[(PtXYZ)-A-(Pt X′Y′Z′)], or salts thereof, where X, Y, Z, X′, Y′, and Z′ may be the same or different and are

anionic groups, or

neutral groups which may be substituted or unsubstituted; and

A is a bridging polyamine having a general formula selected from the group consisting of

H₂N(CH₂)_xNBB′(CH₂)_yNH₂ where x ranges from 1 to 10 and y ranges from 1 to 10, or

H₂N(CH₂)_xNBB′(CH₂)_yNBB′(CH₂)_xNH₂ where x ranges from 1 to 10 and y ranges from 1 to 10,

where B and B′ are hydrogen or a labile blocking group and may be the same or different, and may be the same or different at each location, and where B′ may be present or absent,

and wherein when said anionic groups or neutral groups of said linear polyamine-bridged platinum compound are in a 1,1/t,t configuration with respect to said bridging polyamine, said labile blocking group is not tBOC;

and wherein

i) said anionic groups are selected from the group consisting of halide, pseudohalide, substituted pseudohalide, sulphate, phosphate, phosphonate, nitrate, carboxylate, substituted carboxylate, dicarboxylate, and substituted dicarboxylate;

ii) said neutral groups are selected from the group consisting of ammonia, primary or secondary amines, a “dangling” diamine H₂N(CH₂)_nNBB′ where only the —NH₂ moiety is bound to platinum, pyridine, substituted pyridine, quinoline, imidazole, thiazole, pyrimidine, purine, acridine, pyrazole, benzimidazole, and benzothiazole; and for 1,1/c,c configurations, Y, Y′, Z and Z′ may be a chelating bidentate diamine; and

iii) said labile blocking group is an amide protection group,

with the proviso that when x =4, y =3, and at least two of X, Y, Z and X′, Y′, Z′ are NH_3, one of B or B′ is a labile protecting group.