Five- and Six-Coordinated Silver(I) Complexes Formed by a Metallomacrocyclic Ligand with a “Au₂N₂” Donor Group: Observation of Pendulum and Linear Motions and Dual Phosphorescence

Abstract

The six-coordinated silver­(I) complex [Au2Ag­(μ-(PPh2)2py)2­(OTf)2]­(OTf), 4 (py = pyridine, OTf = CF3SO3), and the five-coordinated silver­(I) complex [Au2Ag­(acetone)­(μ-(PPh2)2py)2]­(PF6)3, 6, were prepared by the reaction of the precursor complexes 1(OTf)2 and 1(PF6)2, in which 1 = [Au2(μ-(PPh2)2py)2]2+, with 1 equiv of Ag­(OTf) in dichloromethane and excess of Ag­(PF6) in a mixture of dichloromethane/acetone, respectively. Also, the five-coordinated silver­(I) complex [Au2Ag­(μ-(PPh2)2py)2(py)­(OTf)]­(OTf)2, 5, was obtained by the reaction of 4 with pyridine. The clusters 4–6 were characterized using multinuclear NMR spectroscopy and elemental microanalysis. The single-crystal X-ray diffraction analysis revealed the octahedral and distorted square pyramidal geometries around the silver­(I) centers in the crystal structures of 4 and 6, respectively; a dynamic structure was observed for cluster 5 due to pendulum motion of the Ag­(pyridine) moiety, which was anchored in the metallomacrocyclic unit [Au2(μ-(PPh2)2py)2]2+. Although the crystal structure of 6 did not display disorders for the silver atom and the acetone ligand similar to that observed for 5, the low-temperature NMR spectroscopies and calculations show a dynamic structure for cluster 6 due to linear motion of the Ag­(acetone) moiety. The reaction of the precursor complex 1(PO2F2)2 with 2 equiv of Ag­(PO2F2) yielded the tetranuclear Au2Ag2 cluster [Au2Ag2(PO2F2)2­(μ-(PPh2)2py)2]­(PO2F2)2, 7, with a planar-shaped {Au2Ag2} metal core in which alternating Au and Ag atoms occupy the tetragon vertices and showed a strong argentophillic interaction between the silver­(I) centers. All clusters 4–7 are emissive in the solid state, and the origins of their emissive excited states were determined using time-dependent density functional theory calculations. Cluster 7 showed a dual phosphorescence emission, which displays strong dependence of the contributions of each emissive component onto the excitation wavelength.

Transition Metal Chain Complexes Supported by Soft Donor Assembling Ligands

“…Also using the stepwise approach of Scheme , various Au–Ag–Au complexes were prepared from a 12-membered diauromacrocycle, such as complex [Au 2 Ag­(μ-dpppy) 2 (OTf) 2 ]­(OTf), which display dynamic behavior in solution and are emissive in the solid-state . These dpppy-bridged metal chains are very reminiscent of those reported earlier with the double “short-bite” ligands P,C NHC ,P (see section ).…”

Synthesis of Silver(I) Complexes Containing N and P Donor Ligands

“…al., 2016;Kokunov et. al., 2016;Hasson et al, 2019;Atlı & Gülle, 2019), N^N (III-VII) (Durini et al, 2017;Xing et al, 2020;Fresta et al, 2019), N^N^N (VIII) Artem'ev et al, 2019), P^P (IX-XI) (Kaltzoglou et al, 2007;Bruce et al, 2016;Hutton et al, 1983;Gimeno et al, 1995), P^N (XII, XIII) (Hung-Low & Klausmeyer, 2008;Škoch et al, 2017;Artem'ev, 2020), P^N^P (XIV) (Nayeri et al, 2020) (Figure 1). Ag(I) centres form mononuclear (Medici et al, 2016), binuclear (Medici et al, 2016;Hung-Low & Klausmeyer, 2008;Artem'ev, et.…”

“…Ag(I) centres form mononuclear (Medici et al, 2016), binuclear (Medici et al, 2016;Hung-Low & Klausmeyer, 2008;Artem'ev, et. al., 2020), trinuclear (Artem'ev et al, 2019;Nayeri et al, 2020), tetranuclear (Medici et al, 2016;Nayeri et al, 2020) and polynuclear (Medici et al, 2016;Škoch et al, 2017;Artem'ev et al, 2020) complexes with pyridines, bypyridines, diphosphines and pyridyl phosphines; some of these complexes show weak Ag-Ag interaction. A few basic mononuclear, binuclear and trinuclear Ag(I) complexes with linear, trigonal planar and tetrahedral geometries are shown in Figure 2.…”

“…First examples of emissive square-planar Ag(I) complexes [Ag(N,N′-Py3PO)2]X (X = OTf, ClO4) were reported recently by reacting tris(2pyridyl)phosphine oxide (Py3PO) with Ag(I) salts (Artem'ev et al, 2019). Five-and six-coordinated Ag(I) complexes are less common (Medici et al, 2016;Nayeri et al, 2020, Artem'ev et al, 2019. Two examples of octahedral Ag(I) complexes include [Ag(N,N′,N′′-Py3PO)2]BF4 (Artem'ev et al, 2019) and [Ag(N,N′,N′′-VIII)2]OTf .…”

Selective coordination of coinage metals using orthogonal ligand scaffolds

“…, introducing coordinating anions like CN-, 35,36 triflate, 37 or solvents such as acetonitrile and pyridine. 38–40…”