Complexes of Monocationic Group 13 Elements with Pentaphospha‐ and Pentaarsaferrocene

Reactions of the sandwich complexes [Cp*Fe(η 5 ‐E 5 )] (Cp*=η 5 ‐C 5 Me 5 ; E=P ( 1 ), As ( 2 )) with the monovalent Group 13 metals Tl + , In + , and Ga + containing the weakly coordinating anion [TEF] ([TEF]=[Al{OC(CF 3 ) 3 } 4 ] − ) are described. Here, the one‐dimensional coordination polymers [M(μ,η 5 :η 1 ‐E 5 FeCp*) 3 ] n [TEF] n (E=P, M=Tl ( 3 a ), In ( 3 b ), Ga ( 3 c ); E=As, M=Tl ( 4 a ), In ( 4 b )) are obtained as sole products in good yields. All products were analyzed by single‐crystal X‐ray diffraction, revealing a similar assembly of the products with η 5 ‐bound E 5 ligands and very weak σ‐interactions between one P or As atom of the ring to the neighbored Group 13 metal cation. By exchanging the [TEF] anion of 4 a for the larger [FAl] anion ([FAl]=[FAl{OC 6 F 10 (C 6 F 5 )} 3 ] − ), the coordination compound [Tl{(η 5 ‐As 5 )FeCp*} 3 ][FAl] ( 5 ) without any σ‐interactions of the As 5 ‐ring is obtained. All products are readily soluble in CH 2 Cl 2 and exhibit a dynamic coordination behavior in solution, which is supported by NMR spectroscopy and ESI‐MS spectrometry as well as by osmometric molecular‐weight determination. For a better understanding of the proceeding equilibrium DFT calculations of the cationic complexes were performed for the gas phase and in solution. Furthermore, the 31 P{ 1 H} magic‐angle spinning (MAS) NMR spectra of 3 a–c are presented and the first crystal structure of the starting material 2 was determined.