Carbonium ions

Cover of: Carbonium ions |

Published by Wiley-Interscience in New York, (Chichester) .

Written in English

Read online


  • Carbonium ions.

Edition Notes

Includes bibliographical references and index.

Book details

Statementedited by George A. Olah, Paul von R. Schleyer. Vol.4, Major types (continued).
SeriesReactive intermediates in organic chemistry
ContributionsOlah, George A. 1927-, Schleyer, Paul von R. 1930-
The Physical Object
Paginationxiii p.,p.1501-1960 :
Number of Pages1960
ID Numbers
Open LibraryOL19901574M

Download Carbonium ions

Carbonium ion, any member of a class of organic molecules with positive charges localized at a carbon n carbonium ions can be prepared in such a way that they are stable enough for study; more frequently they are only short-lived forms (intermediates) occurring during chemical reactions.

Carbonium ions are, in fact, one of the most common classes of intermediates in organic. Comparison with other published data on reactions leading to α-sulphuror α-oxygen-substituted carbonium ions shows that kO/kS ratios may range between ca. and ca. Scott Obach, A.S.

Kalgutkar, in Comprehensive Toxicology, Carbocations. Carbocations (carbonium ions) are species with positively charged carbon centers and are highly reactive hard formed during the metabolism of xenobiotics, they are generally short-lived because they can readily react with water to form alcohols.

The carbonium ion’s charge is not stable, and the acid sites on the catalyst are not strong enough to form many carbonium ions. Nearly all the cat cracking chemistry is carbenium ion chemistry.

A carbenium ion, R CH 2 +, comes either from adding a positive charge to an olefin or from removing a hydrogen and two electrons from a paraffin (Eqs.

Find many great new & used options and get the best deals for Carbonium Ions, an Introduction by Donald Bethell and V.

Gold (, Hardcover) at the best. Carbonium Ions on *FREE* shipping on qualifying offers. ISBN: OCLC Number: Notes: Includes index. Description: xii, pages: illustrations ; 24 cm. Contents: v. General aspects and. Additional Physical Format: Online version: Olah, George A. (George Andrew), Carbonium ions.

New York, Interscience Publishers [] (OCoLC) Summary This chapter contains sections titled: Introduction Alkyl Cations Ricycloalkyl and Polycycloalkyl Cations Cyclopropyl Carbonium Ions Alkenyl Cations of the Allylic Type Cyclopropenyl Cation.

Definitions. A carbocation was previously often called a carbonium ion but chemists question the exact meaning. In present-day chemistry, a carbocation is any positively charged carbon atom. Two special types have been suggested: carbenium ions are trivalent and carbonium ions are pentavalent or hexavalent.

University level textbooks only discuss carbocations as if they are carbenium ions, or. “Such organic ions carrying a positive charge on Carbon-atom are Carbonium ions book as Carbonium ion or Carbocations.” These are named by adding the ‘Carbonium ion’ after the name of parent alkyl group.

There are also termed as Primary, secondary & tertiary depending upon the nature of Carbon-atom bearing positive charge. +5 or +6 in the carbonium ions (protonated alkanes, named by analogy to ammonium). This nomenclature was proposed by G. Olah.[3] University-level textbooks discuss carbocations only as if they are carbenium ions, or discuss carbocations with a fleeting reference to the older phrase of carbonium ion or carbenium and carbonium ions.

Carbonium ions are carbocations with a pentacoordinated carbon atom, where the electronic octet is maintained. They possess a three center two electron bond in order to keep the tetravalence of. The disclosure describes a process for the production of a cellulosic feedstock for enzymatic hydrolysis and/or a lignin fraction for chemicals production, characterized in that Carbonium ions book the raw material is lignocellulosic biomass b) the biomass is treated in hot water c) at least one Cited by: 1.

Carbonium ions, an introduction, [D. Gold, Victor, Bethell] on *FREE* shipping on qualifying : Bethell, D. Gold, Victor. Development of the carbonium ion mechanism of catalytic cracking in is reviewed. Studies of the thermal and catalytic cracking of pure hydrocarbons played a key role, and were complemented by earlier hypotheses of Whitmore regarding the probable carbonium ion intermediates in low-temperature acid-catalyzed hydrocarbon reactions.

Carbonium Ions by Non Stated A copy that has been read, but remains in clean condition. All pages are intact, and the cover is intact. The spine may show signs of wear. Pages can include limited notes and highlighting, and the copy can include previous owner inscriptions. The dust jacket is missing.

At ThriftBooks, our motto is: Read More, Spend Less. Seller Rating: % positive. Define carbonium ion. carbonium ion synonyms, carbonium ion pronunciation, carbonium ion translation, English dictionary definition of carbonium ion.

An organic cation, such as H5C+, having a hypervalent carbon atom and a positive charge localized on the carbon atom. n a positively charged organic ion. Carbonium definition is - an organic ion carrying a positive charge on a carbon atom.

All carbocations (previously known as carbonium ions) carry a positive charge on a carbon atom. The name tells you that - a cation is a positive ion, and the "carbo" bit refers to a carbon atom.

However there are important differences in the structures of various types of carbocations. The different kinds of carbocations. Primary carbocations. carbonium ions Source: PAC,67, (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations ).

A carbenium ion is a positive ion with the structure RR′R″C +, that is, a chemical species with one trivalent carbon that bears a +1 electric charge. In older literature the name carbonium ion was used for this class, but now it refers exclusively to another family of carbocations, the carbonium ions, where the charged carbon is pentavalent.

Leaving aside (2) for awhile, the stability is (1) > (4) > (3) as these are tertiary, secondary, and primary respectively.

This stability order has to do with hyperconjugation. The nitro group on (3) is a “wild card” to me: it might be better at h. Carbonium Ions molecular particles containing a triva-lent positively charged carbon atom. Carbonium ions are highly reactive and therefore unstable. They form on heterolytic cleavage of the C—X bond (the electron pair which effects this bond is removed with the X group): For example, the action of strong acids on triphenyl carbinol yields a.

The Stability of Carbonium Ions Organic chemists are taught that carbonium ion stability is predominantly due to electronic factors such as whether they are primary, secondary, tertiary, allylic, benzylic etc.

What is mentioned much less is that their relative stability is also very sensitive to their geometries, and in particular the angles of. carbonium ions, radical ions, nitrenes, car- benes, and free radicals.

The book surveys the current state of re- search on organic halogen cations, that is, positive halogen ions having two bonds to carbon. Such ions have long been postulated as transient intermediates in organic reac- tions, such as the addition of halogens to : E.

Anacker. Formation of Carbonium Ion / Carbocation, Characteristics of Carbonium Ion / Carbocation, Structure of Carbonium ion / Carbocation and Stability of Carbonium Ion / Carbocation Carbonium ion or.

Increasing temperature could improve both of the diffusion velocity of carbonium ions (+C[2]OH) into initial fibers and the reaction rate of carbonium ions. the carbonium ion model, is shown in Scheme 3. The essential feature of this mechanism involves the intermediacy of a platinum vinyl carbonium ion which, once formed, reacts with the alcohol solvent to yield the alkoxy- carbene ligand.

A platinum vinyl carbonium ion may be formed by one of two routes; (i). Contemporary Problems in Carbonium Ion Chemistry III Arenium Ions - Structure and Reactivity. Authors: Koptyug, V. Editors: Rees, C.

(Ed.) Free Preview. Buy this book eB40 € price for Spain (gross) The eBook version of this title will be available soon; ISBN. Classical and Non‐Classical Carbonium Ions. Book Editor(s): B. Capon. University of Leicester.

Search for more papers by this author. Perkins. King's College, University of London. Search for more papers by this author. Rees. University of Leicester.

Science 12 Jun Vol.Issuepp. DOI: /scienceCited by:   Video shows what carbonium ion means. a carbenium ion or any carbocation. Carbonium ion Meaning. How to pronounce, definition audio dictionary. How to. The key difference between free radical and ion is that the free radicals have one or more unpaired electron, but ions have paired electrons.

We can explain the difference between free radical and ion from the basic properties of an ion and a free radical. An ion can occur as a molecule or atom with a charge (positive or negative) due to the loss or gain of an electron.

n Positively charged organic molecules in which every atom has an octet of electrons which makes it more stable, e.g., RCH=O+R. This account of research on the organometallic chemistry of platinum summarises work which indicates that platinum may induce carbonium ion reactivity in π-bonded hydrocarbon ligands and stabilise carbonium ions in the reactions of σ-bonded unsaturated hydrocarbons.

It is based on a lecture at the Chemical Society annual meeting held at York in April. (chemistry) a carbenium ion or any carbocation Definition from Wiktionary, the free dictionary. Chemistry Lab Resources (for CHM 1XX and 2XX Labs): Citing your sources Here you can find tips about organizing your lab notebook, how to effectively create graphs and table for lab reports, places to locate protocols and property information, and how to properly cite : Dave Zwicky.

\kär-¦ bō-nē-əm-\ [carb- + -onium] () n.A positively charged organic ion such as H 3 C, having one less electron than a corresponding free radical and behaving chemically as if the positive charge were localized on the carbon atom.

a) Producing carbonium ions altering protein structure. b) Producing carbonium ions altering DNA structure. c) Structural antagonism against purine and pyrimidine. d) Inhibition of DNA-dependent RNA synthesis. Tick the anticancer drug, a pyrimidine antagonist: a) Fluorouracil.

b) Mercaptopurine. c) Thioguanine. d) Methotrexate. Methotrexate is. Define carbonium ions. carbonium ions synonyms, carbonium ions pronunciation, carbonium ions translation, English dictionary definition of carbonium ions. n. An organic cation, such as H5C+, having a hypervalent carbon atom and a positive charge localized on the carbon atom.

n a .a sampling of carbonium ions. The parameters for car­ bon and hydrogen are identical to those used in the work on the hydrocarbons.4 The cations investigated fall into four classes: (1) Carbonium ions formed by loss of H-from nor­ mal or branched alkanes (methyl, ethyl, isopropyl, tert­ butyl,5 etc.).Comprehensive and up-to-date coverage of onium ions-an indispensable reference for academic and industrial chemists In Onium Ions, Nobel Prize-winning chemist George Olah joins forces with coauthors Kenneth Laali, Qi Wang, and G.

K. Surya Prakash to offer an in-depth look at the chemistry and reactions of these important electron-deficient compounds.

78088 views Thursday, November 12, 2020