Iodination of cyclo‐E₅‐Complexes (E=P, As)

Abstract

In a high‐yield one‐pot synthesis, the reactions of [Cp*M(η5‐P5)] (M=Fe (1), Ru (2)) with I2 resulted in the selective formation of [Cp*MP6I6]+ salts (3, 4). The products comprise unprecedented all‐cis tripodal triphosphino‐cyclotriphosphine ligands. The iodination of [Cp*Fe(η5‐As5)] (6) gave, in addition to [Fe(CH3CN)6]2+ salts of the rare [As6I8]2− (in 7) and [As4I14]2− (in 8) anions, the first di‐cationic Fe‐As triple decker complex [(Cp*Fe)2(μ,η5:5‐As5)][As6I8] (9). In contrast, the iodination of [Cp*Ru(η5‐As5)] (10) did not result in the full cleavage of the M−As bonds. Instead, a number of dinuclear complexes were obtained: [(Cp*Ru)2(μ,η5:5‐As5)][As6I8]0.5 (11) represents the first Ru‐As5 triple decker complex, thus completing the series of monocationic complexes [(CpRM)2(μ,η5:5‐E5)]+ (M=Fe, Ru; E=P, As). [(Cp*Ru)2As8I6] (12) crystallizes as a racemic mixture of both enantiomers, while [(Cp*Ru)2As4I4] (13) crystallizes as a symmetric and an asymmetric isomer and features a unique tetramer of {AsI} arsinidene units as a middle deck.

Substituted aromatic pentaphosphole ligands – a journey across the p-block

“…Additional 1 J P-B coupling of 64 Hz is clearly visible in the 31 P NMR spectrum of 2 and is conrmed in its 11 B { 1 H} NMR spectrum. While the dynamic behavior of the Sisubstituted compound 6 in CD 2 Cl 2 solution, even at À80 C, does not allow for determination of P-P coupling constants, its 29 Si(DEPT 135) NMR spectrum shows a clear doublet of Fig. 1 Molecular structures of the cations in 2, 6, 7, 8, 9 and 13 in the solid state; Structural models for the cations in 3, 4, 5, 10 and 12 as well as a list of selected structural parameters (bond lengths and angles) for all compounds can be found in the ESI.…”

“…After recently investigating the complex iodination chemistry of 1 (ref. 29 ) and of the diphosphorus complex [{CpMo(CO) 2 } 2 (μ,η 2:2 -P 2 )], 30 we were wondering if electrophilic halogen transfer could lead to the desired reactivity. Indeed, when a solution of [PCl 4 ][TEF] is added to 1 in o -DFB, the NMR spectra of the crude solution indicate the clean conversion to [Cp*Fe(η 5 -P 5 Cl)][TEF] ( 11 ) and PCl 3 .…”

Halogenation of the Hexaphosphabenzene Complex [(Cp*Mo)2(μ,η6:η6‐P6)]: Snapshots on the Reaction Progress

“…Deposition Numbers 2155218 (2-I 3 ), 2155219 (3), 2155220 (4), 2155221 (5), 215522 (6), 2155223 (8), 2155224 (9), 2155225 (10) 2155226 (11) and 2155227 (12) contain the supplementary crystallographic data for this paper. These data are provided free of charge by the joint Cambridge Crystallographic Data Centre and Fachinformationszentrum Karlsruhe Access Structures service.…”

“…Our recent study on the iodination of the cyclo ‐E 5 complexes [Cp*M(η 5 ‐E 5 )] (M=Fe, Ru; E=P, As) [9] has shown that this is a powerful method for the high‐yield synthesis of new types of functionalized polypnictogen compounds (Scheme 1b, red arrow). By examining different halogen sources, the halogenation of the tetrahedrane compound [{CpMo(CO) 2 } 2 (μ,η 2 :η 2 ‐P 2 )] proved to lead to very diverse reaction products (Scheme 1a, red arrow) [10] …”

Transition‐Metal‐Mediated Functionalization of White Phosphorus

“…The iodination of 140 a and its heavier congener [Cp*Ru(η 5 ‐P 5 )] ( 140 b ) was also investigated by the same group (Scheme 24 c). [70] Layering dichloromethane solutions of 140 with three equivalents of iodine dissolved in MeCN selectively gives the monocationic complexes 143 as insoluble crystalline solids. Compounds 143 feature a unique tripodal cyclo ‐P 3 (PI 2 ) 3 ligand in an all‐cis conformation.…”