Synthesis of metal cyanines

1. A method for preparing a macrocyclic metal cyanine, comprising the step of providing a macrocyclic metal-free cyanine compound and inserting a metal therein using a metal reagent, wherein said metal reagent comprises at least one organic ligand, wherein said organic ligand is acetylacetonate (acac), acetate or C 1-8 alkoxide, and wherein the macrocyclic metal cyanine is 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 Si(A 1 )(A 2 ), Ge(A 1 )(A 2 ), Ga(A 1 ), Mg, Al(A 1 ), TiO, Ti(A 1 )(A 2 ), ZrO,

Zr(A 1 )(A 2 ), VO, V(A 1 )(A 2 ), Mn, Mn(A 1 ), Fe, Fe(A 1 ), Co, Ni, Cu, Zn, Sn, Sn(A 1 )(A 2 ), Pb, Pb(A 1 )(A 2 ), Pd and Pt;

A 1 and A 2 are axial ligands, which may be the same or different, and are selected from —OH, halogen, —OR 3 , a hydrophilic ligand and/or a ligand suitable for reducing cofacial interactions;

R 3 is a selected from C 1-12 alkyl, C 5-12 aryl, C 5-12 arylalkyl or Si(R x )(R Y )(R z ); and

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.

2. The method of claim 1 , wherein the oxidation state of the metal in said metal reagent matches the oxidation state of the metal in said macrocyclic metal cyanine.

3. The method of claim 1 , wherein the metal is vanadium.

4. The method of claim 1 , wherein the metal reagent is VO(acac) 2 .

5. The method of claim 1 , wherein Q 1 , Q 2 , Q 3 and Q 4 are selected from an arylene or heteroarylene group of the formula:

wherein

R 1 and R 2 may be the same or different and are selected from hydrogen, hydroxyl, C 1-12 alkyl, C 1-12 alkyl bearing a hydrophilic or hydrophilizable group, C 1-12 alkoxy, C 1-12 alkoxy bearing a hydrophilic or hydrophilizable group, amino, C 1-12 alkylamino, di(C 1-12 alkyl)amino, halogen, cyano, thiol, C 1-12 alkylthio, nitro, carboxy, C 1-12 alkylcarbonyl, C 1-12 alkoxycarbonyl, C 1-12 alkylcarbonyloxy or C 1-12 alkylcarbonylamino;

T is selected from a substituent comprising a polymeric chain or a C 1-30 hydrocarbyl group;

W is a hydrophilic group;

E is selected from —OH, —O − , C 1-12 alkoxy, C 1-6 alkyl, C 5-12 arylalkyl, C 1-6 alkylcarbonyl, C 5-12 arylalkylcarbonyl, C 1-6 alkoxycarbonyl or C 5-12 arylalkoxycarbonyl;

m is 0, 1 or2;

n is 0, 1 or2; and

p is 0, 1 or 2.

6. The method of claim 5 , wherein R 1 and R 2 are selected from hydrogen or C 1-8 alkoxy.

7. The method of claim 5 , wherein W is selected from a substituent comprising a PEG chain; a substituent comprising an ammonium group; a substituent comprising an acid group, including salts thereof or a substituent comprising a sulfonamide group.

8. The method of claim 5 , wherein W is —SO 3 H or a water-soluble salt thereof.

9. The method of claim 5 , wherein M is 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 ).