Tris(2-Pyridyl)Arsine as a New Platform for Design of Luminescent Cu(I) and Ag(I) Complexes.

The coordination behavior of tris(2-pyridyl)arsine (Py 3 As) has been studied for the first time on the example of the reactions with CuI, CuBr and AgClO 4 . When treated with CuI in CH 2 Cl 2 medium, Py 3 As unexpectedly affords the scorpionate complex [Cu(Py 3 As)I]∙CH 2 Cl 2 only, while this reaction in MeCN selectively leads to the dimer [Cu 2 (Py 3 As) 2 I 2 ]. At the same time, the interaction of CuBr with Py 3 As exclusively gives the dimer [Cu 2 (Py 3 As) 2 Br 2 ]. It is interesting to note that the scorpionate [Cu(Py 3 As)I]∙CH 2 Cl 2 , upon fuming with a MeCN vapor (r.t., 1 h), undergoes quantitative dimerization into the dimer [Cu 2 (Py 3 As) 2 I 2 ]. The reaction of Py 3 As with AgClO 4 produces complex [Ag@Ag 4 (Py 3 As) 4 ](CIO 4 ) 5 featuring a Ag-centered Ag 4 tetrahedral kernel. At ambient temperature, the obtained Cu(I) complexes exhibit an unusually short-lived photoluminescence, which can be tentatively assigned to the thermally activated delayed fluorescence of (M + X) LCT type (M = Cu, L = Py 3 As; X = halogen). For the title Ag(I) complexes, QTAIM calculations reveal the pronounced argentophilic interactions for all short Ag∙∙∙Ag contacts (3.209-3.313 Å).