Oligomer and Polymer: Self Assembly of [Cp*Fe(η⁵‐P₅)] and Ag(I) Salts of Bulky Weakly Coordinating Anions

Reactions between the five‐fold symmetric building block [Cp*Fe(η 5 ‐P 5 )] ( A ) and Ag(I) salts containing bulky weakly coordinating anions [TEF] and [FAL] ([TEF]=[Al{OC(CF 3 ) 3 } 4 ] – , [FAl]=[FAl{OC 6 F 10 (C 6 F 5 )} 3 ] – ) are presented. While, in the presence of Ag[TEF], A leads to the formation of a hitherto condensed 1D coordination polymer [{Ag(η 2 :η 1 ‐ A ) 2 }] n [TEF] n ( 1 ), a new finite tetranuclear Ag(I) complex [{Ag 4 (η 1 ‐ A ) 2 (η 2 :η 1 ‐ A ) 4 (η 1 :η 1 ‐ A ) 2 }][FAL] 4 ( 3 ) was obtained with an Ag(I) salt bearing the weakly coordinating anion [FAl] increased in size. Various coordination modes (η 2 :η 1 ; η 1 :η 1 and η 1 ) of A were observed in the solid‐state structure of 3 , reflecting the adaptive coordination behavior of A towards Ag(I) ions. Structural modifications of the 1D polymer ( 1 ) can be controlled by the addition of a limited amount of MeCN yielding the unwound heteroleptic 1D polymer [{Ag(MeCN) 2 } 3 (η 1 :η 1 :η 1 ‐ A ) 2 ] n [TEF] 3n ( 2 ). Moreover, in the presence of MeCN, the finite oligomeric compound 3 can also be converted into a new heteroleptic 1D polymer [{Ag(MeCN)} 4 (η 1 :η 1 ‐ A ) 5 (η 2 :η 1 ‐ A ) 2 ] n [FAL] 4n ( 4 ). The solid‐state structure of 4 discloses the existence of a unique 1,1,2‐η 2 :η 1 (π,σ) coordination of A along with 1,3‐η 1 :η 1 (σ) and 1,2‐η 1 :η 1 (σ) coordination modes, while 1,2,4‐η 1 :η 1 :η 1 (σ) coordination modes of A were found in 2 . As revealed by X‐ray crystallography, in all the cases, the cationic moieties are well separated from the weakly coordinating anions in the solid state.