Catenation of Metallacycle and Transformation via Disproportionation

Abstract

Self-assembly of Hg II (OTf) 2 (OTf − = trifluoromethylsulfonate) with a bidentate donor, naphthalene-2,6-diylbis(picolinate) (L), in a mixture of 3-pentanone and dichloromethane produces an unusual catenated cyclodimer of [(Hg 2 II ) 2 (OTf) 4 L 2 ] 2 via straightforward formation of reduced Hg 2 II ions as a skeletal synthon. The local geometry around the Hg I ion consists of a striking "weak-bonds showcase" including coordination bond, dative bond, electrostatic interaction, M−M bond, and M•••π interaction. By contrast, the self-assembly reaction in another mixture, acetonitrile with chloroform, gives rise to a cyclodimer of [Hg II 2 (OTf) 4 L 2 ] with retention of the Hg II ion. An unprecedented observation is that [(Hg 2 II ) 2 (OTf) 4 L 2 ] 2 transforms into [Hg II 2 (OTf) 4 L 2 ] via the initiation of [Hg II 2 (OTf) 4 L 2 ], in acetonitrile.

Coordinating nature of M6L12 double-stranded macrocycles: co-ligand competition of perchlorate, water, and acetonitrile depending on metal(ii) ions

“…Research on the construction of new coordination macrocyclic architectures is an important theme in efforts to comprehend the interaction mode between the coordination-driven host and guest molecules in the task-specific applications of recognition, separation, extraction, energy transfer, ion exchange, confinement catalysis, luminescence chemo-sensing, hydrophobicity-modification, and others. [1][2][3][4][5][6][7][8][9][10] Thus, construction of new functional metallacyclic ensembles is a particularly coveted goal, [11][12][13][14][15][16][17] since their specific functions are comparable with those of organic macrocycles such as crown-ethers, cyclodextrins, calixarenes, and cucurbiturils. [18][19][20][21][22][23][24] Self-assembly reactions of metal cations with appropriate hemi-circular bidentate ligands can provide opportunities for efficient use of metallacyclic hosts as guest receptors.…”