Tunable chiral induction and complete determination of chirality in a dinuc
lear triple helicate, [Ga(2)1(3)](6-) (1 = N,N ' -bis(2,3-dihydroxybenzoyl)
-1,4-phenylenediamine, an achiral ligand) is achieved by the use of a chira
l counterion. The counterion, (S)-N-methylnicotinium (s-nic), has stereospe
cific interactions with the helicate. The energy difference, DeltaG, betwee
n the Lambda Lambda and Delta Delta helicates in the asymmetric environment
afforded by enantiopure s-nic is about 1.1 (+/-0.2) kcal/mol.