Two New Quadridentate Schiff Base Complexes of Nickel(II) and Cobalt(III): Synthesis, Structure and Spectral Characterisation

2006 ◽  
Vol 61 (10) ◽  
pp. 1209-1216 ◽  
Author(s):  
Joy Chakraborty ◽  
Raj K. Bhubon Singh ◽  
Brajagopal Samanta ◽  
Chirantan Roy Choudhury ◽  
Subrata K. Dey ◽  
...  

Two novel quadridentate Schiff base complexes, [NiIILH](ClO4)2・H2O (1) and [CoIIIL]- (ClO4)2・H2O (2) [LH, a Schiff base ligand: Ph(OH)C(Me)=NCH2CH2N(CH2CH2NH2)2] have been synthesised and characterised by elemental analyses, spectroscopic and electrochemical studies. The structures of both have been unequivocally established from single crystal X-ray diffraction studies. 1 and 2 crystallise in the monoclinic space group P21/n having cell parameters a = 8.536(1), b = 13.832(4), c = 18.194(2) Å , β = 100.00(10)°, Z = 4 for 1, and a = 10.819(5), b = 14.301(2), c=14.224(1) Å , β =97.04(2)°, Z =4 for 2. The complexes expose a square planar geometry around the metal centers chelated with three different types of nitrogen donor centers of the ligand.

2008 ◽  
Vol 5 (1) ◽  
pp. 130-135 ◽  
Author(s):  
A. A. Osowole

VO(IV), Ni(II) and Cu(II) complexes of the asymmetric Schiff base [(HOC6H3(OCH3)C(C6H5):N(CH2CH2)N:C(CH3)CH:C(C6H5)OH)], and their heteroleptic analogues with triphenyl phosphine and 2,2’-bipyridine have been synthesized and characterized by elemental analyses, conductance, magnetic, infrared and electronic spectral measurements. The ligand is tetradentate coordinatingviathe imine N and enolic O atoms. The Ni(II) and Cu(II) complexes adopt a four coordinate square planar geometry, the VO(IV) complex is five coordinate square-pyramidal and the heteroleptic complexes are 6-coordinate, octahedral. The assignment of geometry is collaborated by magnetic moments and electronic spectra measurements. The compounds are non-electrolyte in nitromethane and are magnetically dilute.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Aderoju Amoke Osowole

4-(Thiophen-3-yl)-aniline undergoes condensation with o-vanillin to form an ONS donor Schiff base, 2-methoxy-6-[(4-thiophene-3-yl-phenylimino)-methyl]-phenol, which forms complexes of the type [ML2]xH2O (where M = Mn, Co, Ni, Cu, Zn, Pd). These complexes are characterized by elemental analysis, 1H nmr, electronic, mass, and IR spectroscopies and conductance measurements. The electronic, IR and CHN data are supportive of a 4-coordinate tetrahedral geometry for Mn(II), Co(II), Ni(II), and Zn(II) complexes and square-planar geometry for Cu(II) and Pd(II) complexes, with the chromophores N2O2. The magnetic data reveals that the complexes are magnetically dilute and mononuclear with exception of the Cu(II) complex, which exhibits some anti-ferromagnetisms. The complexes are air-stable solids, and none is an electrolyte in nitro methane.


2016 ◽  
Vol 45 (47) ◽  
pp. 18967-18976 ◽  
Author(s):  
Archana Choudhary ◽  
Bidisa Das ◽  
Saumi Ray

Square planar Ni(ii)-Schiff base complexes when encapsulated in a supercage of zeolite Y have shown altered optical and magnetic properties and catalytic activities in comparison to their corresponding free states.


2020 ◽  
Vol 36 (05) ◽  
pp. 954-957
Author(s):  
Shivani Prakash ◽  
Anju Kumari Gupta ◽  
Sachin Prakash ◽  
D. Prakash

A series of new hetero binuclear complexes of copper(II) and lead(II) using Schiff base have been synthesized. The Schiff base has been derived from the condensation reaction between Salicylaldehyde and 1,2-Ethylenediamine. The hetero binuclear complexes have been characterized by using elemental analysis, molar conductance measurement, magnetic susceptibility studies, UV-Vis and IR spectra. The studies revealed square planar geometry for the complexes with coordination number four.


Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 607 ◽  
Author(s):  
Yin-Xia Sun ◽  
Ying-Qi Pan ◽  
Xin Xu ◽  
Yang Zhang

An unprecedented dinuclear CuII complex, [Cu2(L2)2], derived from a salamo-like chelating ligand H2L2, was produced by the cleavage of a newly synthesized, half-salamo-like ligand HL1 (2-[O-(1-ethyloxyamide)]oxime-3,5-dichloro-phenol). This was synthesized and characterized by elemental analyses, IR, UV–Vis and fluorescent spectra, single crystal X-ray diffraction analysis, and Hirshfeld surface analysis. X-ray crystallographic analysis indicated that the two CuII (Cu1 and Cu2) ions bore different (N2O3 and N2O2) coordination environments, the penta-coordinated Cu1 ion possessed a slightly twisted tetragonal pyramid geometry with the τ value τ = 0.004, and the tetra-coordinated Cu2 ion showed a slightly twisted square planar geometry. Interestingly, one oxime oxygen atom participated in the coordination reported previously. Moreover, an infinite two-dimensional layered supramolecular network was formed. Compared with HL1, the CuII complex possessed the characteristic of fluorescence quenching.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1794-C1794
Author(s):  
M'hamed Boudraa ◽  
Hasna Bouchareb ◽  
Sofiane Bouacida ◽  
Hocine Merazig

The reactions of 2-thiophene acetic acid and imidazole with manganese (II) chloride resulted in mononuclear [Mn(C6H5O2S)2(C3H4N2)6] (1), or binuclear [Mn2(C6H5O2S)4(C3H4N2)4] (2) and [Mn2(C6H5O2S)4(C3H4N2)4(H2O)] (3) complexes. In the complex (1), the Mn ion is octahedral coordinated by six nitrogen atoms from six imidazole rings and the Mn-O bond lengths are in the range 2.261(4) to 2.275(6) Å. The crystal packing is stabilized by weak C-H...O and N-H...O hydrogen bonds. In the structure of (2), the asymmetric unit is formed from an Mn ion bonded to two N atoms from two imidazole ligands and to three O atoms from three different thiophene acetic acid ligands. Two of these ligands are deprotonated and bridge by the same oxygen atoms between the second manganese ion giving rise to an binuclear complex. In this complex, each Mn cation is located in a slightly distorted square-planar environment and the Mn-N bond lengths are in the range 1,960(3) to 1.976(2) Å. The Mn-O bonds lengths in the square base of the two pyramids are in the range 1.956(5) to 2.000(1) Å. The Mn-O axial bond distance is quite longer than the Mn-O equatorial bond distances and is 2.458(2)Å [1,2]. The crystal packing is stabilized by weak C-H...O and N-H...O hydrogen bonds forming connected layers parallel to (001) planes. When an oxygen of one molecule of water bridges the two metal centers in the complex (2), the environment of the two Mn becomes octahedral and thus we obtain the complex (3). In this latter complex, the Mn-N bonds are in the range 2.192(4) to 2.245(4). All Mn-O bonds are between 2.148(6) and 2.232(7)Å. All structures are disordered in all thiophenyl rings occupy alternatively two positions related to one another by an 180o rotation about the C–C sigma bond [3]. The sulfur and one carbon atom of the ring occupy the same position. The complexes were structurally characterized by single crystal X-ray diffraction analyses, infrared spectroscopy (IR), elemental analyses and thermogravimetric analyses (TGA). Cristal data: (1): MnC30H34N12O4S2 in C2/c, a=11.3492(6), b=13.9186(7), c=22.2101(13), beta= 94.963(4) (2): Mn2C36H36N8O8S4 in P21/n, a=15.996(2), b=10.274(13), c=26.141(3), beta=97.715(9) (3): Mn2C24H38N8O9S4 in P21/n, a=26.206(2), b=8.5421(8), c=19.0694(17), beta= 92.229(4)


2020 ◽  
Vol 11 (4) ◽  
pp. 319-323
Author(s):  
Cemal Koray Ozer ◽  
Gun Binzet ◽  
Hakan Arslan

Herein, we describe the synthesis and characterization of bis(N-(diethylcarbamothioyl)cyclohexane carboxamido)copper(II) complex, cis-[Cu(L-κ2S,O)2], has been prepared by the reaction of N-(diethyl carbamothioyl)cyclohexanecarboxamide ligand with copper(II) acetate. The green colored crystals of the complex were obtained by slow evaporation of their dichloromethane:ethanol solution (2:1, v:v). The crystal structure of cis-[Cu(L-κ2S,O)2] was obtained by single-crystal X-ray diffraction. The crystal structure reveals an monoclinic C2 (no. 5) space group with cell parameters a = 14.848(3) Å, b = 10.543(2) Å, c = 10.511(2) Å, β = 123.84(3)°, V = 1366.7(7) Å3, Z = 2, T = 153(2) K, μ(MoKα) = 0.979 mm-1, Dcalc = 1.327 g/cm3, 4979 reflections measured (6.6° ≤ 2Θ ≤ 50.68°), 2243 unique (Rint = 0.0223, Rsigma = 0.0444) which were used in all calculations. The final R1 was 0.0225 (>2sigma(I)) and wR2 was 0.0490 (all data). The angular structural index parameter, τ4, is equal to 0.40, which confirms the distorted square planar geometry for the title compound. The puckering parameters (q2 = 0.015(3) Å, q3 = 0.576(3) Å, QT = 0.577(3) Å, θ = 1.6(3)° and φ = 20(11)°) of the title complex show that the cyclohexane ring adopts a chair conformation. The two ethyl groups of the diethyl amine group have anti-orientation with respect to one another. The crystal packing shows the molecules stacked in parallel sheets along [010], accompanied by C3-H3A···O1ⁱ (i -x, +y, 1-z) intermolecular contact.


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Ibrahim A. M. Saraireh ◽  
Mohammednoor Altarawneh ◽  
Jibril Alhawarin ◽  
Mahmoud Salman ◽  
Abdel Aziz Abu-Yamin ◽  
...  

Schiff base diethyl 4,4-(pentane-2,4-diylidenebis(azanylylidene))benzoate (1) as a new ligand (L) was prepared by the reaction of acetylacetone with benzocaine in the ratio of 1 : 1. Two transition-metal complexes, [Ni(II)(LCl(HOEt))] (2) and [Zn(II)(LCl(HOEt))] (3), have been synthesized from metal salts with didentate Schiff base ligand (L) and characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR UV-Vis spectroscopy, and magnetic susceptibility. The biological activity of the complexes was studied. In addition, the M06-2x density function theory method and the 6-31G(d) basic set were applied to determine the optimized structures of 1–3 and to determine their IR and 1H NMR, 13C NMR spectra theoretically. The data are in good agreement with the experimental results. The geometries of complexes 2 and 3 were determined to be square-planar for 2 and tetrahedral for 3.


2017 ◽  
Vol 72 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Madhusudan Nandy ◽  
Debnath Saha ◽  
Corrado Rizzoli ◽  
Shyamapada Shit

AbstractA new trinuclear heterometallic complex, [(CuL)Na(CuL)]·ClO4 (1), has been prepared using a Schiff base, H2L (where H2L=N,N′-(1,2-phenylene)-bis(3-methoxysalicylideneimine) and characterized by elemental analysis, Fourier transform infra-red (FT-IR) spectroscopy, UV/Vis, magnetic, electrochemical, and single crystal X-ray diffraction methods. The structure analysis reveals that two metallo-ligand [(CuL)] units are connected to each other by a sodium ion resulting in the cationic unit [(CuL)Na(CuL)]+. Both the copper(II) ions display an almost square planar geometry while the sodium ion adopts a trigonal-dodecahedral coordination geometry. The spectroscopic and other physicochemical studies are in good agreement with the crystal structure of the complex.


2011 ◽  
Vol 8 (3) ◽  
pp. 1408-1416 ◽  
Author(s):  
M. S. Suresh ◽  
V. Prakash

A new series of transition metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) were synthesized from the Schiff base ligand derived from 4-aminoantipyrine, furfural ando-phenylenediamine. The structural features were derived from their elemental analyses, infrared, UV-visible spectroscopy, NMR spectroscopy, thermal gravimetric analyses, ESR spectral analyses and conductivity measurements. The data of the complexes suggested square planar geometry for the metals with primary valency two. Antimicrobial screening tests were performed against bacteria. The comparative study of the MIC values of the Schiff base and its metal complexes indicate that the metal complexes exhibit greater antibacterial activity than the free ligand.


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