The electron donor molecule LSD forms a charge-transfer complex with the electron acceptor tetracyanoethylene (TCNE). The charge-transfer complex has a characteristic absorption band, allowing the detection of the presence of LSD. When LSD or other hallucinogen drugs are applied to a silica gel plate and then sprayed with either TCNE or electron acceptor drugs, a color band is detected.
In 1968, Millie and colleagues studied the electronic properties of methoxylated indoles and tryptamines by their ability to form charge-transfer complexes with TCNE or 1,3,5-trinitrobenzene (TNB), another electron acceptor. Many indoles and phenothiazines form a charge-transfer complex with TCNE or TNB; the wavelength of the absorption maximum of the complex is often between 300-720 nm. As shown in the figure below, the authors found a correlation between the absorption maximum of the acceptor-TCNE or acceptor-TNB complexes and kHOMO values of the electron donors (i.e. indoles or tryptamines). The y-axis is 1000/lambda, where lambda is the maximum absorption wavelength of the charge-transfer reaction product.
1-methyl-LSD was among the indoles and phenothiazines that were tested. The charge-transfer complex of TCNE and 1-methyl-LSD (letter p, Figure 1 above) had an absorption maximum at 520 nm. As determined by Huckel calculations, 1-methyl-LSD had kHOMO=0.487. This kHOMO value is slightly larger than Karreman's 1959 report of Ehomo=0.218 for LSD, suggesting slightly less electron donating ability. According to the figure above, the electron-donating ability of 1-methyl-LSD (p) lies between 4-methoxy-indole (i) and 5-methoxy-indole (k). I don't know why Millie and colleagues choose to study 1-methyl-LSD, which has one tenth the potency of LSD, instead of LSD.
TCNE-bezene complexes are used to study the electron-donating properties of different benzene derivatives
The ionization potential of an electron donor molecule can predict the rate of formation of its drug-TCNE complex. This was shown by Domelsmith in 1977. Several different benzene derivatives were mixed with the electron acceptor TCNE, and the rate of formation of benzene-TCNE complexes was measured. When the apparent enthalpy of formation of the benzene-TCNE complexes was plotted versus the average of the first and second ionization potential energies of the benzene molecules, as shown in Figure 12 below, an excellent linear correlation was obtained.
There is no mystery about the physical and chemical forces that bind a hallucinogen drug to biological receptors. The forces may be compared with the physical and chemical forces that bind TCNE to benzene or indoles. Charge-transfer forces predict the extent of drug binding to biological receptors, and the extent of behavior disarrangement produced by mescaline or LSD is correlated with the kHOMO, showing a direct role of charge-transfer forces on the extent of consciousness alteration.
Quantum mechanics is the method used to calculate the kHOMO energy. The dose of structurally diverse hallucinogens to produce consciousness alteration is correlated with the drug's kHOMO value, so it is very likely that quantum electronic properties of matter play a role in the mechanism of consciousness alteration.
References
Domelsmith, L. N., L.L. Munchausen and K.N. Houk (1977). Photoelectron spectra of psychotropic drugs. 1. phenethylamines, tryptamines, and LSD. J. Am. Chem. Soc. 99, 4311-4321.
Fulton A. and L. E. Lyons. (1967). Electron-accepting strength of NAD+. Aust. J. Chem. 20, 2267-2268.
Millie P., J. P. Malrieu, J. Benaim, J. Y. Lallemand and M. Julia. (1968). Researches in the indole series. XX. Quantum mechanical calculations and charge-transfer complexes of substituted indoles. J. Med. Chem. 11, 207-211. 10.1021/jm00308a003
In 1968, Millie and colleagues studied the electronic properties of methoxylated indoles and tryptamines by their ability to form charge-transfer complexes with TCNE or 1,3,5-trinitrobenzene (TNB), another electron acceptor. Many indoles and phenothiazines form a charge-transfer complex with TCNE or TNB; the wavelength of the absorption maximum of the complex is often between 300-720 nm. As shown in the figure below, the authors found a correlation between the absorption maximum of the acceptor-TCNE or acceptor-TNB complexes and kHOMO values of the electron donors (i.e. indoles or tryptamines). The y-axis is 1000/lambda, where lambda is the maximum absorption wavelength of the charge-transfer reaction product.
 |
| From Hallucinogens HOMO, charge-transfer |
1-methyl-LSD was among the indoles and phenothiazines that were tested. The charge-transfer complex of TCNE and 1-methyl-LSD (letter p, Figure 1 above) had an absorption maximum at 520 nm. As determined by Huckel calculations, 1-methyl-LSD had kHOMO=0.487. This kHOMO value is slightly larger than Karreman's 1959 report of Ehomo=0.218 for LSD, suggesting slightly less electron donating ability. According to the figure above, the electron-donating ability of 1-methyl-LSD (p) lies between 4-methoxy-indole (i) and 5-methoxy-indole (k). I don't know why Millie and colleagues choose to study 1-methyl-LSD, which has one tenth the potency of LSD, instead of LSD.
TCNE-bezene complexes are used to study the electron-donating properties of different benzene derivatives
The ionization potential of an electron donor molecule can predict the rate of formation of its drug-TCNE complex. This was shown by Domelsmith in 1977. Several different benzene derivatives were mixed with the electron acceptor TCNE, and the rate of formation of benzene-TCNE complexes was measured. When the apparent enthalpy of formation of the benzene-TCNE complexes was plotted versus the average of the first and second ionization potential energies of the benzene molecules, as shown in Figure 12 below, an excellent linear correlation was obtained.
 |
| From Hallucinogens HOMO, charge-transfer |
There is no mystery about the physical and chemical forces that bind a hallucinogen drug to biological receptors. The forces may be compared with the physical and chemical forces that bind TCNE to benzene or indoles. Charge-transfer forces predict the extent of drug binding to biological receptors, and the extent of behavior disarrangement produced by mescaline or LSD is correlated with the kHOMO, showing a direct role of charge-transfer forces on the extent of consciousness alteration.
Quantum mechanics is the method used to calculate the kHOMO energy. The dose of structurally diverse hallucinogens to produce consciousness alteration is correlated with the drug's kHOMO value, so it is very likely that quantum electronic properties of matter play a role in the mechanism of consciousness alteration.
References
Domelsmith, L. N., L.L. Munchausen and K.N. Houk (1977). Photoelectron spectra of psychotropic drugs. 1. phenethylamines, tryptamines, and LSD. J. Am. Chem. Soc. 99, 4311-4321.
Fulton A. and L. E. Lyons. (1967). Electron-accepting strength of NAD+. Aust. J. Chem. 20, 2267-2268.
Millie P., J. P. Malrieu, J. Benaim, J. Y. Lallemand and M. Julia. (1968). Researches in the indole series. XX. Quantum mechanical calculations and charge-transfer complexes of substituted indoles. J. Med. Chem. 11, 207-211. 10.1021/jm00308a003
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