Syntheses, Crystal Structure, and Magnetic Properties of Mn\\r sub/12sub\\r Single-Molecule Magnets with Naphthalenecarboxylate Bridges, [Mn\\r sub/12sub\\r O\\r sub/12sub\\r (O\\r sub/2sub\\r CC\\r sub/10sub\\r H\\r sub/7sub\\r )\\r sub/16sub\\r (H\\r sub/2sub\\r O)\\r sub/4sub\\r ] and Their Tetraphenylphosphonium Salts