Metal complexes of ditopic dithiophosphonate ligands built on a naphthalenediimide core

Ditopic ligands consisting of two dithiophosphonate donor groups attached to a 1,4,5,8-naphthalenediimide core through ether spacers of different length have been synthesized and characterized. The NDI[(CH2CH2O)(n)(An)PS2NH4](2) ligands (n = 1: 1a-[NH4](2); n = 2: 1b-[NH4](2); NDI = naphthalenediimide; An = anisole) react with Ph3SnCl and (Ph3P)(2)CuNO3 in a 1:2 ratio to yield bimetallic complexes (1a-[SnPh3](2) and 1a-[Cu(PPh3)(2)](2) for n = 1, and 1b-[SnPh3](2) and 1b-[Cu(PPh3)(2)](2) for n = 2), and with Ph2SnCl2 in a 1:1 ratio to form bimetallic ({1a-[SnPh2]}(2)) and monometallic (1b-[SnPh2]) macrocycles. Structural characterization of these compounds revealed monodentate and anisobidentate coordination modes of the dithio phosphonate group, as well as the presence of metal-sulfur secondary bonds. While the ditopic nature of the ligand does not have an influence over the coordination behavior of the individual -PS2 groups, the length of the naphthalenediimide-dithiophosphonate linker lead to different solid-state supramolecular architectures. Cooperative pi-pi stacking and C-H center dot center dot center dot pi interactions organize the supramolecular structures of these complexes, generating two-dimensional sheets (in the case of "short-arm" ligand: 1a-[SnPh3](2) and 1a-[Cu(PPh3)(2)](2)) and mono-dimensional chains (in the case of "long-arm" ligand: 1b-[SnPh3](2)). In the case of {1a-[SnPh2]}(2) and 1b-[SnPh2] metallacycles, pi-pi stacking interactions between NDI central moieties produce infinite pi-pi stacked chains and discrete dimers, respectively. (C) 2013 Elsevier B. V. All rights reserved.