title: Expansion of a 2 + 2 macrocycle into a 6 + 6 macrocycle: template effect of cadmium(II).
abstract: The reaction of trans-1,2-diaminocyclopentane with 2,6-diformylpyridine results in formation of 2 + 2, 3 + 3, and 4 + 4 Schiff base macrocycles as well as trace amounts of 6 + 6 and 8 + 8 macrocycles. In contrast, the 6 + 6 Schiff base macrocycle is a dominant product of the reaction of the isolated 2 + 2 macrocycle with excess of cadmium(II) chloride. The X-ray crystal structure of the protonated amine derivative of the 6 + 6 macrocycle reveals an unusual container-like conformation with the S6 axis.
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: Katarzyna
authors.initials: K
authors.lastname: Ślepokura
authors.forename: Tomasz
authors.initials: T
authors.lastname: Paćkowski
authors.forename: Jerzy
authors.initials: J
authors.lastname: Lisowski
mesh_terms: D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D047028:Macrocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D012545:Schiff Bases / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000588:Amines; D047028:Macrocyclic Compounds; D012545:Schiff Bases; D002104:Cadmium