Opposite influence of calf thymus DNA on the rate of substitution of ethylenediamine, by thiourea, in the complex cations [Pd(bpy)(en)](2+) and [Pd(bromazepam)(en)](2+) (bromazepam=7-bromo-1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepin-2-one)

Calf thymus DNA inhibits the substitution of ethylenediamine, by thiourea, in [Pd(bpy)(en)](2+) and catalyses the same reaction in [Pd(bromazepam)(en) ](2+) (bromazepam = 7-bromo-1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepin- 2-one); this kinetic effect can be related to the different binding modes o f the two complexes to the biopolymer.