One-Pot Conditional Self-Assembly of Multicopper Metallacycles

• Published in: Inorganic chemistry Vol. 49; no. 21; pp. 9902 - 9908
• Main Authors: Shiu, Kom-Bei, Liu, Shih-An, Lee, Gene-Hsiang
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.11.2010
• Subjects: Copper - chemistry; Crystallography, X-Ray; Ligands; Models, Molecular; Molecular Structure; Organometallic Compounds - chemical synthesis; Organometallic Compounds - chemistry
• ISSN: 0020-1669; 1520-510X; 1520-510X
• DOI: 10.1021/ic1008957

The self-assembly of supramolecular metallacycles via the coordination-driven directional bonding approach can be modified to produce some unexpected structural variations. The combination of a flexible ligand-capped dinuclear transition-metal acceptor like [Cu2(dppm)2(NCMe)2]X2 (1X2; dppm = Ph2PCH2PPh2; X− = BF4 −, PF6 −, or BPh4 −) with monodentate−bidentate donors like 2-, 3-, and 4-pyridylcarboxylates produced oligomeric compounds [{Cu2(dppm)2}(μ-(2-PyCO2))]2X2 (2X2), [{Cu2(dppm)2}(μ-(3-PyCO2))]2X2 (3X2), and [{Cu2(dppm)2}(μ-(4-PyCO2))]4X4 (4X4), respectively, as the thermodynamically stable products in one-pot reactions. However, the modified self-assembly is still subject to steric hindrance. The reaction of complex 1(BF4)2 with 6-Me-3-PyCO2H did not produce a polygonal dimeric metallacycle but a simple dinuclear complex, [Cu2(dppm)2(6-Me-3-PyCO2)](BF4) (5(BF4)). The crystal structures of complexes 2(PF6)2, 3(PF6)2, 4(BF4)4, and 5(BF4) were determined using X-ray diffraction.