Pillar[n]arenes (n = 8–10) with two cavities: synthesis, structures and complexing properties

Three pillar[n]arenes (n = 8–10) were synthesized. X-ray analysis demonstrated that, different from early reported small pillar[n]arenes (n = 5, 6), these larger macrocycles gave rise to two cavities. 1H NMR and MS experiments revealed that pillar[9]arene complexed one n-octyltrimethyl ammonium in chloroform, while pillar[10]arene could complex two.