Spectroscopic Studies on Charge-Transfer Complexation of Iodine with Dibenzo-15-crown-5 and Benzo-12-crown-4 in Chloroform, Dichloromethane and 1,2-Dichloroethane

Authors

1 Department of Chemistry, University of Guilan, Rasht, Iran

2 Department of Chemistry, Razi University, Kermanshah, Iran

Abstract

The formation of charge-transfer complexation between dibenzo-15-crown-5 (DB15C5) and benzo-12-
crown-4 (B12C4) (Donor) and iodine is investigated spectrophotometrically in three chlorinated solvents,
chloroform, dichloromethane (DCM) and 1,2-dichloroethane (DCE) solution at 25°C. The change in polarity
of the solvent also doesn’t affect the stoichiometry of the complexes. Values of formation constants reflect
the order of ionization potentials of the donors. The observed time dependence of the charge-transfer band
and subsequent formation of I3- ion are related to the slow formation of the initially formed 1:1 Donor.I2
outer complex to an inner electron donor-acceptor (EDAr) complex, followed by fast reaction of the inner
complex with iodine to form a triiodide ion, as follows:
Donor + I2 → Donor. I2 (outer complex), fast
Donor.I2 (outer complex) → (Donor. I+)I- (inner complex), slow
(Donor . I+)I- (inner complex) + I2 → (Donor .I+)I3-, fast
The pseudo-first-order rate constants for the transformation process were evaluated in different solvent
systems. The stability constants of the resulting EDAr complexes were also evaluated and the solvent effect
on their stability are discussed. The resulting complexes were isolated and characterized by FTIR and 1HNMR
spectroscopy.

Keywords


[1] R.S. Muliken and W. B. Person, “Molecular Complexes”, John Wiley and sons, Inc (1969).
[2] R.S. Muliken, J. Am. Chem. Soc. 70 (1950) 600-608; J. Chem. Phys., 23 (1955) 397-403; Rec. Trav.
Chim 75 (1956) 845-852; J. Phys. Chem. 52 (1952) 801-808.
[3] L. Andrews and R. M. Keefer, J. Org. Chem., 52, (1987) 2690-2694.
[4] M. Tamres and J. Yarwood, “Spectroscopy and Structure of Molecular Complexes”, Plenum, Press, New
York, Chapter 3, 1974.
[5] R. Foster, “Molecular Association” vol. 2. Academic Press New York, (1979).
[6] P. J. Trotter and P. A. White, Appl. Spectrosc. 32 (1978) 232-236.
[7] I. Ikemoto,M. Sakairi,T. Tsutsumi, H. Kuroda, I. Harda, M. Tasumi and H. Shirakawa, Chem. Lett.
(1979) 1189-1198.
[8] N. Kulevsky and K. N. Butamina, Spectro. Chim. Acta., 46A (1991) 79-84.
[9] R. M. Izatt, J. S. Bradshaw, S. A. Nielsen, J. D. L. Amb, J.J. Christensen, D. Sen, Chem. Ev. 85 (1985)
271-339.
[10] R. M. Izatt, K. Pawlak, J. S. Bradshaw and R. L. Bruening, Chem. Rev. 91 (1991) 1721-2085.
[11] R. M. Izatt, J. S. Bradshaw, K. Pawlak, R. L. Bruening, B. J. Tarbet., Chem. Rev. 92 (1992) 1261-1354.
[12] R. M. Izatt, K. Pawlak, J. S. Bradshaw, R. L. Bruening, Chem. Rev. 95 (1995) 2529-2586.
[13] M. Shamsipur, Iran. J. Chem.& Chem. Eng. (1998) 59-64.
[14] A. M. Nour El-Din, Spectrochim. Acta 42A, (1986) 637-640.
[15] A. Semnani and M. Shamsipur, J. Incl. Phenom. 22 (1995) 99-104.
[16] A. Semnani and M. Shamsipur, Polish. J. Chem. 71 (1997) 134-139.
[17] A. Semnani and M. Shamsipur, J. Chem. Soc. Dalton. Trans. 22 (1996) 15-19.
[18] A. Semnani and M. Shamsipur, Spectrochim. Acta 49A (1993) 411-415.
[19] M. Hassani, M. Shamsipur, J. Incl. Phenom. 28 (1997) 39-49.
[20] A. Roohollahi, A. Kakanejadifard, M. Farnia and M. Shamsipur, Polish. J. Chem. 71 (1997) 731-755.
[21] H. P. Hopkins, D. V. Jahagirdar, and F. J. Windler, J. Phys. Chem. 82 (1978) 1254-1257.
[22] E.M. Nour, L.A. Shahada, Spectrochim. Acta 44A, (1988) 1277-1280.
[23] E.M. Nour, Spectrochim. Acta 47A (1974) 743-748.
[24] R.P. Lang, J. Phys. Chem. 78 (1974) 1657 -1662.
[25] L. Andrews, E. S. Prochaska and A. Loewensehuss, Inorg. Chem. 19 (1980) 463 -466.
[26] M. Mizuno, J. Tanaka, I. Harada, J. Phys. Chem. 85 (1981) 1789 -1794.
[27] E.M. Nour, Spectro. Chim. Acta 47A (1991) 743-747.
[28] W. Hirsch, J. Greenman, R. Pizer, Can. J. Chem. 71 (1993) 2171-2175.
[29] A. Semnani, M. Shamsipur, J. Incl. Phenom. 22 (1995) 99-105.
[30] A. Semnani, M. Shamsipur, J. Chem. Soc., Dalton Trans. (1996) 2215-2218.
[31] A. Semnani, M. Shamsipur, Polish. J. Chem. 71 (1997) 134-139.
[32] J. Zolgharnein, M. Shamsipur, Polish. J. Chem. 72 (1998) 2486-2494.
[33] M. Shamsipur, M.H. Mashhadizadeh, J. Incl. Phenom. 38 (2000) 277-286.
[34] M. Shamsipur, N. Samadi, M. Irandoust, Polish. J. Chem. 78 (2004) 1979-1985.
[35] M. Hasani, M. Shamsipur, J. Incl. Phenom. 48 (2004) 135-149.
[36] M. Hasani, S. Akbari, Spectrochim. Acta 67A (2007) 139-144.
[37] M. Hasani, S. Akbari, Spectrochim. Acta 68A (2007) 409-413.
[38] M. Tawres, J. Yarwood, Spectroscopy and Structure of Molecular Complexes, Plenum Press, New York
(1974).
[39] M. Mizumno, J. Tanaka, I. Harada, J. Phys. Chem. 85 (1981) 1789-1795.
[40] M. Ciureanu, V.E. Sahini, Rev. Roum. Chim. 22 (1977) 1441-1449.
N. Alizadeh & M. Shamsipur, J. Iranian Chem. Res. 5 (2) (2012) 93-101
101
[41] N.S. Rao, G.B. Rao, D. Ziessov, Spectrocim. Acta 46A (1980) 1107-1114.
[42] V. Gutmann, The Donor-Acceptor Concepts of Molecular Interactions, Plenum Press, New York (1978)
[43] H.A. Benesi, J.H. Hildebrand J. Am. Chem. Soc. 71 (1949) 2703-2707.
[44] A.A. Boraei, E.M. Abd Alla, M.R. Mahmoud, Bull. Chem. Soc. Jpn. 67 (1994) 603-606.
[45] E.H. EL-Mossalamy, A.S. Amin, A.A. Khalil, Spectrochim. Acta 58A (2002) 67-72.