2019 年 35 巻 p. 69-71
One of the earliest charge-transfer complexes synthesized is dinaphtho[2,1,1′,2′]furan picrate, which was first reported in 1905. Here, we synthesized and structurally characterized this complex. This complex has a stoichiometric ratio of 1:1 and a melting point of 161.4°C. The bond distances and angles of the component molecules are within the range of those reported for structurally similar neutral compounds and picric acid. These characteristics taken together with the feature that the infrared spectra of the complex can be superimposed with those of its component molecules, it is concluded that this complex is in the neutral ground state. The component molecules are stacked alternately, producing a ···DA–DA–DA··· one-dimensional column in the b-axis direction. The compound crystallizes in a monoclinic system and was characterized thus: P21/c, a = 10.0912(18), b = 7.5548(11), c = 27.919(5)Å, β = 94.047(4)°, Z = 4, V = 2123.2(6)Å3. The crystal structure was solved by direct methods and refined by full-matrix least-squares on F2 to final values of R1 = 0.0502 and wR2 = 0.1190.
