Early studies on cis-PtA(2)(d(G*pG*)) (A(2) = diamine or two amines, G* = N7-platinated G) and cis-Pt(NH3)(2)(d(G*pG*)) models for the key cisplatin-DNA cross-link suggested that they exist exclusively or mainly as the HH1 conformer (HH1 = head-to-head G* bases, with 1 denoting the normal direction of backbone propagation). These dynamic models are difficult to characterize. Employing carrier A(2) ligands designed to slow dynamic interchange of conformers, we found two new conformers, Delta HT (head-to-tail G* bases with a Delta chirality) and HH2 (with 2 denoting the backbone propagation direction opposite to normal). However, establishing that the non-HH1 conformations exist as an intrinsic feature of the 17-membered Pt(d(G*pG*)) ring requires exploring a range of different carrier ligands. Here we employ the planar aromatic sp(2) N-donor 5,5'-Me(2)bipy (5,5'-dimethyl-2,2'-bipyridine)ligand, having a shape very different from those of previously used nonplanar sp(3) N-donor bidentate carrier ligands, which often bear NH groups. The 5,5'-Me(2)bipy H6 and H6' protons project toward the d(G*pG*) moiety and hinder the dynamic motion of 5,5'-Me(2)bipyPt(d(G*pG*)). We again found HH1, HH2, and Delta HT conformers with typical properties, supporting the conclusions that the new Delta HT and HH2 conformers exist universally in dynamic cis-PtA(2)(d(G*pG*)) adducts, including cis-Pt(NH3)(2)(d(G*pG*)), and that the carrier ligand typically has little influence on the overall structure of the Pt(d(G*pG*)) macrocyclic ring of a given conformer. The sizes of the G* H8 to H6/H6' NOE cross-peaks indicate little base canting in all 5,5'-Me(2)bipyPt(d(G*pG*)) conformers, suggesting that carrier-ligand NH groups favor the canting of one G* base in the HH1 and HH2 conformers of typical cis-PtA(2)(d(G*pG*)) adducts.