Patent ID: 7452989

Claim:
An IR-absorbing dye which 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 Ti(A 1 )(A 2 ), Zr(A 1 )(A 2 ), V(A 1 )(A 2 ), Si(A 1 )(A 2 ), Ge(A 1 )(A 2 ), Ga(A 1 ), Al(A 1 ), Mn(A 1 ), Fe(A 1 ), Sn(A 1 )(A 2 ), or Pb(A 1 )(A 2 ); and A 1 and A 2 may be the same or different and are axial ligands of formula (IIIa) wherein: C 1 represents a core unit having two or more branching position; each P 1 is independently selected from H, a hydrophilic moiety or a branched 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.