p-Benzoquinone 2,3,5,6-Tetrakis(diisopropyl phosphonate): A Novel, Highly Bent pBenzoquinone

Multiple introduction of phosphonate groups around the quinone oxygen greatly deforms the p-benzoquinone ring through the steric and electronic repulsion. The repulsion produces not a boat but a chair conformation with a bent angle as large as 17.8°.