SynopsisThe complex of acrylonitrile (AN) with trimethylaluminum (AlMe3) was successfully isolated as a white needlelike crystal with a melting point of 42.5OC. In this article the preparation of the complex is described in detail. Cryoscopic and spectral investigations indicated that the complex is formed by an equimolar ratio of AN and AlMe3. From the measurement of the x-ray diffraction photograph of the crystal the repeat period was determined to be 9.47 f 0.05 A.