Whole-molecule disorder of the heterometallic complex diaqua-1κ ² <i>O</i> -dichlorido-2κ ² <i>Cl</i> -(μ-2-formyl-6-methoxyphenolato-1κ ² <i>O</i> ¹ , <i>O</i> ² :2κ <i>O</i> ⁶ ){μ-2-

The new mol-ecular complex [NiPb(C₉H₁₀NO₂)(C₈H₇NO₃)Cl₂(H₂O)₂] with the Schiff base 2-meth-oxy-6-[(methyl-imino)-meth-yl]phenol and <i>ortho</i>-vanillin ligands, both deprotonated, crystallizes in the monoclinic space group <i>P</i>2₁/<i>c</i> with one mol-ecule per asymmetric unit. The heterometallic mol-ecule exhibits a whole-mol-ecule orientational disorder [occupancy ratio 0.711 (6): 0.289 (6)] about a pseudo-twofold rotation axis that roughly bis-ects the mol-ecule along the Ni-Pb axis. The Ni centre coordination is distorted octa-hedral [Ni-N/O_eq = 1.996 (8)-2.021 (7) Å, major component] with two water mol-ecules in the apexes [2.088 (6) and 2.090 (5) Å]. The Pb atom is six-coordinate in a highly distorted tetra-gonal-bipyramidal geometry. Two phenolato and two methoxo O atoms from the deprotonated ligand moieties are nearly coplanar with the metal centre [Pb-O 2.301 (8)-2.740 (10) Å, major component], while the two chlorides are located on opposite sides of the plane [Pb-Cl = 2.821 (5) and 2.868 (5) Å]. The Ni-Pb pair of metals is bridged by two phenolato O atoms enabling a metal-metal separation of 3.441 (3)/3.477 (7) Å. Two intra-molecular O-H⋯Cl hydrogen bonds between coordinated aqua and chloride ligands appear to be a reason for the Cl-Pb-Cl and O-Ni-O angles being far from 180°. In the solid state, the well-separated heterometallic mol-ecules are inter-linked by π-π stacking and weak O-H⋯Cl and C-H⋯Cl/O hydrogen bonds. The mol-ecules show no significant inter-molecular inter-actions: the minimal <i>M</i>⋯<i>M</i> distance in the crystal is about 7.65 Å (Ni⋯Pb).