One‐Dimensional Polymers Based on Silver(I) Cations and Organometallic cyclo‐P₃ Ligand Complexes

Abstract

The synthesis and characterization of the first supramolecular aggregates incorporating the organometallic cyclo-P3 ligand complexes [CpRMo(CO)2(eta3-P3)] (CpR=Cp (C5H5; 1a), Cp* (C5(CH3)5; 1b)) as linking units is described. The reaction of the Cp derivative 1a with AgX (X=CF3SO3, Al{OC(CF3)3}4) yields the one-dimensional (1D) coordination polymers [Ag{CpMo(CO)2(mu,eta3:eta1:eta1-P3)}2]n[Al{OC(CF3)3}4]n (2) and [Ag{CpMo(CO)2(mu,eta3:eta1:eta1-P3)}3]n[X]n (X=CF3SO3 (3a), Al{OC(CF3)3}4 (3b)). The solid-state structures of these polymers were revealed by X-ray crystallography and shown to comprise polycationic chains well-separated from the weakly coordinating anions. If AgCF3SO3 is used, polymer 3a is obtained regardless of reactant stoichiometry whereas in the case of Ag[Al{OC(CF3)3}4], reactant stoichiometry plays a decisive role in determining the structure and composition of the resulting product. Moreover, polymers 3a, b are the first examples of homoleptic silver complexes in which Ag(I) centers are found octahedrally coordinated to six phosphorus atoms. The Cp* derivative 1b reacts with Ag[Al{OC(CF3)3}4] to yield the 1D polymer [Ag{Cp*Mo(CO)2(mu,eta3:eta2:eta1-P3)}2]n[Al{OC(CF3)3}4]n (4), the crystal structure of which differs from that of polymer 2 in the coordination mode of the cyclo-P3 ligands: in 2, the Ag+ cations are bridged by the cyclo-P3 ligands in a eta1:eta1 (edge bridging) fashion whereas in 4, they are bridged exclusively in a eta2:eta1 mode (face bridging). Thus, one third of the phosphorus atoms in 2 are not coordinated to silver while in 4, all phosphorus atoms are engaged in coordination with silver. Comprehensive spectroscopic and analytical measurements revealed that the polymers 2, 3a, b, and 4 depolymerize extensively upon dissolution and display dynamic behavior in solution, as evidenced in particular by variable temperature 31P NMR spectroscopy. Solid-state 31P magic angle spinning (MAS) NMR measurements, performed on the polymers 2, 3b, and 4, demonstrated that the polymers 2 and 3b also display dynamic behavior in the solid state at room temperature. The X-ray crystallographic characterisation of 1b is also reported.

Redox and Coordination Behavior of the Hexaphosphabenzene Ligand in [(Cp*Mo)2(μ,η6:η6‐P6)] Towards the “Naked” Cations Cu+, Ag+, and Tl+

“…2.7 Å). [28] The Cu-P distances of 4 a (ca. 2.4 Å) are a little longer than for the η 2 -coordination in [Cp 2 Mo 2 (μ,η 2 :η 2 -P 2 )] (ca.…”

Highly Dynamic Coordination Behavior of Pn Ligand Complexes towards “Naked” Cu+ Cations

“…The structures of 2 – 4 resemble the species postulated as intermediates of the equilibrium involving the cyclo ‐P 3 ligand B2 and Ag + in solution calculated by DFT methods 5b. Therefore, the structures may be viewed as snapshots of the species in solution.…”

“…This solid‐state structure consistently shows an elongation of the η 2 ‐coordinated PP bonds. It is noteworthy that similar reactions with the cyclo ‐P 3 ligands B1 and B2 with In + , Tl + and Ag + always lead to the formation of one‐dimensional polymers instead of discrete monomeric or dimeric complexes, such as compounds 2 – 4 5b. 7b…”

A Novel Soluble InI Precursor for Pn Ligand Coordination Chemistry

“…The overall coordination mode of the P 3 ‐ligand complexes towards the In + ions can hence be described as μ‐1κ P A :1κ P B :2κ P B —a coordination mode, which is unprecedented for a cyclo ‐P 3 ligand complex. Unlike 12 , the recently published Ag I coordination polymers with cyclo ‐P 3 ligand complexes exhibit μ‐1κ P A :1κ P B :2κ P C and μ‐1κ P A :2κ P B coordination modes 10c. The geometry around the In + centers in 12 can be described as a distorted octahedron including three σ‐bonds and three π‐bonds, the maximum coordination number so far observed for the In–P system.…”