Self-assembly of triangular metallomacrocycles using unsymmetrical bisterpyridine ligands: isomer differentiation via TWIM mass spectrometry

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 44; no. 11; pp. 5139 - 5145
• Main Authors: Liang, Yen-Peng, He, Yun-Jui, Lee, Yin-Hsuan, Chan, Yi-Tsu
• Format: Journal Article
• Language: English
• Published: England 21.03.2015
• Subjects: Isomerism; Ligands; Macrocyclic Compounds - chemistry; Macrocyclic Compounds - isolation & purification; Models, Molecular; Molecular Conformation; Pyridines - chemistry; Spectrometry, Mass, Electrospray Ionization
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c4dt03055a

Three unsymmetrical, 60°-bended bisterpyridine ligands with varying phenylene spacer lengths have been synthesized via the Suzuki-Miyaura coupling reactions. Their self-assembly processes were found to be strongly dependent on the ligand geometry. Upon complexation with Zn(II) ions, only 2,4''-di(4'-terpyridinyl)-1,1':4',1''-terphenyl underwent self-selection to give a trinuclear metallomacrocycle with perfect heteroleptic connectivity and the other two afforded a mixture of constitutional isomers. The metallosupramolecular assemblies were characterized by NMR spectroscopy, electrospray mass spectrometry (ESI MS), and single-crystal X-ray diffraction. In particular, the identification of isomeric architecture was accomplished using tandem mass spectrometry (MS(2)) coupled with traveling wave ion mobility mass spectrometry (TWIM MS).