Infrared matrix isolation of the 1:1 complexes of HCl and ClF with sulfur and nitrogen-containing macrocycles

Abstract

The matrix isolation technique has been combined with IR spectroscopy to isolate and characterize 1 : 1 complexes of HCl, ClF and SO 2 with cyclam, tetramethylcyclam and 1,4,8,11-tetra-thiacyclotetradecane (TTP). Each complex was characterized by a red shift of the acid subunit in the complex; for example the HCl stretch in its complex with TTP was observed at 2386 cm −1 while the ClF stretch in its complex with TTP came at 468 cm −1. These shifts, particularly for the ClF complex, were comparable to complexes with the monomer unit of the macrocycle (i.e. containing a single donor atom), which indicates that cooperativity is not an important factor in the formation of these complexes, in agreement with earlier studies of crown ether complexes.