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1,4,7,10,13,16,19,22‐Octaazacyclotetracosane‐1,4,7,10,13,16,19,22‐octaacetic Acid (H 8 OTEC) and 1,4,7,10,14,17,20,23‐Octaazacyclohexacosane‐ 1,4,7,10,14,17,20,23‐octaacetic Acid (H 8 OHEC): Synthesis and Characterization of Two Large Macrocyclic Polyamine Polycarboxylic Ligands and Some of Their Copper(II) and Lanthanide(III) Complexes
Author(s) -
Schumann Herbert,
Bottgef Ulrike A.,
Zietzke Kerstin,
Hemling Holger,
KociokKohn Gabriele,
Pickardt Joachim,
Ekkehardt Hahnb F.,
Zschunke Adolf,
Schiefnef Birgit,
Gries Heinz,
Radiichel Bernd,
Platzeke Jobannes
Publication year - 1997
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19971300221
Subject(s) - chemistry , amine gas treating , molecule , lanthanide , hydrolysis , octahedron , protonation , crystal structure , medicinal chemistry , crystallography , stereochemistry , organic chemistry , ion
The optimized synthesis of two new macrocyclic polyamine polycarboxylic ligands, 1,4,7,10,14,17,20,23‐octaazacyclohexacosane‐1,4,7,10,14,17,20,23‐octaacetic acid (H 8 OHEC) ( 10 ) and 1,4,7, 10,13,16,19,22‐octaazacyclotetracosane‐1,4,7,10, 13,16,19,22‐octaacetic acid (H 8 OTEC) ( 12 ), is presented. The key step in the synthesis of both is the high yield carboxymethylation of the corresponding macrocyclic amines using tert ‐butyl bromoacetate followed by acidic hydrolysis of the acetate protecting groups. The molecular structures of the intermediates 1,4,7,10,14,17,20,23‐octaazacyclohexacosane (OHEC‐amine) ( 8 ), and octa‐ tert ‐butyl 1,4,7,10,13,16,19,22‐ octaazacyclotetracosane‐1,4,7,10,13,16,19,22‐octaacetate (OTEC‐ester) ( 11 ) are determined by X‐ray crystal structure analysis. OHEC‐amine 8 reacts with 2 equiv. of CuSO 4 yielding the dinuclear complex [Cu 2 (OHEC‐amine)](SO 4 ) 2 ( 13 ). Complex 13 crystallizes with 16 molecules of water. 13 · 16 H 2 O contains two copper atoms, which are coordinated in a strongly distorted octahedral fashion by four nitrogen atoms, one oxygen atom from the sulfate dianion and one oxygen atom from a water molecule. The new ligands 10 and 12 are fully characterized by 1D‐ and 2D‐NMR spectroscopy. Both ligands form dinuclear lanthanide(III) chelates (LnY, Sm, Eu, Gd, Yb, Lu), which are stable and highly water soluble. With lanthanum(III) only mononuclear complexes are formed.