Pressure-Induced Polymerization: Addition and Condensation Reactions

Under pressure of 1–100 GPa, unsaturated organic molecules tend to form covalent bond to each other for a negative enthalpy change, which often produces polymeric materials with extended carbon skeleton. The polymerization reactions typically happen in crystal, which promotes the topochemical process. This review summarized the topochemical polymerization processes of several alkynes, aromatics, and alkynylphenyl compounds, including the critical crystal structures before the reaction, bonding process, and the structure of the products. Secondly, this review also summarized the condensation reaction identified in the polymerization process, including the elimination of small molecules such as NH3, etc.

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The Influence of Disorder in the Synthesis, Characterization and Applications of a Modifiable Two-Dimensional Covalent Organic Framework

Materials ◽

10.3390/ma14010071 ◽

2020 ◽

Vol 14 (1) ◽

pp. 71

Author(s):

Jordan Brophy ◽

Kyle Summerfield ◽

Jiashi Yin ◽

Jon Kephart ◽

Joshua T. Stecher ◽

...

Keyword(s):

Monte Carlo Simulation ◽

Small Molecules ◽

Condensation Reaction ◽

3D Structure ◽

Polymerization Process ◽

Two Dimensional ◽

Porous Structures ◽

Substitution Reactions ◽

The Past ◽

2D And 3D

Two-dimensional covalent organic frameworks (2D-COFs) have been of increasing interest in the past decade due to their porous structures that ideally can be highly ordered. One of the most common routes to these polymers relies on Schiff-base chemistry, i.e., the condensation reaction between a carbonyl and an amine. In this report, we elaborate on the condensation of 3,6-dibromobenzene-1,2,4,5-tetraamine with hexaketocyclohexane (HKH) and the subsequent carbonylation of the resulting COF, along with the possibility that the condensation reaction on HKH can result in a trans configuration resulting in the formation of a disordered 2D-COF. This strategy enables modification of COFs via bromine substitution reactions to place functional groups within the pores of the materials. Ion-sieving measurements using membranes from this COF, reaction of small molecules with unreacted keto groups along with modeling studies indicate disorder in the COF polymerization process. We also present a Monte Carlo simulation that demonstrates the influence of even small amounts of disorder upon both the 2D and 3D structure of the resulting COF.

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Ligand Exchange Reaction in [Co4O4]-Cobalt Cubane: A Versatile Strategy Towards the Preparation of Cobalt Cubane-based Functional Small Molecules and Polymeric Materials

Journal of Molecular Structure ◽

10.1016/j.molstruc.2021.130216 ◽

2021 ◽

Vol 1235 ◽

pp. 130216 ◽

Cited By ~ 1

Author(s):

Muhammad Waqas Ishaq ◽

Raziq Nawaz ◽

Abdul Jalil ◽

Muhammad Ali Hashmi ◽

Tao Zheng ◽

...

Keyword(s):

Small Molecules ◽

Exchange Reaction ◽

Ligand Exchange ◽

Polymeric Materials ◽

Ligand Exchange Reaction

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Correlations between retention volume and molecular size parameters in gel permeation chromatography of small molecules

Australian Journal of Chemistry ◽

10.1071/ch9750189 ◽

1975 ◽

Vol 28 (1) ◽

pp. 189 ◽

Cited By ~ 4

Author(s):

RA Shanks

Keyword(s):

Molecular Weight ◽

Small Molecules ◽

Organic Molecules ◽

Retention Volume ◽

Molecular Size ◽

Gel Permeation Chromatography ◽

Molar Volumes ◽

Small Organic Molecules ◽

Molecular Dimension ◽

Gel Permeation

Gel permeation columns of Bio Beads S-X8 have been used to provide separation of oligomers and other small organic molecules. Results show successful separations up to molecular weight c. 600. The retention times of compounds have been correlated with the largest molecular dimension of the molecules and also with molar volumes.

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A Model Study on the Adsorption of Small Molecules on Organic Molecules and Polymers

Integration of Fundamental Polymer Science and Technology—4 ◽

10.1007/978-94-009-0767-6_48 ◽

1990 ◽

pp. 387-391

Author(s):

Shang Zhang Liu ◽

Yang Gao ◽

Lin You Wu ◽

Bao Qiang Yu ◽

Shu Min Jiang

Keyword(s):

Small Molecules ◽

Organic Molecules ◽

Model Study

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Molecular evolution pathways during nucleation of small organic molecules: solute-rich pre-nucleation species enable control over the nucleation process

Physical Chemistry Chemical Physics ◽

10.1039/d0cp03493b ◽

2020 ◽

Vol 22 (33) ◽

pp. 18663-18671

Author(s):

Shuyi Zong ◽

Jingkang Wang ◽

Xin Huang ◽

Ting Wang ◽

Qi Liu ◽

...

Keyword(s):

Molecular Evolution ◽

Small Molecules ◽

Organic Molecules ◽

Nucleation Process ◽

Small Organic Molecules

The pre-nucleation clusters played a key role in the process of crystallization of organic small molecules, indicating that the dynamics of nucleation could be regulated by changing the structure and size of the pre-nucleation clusters.

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A unified picture of the covalent bond within quantum-accurate force fields: From organic molecules to metallic complexes’ reactivity

Science Advances ◽

10.1126/sciadv.aaw2210 ◽

2019 ◽

Vol 5 (5) ◽

pp. eaaw2210 ◽

Cited By ~ 12

Author(s):

Alessandro Lunghi ◽

Stefano Sanvito

Keyword(s):

Organic Molecules ◽

Energy Surface ◽

Force Fields ◽

Covalent Bond ◽

Organometallic Compounds ◽

Molecular Systems ◽

Physical Chemical ◽

Atomistic Models ◽

General Potential ◽

Unified Description

Computational studies of chemical processes taking place over extended size and time scales are inaccessible by electronic structure theories and can be tackled only by atomistic models such as force fields. These have evolved over the years to describe the most diverse systems. However, as we improve the performance of a force field for a particular physical/chemical situation, we are also moving away from a unified description. Here, we demonstrate that a unified picture of the covalent bond is achievable within the framework of machine learning–based force fields. Ridge regression, together with a representation of the atomic environment in terms of bispectrum components, can be used to map a general potential energy surface for molecular systems at chemical accuracy. This protocol sets the ground for the generation of an accurate and universal class of potentials for both organic and organometallic compounds with no specific assumptions on the chemistry involved.

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Molecular Modeling Investigations of Sorption and Diffusion of Small Molecules in Glassy Polymers

Membranes ◽

10.3390/membranes9080098 ◽

2019 ◽

Vol 9 (8) ◽

pp. 98 ◽

Cited By ~ 11

Author(s):

Niki Vergadou ◽

Doros N. Theodorou

Keyword(s):

Small Molecules ◽

Molecular Simulation ◽

Glassy Polymer ◽

Polymeric Materials ◽

Gas Separations ◽

Polymeric Systems ◽

Wide Range ◽

Multiscale Problem ◽

Polymer Configurations ◽

And Diffusion

With a wide range of applications, from energy and environmental engineering, such as in gas separations and water purification, to biomedical engineering and packaging, glassy polymeric materials remain in the core of novel membrane and state-of the art barrier technologies. This review focuses on molecular simulation methodologies implemented for the study of sorption and diffusion of small molecules in dense glassy polymeric systems. Basic concepts are introduced and systematic methods for the generation of realistic polymer configurations are briefly presented. Challenges related to the long length and time scale phenomena that govern the permeation process in the glassy polymer matrix are described and molecular simulation approaches developed to address the multiscale problem at hand are discussed.

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Intrinsic reactivity of a uranium metallacyclopropene toward unsaturated organic molecules

Dalton Transactions ◽

10.1039/c6dt03005j ◽

2016 ◽

Vol 45 (41) ◽

pp. 16441-16452 ◽

Cited By ~ 22

Author(s):

Lei Zhang ◽

Bo Fang ◽

Guohua Hou ◽

Lin Ai ◽

Wanjian Ding ◽

...

Keyword(s):

Electron Transfer ◽

Small Molecules ◽

Organic Molecules ◽

Transfer Processes ◽

Electron Transfer Processes ◽

Intrinsic Reactivity

A uranium metallacyclopropene shows a rich chemistry in the activation of small molecules by two electron transfer processes.

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Novel Approaches to Nanopatterning: From Surface Monolayer Initiated Polymerization to Hybrid Organometallic-Organic Bilayers

MRS Proceedings ◽

10.1557/proc-705-y2.6 ◽

2001 ◽

Vol 705 ◽

Author(s):

Clifford L. Henderson ◽

Sean Barstow ◽

Augustin Jeyakumar ◽

Kendra McCoy ◽

Dennis W. Hess ◽

...

Keyword(s):

Barrier Layer ◽

Photoelectron Spectroscopy ◽

Single Layer ◽

Polymeric Materials ◽

Polymerization Process ◽

Precursor Film ◽

Imaging Method ◽

Surface Imaging ◽

Imaging Methods ◽

Organometallic Precursor

AbstractThe extendability of conventional subtractive lithographic processing using spin-coated polymeric single layer resists (SLR) faces many challenges as feature sizes in microelectronics push below 100 nm. In addition, the opacity of the polymeric materials traditionally used as SLR resins to future exposure sources presents new challenges as the radiation penetration depth decreases (e.g. 157 nm, EUVL, low keV e-beam). One solution to these problems is the use of surface imaging materials and processes. In such surface imaging methods, exposure in only a thin surface layer is used to create a pattern in a substantially thicker etch barrier layer. Conventional surface imaging approaches have mainly focused on silylation techniques which have experienced a variety of problems. This paper presents an update on two novel surface imaging methods under investigation: (1) surface monolayer initiated polymerization (SMIP) and (2) organometallic-organic bilayer resists.The SMIP process involves using a monolayer that contains a polymerization initiator functionality. Exposure of the monolayer to radiation can deactivate the initiators in selected areas and the remaining initiators can subsequently be used to directly grow patterned polymer structures. This process allows complete decoupling of the imaging properties of the monolayer from the etch properties of the polymer etch barrier. In essence, the polymerization process is used to amplify the pattern initially formed in the monolayer. Recent results are presented that demonstrate the use of x-ray photoelectron spectroscopy in conjunction with dose array experiments to analyze the sensitivity of the initiators used for this process.The other novel surface imaging method presented in this work uses organometallic-organic bilayers. In these systems, thin films of radiation sensitive organometallic precursors are used as an imaging layer in conjunction with thick organic etch barrier layers. Upon exposure, the organometallic precursor film is selectively converted to metal oxide. After exposure, the unexposed regions of the film can be developed away. Subsequent dry pattern transfer in an oxygen plasma can be used to transfer the pattern defined in the thin oxide layer through the organic etch barrier layer. Organometallic precursor films with sensitivities on the order of 70 μC/cm2 are demonstrated which result in oxide films that possess an etch selectivity of 100:1 with respect to novolac in oxygen plasmas. 500 nm line-space patterns are demonstrated as a first lithographic imaging proof-of-concept.

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