# US 5,705,248 A · Spin-transition compounds and their use for storing, processing and/or displaying information

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,705,248 A
- Document ID: US5705248A
- Status: Granted
- Kind: A
- Application number: 08/687,847
- Filed: 1996-07-26
- Granted: 1998-01-06
- Earliest claimed: 1991-11-22
- Assignees: U.S. Philips Corporation
- Inventors: Olivier O. Kahn; Charlotte Jay; Jonas Krober
- Web page: https://patentgrep.com/patent/US5705248A

## CPC

- C07F 15/025: {without a metal-carbon linkage}
- G11B 7/0055: Erasing (G11B7/006, G11B7/0065 take precedence)
- G11B 7/006: Overwriting (G11B7/0065 takes precedence)
- G11B 7/249: containing organometallic compounds (G11B7/246 takes precedence)
- C09K 2323/0273: Polyimidmetalo
- Y10S 428/913: Material designed to be responsive to temperature, light, moisture
- Y10S 430/146: Laser beam
- Y10T 428/21: Circular sheet or circular blank
- Y10T 428/24802: Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Chemical substances are provided which exhibit thermally induced spin transitions between two stable spin states at ambient temperature, said transitions being associated with a hysteresis phenomenon and resulting in an abrupt variation of the color of the molecules for realizing a medium for storing, processing and/or displaying information by way of thermal writing, optical reading and thermal erasing, a particular embodiment of such a medium comprising at least a layer of chemical substances including a lattice with a molecule comprising a metallic element Fe.sub.(II), or Fe.sub.(III) or Co.sub.(II) associated with at least one ligand chosen from the substituted triazoles which are defined by the formula: ##STR1## in which R is H or an alkyl C.sub.n H.sub.2n+1 or R is an amine group NL.sub.2 where L is H and an alkyl radical, said molecule also comprising one or several anions chosen, for example, from BF.sub.4.sup.-, ClO.sub.4.sup.-, Br.sup.-, Cl.sup.-, and the lattice containing a defined quantity of non-ligand water, ensured by the presence of a hygroscopic substance.

## Claims

### Claim 1

A method of preparing a medium for storing, processing and/or displaying information by thermal writing, optical reading and thermal erasing, which medium is addressable, eraseable and re-addressable with data, wherein chemical substances are provided which exhibit thermally induced spin transitions between two stable spin states at ambient temperature, said transitions being associated with a hysteresis phenomenon and resulting in an abrupt variation of the color of the molecules of the chemical substances,
wherein the chemical substances comprise metal-ligand complexes, said complexes containing a quantity of non-ligand water.

### Claim 2

A method of preparing a medium for storing, processing and/or displaying information wherein at least one layer is provided of chemical substances comprising metal-ligand complexes exhibiting thermally induced spin transitions between two stable spin states at ambient temperature, said transitions being associated with a hysteresis phenomenon and resulting in a variation of the metal-ligand bond length and an abrupt variation of the color of the molecules of the chemical substances,
wherein the chemical substances comprise metal-ligand complexes having a metal associated with at least one ligand chosen from the substituted triazoles which are defined by the formula: ##STR4## in which R is an alkyl C.sub.n H.sub.2n+1 or R is a NL.sub.2 group where L is chosen between H and an alkyl group, said molecule also comprising one or several anions selected from the group of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.-, said lattice containing a quantity of non-ligand water, said medium being addressable, eraseable and re-addressable with data.

### Claim 3 (depends on 1)

A method of preparing a medium as claimed in claim 1, wherein said chemical substances are provided on a support.

### Claim 4 (depends on 3)

A method of preparing a medium as claimed in claim 3 which comprises a hydroscopic substance.

### Claim 5 (depends on 4)

A method of preparing a medium as claimed in claim 4, wherein the hygroscopic substance is selected from the group consisting of non-basic and weakly acidic hygroscopic soluble colorless salts comprising a BF.sup.-.sub.4, ClO.sup.-.sub.4, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.- anion

### Claim 6 (depends on 5)

A method as claimed in claim 5, wherein the hygroscopic substance is chosen from the group consisting of iron boron fluoride, magnesium perchlorate, potassium perchlorate, sodium perchlorate and mixtures thereof.

### Claim 7 (depends on 5)

A method as claimed in claim 5, wherein the metal-ligand complex comprises a mixture of ligands.

### Claim 8 (depends on 7)

A method as claimed in claim 7, wherein the mixture of ligands comprises:
(a) a substituted triazole in which the radical R is H, an alkyl, and a free radial, and
(b) an amino-triazole in which the radical R is an NH.sub.2 group, and the amino-triazole is present in the mixture in a lesser amount than other ligands present in the metal-ligand complex.

### Claim 9

A method for preparing a medium for storing, processing and/or displaying information which comprises providing on a support at least one layer of a chemical substance which exhibits a hysteresis phenomenon, wherein the chemical substance comprises:
(1) a metal-ligand complex having a first at least one ligand of substituted triazoles which are defined by the formula: ##STR5## in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group, said metal-ligand complex also comprising at least one anion selected from the group consisting of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.-,
(2) non-ligand water and
(3) a hygroscopic substance, said hygroscopic substance ensuring the presence of non-ligand water,
said medium being addressable, erasable and re-addressable with data.

### Claim 10 (depends on 9)

A method as claimed in claim 9 wherein the metal-ligand complex comprises a metallic element Fe.sub.(II), or Fe.sub.(III) or Co.sub.(II).

### Claim 11

A method for preparing a medium for storing, processing and/or displaying information comprising providing chemical substance which exhibits a hysteresis phenomenon, wherein the chemical substance comprises:
(1) a metal-ligand and complex having a first at least one ligand of substituted triazoles which are defined by the formula: ##STR6## in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group, said metal-ligand and complex also comprising at least one anion selected from the group consisting of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.-,
(2) non-ligand water and
(3) a hygroscopic substance, said hygroscopic substance ensuring the presence of non-ligand water,
said medium being addressable, erasable and re-addressable with data at ambient temperature.

### Claim 12

A method for preparing a medium for storing, processing and/or displaying information which comprises providing on a support a chemical substance which exhibits a hysteresis phenomenon, wherein the chemical substance comprises:
a metal-ligand complex having a first at least one ligand of substituted triazoles which are defined by the formula: ##STR7## in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group, said metal-ligand complex also comprising at least one anion selected from the group consisting of BF.sub.4.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, Br.sup.-, and Cl.sup.-, and (2) non-ligand water, said medium being addressable, erasable and re-addressable with data.

### Claim 13 (depends on 12)

A method for preparing a medium for storing, processing and/or displaying information as claimed in claim 12, wherein the metal-ligand complex is selected from the group consisting of triazole ligand complexes of Fe(II) having the formulae
a) Fe (H Trz).sub.3 (BF.sub.4.sup.-).sub.2
b) Fe (H Trz).sub.3 Cl.sub.2
c) Fe (H Trz).sub.3 (ClO.sub.4.sup.-).sub.2
d) Fe (H Trz).sub.3 (CO.sub.3 .sup.2-) and
e) Fe (H Trz).sub.3 Br.sub.2
wherein Htrz is a triazole ligand of the formula when R is H.

### Claim 14 (depends on 12)

A method of preparing a medium for storing, processing and/or displaying information as claimed in claim 12, wherein the metal-ligand complex is selected from the group consisting of triazole ligand complexes of Fe(II) having the formulae
a) Fe (H Trz).sub.3 (BF.sub.4.sup.-).sub.2
b) Fe (H Trz).sub.3 Cl.sub.2
c) Fe (H Trz).sub.3 (ClO.sub.4.sup.-).sub.2
d) Fe (H Trz).sub.3 (CO.sub.3 .sup.2-)
e) Fe (H Trz).sub.3 Br.sub.2
wherein NH.sub.2 Trz is an amino-triazole ligand of the formula when R is an amino group.

### Claim 15 (depends on 12)

A method of preparing a medium for storing, processing and/or displaying information as claimed in claim 12, wherein the metal-ligand complex is selected from the group consisting of triazole ligand complexes of Fe(II) having the general formulae
a) Fe (Trz) (Htrz).sub.2 (BF.sub.4.sup.-)
b) Fe (H Trz).sub.2 (NL.sub.2 Trz) Cl.sub.2
c) Fe (H Trz).sub.2 (NL.sub.2 Trz) (ClO.sub.4.sup.-).sub.2
d) Fe (H Trz).sub.2 (NL.sub.2 Tr.sub.3) (CO.sub.3.sup.2-)
e) Fe (H Trz).sub.2 (NL.sub.2 Trz) Br.sub.2
f) Fe (Trz.sup.-) (H Trz) (NL.sub.2 Trz) (BF.sub.4.sup.-)
g) Fe (Trz.sup.-) (H Trz) (NL.sub.2 Trz) (Cl.sup.-)
h) Fe (Trz.sup.-) (H Trz) (NL.sub.2 Trz) (ClO.sub.4.sup.-)
i) Fe.sub.2 (Trz.sup.-).sub.2 (H Trz).sub.2 (NL.sub.2 Trz).sub.2 (CO.sub.3.sup.2-)
j) Fe (Trz.sup.-) (HTrz) (NL.sub.2 Trz) (Br.sup.-)
k) Fe (Trz.sup.-)(NL.sub.2 Trz).sub.2 (Cl.sup.-)
l) Fe (Trz.sup.-) (NL.sub.2 Trz).sub.2 (CLO.sub.4.sup.-)
m) Fe.sub.2 (Trz.sup.-).sub.2 (NL.sub.2 Trz).sub.4 (CO.sub.3.sup.2-)
n) Fe (Trz.sup.-)(NL.sub.2 Trz).sub.2 (Br.sup.-)
o) Fe (RTrz) (NL.sub.2 Trz).sub.2 (BF.sub.4.sup.-).sub.2
p) Fe (RTrz) (NL.sub.2 Trz).sub.2 CL.sub.2
q) Fe (RTrz) (NL.sub.2 Trz).sub.2 (ClO.sub.4.sup.-).sub.2
r) Fe (RTrz) (NL.sub.2 Trz).sub.2 (CO.sub.3.sup.2-)
s) Fe (RTrz) (NL.sub.2 Trz).sub.2 Br.sub.2.

### Claim 16 (depends on 12)

A method for preparing a medium for storing, processing and/or displaying information as claimed in claim 12, wherein the metal-ligand complex is selected from the group consisting of triazole ligand complexes of Fe(II) having the general formulae
a) Fe (Trz.sup.-) (H Trz).sub.2 (BF.sub.4.sup.-)
b) Fe (Trz.sup.-) (HTrz).sub.2 (Cl.sup.-)
c) Fe (Trz.sup.-) (HTrz).sub.2 (ClO.sub.4.sup.-)
d) Fe.sub.2 (Trz.sup.-).sub.2 (HTrz).sub.4 (CO.sub.3.sup.2-)
e) Fe (Trz.sup.-) (HTrz).sub.2 (Br.sup.-)
f) Fe (RTrz).sub.3 (BF.sub.4.sup.-).sub.2
g) Fe (RTrz).sub.3 Cl.sub.2
h) Fe (RTrz).sub.3 (CLO.sub.4.sup.-).sub.2
i) Fe (RTrz).sub.3 (CO.sub.3.sup.2-)
j) Fe (RTz).sub.3 Br.sub.2
k) Fe (Trz.sup.-) (RTrz).sub.2 (BF.sub.4.sup.-)
l) Fe (Trz.sup.-) (RTrz).sub.2 (Cl.sup.-)
m) Fe (Trz.sup.-) (RTrz).sub.2 (ClO.sub.4.sup.-)
n) Fe.sub.2 (Trz.sup.-).sub.2 (RTrz).sub.4 (CO.sub.3.sup.2-)
o) Fe (Trz.sup.-) (RTrz).sub.2 (Br.sup.-)
p) Fe (HTrz) (NL.sub.2 Trz).sub.2 (BF.sub.4.sup.-).sub.2
q) Fe (HTrz) (NL.sub.2 Trz).sub.2 Cl.sub.2
r) Fe (HTrz) (NL.sub.2 Trz).sub.2 (ClO.sub.4.sup.-).sub.2
s) Fe (HTrz) (NL.sub.2 Trz).sub.2 (CO.sub.3.sup.2-)
t) Fe (HTrz) (NL.sub.2 Trz).sub.2 Br.sub.2
u) Fe (RTrz).sub.2 (NL.sub.2 Trz) (BF.sub.4).sub.2
v) Fe (RTz).sub.2 (NL.sub.2 Trz) Cl.sub.2
w) Fe (RTrz).sub.2 (NL.sub.2 Trz) (ClO.sub.4.sup.-).sub.2
x) Fe (RTrz).sub.2 (NL.sub.2 Trz) (CO.sub.3.sup.2-)
y) Fe (RTrz).sub.2 (NL.sub.2 Trz) Br.sub.2
z) Fe (Trz.sup.-) (RTrz) (NL.sub.2 Trz) (BF.sub.4.sup.-)
aa) Fe (Trz.sup.-) (RTrz) (NL.sub.2 Trz) (Cl.sup.-)
bb) Fe (Trz.sup.-) (RTrz) (NL.sub.2 Trz) (ClO.sub.4.sup.-)
cc) Fe (Trz.sup.-) (RTrz) (NL.sub.2 Trz) (CO.sub.3.sup.2-)
dd) Fe (Trz.sup.-) (RTrz) (NL.sub.2 Trz) (Br.sup.-)
in which R is selected from the group consisting of an alkyl group and NL.sub.2, wherein L is H or an alkyl group,
said medium being inscribable, eraseable and re-inscribable with data at ambient temperature.