Patent ID: 7148345

Claim:
An IR-absorbing naphthalocyanine dye of formula (I): wherein M is Ga(A 1 ); A 1 is an axial ligand selected from —OH, halogen, —OR 3 , —OC(O)R 4 , a hydrophilic ligand andlor a ligand suitable for reducing cofacial interactions; R 1 and R 2 may be the same or different and are selected from hydrogen or C 1-12 alkoxy; R 3 is selected from C 1-12 alkyl, C 5-12 aryl, C 5-12 arylalkyl or Si(R x )(R Y )(R Z ); and R 4 is selected from C 1-12 alkyl, C 5-12 aryl or C 5-12 arylalkyl R x , R y and R z may be the same or different and are selected from C 1-12 alkyl, C 5-12 aryl, C 5-12 arylalkyl, C 1-12 alkoxy, C 5-12 aryloxy or C 5-12 arylalkoxy; W is a hydrophilic group, each W group being independently selected from a substituent comprising a sulfonic acid group (including salts thereof), or a substituent comprising a sulfonamide group; n1 is 0, 1, 2 or 3; n2 is 0, 1, 2 or 3; n3 is 0, 1, 2 or 3; n4 is 0, 1, 2 or 3; provided that at least one of n1, n2, n3 or n4 is greater than 0.