Two silver nitrate complexes with bisphosphines were obtained and characterized: [Ag(dcypm)]
2(NO
3)
2 (
1; dcypm = bis(dicyclohexylphosphino)methane) and [Ag(dppm)]
2(Me
2Pz
H)
n(NO
3)
2 (n = 1,
2a; n = 2,
2b; dppm = bis(diphenylphosphino)methane, Me
2Pz
H = 3,5-dimethylpyrazole). The steric repulsions of bulky cyclohexyl substituents prevent additional ligand coordination to the silver atoms in
1. Compounds obtained feature the bimetallic eight-member cyclic core [AgPCP]
2. The intramolecular argenthophilic interaction (d(Ag···Ag) = 2.981 Å) was observed in complex
1. In contrast, the coordination of pyrazole led to the elongation of Ag···Ag distance to 3.218(1) Å in
2a and 3.520 Å in
2b. Complexes 1 and 2a possess phosphorescence both in the solution and solid state. Time-dependent density-functional theory (TD-DFT) calculations demonstrate the origin of their different emission profile. In the case of
1, upon excitation, the electron leaves the Ag–P bonding orbital and locates on the intramolecular Ag···Ag bond (metal-centered character). Complex
2a at room temperature exhibits a phosphorescence originating from the
3(M + L
P+N)L
PhCT state. At 77 K, the photoluminescence spectrum of complex
2a shows two bands of two different characters:
3(M + L
P+N)L
PhCT and
3LC
Ph transitions. The contribution of Ag atoms to the excited state in both complexes
2a and
2b decreased relative to
1 in agreement with the structural changes caused by pyrazole coordination.
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