Five co-ordinate complexes of bivalent iron, cobalt, nickel, copper, and zinc halides with terdentate Schiff base and azo-ligands containing tertiary nitrogen donor atoms

Abstract

and 2.2'-bis-(NN-dimethylamino)azobenzene (Me,N-ab-NMe,) form complexes with the chlorides or bromides of bivalent iron, cobalt, nickel, copper, and zinc having the general formula MLX,. The stereochemistry of these complexes has been studied by means of magnetic and spectrophotometric measurements. With the exception of Cu(Me,N-baphen-NMe,)CI, and Cu( Me,N-ab-NMe,) CI , , which attain six-co-ordination through chlorine bridging linkages, all are five-co-ordinate complexes.THE isolation of high-spin five-co-ordinate complexes of metals from manganese(@ to zinc(@ by the interaction of the metal salts and alkyl-substituted polyamines such as N(and HN(CH,*CH,*NEtJ,3 led to the conclusion l s 3 that, for the formation of five-co-ordinate complexes, the ligand must be bulky and multidentate in order that crowding around the metal ion should M. Ciampolini and N. Nardi, Inorg. Chem., 1966, 5, 41. a M. Ciampolini and G. P. Speroni, Inorg. Chem., 1966, 5, 45. 2. Dori and H. B. Gray, J . Amer. Chem. SOC., 1966, 88, 1394. prevent a six-co-ordinate configuration being attained. Following our work on the cobalt complexes of Schiff base 4 and azo-ligands 5 containing alkylamino-groups we have tested the generality of the above conclusion by examining the complexes formed between bivalent transition-metal halides and such ligands bearing only tertiary nitrogen donor atoms. The ligands which we have investigated are N-( (3-N'N'-dimethylaminoethy1)pyridinaldimine (I) (paenMeJ , N-(2'-N'N'-dimethylaminophenyl) pyridinaldimine (11) (paphen-P. Bamfield, J .

Manganese Azides Based on Co‐Ligands with a Flexible Tail: Diverse Structural and Magnetic Properties

“…The Schiff-base ligands L 1 , L 2 , and L 3 were prepared according to literature procedures. [13] Elemental analyses (C,H,N) were performed on an Elementar Vario EL analyzer. IR spectra were recorded with a Nicolet Magna-IR 750 spectrometer equipped with a Nic-Plan Microscope.…”

Synthesis, characterization and crystal structures of a pair of azido-bridged polynuclear Schiff base copper(II) complexes with urease inhibitory activity

“…The ligands L1 and L2 were prepared by stirring equimolar amounts (1.0 mmol each) of 2-pyridylaldehyde with N,Ndiethylethane-1,2-diamine, and N-isopropylethane-1,2-diamine, respectively, in 50 mL of methanol using literature methods [12,13]. Yields: 97% for L1 and 95% for L2.…”

Chelating Schiff base assisted azide-bridged Mn(ii), Ni(ii) and Cu(ii) magnetic coordination polymers

“…The Schiff bases were prepared according to the literature methods for analogous compounds. 17 Elemental analyses (C, H, N) were performed on an Elementar Vario EL analyser. IR spectra were recorded on a Nicolet Magna-IR 750 spectrometer equipped with a Nic-Plan Microscope.…”