Applications of the Gibbs Function to Chemical Systems and Subsystems

1996 ◽  
Vol 73 (5) ◽  
pp. 404 ◽  
Author(s):  
Richard M. Noyes
Keyword(s):  
Gibbs Function ◽  
Chemical Systems

Thermodynamics of Chemical Systems

1990 ◽  
Author(s):  
Scott Emerson Wood ◽  
Rubin Battino
Keyword(s):  
Chemical Systems

Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Structure and Activity of Pentacyclic Triterpenes Codrugs. A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Justyna Żwawiak ◽  
Anna Pawełczyk ◽  
Dorota Olender ◽  
Lucjusz Zaprutko
Keyword(s):  
Biological Activities ◽  
Anticancer Activities ◽  
Drug Molecule ◽  
Pentacyclic Triterpene ◽  
Formation Pathway ◽  
Chemical Systems ◽  
Drug Molecules ◽  
Wide Range ◽  
Anti Hiv ◽  
Structure And Activity

: Triterpenes are a wide and important group of compounds that have several promising pharmacological properties, such as hepatoprotective, anti-inflammatory, anti-HIV, antioxidant, or anticancer activities. Such potent substances can be successfully incorporated in more complex chemical systems e.g. codrugs or pro-drugs that have better pharmacological profile. The codrug is connected with a drug formation pathway to chemically cohere at least two drug molecules to improve positive therapeutic efficiency or decrease side effects. The codrug can be cleaved in the organism to generate effective compounds previously used as substrates. This article presents an overview of codrugs that consist of pentacyclic triterpene moiety that is chosen as a basic codrug moiety due to their wide range of vital activities and another drug molecule fragment. It was found that triterpenoid codrugs are characterized by a wide range of biological activities. However, most of them have anticancer potency.

Virtual Work & d’Alembert’s Principle

2018 ◽  
Author(s):  
Peter Mann
Keyword(s):  
Euler Equations ◽  
Virtual Work ◽  
Lagrange Equation ◽  
Classical Mechanics ◽  
Rigid Bodies ◽  
Gibbs Function ◽  
Constraint Force ◽  
Appell Equations ◽  
Jourdain's Principle ◽  
D'alembert's Principle

This chapter discusses virtual work, returning to the Newtonian framework to derive the central Lagrange equation, using d’Alembert’s principle. It starts off with a discussion of generalised force, applied force and constraint force. Holonomic constraints and non-holonomic constraint equations are then investigated. The corresponding principles of Gauss (Gauss’s least constraint) and Jourdain are also documented and compared to d’Alembert’s approach before being generalised into the Mangeron–Deleanu principle. Kane’s equations are derived from Jourdain’s principle. The chapter closes with a detailed covering of the Gibbs–Appell equations as the most general equations in classical mechanics. Their reduction to Hamilton’s principle is examined and they are used to derive the Euler equations for rigid bodies. The chapter also discusses Hertz’s least curvature, the Gibbs function and Euler equations.

Introductory Rotational Dynamics

2018 ◽  
Author(s):  
Peter Mann
Keyword(s):  
Angular Momentum ◽  
Angular Displacement ◽  
Rigid Bodies ◽  
Rotational Dynamics ◽  
Circular Motion ◽  
Uniform Rotation ◽  
Chemical Systems ◽  
Inertial Frames ◽  
Rotating Frames ◽  
Special Case

This chapter discusses the importance of circular motion and rotations, whose applications to chemical systems are plentiful. Circular motion is the book’s first example of a special case of motion using the laws developed in previous chapters. The chapter begins with the basic definitions of circular motion; as uniform rotation around a principle axis is much easier to consider, it is the focus of this chapter and is used to develop some key ideas. The chapter discusses angular displacement, angular velocity, angular momentum, torque, rigid bodies, orbital and spin momenta, inertia tensors and non-inertial frames and explores fictitious forces as well as transformations in rotating frames.

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