학술논문

Topological Classification and Supramolecular Chirality of 21‐Helical Ladder‐Type Hydrogen‐Bond Networks Composed of Primary Ammonium Carboxylates: Bundle Control in 21‐Helical Assemblies
Document Type
Article
Source
Chemistry - A European Journal; March 2008, Vol. 14 Issue: 10 p2984-2993, 10p
Subject
Language
ISSN
09476539; 15213765
Abstract
The supramolecular chirality of 1D ladder‐type hydrogen‐bond networks composed of primary ammonium carboxylates was determined based on topological considerations. Chirality in such networks is based on the absolute configuration of the primary ammonium cation, which arises from discrimination between the two oxygen atoms of the carboxylate anion. The configurations of the cations and anions generate topological diversity in the networks, which are classified into six subgroups. In the Cambridge Structural Database, salts based on ladder type 1constitute over 70 % of salts with a 1D‐ladder‐type network. Ladder type 1, based on a 21‐axis, is not superimposable on its mirror image, which leads to the first definition of right‐ or left‐handedness of 21‐helicity on the basis of supramolecular tilt chirality. Helical assemblies of 21‐type with triaxial chirality can be assembled in various ways to yield chiral bundles and crystals. On the basis of these considerations, we constructed clay mimic structures with several bundle patterns by connecting the hydrogen‐bond networks by using bifunctional molecules. These results open up the possibility of in‐depth crystal engineering based on hydrogen‐bond topology.