The monometallic complex [Pd(L)(PPh 3 )] (mono-Pd) was synthesized using a potentially tridentate hydrazone (H 2 L) and used as precursor to prepare a heterobimetallic ruthenium (II)-palladium (II) complex [Cl 2 (p-cymene)Ru(μ-L)Pd (PPh 3 )] (Ru-Pd). Mono-Pd and Ru-Pd were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), 1 H, 13 C{ 1 H} and 31 P{ 1 H} nuclear magnetic ressonance(NMR) spectroscopy, elemental analysis, cyclic voltammetry, matrix-assisted laser desorption/ ionization -time of flight (MALDI-TOF) mass spectrometry, and computational methods. The mono-Pd was additionally studied by single-crystal X-ray diffraction. The complex [RuCl 2 (p-cymene)(Isoniazid)] (mono-Ru) was also obtained following literature methods aiming a comparison in the catalytic activity. The ring opening metathesis polymerization (ROMP) of norbornene (NBE) using mono-Ru or Ru-Pd as precatalysts in the presence of ethyl diazoacetate (EDA) was evaluated as a function of time (10-60 min) using [NBE]/[EDA]/[Ru] = 5000/28/1 at 50 C. The time increases produced good yields of polyNBE, reaching 38% and 46% for mono-Ru and Ru-Pd, respectively. The polyNBE produced was measured by size-exclusion chromatography (SEC) and reached an order of magnitude of 10 5 gÁmol À1 of M n , with Ð values ranging from 2.51 to 1.86 for mono-Ru and from 3.50 to 1.66 for Ru-Pd. The catalytic activity of mono-Pd and Ru-Pd on ethylene polymerization was assessed with a range of [Al]/[Pd] molar ratio between 350 and 1750, 30-70 C temperature, 2 to 4 h reaction time, and total reaction volume of 25 and 50 ml. Mono-Pd achieved an activity of 22.80 kg PE (mol Pd) À1 h À1 at 60 C after 4 h using [Al]/[Pd] = 1050, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. For Ru-Pd, an activity of 20.35 kg PE (mol Pd) À1 h À1 at 60 C after 4 h was obtained using [Al]/[Pd] = 1750, 7 μmol

No abstract

The complex cis,fac-[RuCl 2 (DMSO-O)(DMSO-S) 3 ] [1] reacted with aniline (NH 2 Ph) under reflux to produce the complex trans,cis,cis-[RuCl 2 (DMSO-S) 2 (NH 2 Ph) 2 ] [2], whereas at room temperature the resulting complex was cis,fac-[RuCl 2 (DMSO-S) 3 (NH 2 Ph)] [3]. The complexes were characterized by FTIR, EPR, 1 H and 13 C NMR, electronic spectra, and the crystal structure of 2 was determined by single X-ray crystallography. The influence of NH 2 Ph and DMSO as ancillary ligands in the new complexes was then evaluated for ring-opening metathesis polymerization (ROMP) of norbornene (NBE), norbornadiene (NBD), and dicyclopentadiene (DCPD) in presence of ethyl [a]

Monometallic [RuCl2(η6-p-cymene)(pipNH2)] (mono-Ru) and heterobimetallic [RuCl2(p-cymene)](μ-Schiff-pip)Ni(PPh3)Cl] (Ru-Ni) complexes were successfully synthesized. They were fully characterized by FTIR, UV-Vis, and NMR spectroscopic studies, elemental analysis, cyclic voltammetry and computational studies. Complex...

New monomeric ligands inserted in ruthenium polypyridine complexes generated metallomonomers that were copolymerized with NBE by ROMP resulting in metallopolymers.

No abstract

Arene ruthenium(II) complexes bearing the cyclic amines RuCl2(η6‐p‐cymene)(pyrrolidine)] (1), [RuCl2(η6‐p‐cymene)(piperidine)] (2), and [RuCl2(η6‐p‐cymene)(peridroazepine)] (3) were successfully synthesized. Complexes 1–3 were fully characterized by means of Fourier transform infrared, UV–visible, and NMR spectroscopy, elemental analysis, cyclic voltammetry, computational methods, and one of the complexes was further studied by single crystal X‐ray crystallography. These compounds were evaluated as catalytic precursors for ring‐opening metathesis polymerization (ROMP) of norbornene (NBE) and atom‐transfer radical polymerization (ATRP) of methyl methacrylate (MMA). NBE polymerization via ROMP was evaluated using complexes 1–3 as precatalysts in the presence of ethyl diazoacetate (EDA) under different [NBE]/[EDA]/[Ru] ratios, temperatures (25 and 50°C), and reaction times (5–60 min). The highest yields of polyNBE were obtained with [NBE]/[EDA]/[Ru] = 5000/28/1 for 60 min at 50°C. MMA polymerization via ATRP was conducted using 1–3 as catalysts in the presence of ethyl‐α‐bromoisobutyrate (EBiB) as initiator. The catalytic tests were evaluated as a function of the reaction time using the initial molar ratio of [MMA]/[EBiB]/[Ru] = 1000/2/1 at 95°C. The increase in molecular weight as function of time indicates that complexes 1–3 were able to mediate the MMA polymerization with an acceptable rate and some level of control. Differences in the rate of polymerization were observed in the order 3 > 2 > 1 for the ROMP and ATRP.

No abstract