Asymmetric catalytic routes to chiral building blocks of
... Department of Chemistry, Duke University, Durham, NC 27706 Abstract: Asymmetric hydrogenation reactions can provide practical access to a diverse array of chiral building blocks. We have developed a variety of highly selective rhodium and ruthenium hydrogenation catalysts based on chiral 1,2-bis(pho ...
... Department of Chemistry, Duke University, Durham, NC 27706 Abstract: Asymmetric hydrogenation reactions can provide practical access to a diverse array of chiral building blocks. We have developed a variety of highly selective rhodium and ruthenium hydrogenation catalysts based on chiral 1,2-bis(pho ...
High-Accuracy Temperature Measurements Call for Platinum
... For measurements at a distance and with dissimilar lead wires, the 4-wire approach of Figure 1a (Kelvin connection) gives the most accurate results. In this approach the current-carrying wires are separated from the measurement wires; OUT1 provides a 200µA source for the PRTD and OUT2 remains floati ...
... For measurements at a distance and with dissimilar lead wires, the 4-wire approach of Figure 1a (Kelvin connection) gives the most accurate results. In this approach the current-carrying wires are separated from the measurement wires; OUT1 provides a 200µA source for the PRTD and OUT2 remains floati ...
WRL3502.tmp
... General Concepts Alkyl halides are most commonly synthesized from alcohols by replacing the hydroxyl group with a halide substituent. This is an example of nucleophilic aliphatic substitution, which is part of a very important group of reactions. The overall reaction is the same, but the mechanism v ...
... General Concepts Alkyl halides are most commonly synthesized from alcohols by replacing the hydroxyl group with a halide substituent. This is an example of nucleophilic aliphatic substitution, which is part of a very important group of reactions. The overall reaction is the same, but the mechanism v ...
Cyclic Voltammetry 1..
... •The cyclic voltammograms represented with the dashed lines are those obtained with electrical stimulation. ...
... •The cyclic voltammograms represented with the dashed lines are those obtained with electrical stimulation. ...
A-level Chemistry Question paper Unit 4 - Further Physical
... (c) State the effect of an increase in temperature on the position of this equilibrium and on the value of Kc for this reaction. Effect on position of equilibrium ....................................................................................... Effect on the value of Kc ....................... ...
... (c) State the effect of an increase in temperature on the position of this equilibrium and on the value of Kc for this reaction. Effect on position of equilibrium ....................................................................................... Effect on the value of Kc ....................... ...
Topic 19 notes - A
... Addition polymers (polyalkenes) are long chain hydrocarbons which are saturated and non-polar. Their structure results in their having a number of characteristic properties: a) Since the hydrocarbon chains are often very long, the Van der Waal's forces between the chains are often very strong and th ...
... Addition polymers (polyalkenes) are long chain hydrocarbons which are saturated and non-polar. Their structure results in their having a number of characteristic properties: a) Since the hydrocarbon chains are often very long, the Van der Waal's forces between the chains are often very strong and th ...
CH 3
... All enantiomers have a stereogenic center carbon. This makes the molecule chiral having a non-superimposable mirror image. When we name these enantiomers it is necessary to distinguish them from one another. As it turns out each enantiomer in the pair has opposite configuration. Configuration is th ...
... All enantiomers have a stereogenic center carbon. This makes the molecule chiral having a non-superimposable mirror image. When we name these enantiomers it is necessary to distinguish them from one another. As it turns out each enantiomer in the pair has opposite configuration. Configuration is th ...
SPH3U1: ELECTRICITY AND MAGNETISM TEST Answer Section
... ____ 19. An electric toaster draws 5.00 A from a 120-V outlet for 3.0 h. If electricity costs 9.90¢ per kilowatt hour, the total cost would be a. $0.18 d. $18.00 b. $1.80 e. $20.20 c. $6.00 ____ 20. Two separate wires are placed side by side. When a current travels through them, they repel one anoth ...
... ____ 19. An electric toaster draws 5.00 A from a 120-V outlet for 3.0 h. If electricity costs 9.90¢ per kilowatt hour, the total cost would be a. $0.18 d. $18.00 b. $1.80 e. $20.20 c. $6.00 ____ 20. Two separate wires are placed side by side. When a current travels through them, they repel one anoth ...
Lecture 1: Electrical properties of materials 1 Introduction
... (b) after an electron excitation from the valence band into the conduction band, in which both a free electron and a hole are generated. 4.1 Ohm’s Law One of the most important electrical characteristics of a solid material is the ease with which it transmits an electric current. Ohm’s law relates t ...
... (b) after an electron excitation from the valence band into the conduction band, in which both a free electron and a hole are generated. 4.1 Ohm’s Law One of the most important electrical characteristics of a solid material is the ease with which it transmits an electric current. Ohm’s law relates t ...
Unit 3 review - SD43 Teacher Sites
... b) How would you investigate what other fruits or vegetables share this property? 33. What is the relationship between the resistance and the power rating of an electrical device connected to a constant potential difference? (Hint: Use the equations P=IV and V=IR to answer the question. You may need ...
... b) How would you investigate what other fruits or vegetables share this property? 33. What is the relationship between the resistance and the power rating of an electrical device connected to a constant potential difference? (Hint: Use the equations P=IV and V=IR to answer the question. You may need ...
Supported Homogeneous Catalysts
... the polymer support is the most important feature of the work with titanocene (23). A necessary feature of a homogeneous catalyst is the existence of a free coordination site on the metal atom to which alkene molecules can attach themselves. Often attempts to produce a free site results in polymeris ...
... the polymer support is the most important feature of the work with titanocene (23). A necessary feature of a homogeneous catalyst is the existence of a free coordination site on the metal atom to which alkene molecules can attach themselves. Often attempts to produce a free site results in polymeris ...
chapter twenty-two organic and biological molecules
... When the two strands of a DNA molecule are compared, it is found that a given base in one strand is always found paired with a particular base in the other strand. Because of the shapes and side atoms along the rings of the nitrogen bases, only certain pairs are able to approach and hydrogen bond wi ...
... When the two strands of a DNA molecule are compared, it is found that a given base in one strand is always found paired with a particular base in the other strand. Because of the shapes and side atoms along the rings of the nitrogen bases, only certain pairs are able to approach and hydrogen bond wi ...
EE2010 - Second Mid Term Exam Model Answer
... For the circuit shown in Figure (3-A), find the following: (a) Find the average power dissipated in the line in Figure (3). (b) Find the capacitive reactance that when connected in parallel with the load will make the load look purely resistive. (c) What is the equivalent impedance of the load in (b ...
... For the circuit shown in Figure (3-A), find the following: (a) Find the average power dissipated in the line in Figure (3). (b) Find the capacitive reactance that when connected in parallel with the load will make the load look purely resistive. (c) What is the equivalent impedance of the load in (b ...
Metalloradicals
... the reaction mixture of CoII(3,5-DitBu-ChenPhyrin) with EDA by EPR spectroscopy. The electronic structure of C is noteworthy. The species is a carbon-centered radical and is best described as a one-electron-reduced Fischer-type carbene. These results clearly underline the general importance of redox ...
... the reaction mixture of CoII(3,5-DitBu-ChenPhyrin) with EDA by EPR spectroscopy. The electronic structure of C is noteworthy. The species is a carbon-centered radical and is best described as a one-electron-reduced Fischer-type carbene. These results clearly underline the general importance of redox ...
Practice Final
... ____ 17. ____ is chemical shorthand that uses symbols to tell what elements are in a compound and their ratios. a. formula b. bond ____ 18. ____ is any characteristic of a substance such as flammability, that indicates whether or not it can undergo a chemical change. a. change b. chemical property ...
... ____ 17. ____ is chemical shorthand that uses symbols to tell what elements are in a compound and their ratios. a. formula b. bond ____ 18. ____ is any characteristic of a substance such as flammability, that indicates whether or not it can undergo a chemical change. a. change b. chemical property ...
How Ion-Selective Electrodes Work
... There are two different types of Electrical Conductivity: 1) In Metals the electric current is carried by Electrons. 2) In Liquids the electric current is carried by Ions Every Electrochemical Process (Galvanic Cell, Electrolysis, Electro-Analysis) involves both these types of conductivity. The junc ...
... There are two different types of Electrical Conductivity: 1) In Metals the electric current is carried by Electrons. 2) In Liquids the electric current is carried by Ions Every Electrochemical Process (Galvanic Cell, Electrolysis, Electro-Analysis) involves both these types of conductivity. The junc ...
organic fra - Royal Society of Chemistry
... (suspension A) and a solution of Co(OAc)2·4H2O (62.86mg, 0.25mmol) in 4mL methanol (solution B) were degassed separately. Solution B was then added to suspension A dropwise under nitrogen atmosphere and the resulting mixture was allowed to react for 1 hour. The solvent was then removed in vacuo and ...
... (suspension A) and a solution of Co(OAc)2·4H2O (62.86mg, 0.25mmol) in 4mL methanol (solution B) were degassed separately. Solution B was then added to suspension A dropwise under nitrogen atmosphere and the resulting mixture was allowed to react for 1 hour. The solvent was then removed in vacuo and ...
Microsoft Word
... Thesis entitled "Asymmetric Dihydroxylation and Wittig-Horner approach to the Synthesis of Bioactive Molecules and Heterogeneous Catalysis for Organic Transformations" is divided into five chapters. Chapter 1: describes a brief introduction to the Sharpless Asymmetric dihydroxylation (SAD) and its a ...
... Thesis entitled "Asymmetric Dihydroxylation and Wittig-Horner approach to the Synthesis of Bioactive Molecules and Heterogeneous Catalysis for Organic Transformations" is divided into five chapters. Chapter 1: describes a brief introduction to the Sharpless Asymmetric dihydroxylation (SAD) and its a ...
Topic 8 specification content - A
... carbon-neutral fuel and give reasons why this statement is not valid ...
... carbon-neutral fuel and give reasons why this statement is not valid ...
Soil conductivity
... There are many ways for estimating the bulk relative dielectric constant, one of them with the radar itself. By using some reflection from an object at a known depth and a velocity analysis tool like the one in the GPRSoft PRO software package we can accurately find out the layer's relative dielectr ...
... There are many ways for estimating the bulk relative dielectric constant, one of them with the radar itself. By using some reflection from an object at a known depth and a velocity analysis tool like the one in the GPRSoft PRO software package we can accurately find out the layer's relative dielectr ...
Parallel Resistance, Series/Parallel Circuit Combinations, and
... current I splits into I1 and I2 and since all the charges go either up or down, the sum of the two split currents must be the same as the total current I, i.e. I=I1+I2. Figure 7: Parallel resistor circuit. How many charges go which way is determined by which path offers the least resistance. The mor ...
... current I splits into I1 and I2 and since all the charges go either up or down, the sum of the two split currents must be the same as the total current I, i.e. I=I1+I2. Figure 7: Parallel resistor circuit. How many charges go which way is determined by which path offers the least resistance. The mor ...
Physics Electromagnetism Practice Test Name
... 5. A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then a. positively charged. b. negatively charged. c. charged the same as it was. d. uncharged. ...
... 5. A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then a. positively charged. b. negatively charged. c. charged the same as it was. d. uncharged. ...
CH402 Asymmetric catalytic reactions Prof M. Wills
... Asymmetric catalysis - hydrogenation Rh-diphosphine complexes control asymmetric induction by controlling the face of the alkene which attaches to the Rh. Hydrogen is transferred, in a stepwise manner, from the metal to the alkene. The intermediate complexes are diastereoisomers of different energy ...
... Asymmetric catalysis - hydrogenation Rh-diphosphine complexes control asymmetric induction by controlling the face of the alkene which attaches to the Rh. Hydrogen is transferred, in a stepwise manner, from the metal to the alkene. The intermediate complexes are diastereoisomers of different energy ...
OXAZOLINES: THEIR SYNTHESIS AND BIOLOGICAL ACTIVITY
... high antimicrobial activities, although this effect is not observed in poly (2-ethyl-2-oxazoline)-based ...
... high antimicrobial activities, although this effect is not observed in poly (2-ethyl-2-oxazoline)-based ...
Polythiophene
Polythiophenes (PTs) are polymerized thiophenes, a sulfur heterocycle. They can become conducting when electrons are added or removed from the conjugated π-orbitals via doping. The study of polythiophenes has intensified over the last three decades. The maturation of the field of conducting polymers was confirmed by the awarding of the 2000 Nobel Prize in Chemistry to Alan J. Heeger, Alan MacDiarmid, and Hideki Shirakawa ""for the discovery and development of conductive polymers"". The most notable property of these materials, electrical conductivity, results from the delocalization of electrons along the polymer backbone – hence the term ""synthetic metals"". However, conductivity is not the only interesting property resulting from electron delocalization. The optical properties of these materials respond to environmental stimuli, with dramatic color shifts in response to changes in solvent, temperature, applied potential, and binding to other molecules. Both color changes and conductivity changes are induced by the same mechanism—twisting of the polymer backbone, disrupting conjugation—making conjugated polymers attractive as sensors that can provide a range of optical and electronic responses.A number of comprehensive reviews have been published on PTs, the earliest dating from 1981. Schopf and Koßmehl published a comprehensive review of the literature published between 1990 and 1994. Roncali surveyed electrochemical synthesis in 1992, and the electronic properties of substituted PTs in 1997. McCullough's 1998 review focussed on chemical synthesis of conducting PTs. A general review of conjugated polymers from the 1990s was conducted by Reddinger and Reynolds in 1999. Finally, Swager et al. examined conjugated-polymer-based chemical sensors in 2000. These reviews are an excellent guide to the highlights of the primary PT literature from the last two decades.