Thermally imageable elements imageable at several wavelengths

1. An infrared absorbing compound of the structure:

in which:

Y 1 , Y 2 , and Y 3 are each independently hydrogen, halo, alkyl, phenyl, substituted phenyl, phenylamino, diphenylamino, or phenylthio;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, alkyl, or SO 3 − , with the proviso that two of R 1 , R 2 , R 3 , and R 4 are SO 3 − ;

R 5 and R 6 are each independently alkyl, aryl, aralkyl, hydroxyalkyl, alkoxyalkyl, aminoalkyl, carboxyalkyl, or sulfoalkyl;

R 7 and R 8 are each independently hydrogen, alkyl, or halo;

Ar 1 and Ar 2 are each independently phenyl or substituted phenyl;

Z 1 , and Z 2 are each independently a benzo group or a naphtho group;

Z 3 and Z 4 are each independently two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ; and

n, and n 2 are each independently 0 to 4.

2. The infrared absorbing compound of claim 1 in which:

Y 1 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, methyl, ethyl, or SO 3 − groups;

X 1 and X 2 are each C(CH 3 ) 2 ; and

n 1 and n 2 are each independently 1 to 4.

3. The infrared absorbing compound of claim 1 in which the compound has Structure I.

4. The infrared absorbing compound of claim 3 in which:

Y 2 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 5 and R 6 are each independently an alkyl group of one to four carbon atoms; and

R 7 and R 8 are each independently hydrogen, methyl, ethyl, or chloro.

5. The infrared absorbing compound of claim 4 in which R 1 and R 2 are the same; R 3 and R 4 are the same; R 5 and R 6 are the same and R 7 and R are the same; Z 1 and Z 2 are the same; X 1 and X 2 are the same; and n, and n 2 are the same.

6. The infrared absorbing compound of claim 1 in which the compound has Structure II.

7. The infrared absorbing compound of claim 6 in which:

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar 1 and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.

8. The infrared absorbing compound of claim 7 in which R 1 and R 2 are the same; R 3 and R 4 are the same; X 1 and X 2 are the same; n, and n 2 are the same; and Ar 1 and Ar 2 are the same.

9. The infrared absorbing compound of claim 1 in which the compound has Structure III.

10. The infrared absorbing compound of claim 9 in which:

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar, and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.

11. The infrared absorbing compound of claim 10 in which R 1 and R 2 are the same; R 3 and R 4 are the same; X 1 and X 2 are the same; no and n 2 are the same; and Ar 1 and Ar 2 are the same.

12. An imageable element comprising a top layer over a substrate;

in which:

the top layer comprises a binder; and

the element comprises an infrared absorbing compound of the structure:

in which:

Y 1 , Y 2 , and Y 3 are each independently hydrogen, halo, alkyl, phenyl, substituted phenyl, phenylamino, diphenylamino, or phenylthio;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, alkyl, or SO 3 − , with the proviso that two of R 1 , R 2 , R 3 , and R 4 are SO 3 − ;

R 5 and R 6 are each independently alkyl, aryl, aralkyl, hydroxyalkyl, alkoxyalkyl, aminoalkyl, carboxyalkyl, or sulfoalkyl;

R 7 and R 8 are each independently hydrogen, alkyl, or halo;

Ar 1 and Ar 2 are each independently phenyl or substituted phenyl;

Z 1 , and Z 2 are each independently a benzo group or a naphtho group;

Z 3 and Z 4 are each independently two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ; and

n 1 and n 2 are each independently 0 to 4.

13. The element of claim 12 in which the binder is a phenolic resin.

14. The element of claim 13 in which the top layer additionally comprises a dissolution inhibitor.

15. The element of claim 14 in which:

Y 1 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, methyl, ethyl, or SO 3 − groups;

X 1 and X 2 are each C(CH 3 ) 2 ; and

n 1 and n 2 are each independently 1 to 4.

16. The element of claim 15 in which:

the compound has Structure I;

Y 2 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 5 and R 6 are each independently an alkyl group of one to four carbon atoms; and

R 7 and R 8 are each independently hydrogen, methyl, ethyl, or chloro.

17. The element of claim 15 in which:

the compound has Structure II;

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar 1 and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.

18. The element of claim 15 in which:

the compound has Structure II; and

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar 1 and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.

19. The element of claim 15 in which the element does not comprise an underlayer.

20. The element of claim 15 in which the element additionally comprises an underlayer.

21. The element of claim 20 in which the infrared absorbing compound is in the underlayer.

22. A method for forming an image, the method comprising the steps of:

(a) thermally imaging an imageable element comprising a top layer over a substrate and forming an imaged imageable element comprising imaged regions and unimaged regions in the element; and

(b) developing the imaged imageable element with a developer and removing the imaged regions;

in which:

the top layer comprises a binder; and

the element comprises an infrared absorbing compound of the structure:

in which:

Y 1 , Y 2 , and Y 3 are each independently hydrogen, halo, alkyl, phenyl, substituted phenyl, phenylamino, diphenylamino, or phenylthio;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, alkyl, or SO 3 − , with the proviso that two of R 1 , R 2 , R 3 , and R 4 are SO 3 − ;

R 5 and R 6 are each independently alkyl, aryl, aralkyl, hydroxyalkyl, alkoxyalkyl, aminoalkyl, carboxyalkyl, or sulfoalkyl;

R 7 and R 8 are each independently hydrogen, alkyl, or halo;

Ar 1 and Ar 2 are each independently phenyl or substituted phenyl;

Z 1 , and Z 2 are each independently a benzo group or a naphtho group;

Z 3 and Z 4 are each independently two hydrogen atoms, a cyclohexene residue, or a cyclopentene residue;

X 1 and X 2 are each independently S, O, NH, CH 2 , or C(CH 3 ) 2 ; and

n 1 and n 2 are each independently 0 to 4.

23. The method of claim 22 in which thermal imaging is carried out either with 800 nm±50 nm radiation or 1050 nm±50 nm radiation.

24. The method of claim 23 in which:

Y 1 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 1 , R 2 , R 3 , and R 4 are each independently hydrogen, methyl, ethyl, or SO 3 — groups;

X 1 and X 2 are each C(CH 3 ) 2 ; and

n 1 and n 2 are each independently 1 to 4.

25. The method of claim 24 in which:

the compound has Structure I;

Y 2 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino;

R 5 and R 6 are each independently an alkyl group of one to four carbon atoms; and

R 7 and R 8 are each independently hydrogen, methyl, ethyl, or chloro.

26. The method of claim 24 in which:

the compound has Structure II;

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar 1 and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.

27. The method of claim 24 in which:

the compound has Structure III; and

Y 3 is phenyl, hydrogen, chloro, phenylthio, or diphenylamino; and

Ar 1 and Ar 2 are each independently phenyl, p-methylphenyl, p-methoxyphenyl, or p-chlorophenyl.