Why does ethane have a higher heat capacity than ethene?
Ulrich Abram Disputation am For the investigation of electronical and sterical properties with IR spectroscopy, Ir I carbonyl complexes of the oxazoline ligands were prepared.
The application of the same Ir I metal center guaranteed a high comparability of the carbonyl complexes and the pre-catalysts for C-H activation and hydrogentation.
Furthermore, the oxazolines were applied as ligands in heteroleptic Ru II complexes for surface immobilisation. For the synthesis of box structures, a three-step procedure and for pyrox, mepyrox and quinox a two-step procedure was developed.
Both procedures were optimized to obtain high conversions and to allow easy workup of the single steps. In the first step, commercially available chiral aminols were coupled with carboxylic acids.
Since a large variety of substituted starting materials is commercially available, a comprehensive variation of the target structures is possible. Good to excellent total yields were achieved for 20 structurally related compounds which were prepared in half-gram-scale.
To prepare the complexes, [Ir cis,cis-1,5-cyclooctadiene Cl]2 was initially treated with different silver salts AgPF6, AgBF4, Ag[tetrakis 3,5-bis trifluoromethyl phenyl borate ], to exchange the chloride for a non-coordinating counterion.
Subsequently, the ligand was added to give complexes of the general composition [Ir ligand cod ]X. These complexes were converted into dicarbonyl complexes by addition of stoichiometric amounts of CO gas at atmospheric pressure. The carbonyl stretching frequencies of the square planar dicarbonyl complexes[ir ligand co 2]pf6 turned out to be mainly influenced by the steric properties of the oxazoline ligands, while trigonal bipyramidal monocarbonyl complexes [Ir ligand cis,cis-1,5-cyclooctadiene CO ]PF6 reflected more the electronical properties of the ligands.
The formation of heteroleptic Ru II complexes of the general composition [Ru oxazoline bipyridine X2] was investigated. The complexes were designed to contain an oxazoline ligand carrying the chiral information and a substituted bipyridine ligand, suitable for further functionalisation and immobilisation on an electrode surface.
If the oxazoline was introduced as first ligand, the addition of a bipyridine led to bisheteroleptic bipyridine complexes. If the oxazoline was introduced as second ligand, an inseperable mixture, probably isomers, was obtained. VII 8 The prepared oxazolines were tested as ligands in direct aromatic and aliphatic borylation.
As catalytic system [Ir cis,cis-1,5-cyclooctadiene OCH3 ]2 was used in combination with the respective ligand and bis picanolato diboron served as boron source. Aromatic borylations were carried out in the neat monosubstituted arenes such as toluene, tert-butylbenzene, anisole, cyclohexylbenzene, trifluorotoluene and ethyl benzoate.
Aliphatic borylations of n-octane and n-hexane were unsuccessful under the applied conditions. Hydridosilylether directed -C-H activation was carried out with a catalytic system of [Ir cis,cis-1,5cyclooctadiene OCH3 ]2 and an oxazoline ligand instead of the usually applied 3,4,7,8-tetramethylphenanthroline ligand.
Initially ketones or alcohols were transformed into their hydrido silyl ether derivatives, followed by a -C-H activation which led to the formation of an oxasilolane. Norbornene was added stochiometrically as hydrogen acceptor.
The hydrido silyl ether formation was optimized and the stereochemical influence of the chiral ligands in the C-H activation step was investigated. A racemic mixture of 3,7-dimethyloctanyl oxy diethylsilane served for this purpose as substrate regarding its kinetic resolution.
Precatalysts for homogeneous hydrogenation had the general composition [Ir ligand cod ] [tetrakis 3,5-bis trifluoromethyl phenyl borate ] and were prepared by initial mixing of [Ir cis,cis-1,5cyclooctadiene Cl ]2 with Ag[tetrakis 3,5-bis trifluoromethyl phenyl borate ] and subsequent addition of the oxazoline ligand.
The hydrogenations were carried out in neat substrate or in dichloromethane at 40 bar hydrogen pressure. Die Komplexe wurden ausgehend von [Ir cis,cis-1,5cyclooctadiene Cl]2 durch eine neuentwickelte Syntheseroute dargestellt.
Daraufolgend wurde der Ligand zugegeben, um so Komplexe der allgemeinen Zusammensetzung [Ir Ligand cis,cis-1,5-cyclooctadiene ]X zu erhalten.
Die Komplexe sollten einen chiralen Oxazolinliganden sowie einen substituierten Bipyridin Liganden tragen. Die dargestellten Oxazoline wurden als Liganden in direkter aromatischer und aliphatischer Borylierung verwendet.
In der aromatischen Borylierung fanden monosubstituierte Aromaten wie Toluol, tert-butylbenzol, Anisol, Cyclohexylbenzol, Trifluortoluol und Ethylbenzoat als Substrate Verwendung. Gegenstand der Analyse war die Bestimmung des meta: Die aliphatische Borylierung von n-oktan und n-hexan gelang unter den angewendeten Bedingungen nicht.
Die Bildung der Hydridosilylether wurde optimiert und der stereochemische Einfluss der chiralen Liganden in der C-H Aktivierung untersucht.CHEM Lecture 6: Chapter 6- Alkenes II continued Loved by over million students that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes.
Now I can be the all-star student I want to be. Saarim — University of Michigan. Unformatted text preview: Chapter 6 Addi-on Reac-ons of Alkenes CHE/ Fall Addition Reactions of Alkenes starting material and adding things to it • The most characteristic reaction of alkenes is addition to the double bond • The double bond is polarizable • The double bond is the weakest covalent bond (breaking this bond) • Reagent A-B comes in many flavors.
Feb 08, · Study of the first element – Hydrogen. Answer the following questions: 1. Give a reason why hydrogen can be placed in group 1[IA] and group 17[vIIA] of the periodic table.
Download CBSE Revision Notes for CBSE Class 11 Chemistry States of Matter Three states of matter, intermolecular interactions, types of bonding, melting and boiling points, role of gas laws in elucidating the concept of the molecule, Boyle's law, Charles law, Gay Lussac's law, Avogadro's law, ideal behaviour, empirical derivation of gas equation, Avogadro's number, ideal gas equation.
Test: Introduction to Organic Chemistry Covers molecular orbital theory, acid and base strength, functional group classification, and nomenclature of alkanes and bicyclic molecules. Dec 06, ·, alkynes, aromatic rings, Bromination, oxidation, addition and feelthefish.comUCTION Hydrocarbons are compounds that only contain carbon and hydrogen atoms.
There are three classifications of hydrocarbons such as, alkanes, alkenes, alkynes and aromatic feelthefish.coms are hydrocarbons that contain only carbon-carbon single bonds.