Formation of complexes between aza derivatives of crown ethers and primary alkylammonium salts. Part 8. 12-Crown-4, 15-crown-5, 21-crown-7, and 24-crown-8 derivatives

Abstract

The monoaza-crown ethers (3), (4), and (5) and the diaza-crown ethers (6), (7), (10). and (11) form complexes with primary alkylammonium thiocyanates in organic solvents. The diaza-15-crown-5 system (11) forms well defined 1:1 complexes with the cis-,cis-stereochemistry shown in (16) but the diaza-24-crown-8 derivative (7) forms a 2:1 complex (G:H ratio) with benzylammonium thiocyanate having the cis,cis,trans,trans-stereochemistry (17a). The diaza-24-crown-6 derivative (10) forms weak 1:1 complexes which apparently adopt the double nesting conformation (18).