Synthesis and Reactivity of Organosamarium Diarylpnictide Complexes:  Cleavage Reactions of Group 15 E−E and E−C Bonds by Samarium(II)

Abstract

(C(5)Me(5))(2)Sm (2 equiv) reacts with Ph(2)EEPh(2) to give (C(5)Me(5))(2)SmEPh(2) (E: P, 1; As, 2), while (C(5)Me(5))(2)Sm(THF)(2) (2 equiv) reacts with Ph(2)EEPh(2) to give (C(5)Me(5))(2)Sm(EPh(2))(THF) (E: P, 3; As, 4). 3 and 4 are also available from the reactions of 1 and 2 with THF. 3 and 4 undergo further reaction to produce the THF ring-opened products (C(5)Me(5))(2)Sm[O(CH(2))(4)EPh(2)](THF) (E: P, 5; As, 6).(C(5)Me(5))(2)Sm (4 equiv) reacts with Ph(2)EEPh(2) to give the mixed-valent (C(5)Me(5))(2)Sm(&mgr;-EPh(2))Sm(C(5)Me(5))(2) (E: P, 7; As, 8). These compounds are also available from the reaction of 1 and 2 with (C(5)Me(5))(2)Sm. The X-ray crystal structure of 2, crystallized from hexanes (P2(1)/n; a = 26.188(24) Å, b = 9.911(10) Å, c = 23.280(23) Å, beta = 97.150(12) degrees, V = 5995(2) Å(3), D(calcd) = 1.488 Mg/m(3); Z = 8; T = 156 K), revealed, in addition to a conventional seven-coordinate bent metallocene geometry with 2.698 Å Sm-C(C(5)Me(5)) and 2.970 Å Sm-As average distances, two very different Sm-As-C(Ph) angles, 74.2 and 118.7 degrees. As a result, one phenyl group is closer to the metal (2.901 Å minimum Sm-C distance). 4, crystallized from toluene (P2(1)/n; a = 10.713(9) Å, b = 14.143(11) Å, c = 21.620(16) Å, beta = 101.08(6) degrees, V = 3215(4) Å(3), D(calcd) = 1.492 Mg/m(3); Z = 4; T = 163 K), and 6, crystallized from hexanes (P2(1)/n; a = 9.3958(16) Å, b = 22.245(3) Å, c = 17.931(3) Å, beta = 96.497(11) degrees, V = 3724(1) Å(3), D(calcd) = 1.416 Mg/m(3); Z = 4; T = 163 K), have conventional eight-coordinate, bent metallocene structures.

Frustrated Lewis Pairs: Metal‐free Hydrogen Activation and More

“…[90] Related combinations of Lewis acids and Lewis bases exhibit similar THF ring-opening chemistry. These include systems involving Lewis acidic transition metals, such as U, [91] Sm, [92] Ti, [93] and Zr [90,94] and main-group Lewis acids including carborane, [95] alane, [96] tellurium species, [97] and boranes [98] in combination with either nitrogen-or phosphorus-based Lewis bases (Scheme 53). The most pertinent of these to the present discussion is the zwitterionic species R 2 PH(CH 2 ) 4 OB(C 6 F 5 ) 3 (R = tBu, C 6 H 2 Me 3 ) derived from the treatment of (THF)B-(C 6 F 5 ) 3 with sterically encumbered phosphines.…”

Frustrierte Lewis‐Paare: metallfreie Wasserstoffaktivierung und mehr

“…[90] Verwandte Kombinationen von Lewis-Säuren und -Basen führen zu ähnlichen Resultaten. Dies wurde unter anderem mit Lewis-aciden d-und f-Metallen wie U, [91] Sm, [92] Ti, [93] und Zr [90,94] gezeigt, aber auch mit Lewis-Säuren von Hauptgruppenelementen, z. B. Carboran, [95] Alan, [96] Te-Verbindungen [97] und Boranen [98] in Kombination mit Stickstoff-oder Phosphor-Lewis-Basen (Schema 53).…”

Open Chain Polyarsenides of the Lanthanides

“…[9] In contrastt ot he well-established solid-state chemistry of rare-earth arsenides, [10,11] structurally characterized molecular rare-earth arsenides are uncommon. To the best of our knowledge, only very few structurally characterizedo rgano-arsenide compounds with LnÀAs bonds, namely Ln-AsR 2 [12][13][14][15][16] and Ln-As(R)-Ln, [16,17] are known.R ecently,p olynuclear DyÀAs compounds were investigated in terms of their single-molecule magnet (SMM)b ehaviour by Layfield et al [16] Also recently,w e disclosed the synthesis of three new d/f polyarsenides.…”