LIGAND EXCHANGE THERMOCHROMIC SYSTEMS AND HIGH E LIGANDS FOR SAME

• US 20080105851A1
• Filed: 09/04/2007
• Published: 05/08/2008
• Est. Priority Date: 09/01/2006
• Status: Active Grant

• Current Assignee: Pleotint LLC
• Original Assignee: Pleotint LLC
• Inventors: Ogburn, Paul, Griend, Douglas, Winkle, Derick, Byker, Harlan, Veldkamp, Brad
• Granted Patent: US 8,182,718 B2
• Time in Patent Office: Days
• US Class Current: 252/408.1
• CPC Class Codes: B32B 17/10005 laminated safety glass or glazing
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10174 Coatings of a metallic or dielectric material on a constituent layer of glass or polymer
• CPC Class Codes: B32B 17/10477 thermochromic
• CPC Class Codes: B32B 17/10651 comprising colorants, e.g. dyes or pigments
• CPC Class Codes: B32B 17/10678 comprising UV absorbers or stabilizers, e.g. antioxidants
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: B32B 2369/00 Polycarbonates
• CPC Class Codes: C09K 2211/187 of the iron group metals, i.e. Fe, Co or Ni
• CPC Class Codes: C09K 9/02 Organic tenebrescent materials
• CPC Class Codes: G02F 1/0147 based on thermo-optic effects G02F1/132 takes precedence

Abstract

Ligand exchange of thermochromic, LETC, systems exhibiting a reversible change in absorbance of electromagnetic radiation as the temperature of the system is reversibly changed are described. The described LETC systems include one or more than one transition metal ion, which experiences thermally induced changes in the nature of the complexation or coordination around the transition metal ion(s) and, thereby, the system changes its ability to absorb electromagnetic radiation as the temperature changes. In accordance with certain aspects of the present invention, a thermochromic system is disclosed comprising a transition metal ion and a ligand wherein the ligand comprises a nitrogen-containing five or six membered heterocyclic compound that coordinates through the nitrogen atom to the transition metal ion in a HεMLC formed between the transition metal ion and the ligand. In accordance with other aspects of the present invention, thermochromic systems are disclosed comprising a transition metal ion with particularly useful ligands, such as phosphine compounds, tridentate ligands that coordinate through three nitrogen atoms, bidentate ligands, or ortho hindered pyridine monodentate ligands.

Claims

1. A thermochromic system comprising a transition metal ion and a ligand, the ligand comprising a nitrogen-containing five- or six- membered heterocyclic compound that coordinates through the nitrogen atom to the transition metal ion in a Hε

MLC formed between the transition metal ion and the ligand, wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of the Hε

MLC.

2. The thermochromic system of claim 1 wherein the ligand has the following structure:

3. The thermochromic system of claim 2 wherein the ligand is selected from the group consisting of a substituted or unsubstituted imidazole, benzimidazole, benzothiazole, pyrazole, indazole, imidazopyridine, triazole, thiazole, oxazole, thiatriazole, benzisoxazole, triazolo[1,5-a]pyrimidine, benzisoxazole, thiadiazole, benzothiadiazole, indolenine and mixtures thereof.

4. The thermochromic system of claim 1 wherein the ligand comprises a tridentate ligand that coordinates through 3 nitrogen atoms.

5. The thermochromic system of claim 4 wherein the tridentate ligand has the following structure:

6. The thermochromic system of claim 1 further comprising a halide;

and

the ligand has the following structure;

wherein 1 or 2 of X, Y and Z are (CH₂)_n wherein n=1 to 2 and the others are a direct bond,

each

independently represents a nitrogen-containing five or six membered ring and wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of a Hε

MLC formed between the transition metal ion, the halide and the ligand.

7. The thermochromic system of claim 1 wherein

the ligand comprises a bidentate ligand that coordinates through a nitrogen atom and a phosphorus atom

wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of a Hε

MLC formed between the transition metal ion and the bidentate ligand.

8. The thermochromic system of claim 1 wherein the ligand comprises an ortho hindered pyridine monodentate ligand having the following structure:

9. The thermochromic system of claim 1 wherein the ligand comprises a bidentate ligand that coordinates through an amine nitrogen atom and an imine nitrogen atom.

10. The thermochromic system of claim 9 wherein the bidentate ligand has the following structure:

11. A thermochromic system which comprises:

a) a transition metal ion;

b) a halide; and

c) a ligand capable of forming a HeMLC with the halide and the transition metal ion wherein the ligand has the following structure;

wherein X is selected from the group consisting of (CH₂)_n where n=1 to 4,

where R, R₁, R₂ are independently selected from the group consisting of hydrogen, substituted or unsubstituted, straight or branched alkyl, substituted or unsubstituted aryl, aralkyl and combinations thereof and

wherein each

independently represents a nitrogen-containing five or six membered ring.

12. The thermochromic system of claim 11 wherein each

13. A thermochromic system which comprises:

a) a transition metal ion

b) a phosphine compound of the following structure

wherein R₁, R₂ and R₃ are independently selected from the group consisting of substituted or unsubstituted, straight or branched alkyl, cycloalkyl, substituted or unsubstituted aryl and combinations thereof, wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of a Hε

MLC formed between the transition metal ion and the phosphine compound.

14. The thermochromic system of claim 13 wherein the thermochromic system additionally comprises iodide.

15. A thermochromic system which comprises:

a) a transition metal ion; and

b) 1,4,8,11-tetrathiacyclotetradecane or alkylated derivatives thereof,

wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of a Hε

MLC formed between the transition metal ion and the 1,4,8,11-tetrathiacyclotetradecane.

16. A thermochromic system which comprises:

a) a transition metal ion; and

b) a ligand represented by the following structure

wherein X is selected from the group consisting of N—

R, O, S, and Se,

R represents hydrogen, straight or branched, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, aralkyl and combinations thereof,

wherein heating the system from 25°

C. to 85°

C. causes an increase in the concentration of a Hε

MLC formed between the transition metal ion and the a ligand with the structure above.