Mono(2,6-dinitroaryl)platinum(II) and Mono- and Bis(2,6-dinitroaryl)platinum(IV) Complexes

cis-[Pt(κ2-Ar)(κ1-Ar)(OH2)] (κ2-Ar = κ2C,O-C6(NO2)2-2,6-(OMe)3, κ1Ar = κC-C6(NO2)2-2,6-(OMe)3) reacts either (1) with hydrochloric acid (1:1) to afford cis- and trans-[Pt(κ2-Ar)(μ-Cl)]2 (1a) and C6H(NO2)2-2,6-(OMe)3 (HAr) or (2) with MeC(O)X (1:1) in the presence of atmospheric moisture to give 1a or 1b (X = Br). These complexes react (1) with bidentate ligands to afford [Pt(κ1-Ar)X(L∧L)] (X = Cl, L∧L = bpy (2a); X = Br, L∧L = 1,5-cyclooctadiene (cod; 2b), norbornadiene (nbd; 2c)), (2) with Tl(acac) to give [Pt(κ2-Ar)(acac-κ2O,O)] (3), and (3) with monodentate neutral ligands to render complexes resulting from bridge splitting or/and cleavage of the Pt−O bond ([Pt(κ1-Ar)BrL2] (L = MeCN (4a), XyNC (Xy = C6H3Me2-2,6; 4b), [Pt(κ2-Ar)BrL] (L = MeCN (5a), XyNC (5b), CO (5c)), [Pt(κ1-Ar)(μ-X)L]2 (X = Br, L = 3-hexyne (6a), ethylene (6b), styrene (6c); X = Cl, L = PPh3 (6d)), depending on the nature of the ligand and the molar ratio of the reagents. Complex 6d reacts (1) with monodentate neutral ligands to give [Pt(κ1-Ar)Cl(PPh3)L] (L = PPh3 (7), SMe2 (8a), CO (8b), XyNC (8c1)), (2) with Tl(acac) to afford [Pt(κ1-Ar)(acac-κ2O,O)(PPh3)] (9), (3) with (PPN)Cl to render anionic (PPN)[Pt(κ1-Ar)Cl2(PPh3)] (PPN·10), or (4) with bpy leading to cationic [Pt(κ1-Ar)(bpy)(PPh3)]Cl (11·Cl). If 1 equiv of bpy is used in the latter reaction, the intermediate [Pt(κ1-Ar)(bpy)(PPh3)][Pt(κ1-Ar)Cl2(PPh3)] (11·10) is obtained. The reaction of excess Cl2 with cis-[Pt(κ2-Ar)(κ1-Ar)(H2O)] or trans-[Pt(κ2-Ar)(κ2-Ar)(CO)] gives (OC-6-32)-[Pt(κ2-Ar)2Cl2] (12) or (OC-6-22)-[Pt(κ2-Ar)2Cl2] (13), respectively. Complex 13 gradually transforms in solution into 12. The dimer 6d reacts with 3 equiv of PhICl2 to afford fac-[Pt(κ2-Ar)Cl3(PPh3)] (14). AgClO4 reacts with complex 12, leading to (OC-6-32)-[Pt(κ2-Ar)2(OH2)2](ClO4)2·Et2O (15·Et2O). Complex 12 reacts with 1 equiv of PPh3 to afford cis-[Pt(κ2-Ar)(κ1-Ar)PPh3] or with AsPh3, leading to cis-[Pt(κ2-Ar)(κ1-Ar)AsPh3] (16, 2:1 molar ratio) or (AsPh3OH)[Pt(κ2-Ar)(κ1-Ar)Cl] (17) (1:1 molar ratio). X-ray crystal structures of HAr and complexes 2a·CH2Cl2, 2c, 3, 5a, trans-6b, trans-6c·CDCl3, trans-7·Et2O, 8a, 8c, 9, 11·10·2CHCl3, 12, 13, 16·CHCl3, and 17 have been determined.