Self-Assembled Cage Structures and Ethylene Polymerization Behavior of Palladium Alkyl Complexes That Contain Phosphine-Bis(arenesulfonate) Ligands

Abstract

The phosphine-bis-arenesulfonate ligands PR2(2-SO3Li-5-R1-Ph)(2-SO3–-5-R1-Ph) (Li[OPO–]; Li[1a–e], a: R1 = Me, R2 = Ph, b: R1 = iPr, R2 = Ph, c: R1 = Cy, R2 = Ph, d: R1 = tBu, R2 = Ph, e: R1 = R2 = tBu, f: R1 = R2 = Cy) coordinate as κ2-P,O chelators in (Li-OPO)PdMeL complexes (4a–c,f: L = 4-(5-nonyl)pyridine = py′; 5b–d: L = py; 2e: L = py′). 4a–c,f and 5b–d self-assemble into tetrameric structures in which four (Li-OPO)PdMeL units are arranged around a cubic Li4S4O12 cage formed from the four non-Pd-bound ArSO3Li units and one oxygen from each of the Pd-bound ArSO3– units. The {(Li-OPO)PdMeL}4 assemblies are in equilibrium with monomeric (Li-OPO)PdMeL species in CD2Cl2 and CDCl2CDCl2 solution. Crystallization of 2e from a toluene/pentane mixture at −40 °C yields a trimeric C1-symmetric assembly (6e) in which three (Li-1e)PdMe(py′) units are held together by a Li3S3O9 core. Crystallization of 2e from toluene/pentane at room temperature results in partial loss of py′ and formation of a Pd6 assembly, {(Li-...