Cyclodiphosphazanes with hemilabile ponytails: Synthesis, transition metal chemistry (Ru(II), Rh(I), Pd(II), Pt(II)), and crystal and molecular structures of mononuclear (Pd(II), Rh(I)) and Bi- and tetranuclear rhodium(I) complexes

Abstract

Cyclocliphosphazanes having hemilabile ponytails such as cis-[(BuNP)-Bu-t(OC6H4OMe-o)](2) (2), cis-[(BuNP)-Bu-t(OCH2CH2-OMe)](2) (3), cis-[(BuNP)-Bu-t((OCHCHSMe)-C-2-S-2)](2) (4), and cis-[(BuNP)-Bu-t(OCH2CH2NMe2)](2) (5) were synthesized by reacting cis-[(BuNPCl)-Bu-t](2) (1) with corresponding nucleophiles. The reaction of 2 with [M(COD)Cl-2] afforded cis-[MCl2(2)(2)] derivatives (M = Pd (6), Pt (7)), whereas, with [Pd(NCPh)(2)Cl-2], trans-[MCl2(2)(2)] (8) was obtained. The reaction of 2 with [Pd(PEt3)Cl-2](2), [Ru(eta(6)-p-cymene)Cl-2](2), and [M(COD)Cl](2) (M = Rh, Ir) afforded mononuclear complexes of Pd(II) (9), Ru(II) (11), Rh(l) (12), and Ir(l) (13) irrespective of the stoichiometry of the reactants and the reaction condition. In the above complexes the cyclodiphosphazane acts as a monodentate ligand. The reaction of 2 with [PdCl(eta 3-C3H5)](2) afforded binuclear complex [(PdCl(eta(3)-C3H5)](2){((BuNP)-Bu-t(OC6H4OMe-o))(2)-KP}] (10). The reaction of ligand 3 with [Rh(CO)(2)CI](2) in 1:1 ratio in CH3CN under reflux condition afforded tetranuclear rhodium(l) metallamacrocycle (14), whereas the ligands 4 and 5 afforded bischelated binuclear complexes 15 and 16, respectively. The crystal structures of 8, 9, 12, 14, and 16 are reported.