Oxaphosphacyclophanes Constructed from a Bis(triphenylphosphine oxide) Moiety Linked by Dioxyalkyl Chains: Synthesis...

Oxaphosphacyclophanes, a bis(triphenylphosphine oxide) moiety linked by dioxypropane, dioxybutane, dioxypentane, and dioxyhexane, were synthesized from the reaction of bis(4-hydroxyphenyl)phenylphosphine oxide and dibromoalkanes. Single-crystal X-ray diffraction analysis and exploring intermolecular interactions by using the Hirshfeld surface revealed that the butylene-linked oxaphosphacyclophane (2) had a one-dimensional (1D) supramolecular structure via CH/π interactions between the terminal phenyl group of 2 and a phenylene group of the cavities. In the packing diagram of pentylene-linked oxaphosphacyclophane (3) with antiform, one macrocycle recognized two terminal phenyl groups to form a 1D supramolecular chain via π/π interactions. The syn-form of 3 was obtained by the recrystallization from toluene and CHCl₃. In this crystal, a toluene molecule avoid construction of a 1D chain. The antiform of hexylene-linked oxaphosphacyclophane 4 was obtained by the recrystallization from cyclohexane and CHCl₃. Cyclohexane was captured in the cavity via CH/π interactions. Two molecules of 4 with the syn-form recognized each other to construct a dimeric structure via CH/π interactions.