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Xylooligosaccharides (XOS) are widely used in the food industry as prebiotic components. XOS with high purity are required for practical prebiotic function and other biological benefits, such as antioxidant and inflammatory properties. In this work, we immobilized the recombinant endo-1,4-β-xylanase of Malbranchea pulchella (MpXyn10) in various chemical supports and evaluated its potential to produce xylooligosaccharides (XOS) from hydrothermal liquor of eucalyptus wood chips. Values >90% of immobilization yields were achieved from amino-activated supports for 120 min. The highest recovery values were found on Purolite (142%) and MANAE-MpXyn10 (137%) derivatives, which maintained more than 90% residual activity for 24 h at 70 °C, while the free-MpXyn10 maintained only 11%. In addition, active MpXyn10 derivatives were stable in the range of pH 4.0–6.0 and the presence of the furfural and HMF compounds. MpXyn10 derivatives were tested to produce XOS from xylan of various sources. Maximum values were observed for birchwood xylan at 8.6 mg mL−1 and wheat arabinoxylan at 8.9 mg mL−1, using Purolite-MpXyn10. Its derivative was also successfully applied in the hydrolysis of soluble xylan present in hydrothermal liquor, with 0.9 mg mL−1 of XOS after 3 h at 50 °C. This derivative maintained more than 80% XOS yield after six cycles of the assay. The results obtained provide a basis for the application of immobilized MpXyn10 to produce XOS with high purity and other high-value-added products in the lignocellulosic biorefinery field., The authors gratefully acknowledge FAPESP (São Paulo Research Foundation, grants No: 2018/07522-6) and FCT (POCI-01-0145-FEDER-032206)—transnational cooperation project EcoTech, and National Institute of Science and Technology of Bioethanol, INCT, CNPq 465319/2014-9/FAPESP n ◦ 2014/50884- 5) for financial support. Research scholarships were granted to RCA, DA, and JCSS by FAPESP (Grant No: 2020/00081-4, 2020/15510-8, and 2019/21989-7, respectively), to CCVD and VEP by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Finance Code 001)., info:eu-repo/semantics/publishedVersion

Xylooligosaccharides (XOS) are widely used in the food industry as prebiotic components. XOS with high purity are required for practical prebiotic function and other biological benefits, such as antioxidant and inflammatory properties. In this work, we immobilized the recombinant endo-1,4-β-xylanase of

Made available in DSpace on 2022-05-01T09:47:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The monometallic complex [Pd(L)(PPh3)] (mono-Pd) was synthesized using a potentially tridentate hydrazone (H2L) and used as precursor to prepare a heterobimetallic ruthenium (II)-palladium (II) complex [Cl2(p-cymene)Ru(μ-L)Pd (PPh3)] (Ru-Pd). Mono-Pd and Ru-Pd were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV–Vis), 1H, 13C{1H} and 31P{1H} 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 [RuCl2(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 105 g·mol−1 of Mn, 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)−1 h−1 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)−1 h−1 at 60°C after 4 h was obtained using [Al]/[Pd] = 1750, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. Overall, Ru-Pd showed to be active in both ROMP and ethylene polymerization reactions, being categorized as a bifunctional catalyst. Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista Departamento de Química Universidade Federal do Triângulo Mineiro Instituto de Química de São Carlos Universidade de São Paulo Instituto de Química Universidade Federal de Uberlândia Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista FAPESP: 2018/06340-1 FAPESP: 2018/19395-9

Made available in DSpace on 2022-04-28T19:45:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) In this study, we synthesized the complex [Co(BuSalen)] using the novel tetradentate BuSalen ligand and analyzed its ability as a controlling agent for the photo-induced organometallic-mediated radical polymerization (photo-OMRP) of butyl acrylate (BA) using diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as photo-initiator. BA polymerization with [Co(BuSalen)] reached significant control levels using the [BA]/[CoII]/TPO molar ratio of 600/1/1. The [Co(Salen)] and [Co(Bu2Salen)] complexes were also obtained following literature methods aiming a comparison in the mediating ability in photo-OMRP. [Co(BuSalen)] and [Co(Bu2Salen)] showed better controlling ability, as observed in the copolymerization study (Đ= 2.64, 1.50, and 1.26 for complexes [Co(Salen)], [Co(BuSalen)] and [Co(Bu2Salen)], respectively). Kinetics studies and computational investigations support a reversible termination (RT) mechanism and a tailorable CoII complex reactivity mainly altered by Schiff-base steric factors. Calculated thermodynamic parameters agree with the controlling degree delivered by these complexes, since the polymerization control increases with increasing the ΔG values for the formation of dormant species. Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista FAPESP: 2018/06340-1 FAPESP: 2018/19395-9 FAPESP: 2019/03354-4 CNPq: 307443/2015-9 FAPEMIG: CEX - APQ-03017-16

Made available in DSpace on 2019-10-04T12:16:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-09 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Nickel(II) complexes of Schiff base derived from cycloalkylamines (cycloalkyl = cyclopentyl (cpen), cyclohexyl (chex), and cycloheptyl (chep)) were synthesized: [Ni-II(L-cpen)(2)] (1), [Ni-II(L-chex)(2)] (2), and [Ni-II(L-chep)(2)] (3). The Schiff base-Ni-II complexes 1-3 were characterized by FTIR, UV-Vis, elemental analysis, and computational methods. Electrodeposited films of complexes 1-3 were obtained by potential cycling CH2Cl2 on platinum electrode, and their electrochemical behavior were characterized by cyclic voltammetry. The polymerization of vinyl acetate (VAc) initiated by azobisisobutyronitrile (AIBN) at 55 degrees C were conducted according to an organometallic-mediated radical polymerization (OMRP) mechanism. The best conversions were obtained using a ratio of [VAc]/[AIBN]/[Ni] = 542/3.25/1, reaching 50, 69 and 85% in 12 h for 1, 2 and 3, respectively. The kinetic of polymerization mediated by complex 1 exhibited a linear dependence of ln([VAc](0)/[VAc]) versus time, supporting a constant radical concentration; while for the complexes 2 and 3, the radical concentration was constant for a short period of time. The increase of molecular weights with the conversion coupled with low polydispersities indicate a certain level of control of the polymerization when using the complexes [Ni-II(L (R))(2)] as controlling agents. Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI, Brazil Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Fed Uberlandia, Inst Quim, Uberlandia, MG, Brazil Univ Fed Triangulo Mineiro, Dept Quim, Uberaba, Brazil Univ Sao Paulo, Inst Quim Sao Carlos, Sao Carlos, SP, Brazil Univ Estadual Paulista, UNESP, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2013/11883-0 FAPESP: 2013/10002-0

Novel dimethyl sulfoxide ruthenium(II) complexes of N-heterocyclic carbenes [RuCl2(S-dmso)2(SIMes)] (1), [RuCl2(S-dmso)2(IMes)], (2) [RuCl2(S-dmso)2(SIDip)] (3), and [RuCl2(S-dmso)2(IDip)] (4) were successfully synthesized. The complexes 1–4 were characterized by elemental analysis, FTIR, UV-Vis, 1H and 13C NMR, and computational studies. The polynorbornene (polyNBE) syntheses via ROMP using the complexes 1–4 as pre-catalysts in the presence of ethyl diazoacetate (EDA) were evaluated under different [EDA]/[Ru] and [NBE]/[Ru] ratios, temperatures (25 and 50 °C) and times (5–60 min). Quantitative yields of polyNBEs using [NBE]/[EDA]/[Ru] = 5000/28/1 for 10 min at 25 °C were obtained. The order of magnitude of 105 g mol−1 for Mn and PDI values ranging from 1.2 to 3.5 were measured by SEC. An investigation combining experimental data and computational calculations was performed to elucidate the mechanism of ROMP of NBE mediated by the complexes 1–4 as pre-catalysts. The proposed mechanism suggests the occurrence of a dissociative reaction of the complexes 1–4, losing a dmso ligand as the first step, resulting in a 14-electron species, which reacts with EDA to form the metal-carbene, followed by discoordination of the second dmso molecule for coordination of NBE.

The [Ru(PPh3)2Cl-piperidine(4-aminomethyl)] complex (mono-Ru) was synthesized from [Ru(PPh3)3Cl2] and 4-(aminomethyl)piperidine, whereas the [(PPh3)PdCl(Shiff-pip)] complex (mono-Pd) was obtained by reacting [Pd(PPh3)2Cl2] with its respective Schiff base ligand, both at a 1:1 molar ratio. The heterobimetallic [RuCl2(PPh3)2](μ-Schiff)Pd(PPh3)Cl] complex (Ru/Pd) was synthesized via a one-pot, three-component reaction of mono-Ru, [(Pd(PPh3)2Cl2] and salicylaldehyde. All complexes were fully characterized by FTIR, UV-Vis, and NMR spectroscopy, as well as elemental analysis, MALDI-TOF mass spectrometry, cyclic voltammetry, and computational studies. Ru/Pd was able to polymerize norbornene (NBE) by two different mechanisms: ROMP and vinyl polymerization. The Ru fragment was active for ROMP of NBE, reaching yields of 68 and 31% for mono-Ru and Ru/Pd, respectively, when the [NBE]/[Ru] = 3000 molar ratio and 5 μL EDA addition were employed at 50 °C. The poly(norbornene) (polyNBE) obtained presented an order of magnitude of 104 g mol−1 and Ð values between 1.48 and 1.79. For the vinyl polymerization of NBE, the Pd fragment was active using MAO as a cocatalyst, reaching a yield of 47.0% for Ru/Pd and quantitative yields for mono-Pd when [Al]/[Pd] = 2500 and [NBE]/[Pd] = 20,000 molar ratios were employed, both at 60 °C.

Made available in DSpace on 2021-06-25T10:32:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-14 A series of new manganese(ii) complexes were prepared with three bidentate Schiff-base ligands derived by condensation of salicylaldehyde and different cycloalkylamines (cycloalkyl = cyclopentyl, cyclohexyl, and cycloheptyl): [Mn(CyPen-Salicyl)2] (1), [Mn(CyHex-Salicyl)2] (2), and [Mn(CyHep-Salicyl)2] (3). The complexes 1-3 were characterized by FTIR, UV-vis and EPR spectroscopy, elemental analysis, cyclic voltammetry, and computational methods. The manganese(ii) complexes (1-3) were used as controlling agents for the polymerization of vinyl acetate (VAc) initiated by AIBN according to an organometallic-mediated radical polymerization (OMRP) mechanism. The VAc polymerization mediated by the Mn complexes suggests that the control level can be slightly tuned through substitution of the cycloalkyl group on the Schiff-base ligand. Kinetics studies and computational investigations support an RT mechanism and a tailorable Mn complex reactivity mainly altered by steric factors of the Schiff-base ligands. The calculated thermodynamic parameters agree with the mediating ability of these complexes, since the degree of polymerization control decreases with increasing steric hindrance of the Schiff-base ligands, as well as with increasing ΔG values for the formation of dormant species. Faculdade de Ciências e Tecnologia UNESP-Univ. Estadual Paulista Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 CEITEC-Central European Institute of Technology Brno University of Technology, Purkyňova 123 Instituto de Física de São Carlos Usp Universidade de São Paulo Faculdade de Ciências e Tecnologia UNESP-Univ. Estadual Paulista

Made available in DSpace on 2020-12-12T01:16:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 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. Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista Instituto de Química de São Carlos Universidade de São Paulo Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 Departamento de Química Universidade Federal do Triangulo Mineiro Programa de Pós‐Graduação em Ciências Exatas e Tecnológicas at Universidade Federal de Goiás Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista FAPESP: 2017/06329-5 FAPESP: 2018/06340-1

Made available in DSpace on 2020-12-12T01:09:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The synthesis, spectroscopic properties and crystal structure of the novel complex fac-[RuCl2(DMSO-S)3(n-butylamine)] (DMSO-S = sulfur-bonded dimethylsulfoxide) have been reported. The coordination environment of the ruthenium atom is best described as a distorted octahedral, where three DMSO ligands occupy one face of the octahedron, while the two chlorido and the amine ligand occupy the other one. The catalytic activity of fac-[RuCl2(DMSO-S)3(n-butylamine)] was probed in two processes, ring-opening metathesis polymerization (ROMP) and atom-transfer radical polymerization (ATRP). The ROMP of norbornene (NBE) was carried out in the presence of ethyl diazoacetate (EDA) for 5 min at 50 °C which afforded yields around 80%. Poly(norbornadiene) was only produced by photoinduced ROMP leading to 27% yield. The catalytic activity for ATRP of methyl methacrylate (MMA) and styrene (St) for 8 h resulted in 88 and 33%, respectively. Instituto de Química de São Carlos Universidade de São Paulo, 13560-970 Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, 19060-900 Departamento de Química Universidade Federal do Triângulo Mineiro, 38025-440 Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, 19060-900 FAPESP: 2017/06329-5 FAPESP: 2018/06340-1

Cinnamyl alcohol (AC) and cinnamyl acetate (ACM) were used as substrates in olefin metathesis reactions catalyzed by RuCl2(PCy3)2(=CHPh), first-generation Grubbs catalyst-G1, and RuCl2(PCy3)(H2IMes)(= CHPh), second-generation Grubbs catalyst-G2. The reactions occurred in the same reaction conditions for both substrates, 50 °C, for 24 h, in the proportions Ru:substrate of 1:1 and 1:10 mol. At the end of each experiment, the reaction mixture was evaluated by GC-MS and NMR of 13C{1H}. The results revealed different products when G1 and G2 are applied in the metathesis of AC, 1,5-diphenyl-2-pentene and stilbene, respectively. When ACM is the substrate, no product is noted with G1 and stilbene was the compound obtained with G2 as catalyst. In this study, we have presented a discussion about the electronic and steric influence of the ancillary ligands in the yield and type of product formed in the catalytic process.

Made available in DSpace on 2021-06-25T10:14:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A series of cobalt(II)-α-diimine complexes derived from cycloalkylamines (cycloalkyl = cyclopentyl (1a), cyclohexyl (1b), cycloheptyl (1c), and cyclooctyl (1d)) were synthesized: [CoCl2(Pent-DAB)] (2a), [CoCl2(Hex-DAB)] (2b), [CoCl2(Hept-DAB)] (2c), and [CoCl2(Oct-DAB)] (2d). The α-diimines 1a-d were characterized by FTIR, UV–Vis, and 1H- and 13C NMR spectroscopy, while their respective cobalt(II) complexes (2a-d) were characterized by elemental analysis, FTIR, UV–Vis, EPR, and computational studies. The ability of complexes 2a-d to mediate the vinyl acetate (VAc) polymerization initiated by AIBN, according to a cobalt-mediated radical polymerization (CMRP) mechanism, was explored. A mechanistic investigation of radical trapping based on the combination of theoretical and experimental results for CMRP using 2a-d was conducted. This study shows that the activation/deactivation equilibrium exerted by 2a-d occurs by only one of the faces of the complexes via reversible-termination mechanism. The molecular weight increased in direct proportion to the monomer conversion in the early stages of polymerization for complexes 2a and 2b, while uncontrolled polymerization was observed for 2c and 2d. The molecular weights indicate that the steric effect operated by the cycloalkyl substituents plays an important role in the polymerization control, and that a greater steric hindrance disfavors the dormant state for CMRP equilibrium. Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, CEP 19060-900 Instituto de Física de São Carlos USP Universidade de São Paulo, CEP 13563-120 Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, CEP 19060-900

Made available in DSpace on 2022-04-28T19:45:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-15 Three new cobalt(II) complexes with non-symmetrically-substituted N2O2 tetradentate Schiff-base ligands, prepared from the 1:1:1 condensation of 3-etoxy-salicylaldehyde, salicylaldehyde and ethylenediamine (H2Etsal − 1), o-phenylenediamine (H2Phsal − 2) or 1,2-cis,trans-cyclohexyldiamine (H2Cysal − 3), were synthesized. The complexes 1–3 were characterized by UV–Vis, FTIR, and MALDI-TOF spectroscopy, elemental analysis, molar conductance, cyclic voltammetry, and computational methods. The CoII-Schiff-base complexes (1–3) were used as controlling agents for the polymerization of n-butyl acrylate (BA) photoinitiated by diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), according to an organometallic-mediated radical polymerization (OMRP) mechanism. Although, all complexes have presented good control ability, the polymerization mediated by complex 1 showed the best control over molecular weight (Mn matching with Mn,th) and dispersity (Ð < 1.50). Kinetic results and computational investigations support the activation/deactivation equilibrium, exerted by complexes 1–3, occurring by one face of the complexes via reversible termination (RT) mechanism.minim. Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, CEP 19060-900 Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 Faculdade de Ciências e Tecnologia UNESP – Univ. Estadual Paulista, CEP 19060-900

Made available in DSpace on 2018-12-11T16:50:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-08-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Ring-opening metathesis polymerization (ROMP) of norbornadiene (NBD) with [RuCl2(PPh3)2(pyrrolidine)] as the starting complex was evaluated as a function of reaction time, solvent volume, and atmosphere type at 25 °C. Quantitative yields of polyNBD were obtained either under inert argon atmosphere or in air, with 2 mL of CHCl3, for 30 min. Copolymerization of NBD with norbornene (NBE) resulted in 100–70% yield under argon, depending on the NBE/NBD molar ratio, and in 70% yield in air, with 2 mL, for 120 min. TGA, DSC, and DMA measurements and swelling tests supported the occurrence of cross-linking in homopolyNBD and in the copolymers isolated from polymers. SEM micrographs showed porous polymeric NBD materials with pores that decreased in size when increasing the amount of NBD in the starting reaction composition. Results from amine parent complexes when the amine was piperidine or perhydroazepine are also discussed, with high cross-linking degree from reaction with the pyrrolidine complex. Instituto de Química de São Carlos Universidade de São Paulo, CP 780 Centro de Ciências da Natureza Universidade Estadual do Piauí Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista FAPESP: 2011/12571-7 FAPESP: 2012/23948-7

Made available in DSpace on 2018-12-11T16:49:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-15 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Ruthenium(II) complexes of Schiff base derived from cycloalkylamines (cycloalkyl = cyclopentyl (1a), cyclohexyl (1b), cycloheptyl (1c), and cyclooctyl) (1d) were synthesized: [RuCl(CyPen-Salen)(PPh3)2] (2a), [RuCl(CyHex-Salen)(PPh3)2] (2b), [RuCl(CyHep-Salen)(PPh3)2] (2c), and [RuCl(CyOct-Salen)(PPh3)2] (2d). The Schiff base-RuII complexes 2a-d were characterized by elemental analysis, FTIR, UV-Vis, 1H-, 13C and 31P NMR, and cyclic voltammetry. The complexes 2a-d were evaluated as catalytic precursors for ROMP of norbornene (NBE) and for ATRP of methyl methacrylate (MMA). The syntheses of polynorbornene (polyNBE) via ROMP with complexes 2a-d as pre-catalysts were evaluated under different reaction conditions ([HCl]/[Ru], [EDA]/[Ru], [NBE]/[Ru], and temperature). The highest yields of polyNBE were obtained with [NBE]/[HCl]/[Ru] = 5000/25/1 M ratio in the presence of 5 μL of EDA for 60 min at 50 °C. MMA polymerization via ATRP was conducted using the complexes 2a-d 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 85 °C. The linear correlation of ln([MMA]0/[MMA]) and time indicates that the concentration of radicals remains constant during the polymerization and that the ATRP of MMA mediated by 2a-d proceeds in a controlled manner. Molecular weights increased linearly with conversion, however, the experimental molecular weights were higher than the theoretical ones. Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista Instituto de Química de São Carlos Universidade de São Paulo Instituto de Química UFU Universidade Federal de Uberlândia Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista FAPESP: 2013/10002-0

Made available in DSpace on 2018-11-26T15:44:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The novel, non-carbene complex -[RuCl2(PPh3) (2)(azocane)] (1) of trigonal bipyramid geometry was synthesized, characterized (CHN elementary analysis, FTIR, EPR, and 31P NMR), and applied as catalyst precursor for ring opening metathesis polymerization (ROMP) and atom transfer radical polymerization (ATRP). ROMP of norbornene (NBE) resulted in 70% yield at 50 degrees C in 60 min, with [NBE]/[1] = 5000, and 15% yield from ROMP of norbornadiene was obtained under the same conditions. ATRP of methyl methacrylate (MMA) resulted in ca. 20% conversion at 85 degrees C in 9 h, with [MMA]/[1] = 1000, and increased to ca. 50% in the presence of Al(OiPr) (3), with narrower PDI values. With [MMA]/[1] = 200, ca. 50% yield was obtained at 85 degrees C in 6 h either in the absence or presence of Al(OiPr) (3). ATRP of styrene resulted in 9 and 16% conversion at 110 degrees C in 7 h in the absence or presence of Al(OiPr) (3), respectively, with [St]/[1] = 1000. Results are discussed considering the five-coordinated molecular geometry of the starting complex and the arrangements required in ROMP and ATRP to initiate the reactions. Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI, Brazil Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2013/10002-0 FAPESP: 2011/12571-7 FAPESP: 06/57577-4

Made available in DSpace on 2018-11-26T15:37:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-24 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Prope The catalytic activity of the five-coordinated [RuCl2(PPh3)(S-dmso)(2)] complex was investigated for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and for atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). Syntheses via ROMP of polyNBE were dependent on the ethyl diazoacetate (EDA) amount, used as starting carbene source, monomer concentration, temperature, and reaction time. The best polyNBE yields were obtained at 50 degrees C for 120 min with [NBE]/[Ru] = 5000 in presence of 5 mu L of EDA. MMA polymerization via ATRP was conducted as a function of time with different ethyl 2-bromoisobutyrate initiator and monomer concentrations. The kinetic data for ATRP show linear increase between MMA conversion and molecular weight. Kinetic studies with the six-coordinated [RuCl2(S-dmso)(3)(O-dmso)] complex also showed an increase in the molecular weight with conversion, but with a marked deviation from theoretical molecular weights. This is consistent with the better control in the polymerization supported by electronic and steric properties of the PPh3 ligand in the title complex (C) 2016 Elsevier B.V. All rights reserved. Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2013/10002-0 Prope: 2180/002/14-PROPe/CDC

Made available in DSpace on 2020-12-12T00:58:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-11-10 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) The complex cis,fac-[RuCl2(DMSO–O)(DMSO–S)3] [1] reacted with aniline (NH2Ph) under reflux to produce the complex trans,cis,cis-[RuCl2(DMSO–S)2(NH2Ph)2] [2], whereas at room temperature the resulting complex was cis,fac-[RuCl2(DMSO–S)3(NH2Ph)] [3]. The complexes were characterized by FTIR, EPR, 1H and 13C NMR, electronic spectra, and the crystal structure of 2 was determined by single X-ray crystallography. The influence of NH2Ph 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 diazoacetate (EDA) with different [monomer]/[Ru] molar ratios. Homopolymers of NBE with molecular weights in the order of magnitude of 105 g.mol–1 and insoluble polymers in CHCl3 from NBD and DCPD were obtained in different yields depending of the starting complex, reaction time (5 and 30 min), and temperature (25 and 50 °C). Valorous results were obtained for polyNBD, polyDCPD, and copolymerizations from NBE with NBD or DCPD using the new complexes, affording higher yields than with 1. In conclusion, beneficial effects are observed when DMSO and the weak σ-donor NH2Ph ligands are arranged in the same coordination sphere of Ru(II) pre-catalysts for ROMP. Instituto de Química de São Carlos Universidade de São Paulo Departamento de Química Universidade Federal do Triângulo Mineiro Faculdade de Ciências e Tecnologia UNESP Univ. Estadual Paulista Faculdade de Ciências e Tecnologia UNESP Univ. Estadual Paulista FAPESP: 2017/06329-5 FAPESP: 2018/06340-1

Made available in DSpace on 2019-10-04T12:15:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Two novel monomers, norbornenyl buriti olein (NBO) and norbornenyl buriti ester (NB-FAME), were synthesized by reactions of 5-norbornene-2-carboxylic acid with triglycerides and with methyl esters from buriti oil, respectively. No polymers were produced via ROMP of NBO or NB-FAME using Grubbs second-generation catalyst at 30 degrees C for 1 h. However, copolymers of NBO or NB-FAME in the presence of norbornene (NBE) were obtained raising the initial compositions of the buriti oil-derived monomers from 20 to 80%, under the same conditions. The polymers were insoluble in water and typical organic solvents. In chloroform at 30 degrees C for 48 h, the polymers from synthesis with 80 wt% of buriti oil-derived monomers resulted in a mass gain of 1709% for polymer from NBO and 929 wt% for polymer from NB-FAME. SEM micrographs showed smooth morphologies and non-porous surfaces, which differ from the porous polyNBE. TGA analyses indicated thermal stability up to 200 degrees C. The poly(NBO-co-NBE) and poly(NB-FAME-co-NBE) have been proved to be the final products. Univ Sao Paulo, Inst Quim Sao Carlos, CP 780, BR-13560970 Sao Carlos, SP, Brazil Univ Estadual Piaui, Ctr Ciencias Nat, BR-64002150 Teresina, PI, Brazil Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2017/06329-5

Made available in DSpace on 2018-12-11T16:51:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-02-24 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) This study describes the synthesis and characterization of three α-diimine-cobalt complexes of the type [CoCl2(R-DAB)] (R-DAB = R–N[dbnd]CH–CH[dbnd]N–R; R = Mes, Dipp and Dipp∗) and their application as mediators for the cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) using 2,2′-Azobis(2-methylpropionitrile) (AIBN) as initiator. The complexes were characterised by elemental analyses, FTIR, UV–Vis, electron paramagnetic resonance spectroscopy, cyclic voltammetry, and computational methods. The systematic variation of the reaction conditions, such as [initiator]/[Co] and [monomer]/[Co] molar ratios at 65 °C, affected the polymerization rates and the molecular weights, reaching a certain level of control. The VAc polymerization was initiated by AIBN in the presence of DMSO using the α-diimine-cobalt complexes as mediators with [DMSO]/[Co] = 1 at 65 °C. The control over the polymer produced was not improved after the addition of DMSO. Kinetics studies and computational investigations support a tailorable cobalt complex reactivity mainly altered by steric factors of the α-diimine ligands. Faculdade de Ciências e Tecnologia UNESP Universidade Estadual Paulista Instituto de Química UFU Universidade Federal de Uberlândia Instituto de Física de São Carlos USP Universidade de São Paulo Instituto de Química de São Carlos USP Universidade de São Paulo Faculdade de Ciências e Tecnologia UNESP Universidade Estadual Paulista

Made available in DSpace on 2018-12-11T16:52:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Dimethyl sulfoxide ruthenium(II) complexes of N-heterocyclic carbenes derived from cycloalkylamines (cycloalkyl = cyclopentyl (1a), cyclohexyl (1b), cycloheptyl (1c), and cyclooctyl (1d)) were synthesized: [RuCl2(S-dmso)2(IPent)] (2a), [RuCl2(S-dmso)2(IHex)] (2b), [RuCl2(S-dmso)2(IHept)] (2c), and [RuCl2(S-dmso)2(IOct)] (2d). The imidazolium salts 1a-1d were characterized by FTIR, UV–vis, and 1H and 13C NMR spectroscopy, while their respective dimethyl sulfoxide ruthenium(II) complexes (2a-2d) were characterized by elemental analysis, FTIR, UV–vis, 1H and 13C NMR, and cyclic voltammetry. The complexes 2a-2d were evaluated as catalytic precursors for ROMP of norbornene (NBE) and for ATRP of methyl methacrylate (MMA). The polynorbornene (polyNBE) syntheses via ROMP using the complexes 2a-2d as pre-catalysts were evaluated under reaction conditions of [EDA]/[Ru] = 28 (5 μL), [NBE]/[Ru] = 5000 at 50 °C as a function of time. The polymerization of MMA via ATRP was conducted using the complexes 2a-2d in the presence of ethyl 2-bromoisobutyrate (EBiB) as the initiator. All tests were using the molar ratio [MMA]/[EBiB]/[Ru] = 1000/2/1 and conducted at 85 °C. The linear correlation of ln([MMA]0/[MMA]) and time clearly indicates that the concentration of radicals remains constant during the polymerization and that the ATRP of MMA mediated by 2a-2d proceeds in a controlled manner. Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista, CEP 19060-900 Instituto de Química de São Carlos Universidade de São Paulo, CEP 13560-970 Instituto de Química UFU Universidade Federal de Uberlândia, CEP 38400-902 Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista, CEP 19060-900

Olefin metathesis of ethyl linoleate (EL) was investigated under different conditions of substrate amount, temperature, and catalyst. Second-generation Grubbs catalyst (G2) was used in experiments at 20 and 50 ºC for 24 and 48h, whereas first-generation Grubbs catalyst (G1) and [RuCl2(PPh3)2perhydroazepine] (LN) were used in experiments at 50 ºC for 24h, with the latter also being investigated in the presence or absence of SnCl2 as co-catalyst. Catalytic products were analyzed for GC-MS and discussed in terms of relative percent of the metathesis products. With G2 as catalyst, GC-MS chromatograms were similar in all the amounts of EL investigated at 50 ºC for 24h, except for ethyl hexadec-9-enoate (compound K), which was obtained with different percentage as a function of EL amount (55% for 2 and 5 mL and 65% for 8 mL). An α,ω-dicarboxylic acid with m/z = 444.00 (compound L) was produced from the experiments at 50 ºC for 24h with similar percentage as a function of EL amount. However, the relative percentage of L changed with the increase of EL volume in the experiments at 20 ºC (ca. 18, 27, and 28%, with 2, 5, and 8 mL of EL, respectively). The olefin metathesis of EL conducted by G1 reached lower selectivity than that conducted by G2 for 24h at 50 ºC. Several intense peaks reached with G1 were similar to those obtained with G2, in addition to new peaks of medium intensity. Compound L showed higher m/z, similar to that presented with G2, but with lower relative proportion in the mixture. LN was inert for olefin metathesis of EL; however, it was activated in the presence of SnCl2 at 50 ºC for 24h. Different compounds and selectivity as a function of the catalyst type and reaction conditions were obtained.

Made available in DSpace on 2018-11-26T15:44:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-01-01. Added 1 bitstream(s) on 2019-10-09T18:25:15Z : No. of bitstreams: 1 S0103-50532017000801407.pdf: 978649 bytes, checksum: ec9cc05b528c82635d0a00ddee6abbb0 (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Prope Ruthenium benzylidene complexes were evaluated as catalysts in atom-transfer radical polymerization (ATRP) of methyl methacrylate (MMA) under different reaction conditions. The mechanism by which Grubbs 1st and 2nd generation catalysts mediate olefin metathesis has been studied, little is known regarding the mechanism of ATRP reaction promoted by these complexes. Conversion and semilogarithmic kinetic plots as a function of time were correlated to the different catalysts and reaction conditions; especially in the presence of Al(OiPr)(3) as additive. Molecular weight (M-n) and polydispersity index (PDI) values changed with different catalysts in the presence or absence of Al(OiPr)(3). Kinetic studies by H-1 NMR revealed that two complexes in the presence of Al(OiPr)(3) are converted into ATRP-active with the dissociation of PCy3, but with the benzylidene group preserved. More controlled polymerizations were achieved using Grubbs 1st and, the presence of Al(OiPr)(3) improved the control levels for both catalysts. Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil Univ Estadual Piaui, GERATEC, Dept Quim, BR-64002150 Teresina, PI, Brazil Univ Estadual Paulista, Fac Ciencias & Tecnol, BR-19060900 Presidente Prudente, SP, Brazil FAPESP: 2013/10002-0 Prope: 2180/002/14-PROPe/CDC

Made available in DSpace on 2018-12-11T16:50:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-10-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Atom transfer radical polymerizations (ATRP) of styrene (St) and methyl methacrylate (MMA) mediated by [RuCl2(PPh3)2(amine)] complexes, with amine = pyrrolidine (1), piperidine (2), or perhydroazepine (3), were investigated as a function of time, temperature, and concentrations of monomers and 2-bromoisobutyrate as initiator. The plots of ln([M]0/[M]) vs. time and molecular weights vs. monomer conversion were linear and the dispersity indexes decreased with increasing monomer conversions. The complexes 1, 2, and 3 were able to mediate the polymerizations with acceptable rate and level of control. Differences in the rate and control of polymerization were observed in the order 3 > 2 > 1 for both monomers. The activities were discussed considering the steric hindrance and electronic characteristics of the amines as ancillary ligands in the metal centres, considering studies by cyclic voltammetry and NMR. Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista Instituto de Química de São Carlos Universidade de São Paulo Centro de Ciências da Natureza Universidade Estadual do Piauí Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista FAPESP: 2013/10002-0

Made available in DSpace on 2022-04-28T18:59:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-01 [RuCl2(S-DMSO)2(X-py)2] type complexes, with X = H (1), 4-CONH2 (2), or 3-CONH2 (3), exhibited trans,cis,cis conformational isomer (species A), with additional cis,cis,cis isomer type (species B) for 1. Electronic spectra with bands in the wavelength range of 270-450 nm were unchanged for 120 min at 25 °C in CH3CN. Irradiation at 350 nm provided replacement of DMSO ligands by CH3CN solvent molecules. Cyclic voltammetry studies in CH3CN revealed an electrochemical-chemical process with a Ru-(S-DMSO) to Ru-(O-DMSO) linkage isomerization for species B from 1. The complexes were inactive for the ring-opening metathesis polymerization (ROMP) of norbornene (NBE) for 60 min at 25°C. However, polyNBE was produced by aging the complex solutions for 90-200 min at 25°C, raising the temperature to 50°C, irradiating the solutions at 350 nm for 5-10 min or when the complexes were in the presence of NBu4ClO4. © 2014 Elsevier B.V. All rights reserved. Instituto de Química de São Carlos Universidade de São Paulo, P.O. Box 780, 13560-970 São Carlos, SP Faculdade de Ciencias e Tecnologia Universidade Estadual Paulista, 19060-900 Presidente Prudente, SP Faculdade de Ciencias e Tecnologia Universidade Estadual Paulista, 19060-900 Presidente Prudente, SP

Made available in DSpace on 2019-10-06T15:52:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A series of [RuCl(dppb)(μ-Cl)3Ru(dppb)(amine)] complexes, where amine is pyrrolidine (1), piperidine (2) or perhydroazepine (3), were synthesized and characterized by elemental analysis, FTIR, UV–Vis, and 1H, 13C{1H} and 31P{1H} NMR spectroscopy. The electrochemistry properties of the complexes 1–3 were investigated by cyclic voltammetry and exhibited two successive single-electron oxidation processes. The presence of two redox pairs suggests the formation of a dimeric species in which two different fragments, {Ru(amine)(dppb)} and {RuCl(dppb)}, were connected via three μ-chloro bridges. The complexes 1–3 were evaluated as catalytic precursors for ROMP of norbornene (NBE) and norbornadiene (NBD), as well as for ATRP of methyl methacrylate (MMA). The polynorbornene (polyNBE) syntheses via ROMP using the complexes 1–3 as pre-catalysts were assessed under reaction conditions of [EDA]/[Ru] = 28 (5 μL) and [NBE]/[Ru] = 5000 as a function of time at 25 or 50 °C. Polymerization of MMA via ATRP was conducted using the complexes 1–3 in the presence of ethyl 2-bromoisobutyrate (EBiB) as initiator. Differences in the catalytic activities and polymerization controls were observed in the order 3 > 2 > 1 for both reactions. The activities were discussed considering the steric hindrance and electronic characteristics of the amines as ancillary ligands in the metal center using cyclic voltammetry and NMR studies. Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista Instituto de Química de São Carlos Universidade de São Paulo Instituto de Química Universidade Federal de Uberlândia, P.O. Box 593 Instituto de Ciências Exatas e Naturais Do Pontal Universidade Federal de Uberlândia, Rua Vinte, 1600 Faculdade de Ciências e Tecnologia UNESP Univ Estadual Paulista CAPES: 001 FAPESP: 2017/06329-5 FAPESP: 2018/06340-1

The [RuCl3(PCy3)2] complex presented high reactivity toward ring opening metathesis polymerization (ROMP) of norbornadiene (NBD) in a non-degassed solution upon addition of ethyl diazoacetate (EDA). Quantitative yields of polyNBD were obtained instantaneously at 25 °C. ROMP of norbornene (NBE) occurred better at 50 °C for 60 min, with 95% of isolated polyNBE. Copolymers with different porous structures were obtained from ROMP of NBE in the presence of NBD with different starting [NBE]/[NBD] molar ratios at 25 °C. SEM micrographs showed a more organized porous structure as the NBD loading decreased. A well-defined honeycomb-like pattern was recorded for the copolymer from the run with an NBE : NBD molar ratio load of 5000 : 500. The Tg values varied from 37 °C in polyNBE to 90 °C in poly[NBE-co-NBD] as the NBD loading increased.

Ring Opening Metathesis Polymerization (ROMP) of cyclic olefins is a powerful transition metal-catalyzed reaction for syntheses of polymers and copolymers. The key feature of this reaction is the [2+2]-cycloaddition mechanism, with retention of the olefinic unsaturation in the polymer chain and occurrence of living polymerization. With the development of metal-carbene type catalysts for this process, many addressed polymeric materials have been successfully prepared to be employed in several fields of the science and technology. This review summarizes recent examples of syntheses of polymers with amphiphilic features such as block, graft, brush or star copolymers; as well syntheses of biomaterials, dendronized architectures, photoactive polymers, cross-linked or self-healing materials, and polymers from renewed supplies.

The reactivity of the new complex [RuCl2(PPh3)2(3,5-Me2piperidine)], complex 1, was investigated for ring opening metathesis polymerization (ROMP) of norbornene (NBE) and norbornadiene (NBD) in the presence of ethyl diazoacetate (EDA) in CHCl3. The aim is to observe the combination of PPh3 and an amine as ancillary ligands concerning the steric hindrance and the electronic perturbation in the properties of the N-bound site when replacing the amines. Thus, the results with 1 were compared to the results obtained when the amine is piperidine (complex 2). Reaction with 1 provides 70% yield of isolated polyNBE (Mn = 8.3 × 104 g/mol; PDI = 2.03), whereas 2 provides quantitative reaction (Mn = 1.2 × 105 g/mol; PDI = 1.90) with [NBE]/[Ru] = 5000, [EDA]/[Ru] = 48 and 1.1 μmol of Ru for 5 min at 25 °C. The resulting polymers showed c.a. 62% of trans-polyNBE, determined by 1H NMR, and Tg = 32 °C, determined by DSC and DMTA. For ROMP of NBD, 1 showed quantitative yield with PDI = 2.62 when [NBD]/[Ru] = 5000 for 20 min at 25 °C, whereas the reaction with 2 reached 55% with PDI = 2.16 in the same conditions. It is concluded that the presence of the two methyl groups in the piperidine ring provides an increase in the induction period to produce the Ru-carbene species justifying better polyNBE results with 2, and a greater amine ⟶ σ Ru ⟶ π monomer synergism which contributed to the best activation of less tensioned olefin as NBD.

The novel [RuCl 2 (PPh 3 ) 2 (4-CH 2 R-pip)] complexes, with R = H (complex 1 ), Ph ( 2 ) or OH ( 3 ), were synthesized and applied as initiators for ROMP of norbornene (NBE) and norbornadiene (NBD) under different reaction times, temperatures and monomer concentrations. There is a clear difference in the homopolymer yields in the order 1 > 2 > 3 at [monomer]/[Ru] molar ratio of 5000, at 25 °C for 5–60 min. Difference in the yields tends to disappear at 50 °C, with quantitative yields for 15–30 min with any type of initiator. Results from copolymers obtained at RT for 60 min from fixed amounts of NBE with four different amounts of NBD suggest that the type of initiator also affects the reactions, with more insertion of NBD with 1 . The occurrence of cross-linking enhanced as the NBD loading increased, evidenced by decrease in the M c and increase in the T g values, besides the influence of the type of initiator.

Copolymers of norbornene (NBE) with norbornadiene (NBD) were obtained via ROMP with [RuCl2(PPh3)2(L)] type complexes as initiators (1 for L = piperidine and 2 for L = 3,5-Me2piperidine). The reactions were performed using a fixed quantity of NBE (5000 equivalents/[Ru]) for different concentrations of NBD (500, 1000, 1500 and 2000 equivalents/[Ru]) in CHCl3, initiated with ethyl diazoacetate at room temperature. The presence of NBD in the NBE chains was characterized by 1H and 13C NMR. Whereas the copolymer microstructure was influenced neither by the NBD quantity nor by the initiator type, the Mn and PDI values were improved when increasing the NBD quantity in the medium. When raising the NBD amount, DMA results indicated increased cross-linking with increasing Tg and E′ storage modulus, as well as the fact that SEM micrographs indicated decreased pore sizes in the porous isolated copolymers.

The ring-opening metathesis polymerization (ROMP) of norbornene (NBE) occurs in the presence of the fac-[RuCl2(S-DMSO)3(O-DMSO)] complex and ethyldiazoacetate (5 μL), where DMSO is S- or O-bonded dimethylsulfoxide. The yield is 62% (PDI = 1.64) at room temperature for 5 min and 88% (PDI = 1.93) at 50 ºC for 30 min, with [NBE]/[Ru] = 516 in CHCl3. The yield is 90% (PDI = 1.64) in the presence of NBu4ClO4 at room temperature for 5 min. The complex is practically inactive when one or two molecules of DMSO are replaced by pyridine, imidazole, 2-methyl-imidazole or benzimidazole. The in situ formation of the catalytic species and the behavior of the DMSO molecules as ancillary ligands in the reactivity of the RuII complexes are discussed. A polimerização via metátese por abertura de anel (ROMP) de norborneno (NBE) ocorre em presença do complexo fac-[RuCl2(S-DMSO)3(O-DMSO)] e etildiazoacetato (5 μL), onde DMSO é dimetilsulfóxido coordenado pelo átomo de enxofre ou de oxigênio. O rendimento é 62% (PDI = 1,64) à temperatura ambiente por 5 min e 88% (PDI = 1,93) a 50 ºC por 30 min, com [NBE]/[Ru] = 516 em CHCl3. Na presença de NBu4ClO4 o rendimento é 90% (PDI = 1,64) à temperatura ambiente por 5 min. O complexo é praticamente inativo quando uma ou duas moléculas de DMSO são substituídas por piridina, imidazol, 2-metil-imidazol ou benzoimidazol. A formação in situ da espécie catalítica e os comportamentos das moléculas de DMSO como ligantes ancilares nas reatividades dos complexos de RuII são discutidas nesse trabalho.