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

(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.