Synthesis and Anion Sensing of Water-Soluble Metallomacrocycles

• Published in: Inorganic chemistry Vol. 50; no. 13; pp. 6055 - 6062
• Main Authors: Yao, Liao-Yuan, Qin, Lin, Xie, Ting-Zheng, Li, Yi-Zhi, Yu, Shu-Yan
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.07.2011
• Subjects: Anions - chemistry; Crystallography, X-Ray; Macrocyclic Compounds - chemistry; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry; Palladium - chemistry; Platinum - chemistry; Solubility; Stereoisomerism; Water - chemistry
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic200047t

The self-assembly of (TMEDA)Pd(NO3)2 or (TMEDA)Pt(NO3)2 (where TMEDA = N 1,N 1,N 2,N 2-tetramethylethane-1,2-diamine) and anthracene- or ferrocene-based diimidazole ligands (L1–3) in aqueous solution affords a series of positively charged [M2L2]4+ dimetallomacrocycles. Their structures were characterized by 1H NMR and electrospray ionization mass spectrometry and in the cases of {[(TMEDA)Pd]2L1 2}(NO3)4 (1), {[(TMEDA)Pd]2L1 2}(PF6)4 (1a), and {[(TMEDA)Pd]2L3 2}(NO3)4 (4) by single-crystal X-ray diffraction analysis. Interestingly, the NMR spectra of 1 and 1a revealed that the difference of their structures, as confirmed by X-ray diffraction analysis, was that a NO3 – of 1 was encapsulated inside the cavity of the basket-shaped metallomacrocycle by C–H···O hydrogen bonds, while PF6 – of 1a was bound outside by C–H···F hydrogen bonds. The fluorescence titration experiment exhibited the formation of 1:1 host–guest complexation for anthracene-based positively charged [M2L2]4+-type metallomacrocycles with NO3 –. The interactions between metallomacrocycles and various anions were investigated via fluorescence titration and cyclic voltammetry studies, respectively.