths.
101. The DeVoe method is equivalent to the time-dependent Hartree method [(a) McLachlan, A. D.; Ball, M. A. Mol. Phys. 1964, 8, 581-595. (b) Harris, R. A. J. Chem. Phys. 1965, 43, 959-970. (c) Rhodes, W.; Chase, M. W. Rev. Mod. Phys. 1967, 39, 348-361], which also considers interactions to all orders and takes the monomer band shape into account. Recent studies of photosynthetic reaction centers [(d) Won Y.; Friesner, R. A. J. Phys. Chem. 1988, 92, 2208-2214. (e) Jordanides, X. J.; Scholes, G. D.; Fleming, G. R. J. Phys. Chem. B 2001, 105, 1652-1669] have treated the vibronic contributions to exciton band shapes without introducing arbitrary band shapes and bandwidths.
102. The DeVoe method is equivalent to the time-dependent Hartree method [(a) McLachlan, A. D.; Ball, M. A. Mol. Phys. 1964, 8, 581-595. (b) Harris, R. A. J. Chem. Phys. 1965, 43, 959-970. (c) Rhodes, W.; Chase, M. W. Rev. Mod. Phys. 1967, 39, 348-361], which also considers interactions to all orders and takes the monomer band shape into account. Recent studies of photosynthetic reaction centers [(d) Won Y.; Friesner, R. A. J. Phys. Chem. 1988, 92, 2208-2214. (e) Jordanides, X. J.; Scholes, G. D.; Fleming, G. R. J. Phys. Chem. B 2001, 105, 1652-1669] have treated the vibronic contributions to exciton band shapes without introducing arbitrary band shapes and bandwidths.
103. The DeVoe method is equivalent to the time-dependent Hartree method [(a) McLachlan, A. D.; Ball, M. A. Mol. Phys. 1964, 8, 581-595. (b) Harris, R. A. J. Chem. Phys. 1965, 43, 959-970. (c) Rhodes, W.; Chase, M. W. Rev. Mod. Phys. 1967, 39, 348-361], which also considers interactions to all orders and takes the monomer band shape into account. Recent studies of photosynthetic reaction centers [(d) Won Y.; Friesner, R. A. J. Phys. Chem. 1988, 92, 2208-2214. (e) Jordanides, X. J.; Scholes, G. D.; Fleming, G. R. J. Phys. Chem. B 2001, 105, 1652-1669] have treated the vibronic contributions to exciton band shapes without introducing arbitrary band shapes and bandwidths.
104. The point-dipole approximation is used here with the DeVoe method, and the monopole approximation with the matrix method, as is commonly the case. It should be noted, however, that the monopole approximation can be used in the DeVoe method49 and the point-dipole approximation can be used with the matrix method.
105. eff + 1)/3 is more rigorously correct for two dipoles included in distinct cavities separated by the solvent. Moreover, when the two dipoles lie so close to each other as to be included in a single cavity, the effect of the solvent may suppress (up to 25%) or enhance (up to 10%) the interaction, depending on the geometry. The authors conclude that this "enhancement/suppression effect [...] may explain the excellent agreement of some quantum chemistry calculations [of excitation energy transfer] to experimental results without considering the effects of the medium".
106. (a) Zobel, E., Diplomarbeit, RTWH Aachen, 1989.
107. (b) Kramer, B., Dissertation, RTWH Aachen, 1991.
108. Weiss, C.; Kobayashi, H.; Gouterman, M. J. Mol. Spectrrosc. 1965, 16, 415-450.
109. 4h geometry was imposed on the experimental structure.
110. Marques, H. M.; Brown, K. L. Coord. Chem. Rev. 2002, 225, 123-158.
111. (a) Halgren, T. A. J. Comput. Chem. 1996, 17, 490-519.
112. (b) Halgren, T. A. J. Comput. Chem. 1996, 17, 520-552.
113. (c) Halgren, T. A. J. Comput. Chem. 1996, 17, 553-586.
114. (d) Halgren, T. A.; Nachbar, R. B. J. Comput. Chem. 1996, 17, 587-615.
115. (e) Halgren, T. A. J. Comput. Chem. 1996, 17, 616-641.
116. 3 (GB/SA solvation model), with default parameters and convergence criteria, except that the maximum number of minimization steps was set to 50 000, and the convergence threshold was set to 0.005 kJ/mol. MC conformational searches were run with default parameters and convergence criteria, sampling all the structures within 10 kJ/mol over 1000 fully optimized steps. MC/SD simulations were run with default parameters and convergence criteria, and the following conditions: temperature 300 K, time step 1.0 or 1.5 ps, equilibration time 2 ps, simulation time 1 ns, 1:1 ratio between MC and SD steps; bond-length constraints were not used. DFT B3LYP/6-31G** calculations were run with Jaguar 4.1 (Schrödinger, Inc., Portland, OR).
117. Chang, G.; Guida, W. C.; Still, W. C. J. Am. Chem. Soc. 1989, 111, 4379-4386.
118. Guarnieri, F.; Still, W. C. J. Comput. Chem. 1994, 15, 1302-1310.
119. Jiang, H. Structural Studies of Biologically Active Natural Products; Ph.D. Thesis, Columbia University New York, 1998; pp 68-107.
120. b transition and the aromatic long axis. CNDO-S/CI calculations were carried out with a CNDO/M program, according to Del Bene and Jaffé's formulation (Del Bene, J.; Jaffé, H. H. J. Chem. Phys. 1968, 49, 1221-1229), with Mataga approximation of two-electron repulsion integrals. One hundred singly excited states, with maximum energy values of 7.0 eV, were included in the CI. DFT (B3LYP/6-31G**) optimized structures were used as the input geometries.
121. Allen, F. H. Acta Crystallogr., Sect. B: Struct. Sci. 2002, B58, 380-388.
122. Numbers 5′,10′,15′, and 20′ refer to the meso positions of the porphyrin at position C-3 and 5″,10″,15″, and 20″ to the porphyrin at C-17. When referring to transition dipole directions, with 5-15 (or 10-20) both 5′-15′ and 5″-15″ (or 10′-20′ and 10″-20″) are intended.
123. (a) Jones, G. I. L.: Owen, N. L. J. Mol. Struct. 1973, 18, 1-32.
124. (b) Exner. O. In The Chemistry of Double-Bonded Functional Groups: Patai, S., Ed.; Wiley: London, 1977; Vol. 1, pp 1-92.
125. In the two model compounds S1 and S2 (Figure S1, Supporting Information), a portion of the steroidal skeleton was included in order to keep the aliphatic ring rigid and assess the effect of the close stereogenic centers. Thus, the torsional energy curves are not symmetrical around 0°. For S2 (including C/D rings), actual minima are at -30/+40° and -45/+35°, as a consequence of the steric hindrance provided by the metal group.
126. In the over 2650 entries for benzoate esters in the CSD, the s-trans conformation of the ester linkage is ubiquitous. Only 4 structures are exceptional, all of which are ansa compounds, where the s-cis conformation is locked by the para bridging chain.
127. (a) Le Fevre, R. J. W.; Sundaram, A. J. Chem. Soc. 1962, 3904-3915.
128. (b) Pinkus, A. G.; Lin, E. Y. J. Mol. Struct. 1975, 24, 9-26.
129. (a) Wolberg, A. J. Mol. Struct. 1974, 21, 61-66.
130. (b) Chachaty, C.; Gust, D.; Moore, T. A.; Nemeth, G. A.; Liddell, P. A.; Moore, A. L. Org. Magn. Reson. 1984, 22, 39-46.
131. (c) Anderson, H. L. Chem. Commun. 1999, 2323-2330.
132. (a) Eaton, S. S.; Eaton, G. R. J. Am. Chem. Soc. 1975, 97, 3660-3666.
133. (b) Schrijvers, R.; van Dijk, M.; Sanders, G. M.; Sudholter, E. J. R. Recl. Trav. Chim. Pays-Bas 1994, 113, 351-354.
134. (c) Noss, L.; Liddell, P. A.; Moore, A. L.; Moore, T. A.; Gust, D. J. Phys. Chem. B 1997, 101, 458-465.
135. (a) Altona, C.; Geise, H. J.; Romers, C. Tetrahedron 1968, 24, 13-32.
136. (b) Duax, W. L.; Weeks, C. M.; Rohrer, D. C. Top. Stereochem. 1976, 9, 271-383.
137. 12 varies only slightly (+58.1-59.4°) for compound 2-αβ in the lowest energy conformation.
138. Crossley, M. J.; Field, L. D.; Forster, A. J.; Harding, M. M.; Sternhell, S. J. Am. Chem. Soc. 1987, 109, 341-348.
139. The introduction of a weighting factor for the intensity of the 10-20 component corresponds to a conformational averaging of this component preceding the exciton interaction. A more rigorous approach would be represented by a spectral averaging following the interaction between dipoles with full intensity. This requires a lengthier procedure consisting of fractionating such motion into several steps for each porphyrin, and calculating the Boltzmann-weighted average of all possible combinations.
140. The major source of the remaining differences between experimental and calculated spectra is probably represented by our conformational, rather than spectral, averaging. Other factors conceivably playing minor roles are (a) the point-dipole approximation (the shortest interchromophoric distances are around 24 Å); (b) the solvent effect (see note 53); (c) the presence of other mechanisms contributing to the optical activity. It is reasonable to rule out porphyrin ring distortions for compounds 2-αβ, 2-ββ, and 2-βα. The chiral perturbation exerted by the steroidal skeleton on the B transition is also negligible: the monoester formed by 5α-androstan-17β-ol and TPP-COOH shows only a weak positive Cotton effect at 417 nm, Δε = + 4.3. This 17β isomer has the most intense CD spectrum among mono-porphyrin derivatives of steroids (because of the proximity to the stereogenic center and the rigid environment of the chromophore, cis to the 13β methyl group). The intensity is still too low to interfere with the more intense exciton-coupled spectra, although it may account for bis-porphyrin derivatives with long-distance coupling.
141. The major source of the remaining differences between experimental and calculated spectra is probably represented by our conformational, rather than spectral, averaging. Other factors conceivably playing minor roles are (a) the point-dipole approximation (the shortest interchromophoric distances are around 24 Å); (b) the solvent effect (see note 53); (c) the presence of other mechanisms contributing to the optical activity. It is reasonable to rule out porphyrin ring distortions for compounds 2-αβ, 2-ββ, and 2-βα. The chiral perturbation exerted by the steroidal skeleton on the B transition is also negligible: the monoester formed by 5α-androstan-17β-ol and TPP-COOH shows only a weak positive Cotton effect at 417 nm, Δε = + 4.3. This 17β isomer has the most intense CD spectrum among mono-porphyrin derivatives of steroids (because of the proximity to the stereogenic center and the rigid environment of the chromophore, cis to the 13β methyl group). The intensity is still too low to interfere with the more intense exciton-coupled spectra, although it may account for bis-porphyrin derivatives with long-distance coupling.
142. The major source of the remaining differences between experimental and calculated spectra is probably represented by our conformational, rather than spectral, averaging. Other factors conceivably playing minor roles are (a) the point-dipole approximation (the shortest interchromophoric distances are around 24 Å); (b) the solvent effect (see note 53); (c) the presence of other mechanisms contributing to the optical activity. It is reasonable to rule out porphyrin ring distortions for compounds 2-αβ, 2-ββ, and 2-βα. The chiral perturbation exerted by the steroidal skeleton on the B transition is also negligible: the monoester formed by 5α-androstan-17β-ol and TPP-COOH shows only a weak positive Cotton effect at 417 nm, Δε = + 4.3. This 17β isomer has the most intense CD spectrum among mono-porphyrin derivatives of steroids (because of the proximity to the stereogenic center and the rigid environment of the chromophore, cis to the 13β methyl group). The intensity is still too low to interfere with the more intense exciton-coupled spectra, although it may account for bis-porphyrin derivatives with long-distance coupling.
143. Cech, C. M. Polynucleotide Circular Dichroism Calculations: Use of All Order Polarizability Theory; Ph.D. Thesis. University of California Berkeley, 1975.
144. Allen, P. R.; Reek, J. N. H.; Try, A. C.; Crossley, M. J. Tetrahedron: Asymmetry 1997, 8, 1161-1164.
145. Crossley, M. J.; Hambley, T. W.; Mackay, L. G.; Try, A. C.; Walton, R. J. Chem. Soc., Chem. Commun. 1995, 1077-1079.
146. Probably due to the very intense coupling, the through-space exciton interaction is dominant for 5 even if other mechanisms of optical activity may contribute, such as: (a) the inherent chirality of porphyrin rings distorted by the presence of tert-butyl groups; (b) the through-bond porphyrin - porphyrin conjugation (Piet, J. J.; Taylor, P. N.; Anderson, H. L.; Osuka, A.; Warman, J. M. J. Am. Chem. Soc. 2000, 122, 1749-1757).
147. Probably due to the very intense coupling, the through-space exciton interaction is dominant for 5 even if other mechanisms of optical activity may contribute, such as: (a) the inherent chirality of porphyrin rings distorted by the presence of tert-butyl groups; (b) the through-bond porphyrin - porphyrin conjugation (Piet, J. J.; Taylor, P. N.; Anderson, H. L.; Osuka, A.; Warman, J. M. J. Am. Chem. Soc. 2000, 122, 1749-1757).
148. βN-Zn directions define for the (S,S)-(-) enantiomer a positive chirality, in disagreement with the observed negative couplet. Moreover, just a slight rotation of the dipole toward the N-N directions is sufficient to reverse the defined chirality.
149. Ema, T.; Misawa, S.; Nemugaki, S.; Sakai, T.; Utaka, M. Chem. Lett. 1997, 487-488.
150. A simulated annealing procedure (heating from 0 to 300 K in 1 ps, 50-100 ps at 300 K, cooling from 300 to 0 K in 5 ps, simulation step 1 fs) run on 6 systematically converged to a set of edge-to-face stacked structures, with center-to-center distance around 8.5 Å. Minimized energies are above the 10 kJ/mol threshold from the minimum found by MC simulations. The calculated CD for these structures (DeVoe method, circular oscillator model) shows a negative couplet with A ≈ -780 and no flanking bands.
151. max = 32 nm) were substantially overestimated.
152. Yoshida, N.; Ishizuka, T.; Osuka, A.; Jeong, D. H.; Cho, H. S.; Kim, D.; Matsuzaki, Y.; Nogami, A.; Tanaka, K. Chem. Eur. J. 2003, 9, 58-75.
153. In the minimized MMFFs structures for 2-αα, the porphyrin rings show distortions from planarity of the saddling type (Jentzen, W.; Song, X. Z.; Shelnutt, J. A. J. Phys. Chem. B 1997, 101, 1684-1699). Alternate pyrrole rings are tilted above and below the mean plane; the average RMS deviations from planarity are about 0.38 Å. This nonplanar distortion is a mechanism for relieving steric crowding in the αα isomer. Both the DeVoe and the MATMAC calculations use transition parameters developed for planar porphyrins, so the use of these parameters in calculations with nonplanar porphyrins inevitably introduces some errors. However, the results are expected to be qualitatively correct.
154. (a) Scheidt, W. R.; Lee, Y. J. Struct. Bond. 1987, 64, 1-70.
155. (b) Hunter, C. A.; Sanders, J. K. M. J. Am. Chem. Soc. 1990, 112, 5525-5534.
156. (a) Abraham, R. J.; Bedford, G. R.; McNeillie, D.; Wright, B. Org. Magn. Reson. 1980, 14, 418-425.
157. (b) Abraham, R. J.; Marsden, I. Tetrahedron 1992, 48, 7489-7504.
158. (c) Abraham, R. J.; Medforth, C. J. Magn. Reson. Chem. 1990, 28, 343-347.
159. Leighton, P.; Cowan, J. A.; Abraham, R. J.; Sanders, J. K. M. J. Org. Chem. 1988, 53, 733-740.
160. Della Sala, F.; Widany, J.; Frauenheim, T. Phys. Status Solidi B 2000, 217, 565-575.
161. The experimental CD spectra of 2-αα in different solvents at room temperature (Figure 8 and Table S4, Supporting Information) are uniquely characterized by multiple bands, with one strongly red-shifted band of unpredictable sign that breaks down spectral symmetry and conservation. This band might result from the presence of other sources of optical activity than the coupled-oscillator mechanism, notably: (a) inherent chirality of distorted porphyrin rings (as found in the calculated structure); (b) chirality of aromatic π-π conjugated system; (c) in the case of aromatic solvents (benzene and toluene), contribution from solvent molecules strongly interacting with the chromophores (see for example: Arai, T.; Takei, K.; Nishino, N.; Fujimoto, T. Chem. Commun. 1996, 2133-2134).
162. The experimental CD spectra of 2-αα in different solvents at room temperature (Figure 8 and Table S4, Supporting Information) are uniquely characterized by multiple bands, with one strongly red-shifted band of unpredictable sign that breaks down spectral symmetry and conservation. This band might result from the presence of other sources of optical activity than the coupled-oscillator mechanism, notably: (a) inherent chirality of distorted porphyrin rings (as found in the calculated structure); (b) chirality of aromatic π-π conjugated system; (c) in the case of aromatic solvents (benzene and toluene), contribution from solvent molecules strongly interacting with the chromophores (see for example: Arai, T.; Takei, K.; Nishino, N.; Fujimoto, T. Chem. Commun. 1996, 2133-2134).
163. The experimental CD spectra of 2-αα in different solvents at room temperature (Figure 8 and Table S4, Supporting Information) are uniquely characterized by multiple bands, with one strongly red-shifted band of unpredictable sign that breaks down spectral symmetry and conservation. This band might result from the presence of other sources of optical activity than the coupled-oscillator mechanism, notably: (a) inherent chirality of distorted porphyrin rings (as found in the calculated structure); (b) chirality of aromatic π-π conjugated system; (c) in the case of aromatic solvents (benzene and toluene), contribution from solvent molecules strongly interacting with the chromophores (see for example: Arai, T.; Takei, K.; Nishino, N.; Fujimoto, T. Chem. Commun. 1996, 2133-2134).
164. (a) Tamiaki, H.; Suzuki, S.; Maruyama, K. Bull. Chem. Soc. Jpn. 1993, 66, 2633-2637.
165. (b) Takei, F.; Hayashi, H.; Onitsuka, K.; Kobayashi, N.; Takahashi, S. Angew. Chem., Int. Ed. 2001, 40, 4092-4094.
166. Flores, V.; Nguyen, C. K.; Sindelar, C. A.; Vasquez, L. D.; Shachter, A. M. Tetrahedron Lett. 1996, 37, 8633-8636.
167. Fan, J.; Whiteford, J. A.; Olenyuk, B.; Levin, M. D.; Stang, P. J.; Fleischer, E. B. J. Am. Chem. Soc. 1999, 121, 2741-2752.
168. (a) Arai, T.; Takei, K.; Nishino, N.; Fujimoto, T. Chem. Commun. 1996, 2133-2134.
169. (b) Liu, H.-Y.; Huang, J.-W.; Tian, X.; Jiao, X.-D.; Luo, G.-T.; Ji, L.-N. Chem. Commun. 1997, 1575-1576.
170. (c) Liu, H.-Y.; Huang, J.-W.; Tian, X.; Jiao, X.-D.; Luo, G.-T.; Ji, L.-N. Inorg. Chim. Acta 1998, 272, 295-299.