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Two new POM‐based compounds modified by lanthanide–Schiff base complexes with interesting NLO properties
Author(s) -
Luo Xi-Ming,
Cui Chen-Hui,
Cao Jia-Peng,
Lin Qing-Fang,
Xu Yan
Publication year - 2018
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229618011853
Subject(s) - lanthanide , schiff base , base (topology) , chemistry , combinatorial chemistry , nuclear chemistry , materials science , polymer chemistry , organic chemistry , mathematics , ion , mathematical analysis
Two POM‐based lanthanide derivatives, namely {triaqua[2,6‐diacetylpyridine bis(semicarbazone)‐κ 5 O , N , N ′, N ′′, O ′]terbium(III)}‐μ‐oxido‐[tricosa‐μ 2 ‐oxido‐dodecaoxido‐μ 12 ‐phosphato‐dodecamolybdenum(VI)] pentahydrate ( 1 ), [Tb(C 11 H 15 N 7 O 2 )(H 2 O) 3 ][PMo 12 O 40 ]·5H 2 O, and the dysprosium(III) analogue ( 2 ), have been isolated successfully by the reaction of Keggin–POM [PMo 12 O 40 ] 3− (abbreviated as PMo 12 ), the Ln 3+ ion and the Schiff base 2,6‐diacetylpyridine bis(semicarbazone) (DAPSC) ligand under hydrothermal conditions. [Ln(DAPSC)(H 2 O) 3 ][PMo 12 O 40 ]·5H 2 O is a PMo 12 ‐supported cluster featuring a lanthanide–Schiff base complex [denoted Ln– L (Schiff base) ]. Single‐crystal X‐ray diffraction analysis reveals that the Ln III ion is in a distorted tricapped trigonal prismatic arrangement, coordinated by six O atoms and three N atoms. Two O atoms and three N atoms are provided by one DAPSC ligand, while the additional O atoms originate from a PMo 12 cluster and three water molecules. Hydrogen‐bonding interactions between adjacent clusters form an interesting three‐dimensional supramolecular structure. The identities of 1 and 2 were characterized by IR spectroscopy, thermogravimetric analysis and powder X‐ray diffraction. Interestingly, both compounds possess excellent two‐photon absorption (TPA) responses to the third‐order nonlinear optics (NLO) (2264 GM for 1 and 941 GM for 2 ), suggesting that they have potential applications in the field of nonlinear optics (NLO). To our knowledge, 1 and 2 are the first POM‐based Ln– L (Schiff base) complexes showing excellent two‐photon responses. Meanwhile, the electrochemical properties of both compounds were studied in detail.