Mesoionic carbene−iridium complex 1a has been investigated in the hydrogen isotope exchange (HIE) reaction of anilines. By employing 1 mol % of 1a as catalyst, anilines were selectively deuterated at the ortho-position with high deuteration levels. High ortho-selectivity was observed for anilines with various competing directing groups, which is in contrast with catalytic results of Kerr's catalysts.
In this study, we use implicit leadership theory to investigate how leader integrity, one of the most important traditional Chinese virtues, influences subordinates' organizational citizenship behaviour (OCB) in the Chinese context. The results of our survey reveal that leader integrity is associated with subordinates' OCB, and that this relationship is fully mediated by leader effectiveness. In addition, traditionality moderated the relationship between leader integrity and leader effectiveness; the relationship was significant among less traditional subordinates, but insignificant among more traditional subordinates. We conclude with a discussion of the theoretical and managerial implications for leaders in China.
Different from the traditional electrophilic polymerization
method
of thermoplastic elastomer, here, we adopted a new nucleophilic reaction
route, which did not need extreme high temperature and vacuum condition
to prepare a novel kind of semi-aromatic thermoplastic polyether amide
elastomers. First, difluoro-terminated semi-aromatic di-amide monomer
containing long chain ether (or 1,12-diaminododecane) was synthesized
through facile interfacial electrophilic substitution reaction. Then,
they were conducted to react with hydroquinone under atmospheric pressure
to yield polyether amide elastomer. Additionally, a small amount of
branched structure with trifluoro-terminated semi-aromatic amide monomer
was designed and further introduced into the polymer chain to adjust
the mechanical property. These semi-aromatic polyamide elastomers
were found to have excellent thermal properties with glass transition
temperature (T
g) of −39.5 to −34.8
°C, melting temperature (T
m) of 227.3–260.4
°C [which is much higher than that of the commercial products
such as Pebax5533 (Arkema, Paris, France) (T
m = 159 °C)], the 5% weight-loss temperature (T
d,5%) of 376.3–408.7 °C, and Vicat
softening temperature of 73.0–223.6 °C. The mechanical
properties of these resultant elastomers were good and can be controlled
with different copolymerization ratios of soft, hard, and branched
segments. The tensile strength, elongation at break, and elasticity
modulus were in the range of 9.8–23.4 MPa, 87.6–712.3%,
and 30.8–362.0 MPa, respectively. Besides, such a series of
copolymers showed a relatively low water absorption of 1.57–3.67%.
Interestingly, it was found that these resultant polyether amide elastomers
had better organic solvent resistance and acid–base corrosion
than the traditional TPAE-containing ester bond (−COO−)
in the polymer molecular chain. It can be potentially applied in the
chemical mechanical seal, especially in the high temperature and corrosion
environment.
A novel tri-acyl chloride monomer containing reductive thioether units (T-TDC) was prepared. It was conducted to partially replace trimesoyl chloride (TMC) and react with m-phenylenediamine (MPD) by interfacial polymerization to prepare a series of T-TDC/TMC/MPD copolymer thin-film-composite reverse-osmosis polyamide membranes. Through this routine, the reductive thioether units was introduced into the film molecular chain to protect amide bonds from being chlorinated by oxidizing during the membrane cleaning process. The enhanced chlorine resistance of these resultant membranes was revealed by FT-IR and XPS characterization: it could be found thioether was prior to amide oxidation, and its oxidation process can be divided into two steps (the thioether units was first converted to sulfoxide groups, and then further oxidized to sulfone groups). Through this routine, the active chlorine was consumed partially, then the amide bond was protected. The experiment result is consistent with the DFT theoretical calculation. The chlorine exposure concentration of the normalized flux and rejection decreased to 1 increased gradually with the addition of copolymerization ratio of T-TDC, especially for the sample 20%-TTDC-TFC, its chlorine exposure concentration was 3 and 4 times higher respectively than that of 0%-TTDC-TFC when its normalized flux and rejection at 1. In addition, it can be found that the polar sulfone and sulfoxide groups can form hydrogen bonds to prevent the membrane from degrading immediately. This method provides an effective way for improving the service life of RO film.
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