Five Metal(II) Coordination Polymers Constructed from Two Vanillin Derivatives: From Discrete Structure to 3D Diamondoid Network

Abstract

Two vanillin derivatives, 4-hydroxy-3-methoxybenzaldehyde nicotinoylhydrazone (L 1 ) and 4-hydroxy-3-methoxybenzaldehyde salicyloylhydrazone (L 2 ), were synthesized. The two flexible ligands have been employed to assemble with Pb(II), Cu(II), or Co(II) ion, leading to the formation of five coordination polymers varying from zero-to three-dimensional structures. Complex [Pb 2 (L 1 ) 2 (NO 3 ) 2 ] 3 3H 2 O (1) features a novel 3D diamond-like coordination network based on binuclear units as binodes and hydrazone ligands, L 1 , as linkers. However, complex Pb 2 (L 1 ) 2 (OAc) 2 (H 2 O) 2 (2) presents a 1D doublestrand chain structure. Two factors, the second ligand (acid ligand) and different coordination ability of water molecules, are investigated to further explore its relationship with the resultant crystalline architectures in complexes 1 and 2. The donor atoms in the two lead(II) complexes 1 and 2 can cluster to one side leaving an "open" coordination site to accommodate the stereochemically active 6s 2 lone pair. Complex Cu(L 2 ) 2 (3) shows a 1D double-strand chain structure. There is an extended onedimensional structure in complex [Co 3þ (L 2 ) 2 (C 5 H 5 N) 2 ] 3 ClO 4 (4), while [Co 2þ (L 2 ) 2 (C 5 H 5 N) 2 ] 3 2CH 3 OH 3 H 2 O (5) displays a discrete structure.

Synthesis, structures and magnetic properties of di- and tetranuclear manganese complexes derived from a 3-methoxysalicylaldehyde benzoylhydrazide ligand

“…During the last several years, a number of manganese clusters with various different oxidation states and defined geometries have been reported and studied. These include structurallycharacterized species with Mn 8 [7], Mn 10 [8], Mn 12 [9], Mn 24 [10] and so on. Nanoscale homochiral manganese clusters with general formula of f½Mn III 3 Mn II ðOÞðH 2 OÞ 3 ðLÞ 3 4 ½Mn III 6 Cl 4 O 4 g½Mn III 3 ðOÞðH 2 OÞ 3 ðLÞ 3 ðOHÞ 4 Á 21H 2 O Á 3MeOH, exhibiting both ferroelectric and ferromagnetic properties were successfully synthesized by utilizing two enantiomeric Schiff base ligands, R-and S-H 3 L [11].…”

“…Nanoscale homochiral manganese clusters with general formula of f½Mn III 3 Mn II ðOÞðH 2 OÞ 3 ðLÞ 3 4 ½Mn III 6 Cl 4 O 4 g½Mn III 3 ðOÞðH 2 OÞ 3 ðLÞ 3 ðOHÞ 4 Á 21H 2 O Á 3MeOH, exhibiting both ferroelectric and ferromagnetic properties were successfully synthesized by utilizing two enantiomeric Schiff base ligands, R-and S-H 3 L [11]. Another famous giant manganese cluster is [Mn 84 O 72 (O 2 CMe) 78 (OMe) 24 (MeOH) 12 (H 2 O) 42 (OH) 6 ]ÁxH 2 OÁyCHCl 3 , which has a 4 nm diameter torus structure, exhibits both magnetization hysteresis and quantum tunneling of magnetization, and crystallizes as supramolecular nanotubes [6].…”

Two new lead(II) coordination polymer and discrete complex containing bipyridine ligands with different positioned methyl substituents: synthesis, characterization, crystal structure determination, and luminescent properties

“…Melting points were measured on a Kofler Heizbank Rechart type 7841 melting point apparatus and are uncorrected. 1 H and 13 C NMR spectra were recorded on a Bruker 500 DRX Scheme 1 Possible coordination modes of nitrate ligand with Pb(II) Scheme 2 Methyl-substituted 2,2 0 -bipyridine ligands in complexes 1 (5,5 0 -dmbpy) and 2 (6,6 0 -dmbpy) spectrometer, for protons at 500 MHz and for carbons at 125 MHz, in DMSO-d 6 A solution of 6,6 0 -dimethyl-2,2 0 -bipyridine (0.21 g, 1.1 mmol) in CH 3 OH (15 mL) was added to a solution of Pb(NO 3 ) 2 (0.37 g, 1.1 mmol) in CH 3 OH (15 mL) at room temperature and the resulting white precipitant was dissolved in DMSO. The suitable crystals for X-ray diffraction experiment were obtained by methanol diffusion in a solution of white precipitant in DMSO.…”

“…The incorporation of Pb(II) metal ion in the coordination and coordination polymeric systems, in view of their interesting properties and structural features (e.g., adoption of different coordination numbers and the possible occurrence of stereochemical activity for their valence shell lone electron pairs) has been of great interest, in recent years [6][7][8][9][10][11][12].…”

Synthesis, structure, and magnetic properties of heterometallic {Zn2Ln2} (Ln=Tb, Dy, Ho) compounds with parallelogram-like cores

“…However, the Zn-Ln system has been infrequently studied [15] [18] and (ii) the o-vanillin group displays a variety of bonding geometries including monodentate, bidentate bridging, and chelate bridging [19].…”