Positional isomeric and N-donor auxiliary chelating ligand effect on engineering crystalline architectures of four lead(II) complexes with diverse fluorescent properties

Abstract

This work presents an investigation on the positions of the substituent and N-donor auxiliary chelating ligand (bipy/phen) effect on engineering of crystalline architectures of four Pb(II) complexes with a pair of methyl-substituted 3-sulfobenzoic isomers: [Pb(4-msba)(phen)(H₂O)] (1), [Pb(4-msba)(bipy)(H₂O)]·H₂O (2), [Pb(5-msba)(phen)₂]·9H₂O (3), and [Pb₂(5-msba)₂(bipy)₂(H₂O)₂] (4) (4/5-msba = 4/5-methyl-3-sulfobenzoate, phen = 1,10-phenanthroline and bipy = 2,2′-bipyridine). The lead(II) ions exhibit hemidirected geometry in 1–4. The positions of the methyl as well as the auxiliary chelating ligands influence coordination modes of the sulfonates and thus determine the architectures. As the position of methyl in aromatic ring changes from 4 to 5, the structures change from 2-D sheet-like compounds for 1 and 2 to 0-D dimeric species for 3 and 4. A water cluster (H₂O)₁₈ exists in 3, which further assembles into a water tape with a new pattern T4(3)4(3)10(3)A4. Complex 3 loses crystallinity rapidly in the open air and turns into [Pb(5-msba)(phen)₂]·2H₂O (3A). Thermal stabilities and solid state fluorescent properties of 1, 2, 3A, and 4 have been studied.

Keywords:

• Positional isomeric effect
• Lead(II) complexes
• Crystal structures
• Characterization
• Fluorescence spectra

Supplementary material

Crystallographic data have been deposited with the Cambridge Crystallographic Data Center with Nos. 679921 (1), 679920 (2), 766587 (3), and 766588 (4). Copies of the data can be obtained free of charge via the Internet at http://www.ccdc.cam.ac.uk/conts/retrieving.html.

Acknowledgments

The Natural Science Foundation of Jiangsu Province (BK2012680), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Jiangsu Government Scholarship for Overseas Studies, and the foundation from Key Laboratory of Environmental Material and Environmental Engineering of Jiangsu Province are gratefully acknowledged.