| Progress toward the syntheses of new tetranuclear bimetallic complexes of copper(II) and ruthenium(II) was realized. The designed triads comprise a central binuclear copper(II) complex with a tetraiminodiphenolate macrocyclic Robson-type compartmental ligand. In the envisioned complexes, the macrocyclic core is further functionalized by attachment of two polypyridyl ruthenium(II) complexes. A novel dibrominated dicopper(II) Robson complex was formed by the 2:2:2 condensation reaction of 4-bromo-2,6-diformylphenol and 1,3-diaminopropane with cupric chloride. Similarly, a new dibrominated dizinc(II) was synthesized from zinc tetrafluoroborate and the same diamine and dialdehyde. The new dicopper(II) complex did not heterocouple with borylated substrates under explored Suzuki reaction conditions. 5-Bromo-2-(methoxymethoxy)benzene-1,3-dicarboxaldehyde successfully heterocoupled with 4-tert-butylphenylboronic acid under Suzuki conditions. 4'-(4-Neopentylglycolatoboronphenyl)-2,2':6',2"-terpyridine also coupled with 5-bromo-2-(methoxymethoxy)benzene-1,3-dicarboxaldehyde to give, after deprotection, 2,6-diformyl-4-(4-[2,2':6',2"-terpyridin]-4'-ylphenyl)phenol. This new dialdehyde, a precursor to the title complexes, was treated with (4'-(4-methylphenyl)-2,2':6',2"-terpyridine)RuCl3 under reducing conditions however, the desired [(4'-(4-methylphenyl)-2,2':6',2"-terpyridine)Ru(4'-(3,5-diformyl-4-hydroxyphenyl)-2,2':6',2"-terpridine)] 2+ was neither isolated from nor detected in the reaction mixture. |
