Pentafluoro(aryl)‐λ6‐tellanes and Tetrafluoro(aryl)(trifluoromethyl)‐λ6‐tellanes: From SF5 to the TeF5 and TeF4CF3 Groups

The TeF₅ group is significantly underexplored as a highly fluorinated substituent on an organic framework, despite it being a larger congener of the acclaimed SF₅ group. In fact, only one aryl‐TeF₅ compound (phenyl‐TeF₅) has been reported to date, synthesized using XeF₂. Our recently developed mild TCICA/KF approach to oxidative fluorination provides an affordable and scalable alternative to XeF₂. Using this method, we report a scope of extensively characterized aryl‐TeF₅ compounds, along with the first SC‐XRD data on this compound class. The methodology was also extended to the synthesis and structural study of heretofore unknown aryl‐TeF₄CF₃ compounds. Additionally, preliminary reactivity studies unveiled some inconsistencies with previous literature regarding phenyl‐TeF₅. Although our studies conclude that the arene‐based TeF₅ (and TeF₄CF₃) group is not quite as robust as the SF₅ group, we find that the TeF₅ group is more stable than previously thought, thus opening a door to explore new applications of this motif.     

6‐Propylamino‐2,6‐propylepimino‐2,4,4,8,8‐pentakis(pyrrolidin‐1‐yl)‐1,3,5,7,2λ5,4λ5,6λ5,8λ5‐tetraazatetraphosphorocine

The title compound, C₂₆H₅₅N₁₁P₄, consists of a bicyclic phosphazene ring with five bulky pyrrolidino and one propyl­amino group, together with a second propyl­amino group bridging the two P atoms. The asymmetric unit contains two mol­ecules with very similar conformations. The bulky substituents are instrumental in determining the bicyclic P₄N₅ ring conformation. Each of the fused six‐membered N₃P₃ rings is in a sofa conformation. The P—N distances in the bridge are non‐equivalent and one of them is the longest P—N bond in the mol­ecule. The hybridization of the bridging N atom is pyramidal. The single and double P—N bonds cannot easily be distinguished, since they retain their phosphazenic character in the phosphazene macro‐rings.     

B(C6F5)3‐Catalyzed Selective Chlorination of Hydrosilanes

The chlorination of Si−H bonds often requires stoichiometric amounts of metal salts in conjunction with hazardous reagents, such as tin chlorides, Cl₂, and CCl₄. The catalytic chlorination of silanes often involves the use of expensive transition‐metal catalysts. By a new simple, selective, and highly efficient catalytic metal‐free method for the chlorination of Si−H bonds, mono‐, di‐, and trihydrosilanes were selectively chlorinated in the presence of a catalytic amount of B(C₆F₅)₃ or Et₂O⋅B(C₆F₅)₃ and HCl with the release of H₂ as a by‐product. The hydrides in di‐ and trihydrosilanes could be selectively chlorinated by HCl in a stepwise manner when Et₂O⋅B(C₆F₅)₃ was used as the catalyst. A mechanism is proposed for these catalytic chlorination reactions on the basis of competition experiments and density functional theory (DFT) calculations.     

o-1λ5,3λ5-Diphosphaphenylen-bis(diphenylphosphan) und seine chelatbildenden Eigenschaften

o-1λ⁵,3λ⁵-Diphosphaphenylene-bis(diphenylphosphane) and its Chelating Properties Bis(diphenylphosphanyl)acetylene and 1,1′,3,3′-tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete react at higher temperatures to yield the title compound 5 , which forms easily the chelate complex 6 with nickel(II) chloride.