An organic species which has a carbon atom bearing only six electrons in its outermost shell and has a positive charge is called carbocation.
The positively charged carbon of carbocation is sp2 hybridized.
The unhybridized p-orbital remains vacant.
They are highly reactive and act as reaction intermediate.
They are also called carbonium ion.
This is Power Point Presentation on Topic "Electrophilic Aromatic Substitution Reactions" as per syllabus of "University of Mumbai" for S.Y. B. Pharmacy (Sem.: IV) students.
An organic species which has a carbon atom bearing only six electrons in its outermost shell and has a positive charge is called carbocation.
The positively charged carbon of carbocation is sp2 hybridized.
The unhybridized p-orbital remains vacant.
They are highly reactive and act as reaction intermediate.
They are also called carbonium ion.
This is Power Point Presentation on Topic "Electrophilic Aromatic Substitution Reactions" as per syllabus of "University of Mumbai" for S.Y. B. Pharmacy (Sem.: IV) students.
This presentation describes the concept of Hyperconjugation in simple words, gives definition of hyperconjugation, explains why it is called as 'No bond Resonance' and gives the effects of hyperconjugation on the chemical properties of compounds: alkyl cations and their relative stability, alkyl radicals and their relative stability, alkenes and their relative stability, bond length, anomeric effect and Baker - Nathan effect.
Carbocations and factors affecting their stabilitykoskal
A carbocation is a species where a carbon atom bonds to three carbon atoms and has a positive charge. Carbocations are electron deficient species and therefore very reactive and unstable. Anything which donates electron density to the electron-deficient center will help to stabilize them.
This presentation describes the concept of Hyperconjugation in simple words, gives definition of hyperconjugation, explains why it is called as 'No bond Resonance' and gives the effects of hyperconjugation on the chemical properties of compounds: alkyl cations and their relative stability, alkyl radicals and their relative stability, alkenes and their relative stability, bond length, anomeric effect and Baker - Nathan effect.
Carbocations and factors affecting their stabilitykoskal
A carbocation is a species where a carbon atom bonds to three carbon atoms and has a positive charge. Carbocations are electron deficient species and therefore very reactive and unstable. Anything which donates electron density to the electron-deficient center will help to stabilize them.
This presentaion describes about the basic principle effects in organic chemistry like inductive,mesomeric,electromeric, resonance and hyperconjugation. this presentation contains some JAM competitive questions.
A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. The bond may result from the electrostatic force of attraction between atoms with opposite charges, or through the sharing of electrons as in the covalent bonds
7. In many respects metal binding is similar to the binding of a prot.pdfezhilvizhiyan
7. In many respects metal binding is similar to the binding of a proton. For instance the N- atom
of thiocyanate can be protonated to produce (H-NCS). Similarly, protonation of the cyanide
anion (CN-) can be observed at the C-atom to produce H-CN. In apparent contrast to this
analogy, metal coordination to (NCS) can be observed at either N- or S- atoms (M-NCS and
NCS-M) whereas protonation only occurs at the N-atom. Provide an explanation for this
behavior. Similarly, why is the cyanide anion only capable of binding metals and protons at the
C-atom?
Solution
SCN- shares its negative charge approximately equally between sulfur and nitrogen (-S-CN or
S=C=N-). As a consequence, thiocyanate can bind either sulfur or nitrogen center. it is an
ambidentate ligand. [SCN] can also bridge two (MSCNM) or even three metals.
Carbon atom of CO has nonbonding (or weakly anti-bonding) sp-hybridized electron pair which
is make bond with metal. And also, the highest occupied molecular orbital (HOMO) of CO
shows electron density more in carbon of CO. Due to this reason metal coordinate with C of CO.
Metal ......CO bonding explained in below.
Carbon monoxide binds to transition metals using \"synergistic * back-bonding.\" The bonding
has three components, giving rise to a partial triple bond (in CO). A coordination bond arises
from overlap of the nonbonding (or weakly anti-bonding) sp-hybridized electron pair on carbon
with a blend of d-, s-, and p-orbitals on the metal. A pair of bonds arises from overlap of filled
d-orbitals on the metal with a pair of -antibonding orbitals projecting from the carbon atom of the
CO, this back binding requires that the metal have d-electrons, and that the metal is in a
relatively low oxidation state (<+2) which makes the back donation process favorable.
A carbanion is an ion with a negatively charged carbon atom. The most stable carbanions have six electrons in the valence shell of the carbon atom. Carbanions are important in organic chemistry because they can act as nucleophiles, which means they can donate electrons to other molecules. Carbanions are also important in biochemistry because they can be used to transfer electrons between molecules
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
We all have good and bad thoughts from time to time and situation to situation. We are bombarded daily with spiraling thoughts(both negative and positive) creating all-consuming feel , making us difficult to manage with associated suffering. Good thoughts are like our Mob Signal (Positive thought) amidst noise(negative thought) in the atmosphere. Negative thoughts like noise outweigh positive thoughts. These thoughts often create unwanted confusion, trouble, stress and frustration in our mind as well as chaos in our physical world. Negative thoughts are also known as “distorted thinking”.
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
3. Acarbocation is a species where a carbon atom bonds to three carbon
atoms and has a positive charge.
Carbocations are electron deficient species and therefore very reactive
and unstable.
Anything which donates electron density to the electron-deficient
center will help to stabilize them.
CARBOCATIONS & STABILITY
4. Neighboringcarbon atoms (inductiveeffect)
Neighboring carbon-carbonmultiple bonds(resonance effect)
Neighboringatoms withlone pairs(resonance effect)
Factors that stabilize them are the following:
CARBOCATIONS & STABILITY
5. How carbocations are stabilized by neighboring carbons atoms?
The stability of carbocations decreases as the number
of carbons attached to the C+ decreases.
That means that tertiary carbocations are more stable
than secondary that in turn are more stable than
primary (Fig. 1)
CARBOCATIONS & STABILITY
6. Fig. 1: Carbocation stability increases as methyl substitution increases
around the electron deficient carbon C+. The methyl groups (-CH3 ) are
electron donating and therefore stabilize the positive charge (inductive
effect).
CARBOCATIONS & STABILITY
7. An explanation for this is that the
methyl group (-CH3) acts as an
electron-donor and therefore
stabilizes the positively
charged cation.
Remember that the C atom has an
electronegativity of 2.5 and that
H 2.2.
CARBOCATIONS & STABILITY
8. Abetter explanation is that electrons are
donated from the C-H bonds to the empty
p orbital of the C+ therefore stabilizing the
carbocation through hyperconjugation
(the more the - CH3 groups attached to
the C+ the more stable the carbocation
becomes).
CARBOCATIONS & STABILITY
9. How carbocations are stabilized by carboncarbon multiple bonds
(resonance)?
Carbocations where the C+ is adjacent to another
carbon atom that has a double or triple bond have
extra stability because of the overlap of the empty p
orbital of the carbocation with the p orbitals of the π
CARBOCATIONS & STABILITY
10. bond. This overlap of the orbitals allows the
charge to be shared between multiple
atoms – delocalization of the charge - and
therefore stabilizes the carbocation.
CARBOCATIONS & STABILITY
11. Fig. 2: Carbocation stabilization by multiple bonds
adjacent to the C+ atom through p-orbital overlap
12. This effect is called charge delocalization and is shown
by drawing resonance structures where the charge
moves from atom to atom.
It greatly stabilizes even primary carbocations –
normally very unstable – that are adjacent to a
carboncarbon multiple bond.
CARBOCATIONS & STABILITY
13. Fig. 3: Carbocation stabilization by multiple bonds
adjacent to the C+ atom
CARBOCATIONS & STABILITY
14. How carbocations are stabilized by adjacent atoms with
lone pairs?
Adjacent atoms with lone pairs act as electron donors to the
electron-poor carbocation.
This results in forming a double bond (π bond) and the charge
is delocalized to the atom donating the electron pair (π
donation). Nitrogen and oxygen atoms are the most powerful π
donors. However, even halogen atoms stabilize carbocations
through donation of a lone pair
15. Fig. 4: Stabilization of the carbocation by lone pair donation. The
O atom donates an electron pair to the C+ atom and a double
bond is formed. The positive charge is delocalized to the oxygen
atom providing extra stability.
CARBOCATIONS & STABILITY
