Search

Reactions of half-sandwich iridium and rhodium complexes [Cp*MCl2]2 (1a: M = Ir, 1b: M = Rh) and the half-sandwich ruthenium complex [(p-cymene)RuCl2]2 (1c) with 4DPDS gave the corresponding binuclear complexes [{Cp*MCl2]2}(m-4DPDS) (2a: M = Ir, 2b: M = Rh) and [{(p-cymene)RuCl2]2}(m-4DPDS) (2c), which can be converted into binuclear metallamacrocycles. The metallamacrocycles [Cp*M(m-4DPDS)Cl]2(2+) (3a: M = Ir, 3b: M = Rh) and [(p-cymene)Ru(m-4DPDS)Cl]2(2+) (3c) are composed of two half-sandwich units and two 4DPDS ligands with the same chirality. The macrocycle 3c is chiral and changes its shape slightly depending on the guests accommodated above and below the cavities.

A series of binuclear half-sandwich p-cymene ruthenium complexes bearing oxamidato ligands [(p-cymene)(2)Ru(2)(mu-N,N'-bis(aryl)oxamidato)Cl(2)] (1-3) was synthesized by the reactions of the lithium salts of oxamide with [(p-cymene)RuCl(2)](2), respectively. Treatment of the binuclear complexes (1-3) with bidentate ligands such as 4,4'-bipyridine (4,4'-bpy) and trans-1,2-bis(4-pyridyl)ethylene (bpe) in the presence of AgOTf (OTf = CF(3)SO(3)) gave the corresponding tetranuclear complexes generally formulated as [(p-cymene)(4)Ru(4)(mu-N,N'- bis(aryl)oxamidato)(2)(mu-4,4'-bpy)(2)](OTf)(4) (4a-c) and [(p-cymene)(4)Ru(4)(mu-N,N'-bis(aryl)oxamidato)(2)(mu-bpe)(2)](OTf)(4) (5a-c) in high yields. All compounds (1-3, 4a-5c) have been characterized by NMR and IR spectra and elemental analyses. The molecular structures of , and have been determined by single-crystal X-ray analyses. The molecular structures of tetranuclear complexes and showed that two binuclear fragments as building blocks were connected by 4,4'-bpy or bpe to construct a rectangular cavity with the dimensions 5.57 x 11.28 A (4a) and 5.56 x 13.65 A (5a).