l- and d-[Ln(HCO₂)(SO₄)(H₂O)]_n (Ln = La, Ce, Pr, Nd, and Eu): Chiral Enantiomerically 3D Architectures Constructed by Double −[Ln–O]_n– Helices

29/septiembre/2012

Paulina Levario

A total of 10 three-dimensional chiral coordination compounds l- and d-[Ln(HCO₂)(SO₄)(H₂O)]_n (Ln = La, Ce, Pr, Nd, and Eu) have been synthesized without any chiral auxiliary and characterized by IR, thermogravimetric, and elemental analyses. Their structures were determined by single-crystal X-ray structural analysis, which shows that l-[Ln(HCO₂)(SO₄)(H₂O)]_n (Ln = La, Ce, Pr, Nd, and Eu) crystallize in space group P4₃ and are laevogyrate and isostructural. The chiral frameworks of l-[Ln(HCO₂)(SO₄)(H₂O)]_n are constructed from l-helical Ln–O cluster chains, while adjacent l-type helical −[Ln–O]_n– chains are connected through O–Ln–O linkages to form chiral intertwined Ln–O double helices of left-handedness.d-[Ln(HCO₂)(SO₄)(H₂O)]_n crystallize in space group P4₁, and their chiral frameworks consist of d-helical Ln–O cluster chains. The observed second-harmonic-generation efficiencies of [La(HCO₂)(SO₄)(H₂O)]_n, Ce(HCO₂)(SO₄)(H₂O)]_n, [Pr(HCO₂)(SO₄)(H₂O)]_n, [Nd(HCO₂)(SO₄)(H₂O)]_n, and [Eu(HCO₂)(SO₄)(H₂O)]_n are 0.7, 0.8, 0.7, 0.5, and 0.7 times that of urea, respectively. It is particularly interesting that [Pr(HCO₂)(SO₄)(H₂O)]_n shows good two-photon absorption.

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l- and d-[Ln(HCO2)(SO4)(H2O)]n (Ln = La, Ce, Pr, Nd, and Eu): Chiral Enantiomerically 3D Architectures Constructed by Double −[Ln–O]n– Helices

Weiwei Ju, Deng Zhang, Dunru Zhu, and Yan Xu

Inorganic Chemistry Article ASAP

DOI: 10.1021/ic302134m

Publication Date (Web): November 26, 2012

Copyright © 2012 American Chemical Society

http://pubs.acs.org/doi/abs/10.1021/ic302134m