NMR characterization ligands 8, 10, 11, and 12 and metallacycles 1, 2, and 3. Partial (A−D) 31P and (E−K) 1H NMR spectra (CD3COCD3, 295 K) of platinum acceptor 8 (A and E), ligands 10 (G), 11 (I), and 12 (K), and metallacycles 1 (B and F), 2 (C and H), and 3 (D and J).