The synthesis and characterization of phosphine functionalized crown ethers by use of spectroscopic and x-ray methods

The phosphine(III) crown ethers, [4'-(N-phenylaza-15crown-5)]3P (1), [4'-(N-phenylaza-l8-crown-6)]3P (2), [4'-(Naza-18-crown-6)]2-Ph-P (3), and [4'-(benzo-15-crown-5)]3P (4) were synthesized by using an electrophilic bromination of the crown phenyl ring (with a tribromide ion) followed by the preparation of a lithium salt and subsequent reaction of the resulting lithiocrowns with P(III) reagents. The oxide of compound 1 was completely characterized by an X-ray diffraction study, which showed that structurally there is not a significant difference in P-O bond distances and OPC bond angles with [4'-(N-phenylaza-15-crown-5)]-Ph2-P=O. Thespectroscopic data of compound 1 and 2 were compared. It appears that 1 and 2 are similar in P environment; also they are more air sensitive than 3 and 4. In addition, a discussion about compounds 1-4, and a literature review of the preparation of phosphines are included.