Examination of the structure in solid state of amino analogs of 4,4′-[1,5-pentanediylbis(oxy)]bisbenzonitrile by means of X-ray diffraction, C CP/MAS NMR, and theoretical calculations

A single crystal of X-ray diffraction structures is presented for 4,4′-[1,5-(3-oxapentanediylbis(amino))]bisbenzonitrile 2 and 4,4′-[1,5-(N-methyl-3-azapentane-diylbis(oxy))]bisbenzonitrile 3. The molecular structures of these derivatives differ especially in conformations of the central linker: in 2 this linker adopts a trans/gauche conformation, whereas in 3 – a fully extended conformation. The N atoms in various positions of the aliphatic linker change dramatically the molecular packing mode of both bisnitriles. But in both cases the nitrile groups take part in intermolecular hydrogen bonds: a type of NH···N in 2 and of CH···N in 3. Various conformations of both molecules were reflected in ¹³C CP/MAS NMR spectra in solid state as single and double resonance patterns for 2 and 3, respectively. A preliminary anticancer assay against 60 cell lines of 3 reveals strong growth inhibition of leukemia, melanoma, and renal cancer cells.