Spectroscopic characterization and thermal structural analysis of the charge-transfer complexes formed in the reaction of 1-methylpiperazine with σ- and π-acceptors

Charge-transfer complexes between 1-methylpiperazine (1MPIPZ) as a donor with the π-acceptors 7,7,8,8-tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), 2,3,5,6-tetrachloro-1,4-benzoquinone (chloranil = CHL) and σ-acceptor iodine (I2) have been studied spectrophotometrically in chloroform at room temperature by electronic and infrared spectra as well as elemental and thermal analysis. The obtained results indicate the formation of 1:3 M ratio for 1MPIPZ with TCNQ and TCNE, and 1:1 M ratio for 1MPIPZ with DDQ, CHL, and I2. Based on the obtained data, the formed charge-transfer complexes were formulated as [(1MPIPZ)(TCNQ)3], [(1MPIPZ) (TCNE)3], [(1MPIPZ)(DDQ)], [(1MPIPZ)(CHL)] and [(1MPIPZ)2I]+ I 3 - .