TY - JOUR
T1 - Kinetically stable Ln III complexes comprising a trinuclear core sandwiched between two thiacalix[4]arene ligands self-assembled in water (Ln III = Nd III, Yb III)
AU - Iki, Nobuhiko
AU - Hiro-Oka, Shouichi
AU - Nakamura, Mami
AU - Tanaka, Teppei
AU - Hoshino, Hitoshi
PY - 2012/8
Y1 - 2012/8
N2 - In aqueous solutions, thiacalixarene (TCAS) and Ln III (= Nd III, Yb III) self-assembled over a long period of time (1 d) to form 3:2 complexes Ln III 3·TCAS 2 in which the Ln III 3 core is sandwiched between two TCAS ligands, which results in a high kinetic stability. This was not expected from the exo-coordination fashion of TCAS with the O,S,O donors found in the 1:1 complex Ln III·TCAS, and thus this feature was attributed to the multiple bonds between the Ln III 3 core and TCAS. Our observations open an exciting possibility of designing kinetically stable Ln III complexes by using exo-type ligands as scaffolds to sandwich a multi-Ln III core rather than endo-type ones to encapsulate a Ln III core. Lanthanides(III) (Ln = Nd, Yb) and thiacalix[4]arene (TCAS) self-assembled in water to form Ln 3·TCAS 2, over a period of 1 d. The high kinetic stability of Ln 3·TCAS 2 revealed by HPLC was unexpected from the tridentate coordination fashion of TCAS in Ln·TCAS. This suggests a new way to design kinetically stable complexes through the formation of clusters.
AB - In aqueous solutions, thiacalixarene (TCAS) and Ln III (= Nd III, Yb III) self-assembled over a long period of time (1 d) to form 3:2 complexes Ln III 3·TCAS 2 in which the Ln III 3 core is sandwiched between two TCAS ligands, which results in a high kinetic stability. This was not expected from the exo-coordination fashion of TCAS with the O,S,O donors found in the 1:1 complex Ln III·TCAS, and thus this feature was attributed to the multiple bonds between the Ln III 3 core and TCAS. Our observations open an exciting possibility of designing kinetically stable Ln III complexes by using exo-type ligands as scaffolds to sandwich a multi-Ln III core rather than endo-type ones to encapsulate a Ln III core. Lanthanides(III) (Ln = Nd, Yb) and thiacalix[4]arene (TCAS) self-assembled in water to form Ln 3·TCAS 2, over a period of 1 d. The high kinetic stability of Ln 3·TCAS 2 revealed by HPLC was unexpected from the tridentate coordination fashion of TCAS in Ln·TCAS. This suggests a new way to design kinetically stable complexes through the formation of clusters.
KW - Calixarenes
KW - Cluster compounds
KW - Lanthanides
KW - S ligands
KW - Self-assembly
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U2 - 10.1002/ejic.201200464
DO - 10.1002/ejic.201200464
M3 - Article
AN - SCOPUS:84864401003
SP - 3541
EP - 3545
JO - Berichte der deutschen chemischen Gesellschaft
JF - Berichte der deutschen chemischen Gesellschaft
SN - 0365-9496
IS - 22
ER -