Four Schiff base complexes, [Cu2(L1)2(μ-NCS)2] (1), [Cu2(L2)2(μ-N3)2] (2), Cu[Cu(CH3COO)(L3)]2 (3), and [Zn{Zn(C3H4N2)(L3)}2(NO3)](NO3) (4) (where L1 = 2-[(pyridin-2-ylmethylimino)methyl]phenol, L2 = 1-[(pyridin-2-ylmethylimino)methyl]naphthalen-2-ol, and L3 = bis(salicylidene)-1, 3-propanediamine), were synthesized and characterized by elemental analyses, infrared spectroscopy, and single crystal X-ray determinations. Both 1 and 2 are structurally similar di-nuclear complexes, which are located at crystallographic inversion centers (with the center of the central Cu2N2 ring). In 1, each copper atom has a slightly distorted square pyramidal configuration, coordinated by two nitrogen atoms and one oxygen atom from L1 and another two terminal nitrogen atoms from two bridging thiocyanate anions. The Cu···Cu separation is 3.466(3) A. The structure of 2 is similar to that of 1, with Cu···Cu separation of 3.368(2) A. Both 3 and 4 are linear tri-nuclear complexes. In 3, the central Cu2+ ion is located on an inversion centre and has a distorted octahedral coordination involving four bridging O atoms from two Schiff base ligands (L3) in the equatorial plane and one O atom from each bridging acetate group in the axial positions. The coordination around the terminal Cu2+ ions is irregular-square pyramidal, with two O and two N atoms of L3 in the basal plane and one O atom from an acetate group in the apical position. The acetate bridges linking the central and terminal Cu2+ ions are mutually trans. The Cu···Cu separation is 3.009(3) A. In 4, the coordination configuration of the central and the terminal zinc atoms are similar to that of the 3, with Zn···Zn separation of 3.153(4) A. The three Schiff bases and the corresponding three copper complexes exhibit good antibacterial properties, while the zinc complex 4 has nearly no.



Synthesen, Kristallstrukturen und antibakterielle Wirkung von vier Schiff-Base-Komplexen von Kupfer und Zink



Die Schiff-Base-Komplexe, [Cu2(L1)2(μ-NCS)2] (1), [Cu2(L2)2(μ-N3)2] (2), [Cu{Cu(CH3COO)(L3)}2] (3), and [Zn{Zn(C3H4N2)(L3)}2(NO3)](NO3) (4)(L1 = 2-[(pyridin-2-ylmethylimino)methyl]phenol, L2 = 1-[(pyridin-2-ylmethylimino)methyl]naphthalen-2-ol und L3 = bis(salicyliden)-1, 3-propanediamin) wurden synthetisiert und mittels Elementaranalyse, IR-Spektroskopie und Einkristallstrukturanalysen charakterisiert. 1 und 2 sind strukturell ahnliche, zweikernige Komplexe, mit einem Symmetriezentrum in dem zentralen Cu2N2-Ring. In 1 haben die Kupferatome leicht verzerrte quadratisch-pyramidale Koordination und werden von zwei Stickstoffatomen und einem Sauerstoffatom von L1 und zwei anderen terminalen Stickstoffatomen zweier verbruckender Thiocyanat-Anionen koordiniert. Der Cu···Cu-Abstand in 1 betragt 3.466(3) A, der in 2 3.368(2) A. 3 und 4 sind lineare Dreikern-Komplexe. In 3 befindet sich das zentrale Cu2+-Ion auf einem Symmetriezentrum und ist verzerrt oktaedrisch von vier Brucken-O-Atomen zweier Schiff-Base-Liganden (L3) aquatorial und durch je ein O-Atom der beiden Brucken-Acetatgruppen in den Axial-Positionen koordiniert. Die Koordination der terminalen Cu2+-Ionen ist irregular-quadratisch-pyramidal mit je zwei O- und N-Atomen von L3 basal und einem O-Atom einer Acetat-Gruppe in der Apical-Position. Die Acetatbrucken, die die zentralen und terminalen Cu2+-Iions verbinden, sind wechselseitig trans positioniert. Der Cu···Cu-Abstand betragt 3.009(3) A. In 4 ist die Koordination der zentralen und terminalen Zinkatome ahnlich zu der von 3 mit einem Zn···Zn-Abstand von 3.153(4) A. Die drei Schiffschen Basen und entsprechenden drei Kupferkomplexe zeigen gute antibakterielle Eigenschaften, wahrend 4 nahezu unwirksam ist.

Syntheses, Crystal Structures, and Antibacterial Activities of Four Schiff Base Complexes of Copper and Zinc

Cobalt(II), nickel(II), and zinc(II) complexes with bidentate N, N'-bis(β-phenylcinnamaldehyde)-1,2-diiminoethane Schiff base: synthesis and structures

SUMMARY A computerized analysis of the occurrence among 291 dicotyledon families of 107 morphological or biochemical characters is described. The results confirm earlier work and increase the number of characters that are shown to be statistically associated from 26 to 39. Many of these occur more often in rain-forest floras than in the rest of the world. They also occur more often in families that are represented in the fossil record than they do in the present-day world flora, and aile therefore regarded as primitive. Using 30 of these correlated characters, the percentage advancement index of the various families is calculated. Among the most advanced families are Dipsacaceae, Valerianaceae and Hippuridaceae. The most primitive ones are Aextoxicaceae and Degeneriaceae, with Stachyuraceae and Magnoliaceae also very primitive.

A re‐investigation of character correlations among dicotyledons

Synthesis and characterization of a series of copper(II) complexes with azo-linked salicylaldimine Schiff base ligands.

Amino acid schiff base complexes of dimethyldichlorosilane

Complexes of Cu(II), Ni(II) and Co(II) with sulphamerazine salicylaldimine

Potentiometric study of the complexes of sulphamethazine salicylaldimine with Cu(II), Ni(II) and Co(II)

Coordination compounds of Cu (II), Ni (II) and Co (II) with sulphamethazine salicylaldimine (an antitubercular) have been prepared with a view to study their antibacterial activity. These complexes are granular, stable and are quantitatively formed and characterised by elemental analysis. Structures have been assigned based on their infrared, electronic absorption spectral and magnetic susceptibility studies. The antibacterial activity was tested against eleven available pathogens and in some cases complexes are found to be more potent.

Coordination compounds of Cu(II), Ni(II) and Co(II) with sulphamethazine-5-bromo-salicylaldimine

/pdf/ecofriendly-lubricant-oils-performance-in-large-stjh10gy.pdf

Kamal K. Chaturvedi

Papers

Complexes of Cu(II), Ni(II) and Co(II) with sulphamerazine salicylaldimine

Potentiometric study of the complexes of sulphamethazine salicylaldimine with Cu(II), Ni(II) and Co(II)

Coordination compounds of Cu(II), Ni(II) and Co(II) with sulphamethazine-5-bromo-salicylaldimine

Ecofriendly lubricant oils' performance in large hydroelectric thrust bearings

Separation and gravimetric determination of barium using sulfadimethoxin salicylaldimine