Related Experiment Video
Updated: Jun 8, 2025
Combining Solid-state and Solution-based Techniques: Synthesis and Reactivity of ChalcogenidoplumbatesII or IV
Published on: December 29, 2016
Solid-State Replacement in the Polyhedra of Cu2+, Ni2+, and Co2+ upon Dehydration/Rehydration Processes Associated
Yannick Thiery Sakam Nchedoung1, Patrice Kenfack Tsobnang1, Roussin Lontio Fomekong2
1Department of Chemistry, Faculty of Sciences, University of Dschang, P.O. Box 67, Dschang 237, Cameroon.
Abstract:
The significance of thermochromic materials in a wide range of applications makes their research and development highly desirable. Herein, three new thermochromic isomorphous supramolecular materials based on the 5,5'-indigodisulfonate ion of the indigo carmine dye, with formulas [Cu(H2O)6](C16H8N2O8S2)·2H2O (1), [Ni(H2O)6](C16H8N2O8S2)·2H2O (2), and [Co(H2O)6](C16H8N2O8S2)·2H2O (3), are reported. These materials exhibit thermochromic properties, with a color change from red-bronze to grayish-red after the first step of their dehydration process completed around 80 °C (conversion of 1 to [Cu(H2O)2(C16H8N2O8S2) (1')]), and then, this grayish-red color becomes lighter after the second step, which is completed around 230 °C (conversion of 1' to [Cu(C16H8N2O8S2)] (1d)). The 1, 1', and 1d phases have different crystal structures but similar tetragonal bipyramidal geometries around the copper ions. These dehydrated phases rehydrate by exposure to a higher humidity level. Solid-state UV-visible spectroscopy, thermogravimetric analysis, infrared spectroscopy, and X-ray powder diffraction analyses shed light on the structural and chemical changes accompanying the color change of 1, 2, and 3 to their partial dehydrated phases 1', 2', and 3', respectively. These transformations occur with the small modification of the charge transfer energy in the 5,5'-indigodisulfonate ions, indicating the potential of dye-based metall-organic materials for chromic properties.
More Related Videos
10:31Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores
Published on: December 6, 2015
12:30Synthesis of a Thiol Building Block for the Crystallization of a Semiconducting Gyroidal Metal-sulfur Framework
Published on: April 9, 2018
Related Concept Videos
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:37Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
02:42Valence Bond Theory
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...