title: New 2+2, 3+3 and 4+4 macrocycles derived from 1,2-diaminocyclohexane and 2,6-diformylpyridine.
abstract: Two new Schiff base macrocycles - a 4+4 condensation product and a meso-type 2+2 condensation product - were obtained in a reaction of trans-1,2-diaminocyclohexane and 2,6-diformylpyridine. Reduction of these compounds led to the corresponding 4+4 and 2+2 macrocyclic amines. The macrocycles were characterised by NMR spectroscopy and electrospray mass spectrometry. The symmetry and stereochemistry of these macrocycles, as well as of new 3+3 and 4+4 diastereomers identified in solution, has been established. X-Ray structures of the 2+2 and 4+4 Schiff base macrocycles confirm the configurations determined on the basis of spectroscopic investigations. The crystal structures reveal that the centres of the square-shaped 4+4 macrocycles form channels as a result of columnar stacking.
authors.affiliation: Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Gregoliński
authors.forename: Jerzy
authors.initials: J
authors.lastname: Lisowski
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Lis
mesh_terms: D018360:Crystallography, X-Ray; D003500:Cyclization; D003514:Cyclohexylamines / Q000138:chemical synthesis / Q000737:chemistry*; D047028:Macrocyclic Compounds / Q000138:chemical synthesis*; D008958:Models, Molecular; D008968:Molecular Conformation; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: C506704:2,6-diformylpyridine; D003514:Cyclohexylamines; D047028:Macrocyclic Compounds; D011725:Pyridines; C030435:1,2-cyclohexanediamine