Palladium(II) complexes of a bridging amine bis-(phenolate) ligand featuring κ2 and κ3 coordination modes.

Bidentate and tridentate coordination of a 2,4-di-tert-butyl-substituted bridging amine bis-(phenolate) ligand to a palladium(II) center are observed within the same crystal structure, namely di-chlorido-({6,6'-[(ethane-1,2-diylbis(methyl-aza-nedi-yl)]bis-(methyl-ene)}bis-(2,4-di-tert-butyl-phenol))palladium(II) chlorido-(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hy-droxy-phen-yl)meth-yl](meth-yl)amino}-eth-yl)(meth-yl)amino]-meth-yl}phenolato)palladium(II) methanol 1.685-solvate 0.315-hydrate, [PdCl2(C34H56N2O2)][PdCl(C34H55N2O2)]·1.685CH3OH·0.315H2O. Both complexes exhibit a square-planar geometry, with unbound phenol moieties participating in inter-molecular hydrogen bonding with co-crystallized water and methanol. The presence of both κ2 and κ3 coordination modes arising from the same solution suggest a dynamic process in which phenol donors may coordinate or dissociate from the metal center, and offers insight into catalyst speciation throughout Pd-mediated processes. The unit cell contains di-chlorido-({6,6'-[(ethane-1,2-diylbis(methyl-aza-nedi-yl)]bis-(methyl-ene)}bis-(2,4-di-tert-butyl-phenol))palladium(II), {(L 2)PdCl2}, and chlorido-(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hy-droxy-phen-yl)meth-yl](methyl)amino}eth-yl)(meth-yl)amino]-meth-yl}phenolato)palladium(II), {(L 2 X)PdCl}, mol-ecules as well as fractional water and methanol solvent mol-ecules.