TY - JOUR
T1 - The ring size of cyclic amines as a relevant feature in the activity of Ru-based complexes for ROMP
AU - Fonseca, Larissa R.
AU - Nascimento, Eduardo S.P.
AU - Silva Sá, José L.
AU - Lima-Neto, Benedito S.
N1 - Publisher Copyright:
© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.
PY - 2015/5/1
Y1 - 2015/5/1
N2 - The novel complex [RuCl2(PPh3)2(pyrrolidine)] exhibited a square pyramidal (SQP) type geometry, with the amine in the apical position and trans-positioned phosphines. There was activity observed for ROMP of norbornene (NBE) either under air or an inert atmosphere of argon at 25 °C. Saturation profile-fitting describes the curves of yields as a function of time (5-120 min) under either atmosphere. The results were sensitive to the solution volume in the range of 2-8 mL of CHCl3, mainly under air. Quantitative yields under argon for 120 min at any solution volume were obtained. The order of magnitude of 103-105 g mol-1 for Mw and PDI values ranging from 1.6 to 3.5 was measured by SEC. In most of the cases, the ratios of yields from the runs under argon and air were close to the unit, indicating an insignificant loss of reactivity of the active species in the presence of molecular oxygen from air. A parent complex with diethylamine, but with trigonal bipyramidal (TBP) type geometry, was inactive for ROMP. The activity in these types of complexes was compared with that of already reported Ru-amine-based complexes in terms of electronic effects, with an additional discussion involving the synergism in the novel ttt-[RuCl2(PPh3)2(perhydroazepine)(isonicotinamide)] complex.
AB - The novel complex [RuCl2(PPh3)2(pyrrolidine)] exhibited a square pyramidal (SQP) type geometry, with the amine in the apical position and trans-positioned phosphines. There was activity observed for ROMP of norbornene (NBE) either under air or an inert atmosphere of argon at 25 °C. Saturation profile-fitting describes the curves of yields as a function of time (5-120 min) under either atmosphere. The results were sensitive to the solution volume in the range of 2-8 mL of CHCl3, mainly under air. Quantitative yields under argon for 120 min at any solution volume were obtained. The order of magnitude of 103-105 g mol-1 for Mw and PDI values ranging from 1.6 to 3.5 was measured by SEC. In most of the cases, the ratios of yields from the runs under argon and air were close to the unit, indicating an insignificant loss of reactivity of the active species in the presence of molecular oxygen from air. A parent complex with diethylamine, but with trigonal bipyramidal (TBP) type geometry, was inactive for ROMP. The activity in these types of complexes was compared with that of already reported Ru-amine-based complexes in terms of electronic effects, with an additional discussion involving the synergism in the novel ttt-[RuCl2(PPh3)2(perhydroazepine)(isonicotinamide)] complex.
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U2 - 10.1039/c5nj00321k
DO - 10.1039/c5nj00321k
M3 - Article
AN - SCOPUS:84928999896
SN - 1144-0546
VL - 39
SP - 4063
EP - 4069
JO - New Journal of Chemistry
JF - New Journal of Chemistry
IS - 5
ER -