Synthetic, X‐ray Diffraction, Electrochemical, and Density Functional Theoretical Studies of (Indenyl)ruthenium Complexes Containing Dithiolate Ligands

Abstract

Halide substitution of the complexes [(Ind)Ru(L 2 )X] {Ind = η 5 -C 9 H 7 . 1: (L 2 ) = dppf [1,1Ј-bis(diphenylphosphanyl)ferrocene], X = Cl; 2: (L 2 ) = dppm [1,1Ј-bis(diphenylphosphanyl)methane], X = Cl; and 18: (L 2 ) = (CO) 2 , X = I} with the 1,1-dithiolates -S 2 CNR 2 (dialkyl dithiocarbamates for R = Me, Et, and C 5 H 10 ), -S 2 COR (alkyl xanthates for R = Et and iPr), and -S 2 PR 2 (dithiophosphinates for R = Et and Ph) showed that the lability of the indenyl ligand is influenced by the nature of both the coligand and the incoming dithiolate, as well as the solvent. In addition to dithiolate derivatives, the reactions also produced the hydride species [(Ind)Ru(diphos)H] in solvent-and stoichiometry-dependent yields. The observed dependence of lability of Ind on (L 2 ) follows the order, dppf Ͻ dppm ≈ (CO) 2 , in agreement with the electron-donor capability of L 2 , as well as the estimation of lowest activation energy for the η 5 Ǟ η 3 ring slippage process in the series of complexes [(Ind)Ru(L) 2 (S 2 COMe)] (L = PMeH 2 , PH 3 , CO) for

Synthesis, X‐ray Crystal Structures and Electrochemistry of (Indenyl)ruthenium Complexes Containing dppf and Heterocyclic Thiolato/Thione Ligands

“…CH 3 CN, with reversal to [2]PF 6 . Cyclic voltammetry experiments indicated that compounds 4, 5a, [5] + , [6] + , and [7] + could be oxidized in three oneelectron steps at positive potentials. The results support the hypothesis that the oxidation processes occurs at two independent (noncommunicating) sites within the molecules, most likely at the two metal ions (Ru and Fe).…”

“…We had reported a precedence for similar labilizing of the Ind ligand in the reaction of 1 with dialkyl dithiocarbamates and observed that the lability of Ind depends on the incoming dithiolato ligand and the nature of the solvent medium. [7] In this context, we point out that our earlier reaction of [RuClCp(dppf)] with pyridine-2-thiol in the presence of NaBPh 4 resulted only in chlorido substitution to afford the ionic complex, [RuCp(dppf)(pySH)]BPh 4 (D) (where pySH = pyridine-2-thione), arising from thiol/thione tautomerization of pyridine-2-thiol. (Scheme 2).…”

“…The cyclic voltammograms obtained in CH 2 Cl 2 solutions containing 4, 5a, and [5][6][7]PF 6 at two different temperatures are displayed in Figure 5. Each compound displayed three oxidation processes, with similar peak current values indicating that the processes occurred by the same number of electrons (i.e.…”

“…phosphane, [5] monothiolato [6] and dithiolato ligands. [7] We found that most of the [Ru(dppf)(ind)(L)] compounds underwent two or three one-electron oxidation processes, and we proposed that the oxidation processes occurred at different localized (noncommunicating) sites within the molecules. The two proposed localized sites of oxidation were based on observations of how the oxidation potentials shifted as the Ind (or other aromatic ligands), or L groups were systematically varied.…”