Fluorescence, Phosphorescence, and Delayed Fluorescence of Benzil in Imidazolium Ionic Liquids
Dinesh Chandra Khara A and Anunay Samanta A B
+ Author Affiliations
- Author Affiliations
A School of Chemistry, University of Hyderabad, Hyderabad 500 046, India.
B Corresponding author. Email: assc@uohyd.ernet.in
Australian Journal of Chemistry 65(9) 1291-1297 https://doi.org/10.1071/CH12066
Submitted: 2 February 2012 Accepted: 22 March 2012 Published: 11 May 2012
Abstract
Temperature dependence of the emission behaviour of benzil has been studied in three imidazolium ionic liquids differing in their polarity and viscosity. Room temperature absorption and steady-state emission spectra suggest that the ground and excited state conformers of benzil in ionic liquids are similar to those in conventional organic solvents. The non-degassed solutions of benzil in ionic liquids show phosphorescence at room temperature in contrast to conventional solvents where phosphorescence is commonly observed in degassed conditions. This study reveals that a thermally activated reverse intersystem crossing (T1↝S1) process is responsible for the drastic change in phosphorescence intensity with temperature in ionic liquids. The rate constant (
) of this process is found to be dependent on the polarity of the media and is 5 times higher in most polar ionic liquids. The evidence of the presence of multiple conformers of benzil in frozen conditions is obtained from the excitation wavelength dependence of the phosphorescence spectra.
References
[1] N. Jain, A. Kumar, S. Chauhan, S. M. S. Chauhan, Tetrahedron 2005, 61, 1015.| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXksVGguw%3D%3D&md5=441223326d13c11e62196c05a461c170CAS |
[2] M. A. P. Martins, C. P. Frizzo, D. N. Moreira, N. Zanatta, H. G. Bonacorso, Chem. Rev. 2008, 108, 2015.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmvFCjtbg%3D&md5=8a3fe48b996b2d1d71617a4fae7396d3CAS |
[3] J.-C. Plaquevent, J. Levillain, F. Guillen, C. Malhiac, A.-C. Gaumont, Chem. Rev. 2008, 108, 5035.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhsVWks7rI&md5=91911f61d84fb78a848bfa88afe97a52CAS |
[4] T. Welton, Chem. Rev. 1999, 99, 2071.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXkt1artrw%3D&md5=162516de75da8d6812cfbe316e3ff814CAS |
[5] A. Samanta, J. Phys. Chem. Lett. 2010, 1, 1557.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXltlynu74%3D&md5=149427e7122309242ec7eb6ce3268073CAS |
[6] A. Samanta, J. Phys. Chem. B 2006, 110, 13704.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xkslyltbc%3D&md5=35cc34f20fa598e928eed705155eb922CAS |
[7] A. Paul, A. Samanta, J. Phys. Chem. B 2007, 111, 4724.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXjt1Ohuw%3D%3D&md5=4157eda2005711141b5ed4c6a197885fCAS |
[8] P. K. Mandal, A. Samanta, J. Phys. Chem. B 2005, 109, 15172.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXmt1Kgtrc%3D&md5=d77ffea66c5de13abbf74b5195760ba9CAS |
[9] P. K. Mandal, S. Saha, R. Karmakar, A. Samanta, Curr. Sci. 2006, 90, 301.
| 1:CAS:528:DC%2BD28XitFOltLo%3D&md5=5c787533f027f4af4bd02742ad534475CAS |
[10] D. C. Khara, A. Samanta, Indian J. Chem. 2010, 49A, 714.
| 1:CAS:528:DC%2BC3cXpvVOgsbY%3D&md5=8f644d0018f57c5da9920bbb32f3b5a0CAS |
[11] D. C. Khara, A. Samanta, Phys. Chem. Chem. Phys. 2010, 12, 7671.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXotlWmsrk%3D&md5=dff0b90896a24e2b407c8a8f33336020CAS |
[12] R. Karmakar, A. Samanta, J. Phys. Chem. A 2003, 107, 7340.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXmsVegt7Y%3D&md5=75aa277191624c8fd36bb6f4176a151aCAS |
[13] R. Karmakar, A. Samanta, J. Phys. Chem. A 2002, 106, 6670.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38Xks1aqsrw%3D&md5=096f3deafe40cb232b352d6e46045888CAS |
[14] R. Karmakar, A. Samanta, J. Phys. Chem. A 2002, 106, 4447.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XivVOiur0%3D&md5=024eb0bec3ee6fa1068156cc02866676CAS |
[15] H. Weingärtner, Angew. Chem. Int. Edit. 2008, 47, 654.
| Crossref | GoogleScholarGoogle Scholar |
[16] Y. Shim, D. Jeong, M. Y. Choi, H. J. Kim, J. Chem. Phys. 2006, 125, 061102.
| Crossref | GoogleScholarGoogle Scholar |
[17] Y. Shim, J. Duan, M. Y. Choi, H. J. Kim, J. Chem. Phys. 2003, 119, 6411.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXnsVWgsbo%3D&md5=f814dbaa6138264354cb0fe2c5d18987CAS |
[18] M. N. Kobrak, H. Li, Phys. Chem. Chem. Phys. 2010, 12, 1922.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhslelsro%3D&md5=26726e650e0ff99ff0656d198da24f10CAS |
[19] M. N. Kobrak, in Advances in Chemical Physics 2008, Volume 139, pp. 83–135 (Ed. S. A. Rice ) (John Wiley & Sons, Inc.: Hoboken, NJ).
[20] M. N. Kobrak, J. Chem. Phys. 2006, 125, 064502.
| Crossref | GoogleScholarGoogle Scholar |
[21] H. K. Kashyap, R. Biswas, J. Phys. Chem. B 2008, 112, 12431.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVymtbbF&md5=bd48b5a639e9f83a0cd0b1b516cdc92bCAS |
[22] K. Santhosh, A. Samanta, J. Phys. Chem. B 2010, 114, 9195.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXnvFyhs70%3D&md5=56deb6061643d85c8d4adacf5fb700bcCAS |
[23] K. Santhosh, S. Banerjee, N. Rangaraj, A. Samanta, J. Phys. Chem. B 2010, 114, 1967.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXot1Klsw%3D%3D&md5=90f280a4a1761edee5bc8e9dc123acccCAS |
[24] A. Paul, A. Samanta, J. Phys. Chem. B 2007, 111, 1957.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXht1yrsb8%3D&md5=68ba2648eef96fe11d0b2ce0ea64c255CAS |
[25] P. K. Mandal, M. Sarkar, A. Samanta, J. Phys. Chem. A 2004, 108, 9048.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXnvFSis78%3D&md5=e210113fac27de878a61920be7d1c9d9CAS |
[26] D. C. Khara, A. Paul, K. Santhosh, A. Samanta, J. Chem. Sci. 2009, 121, 309.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtVCgsr3O&md5=a7e065309f85a1a134cf7ceb16a4901aCAS |
[27] B. Bhattacharya, A. Samanta, J. Phys. Chem. B 2008, 112, 10101.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXptVGjs78%3D&md5=b1da59f324bdec7b15445c9b362e74daCAS |
[28] C. J. Brown, R. Sadanaga, Acta Crystallogr. 1965, 18, 158.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF2MXntVOhuw%3D%3D&md5=b80551e6efdba8de2ece415d21856184CAS |
[29] N. K. Chaudhuri, M. A. EL-Sayed, J. Chem. Phys. 1967, 47, 1133.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF2sXkslOlt7o%3D&md5=1bc4f24399e7930428d9b97e6182d262CAS |
[30] C. A. Parker, T. Joyce, Chem. Commun. 1968, 1421.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF1MXisVCltg%3D%3D&md5=6fa1d33c12a5799300026541b03cedbaCAS |
[31] S. C. Bera, R. Mukherjee, M. Chowdhury, J. Chem. Phys. 1969, 51, 754.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF1MXks1Gksrc%3D&md5=ddacd9f2931940ec30819de40984a5a9CAS |
[32] D. J. Morantz, A. J. C. Wright, J. Chem. Phys. 1970, 53, 1622.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3cXkslWntbg%3D&md5=e040abb1545dd89cb665c6416ebfa577CAS |
[33] D. J. Morantz, A. J. C. Wright, J. Chem. Phys. 1971, 54, 692.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXkslGjsQ%3D%3D&md5=f766714936a5beebdeb8a8e82f17a1dcCAS |
[34] J. F. Arnett, S. P. McGlynn, J. Phys. Chem. 1975, 79, 626.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2MXhtlWnur4%3D&md5=ebbaf987de2df3aa4a9d06c56c740804CAS |
[35] T.-S. Fang, R. E. Brown, C. L. Kwan, L. A. Singer, J. Phys. Chem. 1978, 82, 2489.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1MXlsVSnsQ%3D%3D&md5=035a8573b738d2f5d1074410afe8a8f1CAS |
[36] T.-S. Fang, R. E. Brown, L. A. Singer, J. Chem. Soc., Chem. Commun. 1978, 116.
| 1:CAS:528:DyaE1cXksVWltLw%3D&md5=284bc7f19a7d779172e2968e3f337ae9CAS |
[37] T.-S. Fang, L. A. Singer, Chem. Phys. Lett. 1978, 60, 117.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1MXos1amtQ%3D%3D&md5=df866ddbd8d72bac579ef81a1bcf995dCAS |
[38] K. Bhattacharyya, D. Roy, M. Chowdhury, J. Lumin, 1980, 22, 95.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXktFGgurs%3D&md5=5ee467085b30109aad6c9da215db01d1CAS |
[39] D. Roy, K. Bhattacharyya, S. C. Bera, M. Chowdhury, Chem. Phys. Lett. 1980, 69, 134.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3cXkt1Gktrw%3D&md5=a210d871987cd4d66a39718851cbaf75CAS |
[40] L. Flamigni, F. Barigelletti, S. Dellonte, G. Orlandi, J. Photochem. 1983, 21, 237.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXhvVynt7k%3D&md5=47401196898292d7664dadb95a4ab45bCAS |
[41] K. Bhattacharyya, M. Chowdhury, J. Photochem. 1986, 33, 61.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28XitlCit7w%3D&md5=5155a402fe7b00e66ea1555fddfead41CAS |
[42] H. Inoue, T. Sakurai, T. Hoshi, J. Okubo, T. Kawashima, J. Chem. Soc., Faraday Trans. II 1986, 82, 523.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL28Xkslygurk%3D&md5=612a861b227cf42edfe63a0316ab9623CAS |
[43] C. Santhosh, P. C. Mishra, J. Photoch. Photobio. A 1990, 51, 245.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXisVansr4%3D&md5=1ac783e81dd58850b6ab241c6e9414bbCAS |
[44] N. Chattopadhyay, C. Serpa, M. I. Silva, L. G. Arnaut, A. J. Formosinho, Chem. Phys. Lett. 2001, 347, 361.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXotVanurg%3D&md5=1c2bc55ef8304c1ddc8489a7f25704e2CAS |
[45] A. K. Singh, D. K. Palit, J. P. Mittal, Chem. Phys. Lett. 2002, 360, 443.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XlsFOgsLg%3D&md5=3ba6a406fe57f8efe97fed2d89621dcdCAS |
[46] B. Bhattacharya, B. Jana, D. Bose, N. Chattopadhyay, J. Chem. Phys. 2011, 134, 044535.
| Crossref | GoogleScholarGoogle Scholar |
[47] S. K. Lower, M. A. El-Sayed, Chem. Rev. 1966, 66, 199.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF28XovVeqtg%3D%3D&md5=a30c63d77f6eb69edfeedf138cf7a343CAS |
[48] A. Paul, P. K. Mandal, A. Samanta, J. Phys. Chem. B 2005, 109, 9148.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXivV2mtrY%3D&md5=9592d6a4a03f1bea44db4717eb00bec0CAS |
[49] J. L. Anthony, J. L. Anderson, E. J. Maginn, J. F. Brennecke, J. Phys. Chem. B 2005, 109, 6366.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXitFensLw%3D&md5=4d583ad27c5fa6cb410b994b8bd7b100CAS |
[50] P. Husson-Borg, V. Majer, M. F. C. Gomes, J. Chem. Eng. Data 2003, 48, 480.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXhvFyjt7c%3D&md5=a7412f13e50027eb1fedfedd6f61281fCAS |
[51] J. Jacquemin, M. F. C. Gomes, P. Husson, V. Majer, J. Chem. Thermodyn. 2006, 38, 490.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XivVSitbg%3D&md5=0fe7b5fdcc5b1e413940aac4522ef444CAS |
[52] J. Kumełan, A. P.-S. Kamps, I. Urukova, D. Tuma, G. Maurer, J. Chem. Thermodyn. 2005, 37, 595.
| Crossref | GoogleScholarGoogle Scholar |
[53] S. Park, O.-H. Kwon, Y.-S. Lee, D.-J. Jang, S. Y. Park, J. Phys. Chem. A 2007, 111, 9649.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXpslShsrY%3D&md5=895777d2a46a9b4ca52c456f99c87904CAS |
[54] T. Okutsu, M. Ooyama, H. Hiratsuka, J. Tsuchiya, K. Obi, J. Phys. Chem. A 2000, 104, 288.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXotVels7o%3D&md5=ce3b52e1d55ccd87e172e0ab2d63f7c7CAS |
[55] A. R. Bertoti, J. C. Netto-Ferreira, Quim. Nova 2009, 32, 1934.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtlGjs7rO&md5=625461adf515f171016095decae9c8a7CAS |
[56] N. J. Leonard, P. M. Mader, J. Am. Chem. Soc. 1950, 72, 5388.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaG3MXhvVCjtg%3D%3D&md5=238b01618896abf747ab4c4e0d8ac0f9CAS |
[57] A. Sarkar, S. Chakravorti, J. Lumin, 1996, 69, 161.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XmtV2htrc%3D&md5=f10a648f64bb2d8ca13e4408e92e0ee1CAS |
[58] D. D. Perrin, W. L. F. Armarego, D. D. Perrin, Purification of Laboratory Chemicals 1980 (Pergamon Press Ltd: Oxford, UK).
[59] R. Duchowicz, M. L. Ferrer, A. U. Acuna, Photochem. Photobiol. 1998, 68, 494.
| Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXmsl2ns7s%3D&md5=c684eab0f33726bacad55935c29d5569CAS |
