Patent ID: 7367665

Claim:
An IR-absorbing metal-cyanine dye, said metal having at least one axial ligand bound thereto, wherein said axial ligand comprises a moiety suitable for reducing intermolecular interactions between adjacent dye molecules, thereby minimixing absorption of visible light, wherein said dye is a metal-cyanine complex of formula (I): wherein Q 1 , Q 2 , Q 3 and Q 4 are the same or different and are independently selected from a C 3-20 arylene group or a C 3-20 heteroarylene group; M is selected from Ga(A 3 ), Al(A 1 ), Mn(A 1 ), Fe(A 1 ) or Pb(A 1 )(A 2 ); A 1 and/or A 2 is of formula (III); wherein C 1 represents a core unit having two or more branching poisons; each P 1 is independently selected from H or a hydrophilic moiety; g 1 is an integer from 2 to 8; q 1 is 0 or an integer from 1 to 6; and each p 1 is independently selected from 0 or an integer from 1 to 6.