Metallophilic Mercuraazamacrocycles Derived from Bis{6‐formyl‐(2,3,4‐trimethoxy)phenyl}mercury: Reactivity with d 10 and d 8 Metal Ions

Coordination Behavior of the Tellurium Incorporated Mercuraazametallamacrocycle and Investigation of d10 ⋅⋅⋅d10 Interactions between Closed Shell (Ag+ Hg2+ ) Metal Ions

Herein, a new tellurium and mercury containing mercuraazametallamacrocycle has been prepared via (2+2) condensation of bis(o-aminophenyl)telluride and bis(o-formylphenyl)mercury(II). The isolated bright yellow solid of mercuraazametallamacrocycle has adopted unsymmetrical figure-of-eight conformation in the crystal structure. To study the metallophilic interactions between closed shell metal ions, the macrocyclic ligand has been treated with two equiv. of AgOTf (OTf=trifluoromethansulfonate) and AgBF4 , which afforded greenish-yellow bimetallic silver complexes. The isolated silver complexes displayed intramolecular Hg⋅⋅⋅Ag, Te⋅⋅⋅Ag interactions as well as intermolecular Hg⋅⋅⋅Hg interactions and formed an extended 1D molecular chain by directing six atoms to interact as TeII ⋅⋅⋅AgI ⋅⋅⋅HgII ⋅⋅⋅HgII ⋅⋅⋅AgI ⋅⋅⋅TeII in a non linear fashion. The Hg⋅⋅⋅Ag, Te⋅⋅⋅Ag interactions have also been studied in solution by 199 Hg, 125 Te NMR spectroscopy, absorption, and emission spectroscopy. In DFT calculations, the Atom in Molecule (AIM) analysis, non-covalent interactions (NCI), natural bonding orbital (NBO) analysis strongly supported for experimental evidences and revealed that the intermolecular Hg⋅⋅⋅Hg interaction is stronger than the intramolecular Hg⋅⋅⋅Ag interactions.

Dinuclear Silver(I) Nitrate Complexes with Bridging Bisphosphinomethanes: Argentophilicity and Luminescence

Two silver nitrate complexes with bisphosphines were obtained and characterized: [Ag(dcypm)]2(NO3)2 (1; dcypm = bis(dicyclohexylphosphino)methane) and [Ag(dppm)]2(Me2PzH)n(NO3)2 (n = 1, 2a; n = 2, 2b; dppm = bis(diphenylphosphino)methane, Me2PzH = 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 + LP+N)LPhCT state. At 77 K, the photoluminescence spectrum of complex 2a shows two bands of two different characters: 3(M + LP+N)LPhCT and 3LCPh 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.

Metallophilic interactions: observations of the shortest metallophilicinteractions between closed shell (d10⋯d10, d10⋯d8, d8⋯d8) metal ions [M⋯M′ M = Hg(ii) and Pd(ii) and M′ = Cu(i), Ag(i), Au(i), and Pd(ii)]

The salt metathesis reaction of two equivalents of 8-lithioquinoline (C₆H₆NLi) with HgBr₂ afforded bis(quinoline-8-yl)mercury, [(C₆H₆N)₂Hg].