Novel charge transfer complexes of the donor 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane and the acceptors iodine, TCNE, and TCNQ

► Three novel CT-complexes of the donor HMHACOD with acceptors iodine, TCNE and TCNQ are obtained. ► CT-complexes are characterized and their reaction stoichiometries are determined using modern analytical methods. ► Factors affecting the CT-processes such as donor atoms, type of groups attached to them as well as molecular steric hindrance are discussed. Novel charge transfer complexes have been formed in the reaction of the interesting powerful electron donor 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane (HMHACOD) with σ-electron acceptor iodine and π-acceptors tetracynoethylene (TCNE) and 7,7,8,8,-tetracyanoquinodimethane (TCNQ). The reactions have been studied spectrophotometrically in chloroform and the formed solid complexes have been isolated and characterized through infrared spectra as well as thermal and elemental analysis. Due to the expected powerful electron donation of the donor (HMHACOD), the reaction stoichiometries, donor:acceptor molar ratio values, are found to be exceptionally high equal to 1:6, 1:16 and 1:3 for iodine, TCNE and TCNQ complexes, respectively. Accordingly the formed charge transfer complexes could be formulated as [(HMHACOD)I] +· I 11 - , [(HMHACOD)(TCNE) 16] and [(HMHACOD)(TCNQ) 3].