Related Experiment Video

Updated: Jun 2, 2026

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
10:33

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation

Published on: February 27, 2019

A dual-polymer electrochromic device with high coloration efficiency and fast response time:

Joo-Hee Kang1, Zhaochao Xu, Seung-Min Paek

  • 1Center for Intelligent Nano-Bio Materials (CINBM), Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 120-750, Korea.

Chemistry, an Asian Journal
|May 12, 2011
PubMed

More Related Videos

Development of Efficient OLEDs from Solution Deposition07:09

Development of Efficient OLEDs from Solution Deposition

Published on: November 4, 2022

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes05:51

Fabrication of White Light-emitting Electrochemical Cells with Stable Emission from Exciplexes

Published on: November 15, 2016

Related Concept Videos

Thermal and Photochemical Electrocyclic Reactions: Overview01:26

Thermal and Photochemical Electrocyclic Reactions: Overview

Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Thermal Electrocyclic Reactions: Stereochemistry01:17

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.