Cationic Functionalisation by Phosphenium Ion Insertion

Abstract

The reaction of [Cp′′′Ni(η3‐P3)] (1) with in situ generated phosphenium ions [RR′P]+ yields the unprecedented polyphosphorus cations of the type [Cp′′′Ni(η3‐P4R2)][X] (R=Ph (2 a), Mes (2 b), Cy (2 c), 2,2′‐biphen (2 d), Me (2 e); [X]−=[OTf]−, [SbF6]−, [GaCl4]−, [BArF]−, [TEF]−) and [Cp′′′Ni(η3‐P4RCl)][TEF] (R=Ph (2 f), tBu (2 g)). In the reaction of 1 with [Br2P]+, an analogous compound is observed only as an intermediate and the final product is an unexpected dinuclear complex [{Cp′′′Ni}2(μ,η3:η1:η1‐P4Br3)][TEF] (3 a). A similar product [{Cp′′′Ni}2(μ,η3:η1:η1‐P4(2,2′‐biphen)Cl)][GaCl4] (3 b) is obtained, when 2 d[GaCl4] is kept in solution for prolonged times. Although the central structural motif of 2 a–g consists of a “butterfly‐like” folded P4 ring attached to a {Cp′′′Ni} fragment, the structures of 3 a and 3 b exhibit a unique asymmetrically substituted and distorted P4 chain stabilised by two {Cp′′′Ni} fragments. Additional DFT calculations shed light on the reaction pathway for the formation of 2 a–2 g and the bonding situation in 3 a.

Synthesis and Multiple Subsequent Reactivity of Anionic cyclo‐E3 Ligand Complexes (E=P, As)

“…Chemie ing [(PHDI)Co(h 4 -P 5 R 2 )] [4,22] reported by Wolf et al and by ourselves for the reaction with the neutral nickel complex [Cp'''Ni(h 3 -P 3 )] yielding cationic species of the type [Cp'''Ni-(h 3 -P 4 R 2 )] + . [23] Thel atter complexes are isoelectronic and isostructural to 7a-c but represent the final products of their reactions and no further rearrangements to species along the lines of 8a-c were found, which are formed after an unprecedented ring contraction reaction. Asimilar structural motif of the latter complexes was already reported for the cationic rhodium complex [(triphos)Rh(h 2 :h 1 -P 4 RR')] + with overall P À Pd istances closely related to those observed for 8a.…”

Reactivity of Cu(I) Nacnac Complexes Toward Polypnictogen Compounds

“…All NMR spectra have been recorded using deuterated benzene- d 6 , toluene- d 8 , or CD 2 Cl 2 that were dried (over Na/K or CaH 2 ), refluxed for 3 h, and then distilled under an inert atmosphere. The compounds [Cp*Fe­(η 5 -E 5 )] (E = P ( 1a ), As ( 1b )), [LCu­(MeCN)] (L = [{N­(C 6 H 3 Me 2 -2,6)­C­(Me)} 2 CH] − ) ( 2 ), L = L 2 = [{N­(C 6 H 3 Me 2 -2,6)­C­(H)} 2 CH] − ) ( 2a )), [Cp‴Co­(η 4 -P 4 )] ( 3 ), and [Cp‴Ni­(η 3 -E 3 )] (E = P ( 4a ), As ( 4b )) were prepared according to literature procedures.…”

“…In addition the question of the reaction progress arose as to whether a mono- or a disubstitution occurs. Herein, we report on the reactivity of [LCu­(MeCN)] ( 2 ) (L = [{N­(C 6 H 3 Me-2,6)­C­(Me)} 2 CH] − ) toward complexes containing aromatic cyclo -E n ligands as end decks: i.e., [Cp*Fe­(η 5 -E 5 )] (E = P ( 1a ), As ( 1b )), [Cp‴Co­(η 4 -P 4 )] (Cp‴ = η 5 -C 5 H 2 t Bu 3 ) ( 3 ), and [Cp‴Ni­(η 3 -E 3 )] (E = P ( 4a ), As ( 4b )) . This results in compounds in which, first, a side-on coordination occurs, revealing a closed E–E bond, whereas, afterward, the second molecule {LCu} tends to be end-on coordinated.…”

Insertion of Phosphenium Ions into a Bicyclo[1.1.0]Tetraphosphabutane Iron Complex

“…That way, new cationic polyphosphorus compounds with catena [ 17 , 18 , 19 , 20 , 21 , 22 ], ring [ 22 , 23 , 24 ] or cage [ 16 , 22 , 25 ] units could be synthesized, in particular by Burford and Weigand, who observed the stepwise opening of the P-P bonds of the P 4 tetrahedron by insertion of [R 2 P] + in a solvent-free reaction set up to the cationic cage compounds [Ph 2 P 5 ] + ( II ), [Ph 4 P 6 ] 2+ and [Ph 6 P 7 ] 3+ , respectively [ 16 ]. Besides P 4 , the tetrahedral complex [Cp‴Ni(η 3 -P 3 )] also reacts with phosphenium cations by insertion into one P-P bond [ 26 ]. In contrast, [Cp*Fe(η 5 -P 5 )] reacts with main group electrophiles, such as, for instance, H + or CH 3 + with the formation of a P-E bond [ 27 ].…”