Metal(II) Complexes of Compartmental Polynuclear Schiff Bases Containing Phenolate and Alkoxy Groups

Abstract

Five mono-nuclear Cu(II) and Ni(II) complexes and one dinuclear Zn(II) complex were synthesized from the Schiff bases N,N'-bis(3-ethoxy-2-hydroxybenzylidene)-1,2-phenylenediamine (H 2 L OEt -phda) and 2-ethoxy-6-({2- [(3-ethoxy-The complexes were structurally characterized with elemental microanalyses, IR, UV-Vis and ESI-MS spectroscopic techniques as well as single crystal X-ray crystallography. The metal centers display distorted square planar geometries in 2-4 and 5 and distorted square pyramidal (SP) in 1, whereas in 6 an intermediate geometry between SP and TBP was observed around the first Zn 2+ ion and a tetrahedral around the second ion, with one acetate is acting as a bridging ligand. In all cases, metal ions were incorporated into the N 2 -O 2 binding site with no involvement of the alkoxy groups in the coordination. The L OEt -ambza-complexes 3-6 revealed significant dihedral angles between the phenol rings and the plane containing the central benzene ring, and large O 2 -O 2 bond distances (5.1-5.9Ǻ). Results are discussed in relation to other related Schiff base complexes.

Electronic Impacts on the Solvent-Free Mechanochemical Synthesis of Salophen Ligands in Ball Mill

“…As a result, the current study adds to our understanding of solid-solid Salophen synthesis in diverse electronic environments employing solvent-free mechanochemistry. In the synthesis of 3a, mechanochemical ball milling was shown to be more effective than most of corresponding solution reactions reported in the literature (about 26% yield) [34][35][36][37][38]. In comparison to the similar Salophen synthesis to date, the current study provided solvent-free, fast reaction, high yield, and easy work-up (Table 3).…”

The Electron Ionization Mass Spectra of ONO, ONNO and O3N3 Type Schiff Base Complexes Containing First Row Transition Metal Ions

“…Mass spectrometry has become increasingly popular in the characterization of coordination compounds due to the development of soft ionization methods over the last two decades. However, most of these studies have been carried out with atmospheric pressure chemical ionization (APCI), atmospheric pressure photoionization (APPI), and especially electrospray ionization (ESI) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. The studies performed by classical ionization methods are very limited [16,[21][22][23][24][25].…”