Phenyl-2-benzothiazole-based α-aminophosphines: synthesis, crystal structure, and photophysical properties

Condensation reactions of diphenylphosphine, 2-(benzo[d]thiazol-2-yl)aniline (NH 2 -pbt) and a series of aldehydes RC(O)H (R = phenyl, 2-furanyl and 4-pyridyl) are carried out to obtain α-aminophosphines Ph 2 P(O)C(R)NH-pbt. In the case of phenyl and 2-furanyl derivatives, respective compounds 1 and 2 are isolated with a yield of 80-85%, and 4-pyridyl analogue 3 is obtained in an insignificant amount. According to single crystal X-ray diffraction data, the compounds crystallize in the chiral space group P 2 1 2 1 2 1 , forming crystals containing only R - or S -enantiomers. Additional substituents R do not strongly affect the spatial geometry of molecules. The photophysical properties of compounds 1 and 2 are similar, and this means that the additional substituents contribute equally to the character of electronic transitions in the compounds.