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Updated: Sep 18, 2025

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Shape-Matching and Halogen Bonding in Chiral Pyrazine-Allene Hosts: Confining an Unstable Guest Conformation
Víctor Rubio-Pisabarro1, Jonathan Álvarez-García1, María Magdalena Cid1
1Departamento de Química Orgánica, Edificio Ciencias Experimentais, Universidade de Vigo, E-36310 Vigo, Spain.
Abstract:
A novel chiral host with axially chiral allenes and pyrazine units was synthesized in high yield via a three-step sequence. In the solid-state, it adopts a twist-boat conformation, forming discrete double chains in an extended network. Host-guest studies with halogen bond donors, analyzed by NMR and X-ray diffraction, revealed size-selective inclusion within the macrocyclic cavity. Remarkably, a syn-gauche conformer of diiodoperfluorobutane was crystallized inside the host, highlighting the role of guest structure, host flexibility, and crystallization conditions.
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