WO2002014438A1

WO2002014438A1 - Infrared chromophores

Info

Publication number: WO2002014438A1
Application number: PCT/AU2001/000999
Authority: WO
Inventors: Lachlan Everett Hall; Kia Silverbrook
Original assignee: Silverbrook Research Pty Ltd
Priority date: 2000-08-14
Filing date: 2001-08-14
Publication date: 2002-02-21
Also published as: EP1311396A1; WO2002014437A1; EP1311396A4; WO2002014435A1; WO2002014075A1; WO2002014434A1; WO2002014437A8

Abstract

Infrared dyes which absorb strongly in the near infrared region of the spectrum but poorly in the visible regions are described. The claimed compounds are the formulas 1-5 wherein X, Y, Y', Z and Z' are independently selected from CO, O, S, Se, Te, CS, CR1R2, SiR1R2, PR1, or R' depending on the formula. -A and -B are as described in the specification.

Description

INFRARED CHROMOPHORES

FIELD OF INVENTION

The present invention relates to compounds that are suitable for use as dyes. In particular, the present invention relates to compounds that are suitable for use as infrared dyes, to compositions containing these compounds, including color light-sensitive material, and to processes for their use as infrared absorbers. The present invention has particular application to infrared printing inks.

CO-PENDING APPLICATIONS

Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present invention:

NPI001, NPI002, NPI003, NPI003A, PI004

The disclosures of these co-pending applications are incorporated herein by cross-reference. Each application is temporarily identified by its docket number. This will be replaced by the corresponding International Patent Application Number when available.

BACKGROUND

Recently there has been renewed interest in "innovative" or "functional" dyes. One area of interest is that of optical recording technology where gallium aluminium arsenide (GaAIAs) and indium phosphide (InP) diode lasers are widely used as a light source. Since dyes absorbing in the near infrared (near-IR) region (i.e., beyond about 700 nanometers in wavelength and less than about 2000 nanometers in wavelength are required and the oscillation wavelengths fall in the near-infrared region, they are suitable candidates for use as infrared dyes.

Infrared dyes have applications in many areas. For example, infrared dyes are important in the optical data storage field, particular in the DRAW (Direct Reading After Writing) and WORM (Write Once, Read Many) disk, which is used for recording. Currently, indolinocyanine dyes, triphenylmethane dyes, naphthalocyanine dyes and indonanaphthalo-metal complex dyes are commercially available for use as organic colorants in DRAW disks. Cyanine dyes can only be used if additives improve the lightfastness.

Another application of infrared dyes is in thermal writing displays. In this application, heat is provided by a laser beam or heat impulse current. The most common type of infrared dyes used in this application are the cyanine dyes, which are known as laser dyes for infrared lasing.

Infrared dyes are also used as photoreceptors in laser printing. Some infrared-absorbing dyes are used in laser filters. They also find application in infrared photography and even have application in medicine, for example, in photodynamic therapy. The compounds of the present invention will now be described in the context of printing inks and the like, but it will be understood by the skilled reader that the compounds described hereunder may be used in other applications, for example, those set out above.

Fast, error-free data entry is important in current communication technology. Automatic reading of digital information in printed, digital and analog form is particularly important. An example of this technology is the use of printed bar codes that are scannable. In many applications of this technology, the bar codes are printed with inks that are visible to the unaided eye. There are, however, applications (e.g. security coding) that require the barcode or other intelligible marking to be printed with an ink that invisible to the unaided eye but which can be detected under UV light or infrared light (IR). For instance, U.S. Pat. No. 5,093,147 describes a method exploiting the process of fluorescence in which a dye is excited by ultra-violet (UV), visible or near-IR radiation and fluorescent light emitted by the dye material is detected. This reference describes a jet printing process used to apply a compatible liquid or viscous substance containing an organic laser dye that is poorly absorptive of radiation in the visible wavelength range of about 400 nm to about 700 nm, and is highly absorptive of radiation in the near-IR wavelength range of about 750 nm to about 900 nm. The dye fluoresces at longer wavelengths in the IR in response to radiation excitation in the near-IR range.

Another example is described in U.S. Pat. No. US Pat No. 5,460,646 (Lazzouni et al) which describes the use of a colorant which is silicon (IV) 2,3-naphthalocyanine bis((Rι)(R₂)(R₃)- silyloxide) wherein R^ R₂, and R₃ are selected from the group consisting of an alkyl group, at least one aliphatic cyclic ring, and at least one aromatic ring.

The infrared absorbing dyes Squarylium and Croconium dyes have been extensively described in the literature (see for example, T. P. Simard, J. H. Yu, J. M. Zebrowski-Young, N. F.

Haley and M. R. Detty, J. Org. Chem. 652236 (2000), and J. Fabian, Chem. Rev. 92 1197 (1992)). These prior art compounds have a central squarylium or croconium moiety connected to traditional electron donors. However, these particular dyes do not absorb at a high enough wavelength and/or also absorb too strongly in the visible spectrum.

SUMMARY OF THE INVENTION

A first embodiment of the invention is an infrared dye according to one of the following formulae:

1 where, X is CO and Y is selected from the group consisting of O, S, Se, Te, CS, CR1R2, NRl,

SiRlR2_, GeRlR2 PRl, R'; or where X and Y are independently selected from the group consisting of O,

S, Se, CS, Te, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; and where Rl and R2, which may be the same or different, are selected from the group R; where X is CO and Y and Z are independently selected from the group consisting of O, S, Se, Te,

CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; or where Y and Z are each CO and X is selected from the group O, S, Se, Te, CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; or where X and Z are each CO and Y is selected from the group O, S, Se, Te, CS, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; or where X and Y are each CO andZ is selected from the group O, S, Se, Te, CS, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; or where X, Y and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2_ NRl,

SiRlR2_, GeRlR2_, PRl, R'; and where Rl and R2, which may be the same or different, are selected from the group R;

where X and Z and Z' are independently selected from the group consisting of O, S, Se, Te, CS,

CR1R2, NRl, SiRlR2, GeRlR2 PRl, R'; Y and Y' are independently selected from the group CR1, N; and where Rl and R2, which may be the same or different, are selected from the group R;

where X and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; Y and Y' are independently selected from the group CR1, N; and where Rl and R2, which may be the same or different, are selected from the group R;

where X and X' are independently selected from the group consisting of O, S, Se, Te, CS, CRlR2_ι NRl, SiRlR2 GeRlR2 PRl, R'; Y, Y', Z and Z' are independently selected from the group CR1, N; and where Rl and R2, which may be the same or different, are selected from the group R; and where R is the group consisting of hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted thioalkyl group and where -A and -B in Formulae 1 to 5 given above are independently selected from moieties containing 2n carbon atoms each of which are connected to three (3) atoms at least one (1) of which is one (1) of the 2n carbon atoms other than a carbon atom that is double bonded to a heteroatom, where n is an integer equal to or greater that 1; where the infrared dye absorbs strongly in the near infrared region of the spectrum but poorly in the visible region of the spectrum

In a preferred embodiment of the invention Formula 1 is selected from the group consisting of:

6

8 9 10

11 12 13

In a preferred aspect of the invention -A and -B are each independently selected from the group consisting of:

33 34 35 36 37 38

39 40 41

42 43 44 45

In a further preferred aspect of the invention -A and -B are the same.

In a further preferred aspect of the invention compounds of Formula 2 are selected from the group consisting of:

17 18 19

In a further preferred aspect of the invention -A and -B are each independently selected from the group consisting of:

46 47 48 49 50 51

58 59 60 61

In a further preferred aspect of the invention compounds of Formula 3 are selected from the group consisting of:

23 24 25

In a further preferred aspect of the invention compounds of Formula 4 are selected from the group consisting of of:

26 27 28

In a further preferred aspect of the invention compounds of Formula 5 are selected from the group consisting of:

29 30 31 32

A preferred embodiment of the invention is an infrared dye composition comprising a compound disclosed herein.

A further preferred embodiment of the invention is an infrared absorbing compound disclosed herein where one or more polar group substituents such as -S0₃H, -NH₂ and -CN are utilized.

A preferred embodiment of the invention is a solvent-based ink composition comprising a compound disclosed herein.

A further preferred embodiment of the invention is a solvent-based ink jet printer ink composition comprising a compound disclosed herein. BRIEF DESCRIPTION OF DRAWINGS

Preferred and other embodiments of the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figures 1 A to 1 C show a calculated absorption spectra for Formula 1 dyes; Figures 2A to 2C show calculated absorption spectra for Formula 2 dyes.

Figure 3 shows calculated absorption spectra for Formula 3 dyes.

Figure 4 shows calculated absorption spectra for Formula 4 dyes.

Figures 5A and 5B: show calculated absorption spectra for Formula 5 dyes.

Figures 6A to 6E show calculated absorption spectra for Formula 1 dyes as function of -A and -B that are the same as each other.

Figures 7A to 7F show calculated absorption spectra for Formula 2 dyes as function of -A and -B that are the same as each other.

BACKGROUND AND APPLICATION INFORMATION

We have identified compounds that may be suitable for use as infrared dyes. Accordingly, the present invention provides, in one aspect, infrared dyes of the following formulae:

1 wherein, X is CO and Y is selected from the group consisting of O, S, Se, Te, CS,

CR1 R2, NR1 , SiR1 R2_, GeR1 R2_, PR1 , R'; or wherein X and Y are independently selected from the group consisting of O, S, Se, CS, Te, CR1 R2 NR1 , SΪR1 R2 GeR1 R2_, PR1, R'; and wherein R1 and R2, which may be the same or different, are selected from the group R;

wherein X is CO and Y and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1 R2 NR1 , SiR1 R2, GeR1 R2, PR1 , R'; or wherein Y and Z are each CO and X is selected from the group O, S, Se, Te, CS, CR1 R2_, NR1 , SiR1 R2, GeR1 R2 PR1 , R'; or wherein X and Z are each CO and Y is selected from the group O, S, Se, Te, CS, CR1 R2_, NR1 , SiR1 R2, GeR1 R2, PR1 , R'; or wherein X and Y are each CO and Z is selected from the group O, S, Se, Te, CS, CR1 R2, NR1 , SiR1 R2, GeR1 R2, PR1 , R'; or wherein X, Y and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1 R2, NR1 , SiR1 R2, GeR1 R2, PR1 , R'; and wherein R1 and R2, which may be the same or different, are selected from the group R;

wherein X and Z and Z' are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2, NR1 , SiR1R2, GeR1R2, PR1, R'; Y and Y' are independently selected from the group CR1, N; and wherein R1 and R2, which may be the same or different, are selected from the group R;

wherein X and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; Y and Y' are independently selected from the group CRl, N; and wherein Rl and R2, which may be the same or

ifferent, are selected from the group R; wherein X and X' are independently selected from the group consisting of O, S, Se, Te, CS, CR1 R2_, NR1 , SiR1 R2, GeR1 R2, PR1 , R'; Y, Y', Z and Z' are independently selected from the group CR1, N; and wherein R1 and R2, which may be the same or different, are selected from the group R; and wherein R is the group consisting of hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted thioalkyl group and wherein -A and -B in Formulae 1 to 5 given above are independently selected from moieties containing 2n carbon atoms each of which are connected to three (3) atoms at least one (1) of which is one (1) of the 2n carbon atoms other than a carbon atom that is double bonded to a heteroatom, wherein n is an integer equal to or greater that 1.

In regard to -A and -B, for example in compound 50 the carbon atom having a double bond to the oxygen (heteroatom) is not counted as one of the carbon atoms and therefore in this case 2n= 6 and in the case of 53, 2n=10

Preferably -A and -B are the same.

The terminal group of -A and/or -B may or may not form part of a ring structure.

The infrared dyes of the present invention may be poorly absorptive of light in the visible range of about 400 to 700 nanometers but highly absorptive in the near infrared range of wavelengths of at least 700 nanometers.

In a further aspect, the present invention provides a composition of matter including a dye in accordance with the first aspect of the invention.

In yet a further aspect, the present invention provides a method for using a dye in accordance with the first aspect.

SYNTHESIS OF COMPOUNDS OF FORMULA 1

The calculated absorption spectra for compounds 6 and 7 of Formula 1 are shown in Figure 1. From Squarylium Dyes

Compounds according to Formula 1 are similar to the squarylium dyes. However, one, or in the case of molecule 6, two carbonyl groups are reduced. The synthesis of such molecules may start from the squarylium dyes. Several methods are known whereby two hydrogens replace the oxygen of an aldehyde or ketone; this process is known as deoxygenation. One such method is the Wolff-Kishner reduction. The first step in the reaction sequence is the formation of the hydrazone by addition of hydrazine and elimination of water. Base attacks the somewhat acidic NH2 group to form an ambident anion that can react with a proton donor to produce a diazene R₂CH-N=NH. The acidic diazene (pKa ~ 23). reacts with base forming an anion that loses nitrogen to give the hydrocarbon. The reaction is normally carried out by heating the ketone with hydrazine hydrate and sodium hydroxide in diethylene glycol, HOCH2CH20CH2CH20H, which has a B/P. of 245°C. Alternatively, the reduction may be carried out in the polar aprotic solvent DMSO at 100°C. The hydrazone forms, and water distills out of the mixture. On refluxing, nitrogen is evolved, and the product is isolated. The end product can be reacted with methyl iodide with a strong base to give the methylated species.

An alternative procedure for the direct reduction of a carbonyl group to a methylene group involves refluxing the aldehyde or ketone with amalgamated zinc and hydrochloric acid (Clemmensen reduction [2]). Amalgamated zinc is zinc with a surface layer of mercury. It is prepared by treating zinc with an aqueous solution of a mercuric salt. Since zinc is higher on the electromotive force scale than mercury, it reduces mercuric ions to mercury. The reduction of the carbonyl compound occurs on the surface of the zinc, and, like many heterogeneous reactions, this reaction does not have a simple mechanism. The Clemmensen reduction is suitable for compounds that can withstand treatment with hot acid. Many ketones are reduced in satisfactory yields.

8 9 10

From Cyclobutanone

The acidity of hydrogen adjacent to carbonyl groups can be utilized by reacting cyclobutanone with a protected alanine in the presence of a base. A good nucleofugic leaving group at the para position of the alanine is needed to ensure that a non-negligible yield is obtained. The product can be reacted with excess methyl iodide with a strong base to give the methylated species.

The sulfur equivalent of Molecules 6 and 7 were found to have large absorption peaks in the visible part of the spectrum.

Ring closure methods may be used to synthesize Molecules 8 and 9. This could be achieved by using, for example, a 1 ,2-ethyl dihalide instead of a methyl halide in the final reaction step for the formation of Molecule 6 above. Different stages of dehydrogenation will give either Molecule 8 or Molecule 9.

An alternative method could be to begin with the oxygenation of spiro[3,4]octa- 5,7-diene (CAS No: 15439-15-3) at the 2 position. The adjacent acidic hydrogens can then participate in substitution reactions with A and B. Dehydrogenation then gives the products of Molecules 8 and 9.

The addition of 1,3-propanedithiol to a squarylium dye under the conditions of an acid catalysis will react with a carbonyl group to give the cyclic thioacetal of Molecule 10.

The calculated absorption spectra for compounds 8, 9 and 10 are shown in Figure 1 B.

11 12 13

The use of other group 4 elements instead of carbon in the formation of Molecule 6 leads to a significant bathochromic shift. However, the absorption peaks in the UV have also been shifted into the red part of the spectrum. Germanium would give an orangish dye and silicon would give a pale yellow dye. Molecule 11 combines both carbon and silicon that does not absorb as far in the infrared as Molecules 12 and 13. However, the infrared peak has been shifted approximately 160nm bathochromically with respect to the squarylium dye while keeping the absorption intensity in the visible spectrum to a relatively low level.

The calculated absorption spectra for compounds 11, 12 and 13 are shown in Figure 1C.

Synthesis of compounds of Formula 2

From Croconium Dyes The more reactive of the carbonyl groups can be converted to acetal or thioacetals. When the ketone is treated with an alcohol and an acid catalyst 14 is formed.

However, with ketones, the equilibrium constant for acetal formation is generally unfavorable. For this reason the reaction is usually carried out with the alcohol as solvent in order to drive the equilibrium to the acetals. The acetals are generally stable to basic conditions.

Desulfurization of thioacetals provides a method for net deoxygenation of aldehydes and ketones and is complementary to the Wolff-Kishner and Clemmensen deoxygenations. Methyl sulfide reacts with the ketone under conditions of acid catalysis (BF₃) to give the thioacetal shown as 16 of Formula 2. Acetals and thioacetals are commonly used as protective groups for carbonyls [3].

Molecule 15 may be produced by the same method as the four member analogues.

The calculated absorption spectra for compounds 14, 15 and 16 of Formula 2 are shown in Figure 2A.

From Cyclopentene A possible alternative method could be to use a derivative of 4-cyclopentene-1,

3-dione (CAS No: 930 60-9) which is very similar to croconic acid. The acidic hydrogens of the beta-diketones can readily react with methyl iodide to give the methylated species. For example: 1 equivalent of NaOH, methyl iodide and water will give 4-cyclopentene-2-methyl-1 , 3-dione. Two equivalents of NaOMe with methyl iodide and methanol will give the di-methyl derivative. Substitution of hydroxy groups for hydrogen in the 4 and 5 positions will enable the product to react with R in a similar process to croconium dyes. This could produce the dyes shown as molecule 15. Different functional groups, instead of the methyl groups at the 2 position could also be used.

From Cyclic a-Diketone α-Diketones may be obtained by the mild oxidation of -hydroxy ketones that are available by the acyloin condensation [4]. α-Diketones is also available by the direct oxidation of simple ketones with selenium dioxide [5]. The adjacent acidic hydrogens to the carbonyl groups will enable aniline to react with the α-Diketone in a basic solution [6]. A substitution reaction using a strong base and, for example methanol may give 14.

The addition of 1 ,2-ethanediol and 1 ,3-propanedithiol, as with Formula 1 molecules, to the croconium dyes under the conditions of an acid catalysis gives the cyclic acetal (17) and the thioacetal (18). The use of silicon again shifts the absorption peak significantly to longer wavelengths. However, appreciable absorption is now occurring in the visible spectrum giving the dye an orange color.

17 18 19

The calculated absorption spectra for compounds 17, 18 and 19 are shown in

Figure 2B.

As for compounds of Formula 1, ring closure may be performed on the beta carbon of the I-diketones. Alternatively, functionalization of the spiro compounds, such as spiro[4,4]nona-1 ,3-diene (CAS No: 766-29-0), could lead to 20. The corresponding compounds for 21 and 22 are spiro[3,4]octa-5,7-diene (CAS No: 15439-15-3) and spiro[2,4]hepta-4,6-diene

(CAS No: 765-46-8) respectively.

Reaction with the side group -A and -B may give 22 and water. This and larger spiro compounds could then be reacted with the appropriate -A and -B to form the dyes shown as Molecules 20, 21 and 22. The calculated absorption spectra for compounds 20, 21 and 22 are shown in Figure 2C. A pattern is seen where an increase in size of the spiro compound results in a lower value of the absorption maximum. This also shifts the peak in the blue part of the visible spectrum down into the ultra-violet wavelengths.

20 21 22

Substitution of silicon for the central spiro carbon atom was found to decrease the maximum absorption wavelength.

COMPOUNDS OF FORMULA 3

23 24 25

The calculated absorption spectra for compounds 23, 24 and 25 shown above of Formula 3 are shown in Figure 3A.

A possible method of synthesis is to start with a thiophene, furan and 2,4- Cyclopentadiene-1 -one (CAS No: 13177-38-3) respectively to give 23, 24 and 25 respectively. However, as the C2 and C5 positions need to be blocked in order to functionalize the C3 and C4 positions it is doubtful that ring closure could be achieved readily.

A more preferred method of synthesis is to begin with p-quinone. Addition of aldehydes to the C2 and C3 positions could give ring closure to give the thiophene and their analogues by standard techniques.

COMPOUNDS OF FORMULA 4

Examples of compounds of Formula 4 are compounds 26, 27 and 28 shown below. The calculated absorption spectra for compounds 26, 27 and 28 are shown in Figure 4.

26 27 28

COMPOUNDS OF FORMULA5

Examples of compounds of Formula 5 are compounds 29, 30, 31 and 32 shown below. The calculated absorption spectra for compounds 29 - 32 are shown in Figure 5A and 5B respectively (R = Λ/-dialkyl aniline).

29 30 31 32

The effect of the R moiety on the absorption spectra of Formula 1 compounds

The calculated absorption spectra of compounds having -A (= -B) groups 33 to 45 shown below is presented in Figures 6A to 6E respectively.

33 34 35 36 37 38

39 40 41

The effect of the -A (= -B) moiety on the absorption spectra of Formula 2 compounds The calculated absorption spectra of compounds having -A (= -B) groups 46 to shown below is presented in Figures 7A to 7H respectively.

47 48 49 50 51

53 54 55 56 57

58 59 60 61 Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The . present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

References

1: J. Fabian, Chem. Rev., 92, 1197, (1992).

2: Journal of Organic Chemistry. 35, 532 (1970); 38, 1735, 1738, 2747 (1973); 40, 271, 3306 (1975); 41 , 1494, 3465 (1976); 46, 4139, 5060 (1981); 48, 254 (1983); 50, 5727 (1985), Journal of the Chemical Society: Chemical Communications: 595 (1972); 237 (1981 ), Organic Syntheses 55 7 (1976), Tetrahedron Letters 27 1719, 1723 (1986)

3: Philip J. Kocienski, Protecting Groups, Georg Thieme Verlag Stuttgart, New York, NY (USA), (1994). 4: A. Streitwieser, C. H. Heathcock and W. M. Kosower, Introduction To Organic Chemistry 4th Ed. p866, Macmillan, New York (1992).

5: A. Streitwieser, C. H. Heathcock and W. M. Kosower, Introduction To Organic Chemistry 4th Ed. p884, Macmillan, New York (1992)

6: M. Sainsbury, Aromatic Chemistry, Oxford University Press, New York p51 (1992).

The present invention has been described with reference to a preferred embodiment and number of specific alternative embodiments. However, it will be appreciated by those skilled in the relevant fields that a number of other embodiments, differing from those specifically described, will also fall within the spirit and scope of the present invention. Accordingly, it will be understood that the invention is not intended to be limited to the specific embodiments described in the present specification, including documents incorporated by cross-reference or reference as appropriate.

Claims

1. An organic molecule according to one of the following formulae:

wherein, X is CO and Y is selected from the group consisting of O, S, Se, Te, CS, CR1R2 NRl,

SiRlR2_, GeRlR2, PRl, R'; or wherein X and Y are independently selected from the group consisting of O, S, Se, CS, Te, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; and wherein Rl and R2, which may be the same or different, are selected from the group R;

wherein X is CO and Y and Z are independently selected from the group consisting of O, S, Se,

Te, CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; or wherein Y and Z are each CO and X is selected from the group O, S, Se, Te, CS, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; or wherein X and Z are each CO and Y is selected from the group O, S, Se, Te, CS, CR1R2_, NRl, SiRlR2 GeRlR2, PRl, R'; or wherein X and Y are each CO and Z is selected from the group O, S, Se, Te, CS, CR1R2 NRl, SiRlR2 GeRlR2 PRl, R'; or wherein X, Y and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2 NRl, SiRlR2_t GeRlR2_ι PRl, R'; and wherein Rl and R2, which may be the same or different, are selected from the group R;

wherein X and Z and Z' are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; Y and Y' are independently selected from the group CRl, N; and wherein Rl and R2, which may be the same or different, are selected from the group R;

wherein X and Z are independently selected from the group consisting of O, S, Se, Te, CS, CR1R2, NRl, SiRlR2 GeRlR2 PRl, R'; Y and Y' are independently selected from the group CRl, N; and wherein Rl and R2, which may be the same or different, are selected from the group R;

wherein X and X' are independently selected from the group consisting of O, S, Se, Te, CS,

CR1R2_, NRl, SiRlR2 GeRlR2 PRl, R'; Y, Y', Z and Z' are independently selected from the group CRl, N; and wherein Rl and R2, which may be the same or different, are selected from the group R; and wherein R is the group consisting of hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a halide atom, a hydroxy group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted thioalkyl group and wherein -A and -B in Formulae 1 to 5 given above are independently selected from moieties containing 2n carbon atoms each of which are connected to three (3) atoms at least one (1) of which is one (1) of the 2n carbon atoms other than a carbon atom that is double bonded to a heteroatom, wherein n is an integer equal to or greater that 1; wherein the infrared dye absorbs strongly in the near infrared region of the spectrum but poorly in the visible region of the spectrum

2. An infrared dye according to claim 1 wherein the dye is of Formula 1 to 5.

3. An infrared compound according to claim 2 having the formula selected from the group consisting of:

11 12 13

3. An infrared dye according to claim 1 or claim 2 wherein -A and -B are each independently selected from the group consisting of:

39 40 41

42 43 44 45

A compound according to claim 2 wherein -A and -B are the same.

5. A compound according to claim 1 of Formula 2.

6. A compound of claim 5 having a formula selected from the group consisting of:

14 15 16

17 18 19

7. A compound according to claim 5 or claim 6 wherein -A and -B are each independently selected from the group consisting of:

46 47 48 49 50 51

52 53 54 55 56 57

58 59 60 61

A compound of claim 1 of Formula 3.

A compound of claim 8 having a formula selected from the group consisting of:

10. A compound of claim 1 of Formula 4.

11. A compound of claim 10 having a formula selected from the group consisting of:

26 27 28

12. A composition of claim 1 of Formula 5.

13. A compound of claim 12 having a formula selected from the group consisting of:

29 30 32

14. An infrared dye composition comprising a compound according to claim 1.

15. An infrared absorbing compound according to claim 1 wherein one or more polar group substituents such as -S0₃H, -NH₂ and -CN are utilized.

16. A solvent-based ink composition comprising a compound according to claim 1.

17. A solvent-based ink according to claim 15 which is ink jet printer ink.