Chemistry of drug interactions: Characterization of charge-transfer complexes of Guaifenesin with various acceptors using spectroscopic and thermal methods

Abstract

The present study deals with the complexation properties of Guaifenesin with two types of acceptors: σ-acceptor (i.e., iodine) and π-acceptors (i.e., dichlorodicyanobenzoquinone, chloranil and picric acid). All the prepared complexes were characterized stoichiometrically and structurally using various spectral techniques, as well as elemental analyses. Thermal decomposition behavior of complexes was studied, and their thermodynamic parameters were calculated using Coats-Redfern and Horowitz-Metzger equations. It has been found that the complexation with PA and CHL acceptors increases the values of enthalpy and entropy, while the complexation with DDQ and iodine acceptors decreases the values of these parameters compared with the free GU donor.

Charge-transfer complexation of TCNE with azithromycin, the antibiotic used worldwide to treat the coronavirus disease (COVID-19). Part IV: A comparison between solid and liquid interactions

“…The changes to the ν(C=C) bands of free TCNE and ν asym (C−N) bands of free AZM observed in their products ( Product 1 and Product 2 ) suggested that the charge transferred from the N−atoms in the AZM molecule to the C=C moiety of the TCNE molecule, which represents a direct n→π* transition, as proposed in Fig. 9 [35] , [51] , [78] , [79] , [80] .

Fig.

…”

Spectrophotometric determination and spectroscopic studies on Schiff base and charge transfer complex of ketorolac tromethamine

“…The aromatic ring of TCNQ is electron deficient in nature due to the presence of four electron withdrawing cyano groups attached to it. The electron donation process from HUMO of the donor to LUMO of acceptor increases the charge density on CN group of TCNQ thus decreases the CN bond order, and hence, lower vibrational wave number is observed after complexation (Adam 2012;Adam and Refat 2014;Refat et al 2014;Refat et al 2015).…”

Charge-transfer chemistry of two corticosteroids used adjunctively to treat COVID-19. Part I: Complexation of hydrocortisone and dexamethasone donors with DDQ acceptor in five organic solvents

“…In the past 10 years, we focused on the investigation of the CT interaction of numerous vital and biological active molecules with different kinds of acceptors [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [97] , [98] , [99] , [100] , [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] . Now, we seek to explore the CT complexation of two anti-inflammatory glucocorticosteroid compounds, hydrocortisone (HC) and dexamethasone (DM), currently used as adjunctive therapeutics in the treatment of COVID-19 in a series of related publications.…”