Advices For Studying Organic Chemistry

4) When the radical weaponry of each calicheamicin γ 1 I is activated, it removes a hydrogen atom from the backbone of DNA. 5) T ...

10.1 INTRODUCTION: Ionic reactions are those in which covalent bonds break heterolytically, and in which ions are involved as r ...

Almost all small radicals are short-lived, highly reactive species. They tend to react in a way that leads to pairing of their ...

i) Although in its free form nitric oxide is a relatively unstable and potentially toxic gas, in biological system it is involve ...

Table 10.1 Single-Bond Homolytic Dissociation Energies ∆H° at 25°C A B A + B Bond Broken (shown in red) kJ mol –1 Bond Broken (s ...

10.2 HOMOLYTIC BOND DISSOCIATION ENERGIES Bond formation is an exothermic process: H• + H• H–H ∆H° = – 435 kJ mol–1 Cl• + Cl• C ...

2 H• + 2 Cl• 2 H–Cl 10.2B HOMOLYTIC BOND DISSOCIATION ENERGIES AND THE RELATIVE STABILITIES OF RADICALS: Bond dissociation ener ...

H 3 CC CH 3 CH 2 H H CH 3 CCH 3 H CH 3 + tert-Butyl radical (a 3o radical) ∆H° = + 381 kJ mol–1 CH 3 CCH 2 CH 3 H Isobutyl radic ...

>>> Tertiary > Secondary >Primary >Methyl C C C C C C H C C C H H H C H H 1) The order of stability of alkyl r ...

Chlorination of methane: At the outset, the only compounds that are present in the mixture are chlorine and methane ⇒ the only ...

1) Halogenation of an alkane (or cycloalkane) with equivalent hydrogens: H 3 CC CH 3 CH 3 CH 3 H 3 CC CH 3 CH 3 ++Cl 2 CH 2 Cl H ...

that is absorbed by chlorine molecules and not by methane molecules. A Mechanism for the Reaction Radical Chlorination of Methan ...

1) The chain reaction accounts for the observation that the light-promoted reaction is highly efficient. Chain-terminating step ...

Chain Initiation Step 1 Cl–Cl 2 Cl• ∆H° = + 243 kJ mol–1 (∆H° = 243) Chain Propagation Step 2 CH 3 –H + •Cl CH 3 • + H–Cl ∆H° = ...

CH 3 • + Cl–Cl CH 3 –Cl + •Cl ∆H° = – 106 kJ mol–1 CH 3 –H + Cl–Cl CH 3 –Cl + H–Cl ∆H° = – 102 kJ mol–1 1) The addition of the v ...

room temperature (298 K) the T∆S° term is 0.8 kJ mol–1. 4) The enthalpy change for the reaction and the free-energy change are a ...

transition state. iii) Bond formation lags behind, and its energy is not all available for bond breaking. 2) Activation energies ...

Figure 10.4 Potential energy diagram for the dissociation of a chlorine molecule into chlorine atoms. 4) The energy of activatio ...

of fluorine and methane explode. 2) Chlorine is the next most reactive –– chlorination of methane is easily controlled by the ju ...

overall heat of reaction ⇒ high reactivity of fluorine toward methane.. vii) Fluorination reactions can be controlled by dilutin ...