Helical or Polar Guest-Dependent <i>Z</i>‘ = 1.5 or <i>Z</i>‘ = 2 Forms of a Sterically Hindered Bis(urea) Clathrate

Abstract

A sterically hindered bis(pyridylurea) species forms clathrates with water, methanol, and ethanol, all exhibiting unusual polar structures with Z‘ > 1. This crystal packing is due to the hindered geometry about the urea oxygen acceptor atoms