Yes, phosphorus trichloride (PCl3) can indeed form complexes with other compounds. As a Lewis acid, PCl3 has an empty orbital available to accept an electron pair from a Lewis base, allowing it to form coordination complexes.
One common example is the formation of adducts with Lewis bases such as ammonia (NH3) or pyridine (C5H5N). These compounds can coordinate with the phosphorus atom of PCl3, donating a lone pair of electrons to form a coordinate bond. The resulting complexes are often written as PCl3·NH3 or PCl3·pyridine, indicating the presence of a coordination bond between the PCl3 and the Lewis base.
These complexes can have different properties compared to PCl3 alone, such as changes in reactivity, solubility, or physical characteristics. The formation of these complexes is often utilized in various chemical reactions and coordination chemistry.