Molecular complexes. Part XXIII. Crystal and molecular structures of α-naphthol–1,2,4,5-tetracyanobenzene and β-naphthol–1,2,4,5-tetracyanobenzene

Abstract

The crystal and molecular structures of the 1 : 1 complexes of α-naphthol and 1,2,4,5-tetracyanobenzene (I) and β-naphthol and 1,2,4,5-tetracyanobenzene (II) have been determined by Fourier methods from diffractometer data and refined by least-squares to R 0.043 for 523 reflections (I), and R 0.104 for 651 reflections (II). Both are monoclinic, space group C2/m with Z= 2 in unit cells of dimensions: (I), a= 9.250(5), b= 13.059(7), c= 6.791(4)A, β= 108.3(1)°; (II), a= 9.578(1), b= 12.754(3), c= 6.798(4)A, β= 108.13(2). The dimensions of the component molecules have been corrected for rigid-body thermal motion and are in agreement with those from previous work. The mode of donor–acceptor overlap of the molecules in the alternate plane-to-plane stacks parallel to the c axes of the crystals gives near-maximisation of the donor–acceptor charge-transfer interactions. The naphthol molecules in both structures are disordered.