2,2′-[(E,E)-1,1′-(2,2-Dimethylpropane-1,3-diyldinitrilo)diethylidyne]diphenol

Tetradentate N2O2Chelated Palladium(II) Complexes: Synthesis, Characterization, and Catalytic Activity towards Mizoroki-Heck Reaction of Aryl Bromides

Four air and moisture-stable palladium(II)-Schiff base complexes,N,N′-bis(α-methylsalicylidene)propane-1,3-diamine palladium(II) (2a),N,N′-bis(4-methyl-α-methylsalicylidene)propane-1,3-diamine palladium(II) (2b),N,N′-bis(3,5-di-tert-butylsalicylidene)propane-1,3-diamine palladium(II) (2c), andN,N′-bis(4-methoxy-salicylidene)propane-1,3-diamine palladium(II) (2d), have been successfully synthesised and characterised by CHN elemental analyses and conventional spectroscopic methods. These complexes were investigated as catalysts in the phosphine-free Mizoroki-Heck cross-coupling reactions of aryl bromides with methyl acrylate.

{5,5′-Dimethoxy-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}palladium(II)

In the title compound, [Pd(C₂₁H₂₄N₂O₄)], the complete mol­ecule is generated by crystallographic mirror symmetry with the Pd and three C atoms lying on the mirror plane. The Pd—O and Pd—N distances are 1.9932 (6) and 2.0029 (7) Å, respectively. The dihedral angle between two benzene rings of the ligand is 79.21 (4)°. In the crystal, C—H⋯O hydrogen bonds link the mol­ecules into layers parallel to the ab plane. These planes are further connected by C—H⋯O inter­actions, forming a three-dimensional network.

N,N'-Bis[(2-hydroxy-phen-yl)(phen-yl)methyl-idene]propane-1,2-diamine

In the the title compound, C(29)H(26)N(2)O(2), two strong intra-molecular O-H⋯N hydrogen bonds involving the hydr-oxy and imine groups generate S(6) ring motifs. The dihedral angles between the pairs of terminal benzene rings are 89.8 (2) and 87.8 (2)°.

2,2'-[(Propane-1,3-diyldinitrilo)bis-(phenyl-methyl-idyne)]diphenol

In the title mol­ecule, C₂₉H₂₆N₂O₂, there are two strong intra­molecular O—H⋯N hydrogen bonds involving the hydr­oxy and imine groups, forming S(6) ring motifs. The dihedral angles between adjacent phenyl rings and phenol-containing planes are 85.27 (19) and 91.38 (18)°. In the crystal structure, weak inter­molecular C—H⋯O hydrogen bonds connect mol­ecules into a two-dimensional network.