Some transition metal complexes derived from mono- and di-ethynyl perfluorobenzenes

Abstract

Transition metal alkynyl complexes containing perfluoroaryl groups have been prepared directly from trimethylsilyl-protected mono- and di-ethynyl perfluoroarenes by simple desilylation/metallation reaction sequences. Reactions between Me(3)SiC[triple bond, length as m-dash]CC(6)F(5) and RuCl(dppe)Cp' [Cp' = Cp, Cp*] in the presence of KF in MeOH give the monoruthenium complexes Ru(C[triple bond, length as m-dash]CC(6)F(5))(dppe)Cp' [Cp' = Cp (); Cp* ()], which are related to the known compound Ru(C[triple bond, length as m-dash]CC(6)F(5))(PPh(3))(2)Cp (). Treatment of Me(3)SiC[triple bond, length as m-dash]CC(6)F(5) with Pt(2)(mu-dppm)(2)Cl(2) in the presence of NaOMe in MeOH gave the bis(alkynyl) complex Pt(2)(mu-dppm)(2)(C[triple bond, length as m-dash]CC(6)F(5))(2) (). The Pd(0)/Cu(i)-catalysed reactions between Au(C[triple bond, length as m-dash]CC(6)F(5))(PPh(3)) and Mo( identical withCBr)(CO)(2)Tp* [Tp* = hydridotris(3.5-dimethylpyrazoyl)borate], Co(3)(mu(3)-CBr)(mu-dppm)(CO)(7) or IC[triple bond, length as m-dash]CFc [Fc = (eta(5)-C(5)H(4))FeCp] afford Mo( identical withCC[triple bond, length as m-dash]CC(6)F(5))(CO)(2)Tp* (), Co(3)(mu(3)-CC[triple bond, length as m-dash]CC(6)F(5))(mu-dppm)(CO)(7) () and FcC[triple bond, length as m-dash]CC[triple bond, length as m-dash]CC(6)F(5) (), respectively. The diruthenium complexes 1,4-{Cp'(PP)RuC[triple bond, length as m-dash]C}(2)C(6)F(4) [(PP)Cp' = (PPh(3))(2)Cp (); (dppe)Cp (); (dppe)Cp* ()] are prepared from 1,4-(Me(3)SiC[triple bond, length as m-dash]C)(2)C(6)F(4) in a manner similar to that described for the monoruthenium complexes -. The non-fluorinated complexes 1,4-{Cp'(PP)RuC[triple bond, length as m-dash]C}(2)C(6)H(4) [(PP)Cp' = (PPh(3))(2)Cp (); (dppe)Cp (); (dppe)Cp* ()], prepared for comparison, are obtained from 1,4-(Me(3)SiC[triple bond, length as m-dash]C)(2)C(6)H(4). Spectro-electrochemical studies of the ruthenium aryl and arylene alkynyl complexes - and -, together with DFT-based computational studies on suitable model systems, indicate that perfluorination of the aromatic ring has little effect on the electronic structures of these compounds, and that the frontier orbitals have appreciable diethynylphenylene character. Molecular structure determinations are reported for the fluoroaromatic complexes , , , and .

Mixed‐Valence Ruthenium Complexes Rotating through a Conformational Robin–Day Continuum

“…This solution corresponds to lowest-energy states calculated previously for [1] + and analogues. [24,50] The symmetrical class III situation is further supported by a negligible dipole moment (µ = 0.0 D), and by the computed single harmonic ν(C≡C) vibrational frequency at 1978 cm -1 (scaled by 0.95, see Computational Details), which compares well with the very strong band at 1974 cm -1 in the experimental spectrum ( Figure 3). TDDFT calculations with trans- [1] + at the same computational level gave a single, very intense (µ trans = 17.5 D) NIR transition at 6566 cm -1 , in good agreement with the most intense peak at 5750 cm -1 in the experimentally determined spectrum of [1] + (even better agreement is obtained with the slightly different CPCM solvent implementation in the Gaussian 09 program, cf.…”

Synthesis and Characterization of Dithia[3.3]metaparacyclophane‐Bridged Dimetallic Ruthenium Acetylide Complexes

“…This in situ procedure avoids the deprotection and isolation of the terminal alkynyl ligands. [14] The 1 H NMR spectra of the intermediate compounds 10-17 clearly showed signals in the range δ = 3-5 ppm that correspond to the characteristic benzylic protons of the dithiacyclophanes. For 10 and 14, the protons of the upperlayer benzene ring, which point toward the bottom aromatic ring, exhibited resonance signals at δ ≈ 5.80 ppm.…”

A simple synthesis of trans-RuCl(CCR)(dppe)2 complexes and representative molecular structures

“…The highest occupied molecular orbitals of ruthenium aryl acetylide complexes have significant aryl acetylide ligand character [22,28,29,59,60,[80][81][82]. The cyclic voltammograms of 3a-f each exhibit two anodic processes, the first being fully reversible, the potential of which reflect the variation in the electronic properties of the aryl substituent ( Table 5).…”

“…As part of a larger study concerned with the electronic structure of transition metal acetylide complexes [28,59,60] we desired convenient access to complexes trans-RuCl(C"CR)(dppe) 2 . However, although cis-1 is often cited as being prepared by the method originally described by Chaudret et al [61] for the preparation of cisRuCl 2 (dppm) 2 , in our hands reaction of RuCl 2 (dmso) 4 [62] with two equivalents of the bis(phosphine) in toluene at 80°C produced only pure trans-1 [10].…”