Syntheses, Structures, and Reactivity of New Pentamethylcyclopentadienyl-Rhodium(III) and -iridium(III) 4-Acyl-5-Pyrazolonate Complexes

Abstract

New [CpM(Q)Cl] complexes (M = Rh or Ir, Cp = pentamethylcyclopentadienyl, HQ = 1-phenyl-3-methyl-4R(C=O)-pyrazol-5-one in general, in detail HQ(Me), R = CH(3); HQ(Et), R = CH(2)CH(3); HQ(Piv), R = CH(2)-C(CH(3))(3); HQ(Bn), R = CH(2)-(C(6)H(5)); HQ(S), R = CH-(C(6)H(5))(2)) have been synthesized from the reaction of [CpMCl(2)](2) with the sodium salt, NaQ, of the appropriate HQ proligand. Crystal structure determinations for a representative selection of these [CpM(Q)Cl] compounds show a pseudo-octahedral metal environment with the Q ligand bonded in the O,O'-chelating form. In each case, two enantiomers (S(M)) and (R(M)) arise, differing only in the metal chirality. The reaction of [CpRh(Q(Bn))Cl] with MgCH(3)Br produces only halide exchange with the formation of [CpRh(Q(Bn))Br]. The [CpRh(Q)Cl] complexes react with PPh(3) in dichloromethane yielding the adducts CpRh(Q)Cl/PPh(3) (1:1) which exist in solution in two different isomeric forms. The interaction of [CpRh(Q(Me))Cl] with AgNO(3) in MeCN allows generation of [CpRh(Q(Me))(MeCN)]NO(3).3H(2)O, whereas the reaction of [CpRh(Q(Me))Cl] with AgClO(4) in the same solvent yields both [CpRh(Q(Me))(H(2)O)]ClO(4) and [CpRh(Cl)(H(2)O)(2)]ClO(4); the H(2)O molecules derive from the not-rigorously anhydrous solvents or silver salts.

Tuned Helical Array of RhIII/IrIII Cp* Complexes with Polypyridyl Ligands

“…The Rh–N bond lengths in 1 and 2 are all within reported values 9a,10,13. The Ir–N distances are comparable with those in related Cp*Ir complexes 3c,3d,9a. The angles N–M–N and N–M–Cl (M = Rh, Ir) are as expected for all the complexes.…”

Synthesis and reactivity of homo-bimetallic Rh and Ir complexes containing a N,O-donor Schiff base

“…These are comparable to the values reported in literature [30]. The Rh-N and Ir-N and bond distances of 2.156 and 2.147 Å are in the normal range [31,32] [32][33][34][35][36][37]. The metal to phosphorus distance is 2.366(11) Å in complex 3 and 2.348 Å in 5.…”

Comparative solution and structural studies of half-sandwich rhodium and ruthenium complexes bearing curcumin and acetylacetone

“…S5 and S6. [24,25,[39][40][41][42][43][44][45]. In the complex with the heavier congener iridium ([Ir( 5 -C5Me5)(acac)(Cl)]) this distance is found to be 1.753 Å and the bite angle is 87.5°, which is slightly different.…”