groups are labile to the ethanolic ammonia treatment such a metal txp derivatized support may be used for stepwise synthesis and upon cleavage and deprotection results in a 3 39 linked metal txp dna conjugate 7a 4 the amide forming reaction may also occur at the conclusion of dna synthesis before deprotection and cleavage from the solid support as depicted in fig1 b a phosphoramidite derivative of a metal texaphyrin complex 7b 2 is prepared by reaction of the monoalcohol 7b 1 with phosphitylating agent and diisopropylethylamine the hydroxyl groups are again protected as the ester for this synthesis the resulting phosphoramidite is coupled on the synthesizer as the final residue to form 7b 3 in this approach deprotection results in a 5 39 linked txp metal complex dna conjugate 7c 2 this txp conjugate has no amide bonds in the linker a txp dna conjugate having the texaphyrin in an internal linkage to the oligonucleotide may be synthesized using this stepwise approach a dihydroxytexaphyrin is treated with dimethoxytrityl chloride in the presence of dimethylaminopyridine and pyridine the resulting monoprotected texaphyrin is treated with phosphitylating agent and diisopropylethylamine to produce a monoprotected phosphoramidite this product is coupled to a growing oligonucleotide during synthesis in place of a nucleotide residue to insert a texaphyrin in an internal linkage the monoconjugate may then be further coupled to.