1D, 2D and 3D networks based on group 11 metal ions and (pyrazin-2-ylmethyl)phosphines: synthesis, metallophilic interactions and emission properties

Abstract

An original series of 1D, 2D and 3D networks based on group 11 metal ions was synthesized using tris(pyrazin-2-ylmethyl)phosphine (L1) and bis(pyrazin-2-ylmethyl)phenylphosphine (L2). The reaction of L1 with CuI results in either 1D chains [Cu2I2(L1)2]n or 2D networks [Cu2I2(L1)]n, while the treatment of L1 and L2 with [Ag(MeCN)4]PF6 in aqueous MeCN produces 3D cationic frameworks [Ag(L1)]n(PF6)n and [Ag(L2)(H2O)]n(PF6)n, respectively. Finally, 1D polymer [Ag3Au(L1)2(MeCN)3]n(BF4)4n containing {AuAg2} cluster units was assembled from phosphine L1, Au(tht)Cl and AgBF4. QTAIM analysis of [Cu2I2(L1)]n and [Ag3Au(L1)2(MeCN)3]n(BF4)4n polymers revealed the presence of pronounced metallophilic Cu∙∙∙Cu and Au∙∙∙Ag interactions. Moreover, the CuI-based networks exhibited a yellow and red emission, which was tentatively attributed to thermally activated delayed fluorescence (TADF) of (M+X)LCT type.