Abstract:

A series of discrete compounds and supramolecular polymers were synthesized by self-assembly of dithioether building blocks and HAuCl₄·3H₂O. In complexes 1 {[AuL^1-MeCl], where L^1-Me is bis(methylthio)methane} and 2 {[Au₂L^2-PhCl₂], where L^2-Ph is 1,2-bis(phenylthio)ethane}, adjacent units are connected via aurophilic interactions. Complex 1, a one-dimensional (1D) supramolecular polymer, and complex 2, a two-dimensional supramolecular network, both feature nearly linear [Au−Au−]_∞ chains. Complexes 4a, 4b, and 4c, all of which contain 1,3-bis(phenylthio)propane (L^3-Ph), are polymorphs having the composition [Au₂L^3-PhCl₂]. Complex 3 {[Au₂L^1-PhCl₂], where L^1-Ph is bis(phenylthio)methane}and complexes 4a and 4b consist of nearly identical 1D supramolecular polymers formed through Au−Au interactions. The third polymorph, 4c, is a molecular complex, as it does not have metal−metal interactions. Complex 5 {[Au₂L^4-PhCl₂], where L^4-Ph is 1,4-bis(phenylthio)butane} is also molecular. UV–vis spectra showed that the absorption bands of these complexes are allowed ligand-centered transitions between 230 and 260 nm. Complexes 1, 2, and 6 {[AuL^3-MeCl], where L^3-Me is 1,3-bis(methylthio)propane} exhibited solid-state luminescence at 5 K with vibronic progressions and band maxima at approximately 570 nm. It is suggested that complex 6 contains [Au−Au−]_∞ chains.