Selected bond lengths (Å) of 2,7-^tBu₂-PTO, 1, 2, 1K2 and 2K2.

	2,7-tBu2-PTO25	1	2	1K2	2K2
C7–O2	1.221(7)	1.289(3)	1.295(3)	1.362(3)	1.344(3)
C8–O1	1.209(7)	1.292(3)	1.291(3)	1.343(3)	1.347(2)
C7–C8	1.545(8)	1.443(3)	1.422(4)	1.382(3)	1.390(3)
C6–C8	1.497(8)	1.438(3)	1.443(4)	1.441(3)	1.429(3)
C1′–C6	1.416(8)	1.414(3)	1.400(4)	1.419(3)	1.423(3)
C1–C1′	1.474(11)	1.437(4)	1.449(5)	1.411(4)	1.415(4)
C1–C2	1.401(7)	1.405(3)	1.408(4)	1.425(3)	1.420(3)
C2–C7	1.472(8)	1.441(3)	1.445(4)	1.434(3)	1.435(3)