| Supramolecular chemistry is a new research field with rapid development and vitality. Currently, it has drawn extensive research attention from material scientists, crystallogrophers, chemists, biologists and other scientists of all disciplines. The design and synthesis of 'host' molecules is the main focus in the area of'host-guest' chemistry. The 'host' molecules of current focus is limited on a few kinds of compounds, and consequently restricts the development of this research field. In order to achieve complexing (capturing) a specific 'guest' molecule (ion), designing and synthesizing the new types of 'host' molecules with unique structures to recognize specific 'guest' molecule (ion) is necessary. In this paper, we present the design and synthesis of several categories of meta-'O'bridged symmetry'calixarene', their solid-state structures have been determined by single crystal X-ray diffraction.1. By the analysis structural conformation of the known hetero-atom bridged calixarenes, we designed several meta-'O'bridged symmetry'calixarene'series, and investigated the synthetic conditions.2. By employing 1,3-diphenols and aza aromatic ring with two substitutions as precursor, we have synthesized eleven symmetry nitrogen containing oxocalixarenes, nine of which have not been reported. Their structures have confirmed by 1H-NMR, 13C-NMR, HRMS, and XRD. Through the structure analysis, we found that some of the structural isomers adopted completely different conformations. For example, dihydroxyoxacalix[2]arene[2]pyrazine adopts an expected 1,3-alternate conformation. In the solid state, four molecules of dihydroxyoxacalix[2]arene[2] pyrazine were found to form a defined host cavity via intermolecular hydrogen bond interactions, and a guest molecule of dichloromethane was encapsulated in the cavity.
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