Oxidative addition reactions of the bridging amido complex Ir2[.mu.-NH(p-tolyl)]2(CO)4: x-ray crystal structure of the 16e-18e dimer Ir2(Me)(I)[.mu.-NH(p-tolyl)]2(CO)4.cntdot.0.25C6H14

Abstract

Oxidative addition reactions of halogens, hydrogen chloride, and methyl iodide with the dinuclear bridging amido complex Irz[p-NH(p-tolyl)l z(C0)4 are described. For Clz, Br2, MeI, and HC1, addition of 1 equiv produces Ir(1)-Ir(II1) dimers, whereas 1 equiv of IZ produces an Ir(I1)-Ir(I1) dimer. Except for the Me1 addition reaction, all of the oxidative addition processes proceed to give Ir(II1)-Ir(II1) dimers as final products. The characterization of the Me1 addition product was performed by an X-ray analysis, showing two iridium centers, with pseudooctahedral and pseudo-square-planar environments, that are separated by 3.209(1) A. Crystal data: CuH19-IIrzNz0~0.25CsH1~; triclinic Pi, a = 12.568 (3) A, b = 12.801(3) A, c = 17.248(3) A, a = 69.82(3)', 0 = 85.45(3)', y = 74.12(3)', V = 2504.8(9) A3, 2 = 4, R(F) = 0.046, and R(wF) = 0.054 for 5389 (F > 5a(F)) reflections.

Intervalent Bis(μ‐aziridinato)MIIMI Complexes (M=Rh, Ir): Delocalized Metallo‐Radicals or Delocalized Aminyl Radicals?

“…The longer Ir À N bond lengths in the apical positions can be explained by the trans-influence of the metal À metal bond, or due to the antibonding character in these apical bonds of the HOMO. [8a] The structure found in the solid state for complex [9] 2 + is maintained in solution for both complexes, according to the NMR spectra. Thus, two non-equivalent faces of the bridging aziridinato ligands (pointing at the "MA C H T U N G T R E N N U N G (cod)A C H T U N G T R E N N U N G (CH 3 CN)" and "MA C H T U N G T R E N N U N G (CH 3 CN) 3 " moieties, respectively) were deduced by the two signals of the methyl groups in the 1 H NMR spectrum.…”

“…A C H T U N G T R E N N U N G (PF 6 ) 2 (M = Rh, [8] 2 + ; M= Ir, [9] 2 + ). The electronic structures of [3] + and [4] + have been elucidated through EPR measurements and DFT calculations showing that their unpaired electron is primarily delocalized over the two metal centers, with minor spin densities at the two bridging amido nitrogen groups.…”

“…Dinuclear amido complexes of these metals are well-known, [5] and some of them have been reported as useful precursors for the synthesis of imido complexes, [6] for the transfer of the amido group to olefins, [7] and in catalyzed CÀC bond formation reactions. [8] Further, studies of the oxidative addition reactions of halocarbons allowed the synthesis of Ir I /Ir III derivatives [9] and the detection of S N 2 profiles in the activation of chloro compounds. [10] Herein we report on the synthesis of new dinuclear amido complexes of rhodium and iridium derived from aziridines as well as on their electrochemical behavior.…”

“…On a preparative scale, both complexes were prepared in good yields by reacting 3 and 4 with two molar equivalents of [FeCp 2 ]PF 6 in acetonitrile. Both complexes have been fully characterized, including a X-ray crystallographic study on complex [9]A C H T U N G T R E N N U N G (PF 6 ) 2 . The molecular structure of dicationic [9] 2 + is shown in Figure 10 while selected distances and angles are given in Table 6.…”

“…The overall geometry of [9] 2 + may be described roughly as formed by two square pyramids sharing an edge of the bases, in such a way that the environment of one metal can be considered distorted octahedral if the other metal occupies the sixth position of coordination. Each Ir center shares the nitrogen atoms of two cis-aziridinato ligands and the apex of each pyramid is occupied by the nitrogen of one acetonitrile ligand.…”