Preparation and characterization of novel poly(alkylidenamine) nitrile ruthenium metallodendrimers

Abstract

Complete functionalization of N,N,N ,N -[tetrakis(cyanoethyl)hexamethylenediamine] [N C(CH2)2]2N(CH2)6N[(CH2)2C N]2 (4) and N,N,N ,N -[tetrakis(cyanoethoxypropyl)hexamethylenediamine] [N C(CH2)2O(CH2)3]2N(CH2)6N[(CH2)3O(CH2)2C N]2 (7) with the organometallic moiety [Ru(η5C5H5)(PPh3)2Cl] and the five-coordinate cis-[RuCl(dppe)2][PF6] [dppe = 1,2-bis(diphenylphosphanyl)ethane] was attained with good yield, respectively, by treating the metallofragment with the core in methanol (at room temperature and in presence of TlPF6 as a chloride abstractor) and in 1,2 dichloroethane (under reflux). These novel nitrile-functionalized poly(alkylidenamine) dendrimers peripherally functionalized with the ruthenium moieties [Ru(η5-C5H5)(PPh3)2]+ and [RuCl(dppe)2]+ (8–11) were fully characterized by NMR (1H, 13C, 31P), TOF-MS and FTIR. The present results represent a step forward in the knowledge of the most adequate synthetic strategy for total coordination of poly(alkylidenamine) nitrile core derivatives to the different ruthenium complex moieties and confirm the versatility of these systems as building blocks in metallodendrimer chemistry.