Method of preparing macrocylic metal cyanine compound

1. A method of preparing a macrocyclic metal cyanine, said method comprising the step of providing a corresponding macrocyclic metal-free cyanine compound dissolved in an organic solvent and adding a metal reagent thereto, said metal reagent being highly soluble in said organic solvent, 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 the group consisting of a C 3-20 arylene group and a C 3-20 heteroarylene group;

M is selected from the group consisting 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 the group consisting of OH, halogen and OR 3 ;

R 3 is a selected from the group consisting of C 1-12 alkyl, C 5-12 aryl, C 5-12 arylalkyl and 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 the group consisting of C 1-12 alkyl, C 5-12 aryl, C 5-12 arylalkyl, C 1-12 alkoxy, C 5-12 aryloxy and 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 said metal reagent comprises one or more ligands for providing said solubility in said solvent.

4. The method of claim 3 , wherein said one or more ligands are selected from the group consisting of acetylacetonate (acac), acetate and C 1-8 alkoxide.

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

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