Towards the design and syntheses of novel triads comprising single Robson-type macrocyclic dicopper(II) cores flanked by two terminal polypyridyl ruthenium(II) complexes.

摘要

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.