Structural insights into 1,4-bis-(neopent-yloxy)pillar[5]arene and the pyridine host-guest system.

The crystal structure of 1,4-bis-(neopent-yloxy)pillar[5]arene, C(95)H(140)N(2)O(10) (TbuP), featuring two encapsulated pyridine mol-ecules, reveals significant host-guest inter-actions. Inter-estingly, the pyridine guests are positioned near the neopent-yloxy substituents instead of the electron-rich aromatic core of the pillar[5]arene. This spatial arrangement suggests a preference for the pyridine mol-ecules to engage with the aliphatic regions of the host. Detailed analysis of the structural characteristics of this host-guest system (TbuP·2Py), as well as its packing pattern within the crystal network, is presented and discussed.