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An improved one‐step method to prepare some diaza‐crown ethers and the cation complexation properties of 4,10‐diaza‐18‐crown‐6 with two transition metal ions
Author(s) -
Krakowiak Krzysztof E.,
Maas Garren E.,
Bradshaw Jerald S.,
Hathaway Jon K.,
Izatt Reed M.
Publication year - 1995
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570320129
Subject(s) - chemistry , crown (dentistry) , 18 crown 6 , titration , 15 crown 5 , metal , transition metal , crown ether , ion , inorganic chemistry , metal ions in aqueous solution , organic chemistry , catalysis , materials science , composite material
4,10‐Diaza‐15‐crown‐5, 4,10‐diaza‐18‐crown‐6, 4,13‐diaza‐21‐crown‐7, and 4,16‐diaza‐24‐crown‐8 were prepared by an improved method from the appropriate oligothylene glycol diiodides and diamines. The thermodynamic values of log K , Δ H and Δ S for the interaction of 4,10‐diaza‐18‐crown‐6 with Pb 2+ and Ag + were determined by a calorimetric titration method and compared with thermodynamic values for interactions of 4,13‐diaza‐18‐crown‐6 with the same cations. The thermodynamic values were found to be different for the two diaza‐crown ligands. 4,10‐Diaza‐18‐crown‐6 and its 4,13‐diaza‐crown analog formed precipitates when treated with Co 2+ , Cd 2+ , Cu 2+ , and Ni 2+ so that no thermodynamic data are reported for these interactions.