The invention provides compounds of the Formula (I),in which W is independently selected from W1, W2, W3, W4, W5,or W represents a pair of substituents independently selected from H, alkyl, aryl or amide in which the amide is optionally part of a linking chain, and the Zn—Zn′ bonds (n=4-17 n′=n+1) are optionally of any whole or partial bond order, Y is Y1or Y represents a pair of substituents independently selected from H, C1-C6 alkyl, Z5 or Z6 aryl, or Y is optionally a bridging structure that may comprise one or more C1-C6 amide, C1-C6 ether, or C1-C6 ester groups, R—R39 are independently selected from no substituent, a lone pair of electrons, H, halogen, C5-C6 aryl, C1-C12 alkyl, amine, C1-C6 alkylamine, C1-C6 amide, nitro, cyano, carboxyl, C1-C6 ester, phosphane, thiol, C1-C6 thioether, OR40, and suitable pairs of adjacent R groups (R—R39) may optionally together form part of a C5 or C6 aryl ring, a Z5 or Z6 ring, R40 is independently selected from H, C1-C6 alkyl, Z5 or Z6 aryl, C1-C6 ester, poly(—C2O—), amine, and C1-C6 alkylamine, Z—Z24 are independently selected from C, N, P, O, and S, and X− is a pharmaceutically acceptable anion, for the treatment of cancer.
