Zig‐Zag Diphosphene Oligomers Linked by Silver(I) Cation

Abstract

Summary of main observation and conclusion The coordination of silver cation to diphosphene Mes*P=PMes* (1, Mes* = tBu3C6H2) was investigated in detail. The reaction of 1 with Ag[Al(ORF)4] (ORF = OC(CF3)3) in the ratios of 2 : 1, 3 : 2 and 1 : 2 led to the formation of the first cationic silver linked diphosphene complexes 2—4. Complexes 2 and 3 contain two and three diphosphene molecules linked by the linear Ag(I) cation, respectively, and they feature unusual zig‐zag topologies. Complex 4 is a dinuclear silver complex, and each Ag(I) center features a tetrahedral geometry, coordinated by one phosphorus atom of diphosphene 1 and three chloro atoms of two CH2Cl2 molecules.

Tetra- and Pentaisopropylcyclopentadienyl Complexes of Group 15 Elements

“…The trans arrangement of the diphosphenes moiety is maintained in silver complex 4 , identical to 3a , with a perfectly planar Ag 2 P 2 moiety, as indicated by an Ag–PP–Ag torsion angle of 180°. The P–Ag bond is 238.2 pm, which is slightly shorter than in the aforementioned diphosphene disilver complex ([Mes*P­(Ag)P­(Ag)­Mes*]­[Al­(OR F ) 4 ] 2 : 240.0 pm). Each silver­(I) cation is tetra-coordinated in a distorted tetrahedral environment, similar to what is found in other silver­(I) tetra­(isonitrile) complexes, with the isonitrile ligands being almost linearly bonded to the silver atoms.…”

“…Complex 4 is obtained as a hexa-solvate in the form of its dodecabromo- closo -dodecaborate salt with three solvent molecules coordinated to each silver atom. Similarly to uncoordinated 3a and 3b and typical for diphosphene silver complexes, 4 ·(solv) 6 exhibits very downfield shifted 31 P NMR resonances (δ 31 P­( 4 ·(MeCN) 6 ) = 403.1 (CD 3 CN); δ 31 P­( 4 ·( i PrCN) 6 ) = 402.9 (CD 3 CN)), which are upfield shifted by ca. Δδ 31 P = 82.4, compared to 3a (Figure ).…”

“…Furthermore, reacting diphosphene 3a with Ag 2 [B 12 Br 12 ] as a silver­(I) source in acetonitrile results in coordination of one silver­(I) cation to each phosphorus atom, giving rise to dicationic complex 4 (Scheme ). Although diphosphenes can be coordinated to different transition metal fragments, coordination to cationic metal centers is quite rare, with, to the best of our knowledge, only one structurally characterized example of a dicationic complex exhibiting two silver­(I) cations …”