A mechanistic investigation of the Suzuki polycondensation reaction using MS/MS methods

2021 ◽  
Author(s):  
Michelle Yan Chi Ting ◽  
Lars Yunker ◽  
Ian C. Chagunda ◽  
Katherine Hatlelid ◽  
Meghan Vieweg ◽  
...  
Keyword(s):  
Catalytic Reactions ◽  
Polycondensation Reaction ◽  
Suzuki Polycondensation ◽  
Mechanistic Investigation ◽  
Reaction Proceeds

Understanding catalytic reactions is inherently difficult because not only is the catalyst the least abundant component in the mixture, but it also takes many different forms as the reaction proceeds....

scholarly journals A Mechanistic Investigation of the Suzuki Polycondensation Reaction Using MS/MS Methods

2021 ◽  
Author(s):  
Michelle Ting ◽  
Lars Yunker ◽  
Ian Chagunda ◽  
Katherine Hatlelid ◽  
Meghan Vieweg ◽  
...  
Keyword(s):  
Active Catalyst ◽  
Multiple Reaction Monitoring ◽  
Catalytic Reactions ◽  
Decomposition Products ◽  
Polymerization Catalysis ◽  
Suzuki Polycondensation ◽  
Mechanistic Investigation ◽  
Reaction Proceeds ◽  
Modern Mass ◽  
Reaction Initiation

<p>Understanding catalytic reactions is inherently difficult because not only is the catalyst the least abundant component in the mixture, but it also takes many different forms as the reaction proceeds. Precatalyst is converted into active catalyst, short-lived intermediates, resting states, and decomposition products. Polymerization catalysis is harder yet to study, because as the polymer grows the identities of these species change with every turnover as monomers are added to the chain. Modern mass spectrometric methods have proved to be up to the challenge, with multiple reaction monitoring (MRM) in conjunction with pressurized sample infusion (PSI) used to continuously probe all stages of the Suzuki polycondensation (SPC) reaction. Initiation, propagation, and termination steps were tracked in real time, and the outstanding sensitivity and low signal-to-noise of the approach has real promise with respect to the depth with which this reaction and others like it can be studied.</p>

scholarly journals A Mechanistic Investigation of the Suzuki Polycondensation Reaction Using MS/MS Methods

2021 ◽  
Author(s):  
Michelle Ting ◽  
Lars Yunker ◽  
Ian Chagunda ◽  
Katherine Hatlelid ◽  
Meghan Vieweg ◽  
...  
Keyword(s):  
Active Catalyst ◽  
Multiple Reaction Monitoring ◽  
Catalytic Reactions ◽  
Decomposition Products ◽  
Polymerization Catalysis ◽  
Suzuki Polycondensation ◽  
Mechanistic Investigation ◽  
Reaction Proceeds ◽  
Modern Mass ◽  
Reaction Initiation

<p>Understanding catalytic reactions is inherently difficult because not only is the catalyst the least abundant component in the mixture, but it also takes many different forms as the reaction proceeds. Precatalyst is converted into active catalyst, short-lived intermediates, resting states, and decomposition products. Polymerization catalysis is harder yet to study, because as the polymer grows the identities of these species change with every turnover as monomers are added to the chain. Modern mass spectrometric methods have proved to be up to the challenge, with multiple reaction monitoring (MRM) in conjunction with pressurized sample infusion (PSI) used to continuously probe all stages of the Suzuki polycondensation (SPC) reaction. Initiation, propagation, and termination steps were tracked in real time, and the outstanding sensitivity and low signal-to-noise of the approach has real promise with respect to the depth with which this reaction and others like it can be studied.</p>

scholarly journals Modeling and experimental study of polyurethane foaming and gelling reactions

2018 ◽  
Author(s):  
◽  
Luay Jaf
Keyword(s):  
Experimental Data ◽  
Foam Height ◽  
Research Process ◽  
Catalytic Reactions ◽  
Polymerization Process ◽  
Gel Point ◽  
Reaction Proceeds ◽  
Polyurethane Foaming ◽  
Kinetics Of ◽  
Insight Into

Numerous reactions take place within a polyurethane polymerization process. Homogeneous and catalytic reactions occur at the same time and intermediate compounds are formed. As the reaction proceeds, long chains of polymer are formed which drastically affect the kinetics of the reaction. Temperature and viscosity profiles of the reacting mixture are two strong indicators of the extent of reaction and the way the reactions are carried out. Therefore, simulating polyurethane gel and foam systems helps interpret temperature and viscosity profiles and gain insight into the kinetics of the system. Using MATLAB program, a model was introduced which simultaneously solves over 80 ordinary differential equations and provide temperature and viscosity profiles as well as concentration profiles, degrees of polymerization, gel point and foam height for individual formulations. Experimental data were used to validate the code showing the model is fundamentally correct. Simulation results showed good fits to the experimental data providing reaction kinetics of the system. The model was modified to simulate reaction systems with minimal change in kinetic parameters. Finally, the simulation studies of this research provide fundamental insights into mechanism of homogenous and catalytic reactions. This research process places high demands on identifying and testing highly-impacting fundamental mechanism during polymerization that have not previously been identified.

scholarly journals Novel Fluorescent Fluorene-Containing Conjugated Polymers: Synthesis, Photophysical Properties, and Application for the Detection of Common Bisphenols

Synlett ◽  
2018 ◽  
Vol 29 (19) ◽  
pp. 2515-2522 ◽  
Author(s):  
Mindy Levine ◽  
Daniel Jones ◽  
Ryan Vallee
Keyword(s):  
Conjugated Polymers ◽  
Photophysical Properties ◽  
Fluorescence Properties ◽  
Polycondensation Reaction ◽  
Suzuki Polycondensation ◽  
Nanoparticle Suspensions ◽  
Stokes Shifts

Eight new fluorescent conjugated polymers were synthesized by the Suzuki polycondensation reaction of 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester and a conjugated dihalogenated monomer. The photophysical properties of these polymers were investigated as well-dissolved solutions in chloroform and as nanoparticle suspensions in water. Several of the polymers had large Stokes shifts (greater than 100 nm) and others demonstrated unique changes in the fluorescence properties in aggregated verse nonaggregated forms. Preliminary applications of these polymers in the detection of common bisphenols are also reported.

scholarly journals Dithienopyrrole-based monomers as an acceptor unit building for synthesis of donor – acceptor conjugated polymers

2016 ◽  
Vol 19 (3) ◽  
pp. 99-107
Author(s):  
Tam Huu Nguyen ◽  
Thu Anh Nguyen ◽  
Viet Quoc Nguyen ◽  
Trung Thanh Nguyen ◽  
Ha Tran Nguyen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Magnetic Resonance ◽  
Conjugated Polymers ◽  
Fourier Transform Infrared ◽  
Polycondensation Reaction ◽  
Suzuki Polycondensation ◽  
Donor Acceptor ◽  
Ft Ir ◽  
Nuclear Magnetic

A new monomer of N-benzoyl dithieno[2,3-b:2’,3’-d]pyrrole (BDP), has been successfully prepared via copper-catalyzed amidation. Then, this monomer was brominated to form 2,6-dibromo-n-benzoyl dithieno[2,3-b:2’,3’-d]pyrrole (DiBDP) monomer. The structures of monomers were confirmed via the nuclear magnetic resonance (1HNMR) and Fourier transform infrared (FT-IR). BDP and DiBDP monomers will be used as monomers for Suzuki polycondensation reaction to synthesize the donor-acceptor (D-A) conjugated polymers.

scholarly journals Coupling photocatalytic water oxidation with organic reduction: strategy for using water to reduce organic molecules

2021 ◽  
Author(s):  
Xinzhe Tian ◽  
Yinggang Guo ◽  
Wenbo Liu ◽  
Yi Zheng ◽  
Yun-Lai Ren ◽  
...  
Keyword(s):  
Water Splitting ◽  
Water Oxidation ◽  
Organic Molecules ◽  
Reductive Coupling ◽  
Aryl Bromides ◽  
Mechanistic Investigation ◽  
Reaction Proceeds ◽  
Novel Method ◽  
High Yields ◽  
First Time

Abstract The utilization of readily available and non-toxic water by photocatalytic water splitting is highly attractive in green chemistry. Herein we report that light-induced oxidative half-reaction of water splitting is effectively coupled with reduction of organic compounds, which opens up, for the first time, an avenue to use water as an electron donor to enable reductive transformations of organic substances. The used photocatalyst (Pd/g-C3N4*) was synthetized by a novel method where Pd/g-C3N4 was irradiated by light in the presence of Na2CO3 and H2O. The present strategy allowed a series of aryl bromides to undergo the reductive coupling to provide biaryl products in low to high yields. Preliminary mechanistic investigation suggests that the reaction proceeds through the single electron transfer from Pd to aryl bromides. This work will guide chemists to use water as a reducing agent to develop green procedures for various organic reactions.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

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