Synthesis and spectroscopic characterization of piperidine/chloranil and piperidine/7,7′,8,8′-tetracyanoquinodimethane charge transfer complexes: X-ray crystal structure of a 7,7-dicyano-8,8-di-piperidinoquinodimethane adduct

Charge transfer reactions of piperidine with p-chloranil (CHL) and 7,7′,8,8′-tetracyanoquinodimethane (TCNQ) in chloroform have produced stable complexes with the general formula [(Pip)2(acceptor)] with a 1:2 acceptor:donor molar ratio. Elemental analysis (CHN), electronic spectra, photometric titration, mid infrared spectra, 1H NMR spectra and thermogravimetric analysis (TGA/DTG) were used to predict the position of the charge transfer interaction between the donating and accepting sites. The crystal structure of the Pip/TCNQ system was determined by single crystal X-ray diffraction.

Graphical abstractCharge transfer reactions of piperidine with p-chloranil (CHL) and 7,7′,8,8′-tetracyanoquinodimethane (TCNQ) in chloroform have been synthesized and characterized. The asymmetric unit of 7,7-dicyano-8,8-di-piperidinoquinodimethane adduct composed of two crystallographic independent [(pip)2TCNQ]2. The piperidine rings of each of the two independent molecules exhibits a chair conformation, while TCNQ fragment is nearly planer.Figure optionsDownload full-size imageDownload as PowerPoint slide