WebEDG = electron donating group; EDG can be recognised by lone pairs on the atom adjacent to the π system, eg: -OCH 3; except-R, ... EWG = electron withdrawing group; EWG can be recognised either by the atom adjacent to the π system having several bonds to more electronegative atoms, or, having a formal +ve or δ +ve charge, eg: -CO 2 R, -NO 2. WebBecause heteroatoms such as oxygen and nitrogen are more electronegative than carbon, you might expect that they would by definition be electron withdrawing groups that destabilize carbocations. In fact, the opposite is often true: if the oxygen or nitrogen atom is in the correct position, the overall effect is carbocation stabilization.

organic chemistry - Effect of electron-donating and …

http://chem.ucalgary.ca/courses/350/Carey5th/Ch12/ch12-8b.html Webexample, an oxygen atom in a hydroxy group (OH) is electron withdrawing by induction, but electron donating by resonance when placed in a position on the structure where resonance is possible This will be explained more fully below. II. RESONANCE Resonance may be defined as bonding or sharing of electrons between more than two atoms (nuclei). child abuse prevention pinwheel garden

Confusion on electron withdrawing and donating effects of alkoxy, …

Web期刊：Journal of Hazardous Materials 文献作者：Hourui Zhang; Lu Zhang; Shuangshi Dong; Xiaoguang Duan; Dongyang Zhu; Bing-Jie Ni; Cong Lyu WebElectron withdrawing groups are usually meta-directing groups. As OH is electron rich species so it can donate its electron easily, the donation of electrons occurs by the oxygen atom. The following picture will give a better understanding of the nature of OH. The ortho and para directing groups are OH and NHCOCH 3. Because of the full or partial positive charge on the element directly attached to the ring for each of these groups, they all have a moderate to strong electron-withdrawing inductive effect (known as the -I effect). They also exhibit electron-withdrawing resonance effects, (known as the -M effect): Thus, these groups make the aromatic ring very electron-poor (δ+) relative to b… child abuse prevention poster