Studies on Divalent Zinc and Cadmium Complexes Containing 1, 2-bis (n-methylbenzimidazolyl)benzene

2012 ◽  
Vol 11 (1) ◽  
pp. 1-14
Author(s):  
Bheemanna HG ◽  
Virupaiah Gayathri ◽  
Nadur Muddanna Nanje Gowda

The reaction of 1,2-bis(N-methylbenzimidazolyl)benzene (N-N) with zinc and cadmium halides and perchlorates in teof–ethanol/acetone/thf yielded white/cream/pale pink complexes of the formulae MX2(N-N) [M = Zn, X = Cl, Br or I; M = Cd, X = Br or I), [(CdCl2)1.5(μ-N-N)]2, [Zn(OClO3)(μ-N-N)1.5]2(ClO4)2 and [Cd(OClO3)(μ-N-N)2]ClO4.H2O. The complexes have been characterized based on elemental analyses, molar conductance measurements, IR, 1H and 13C NMR, FAB–mass spectral studies and thermal analysis. Probable structures have been proposed.

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4908
Author(s):  
Rubina Munir ◽  
Noman Javid ◽  
Muhammad Zia-ur-Rehman ◽  
Muhammad Zaheer ◽  
Rahila Huma ◽  
...  

In this article, a synthesis of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides and their structural interpretation by NMR experiments is described in an attempt to explain the duplication of some peaks in their 1H- and 13C-NMR spectra. Twenty new 6-methyl-1H-pyrazolo[3,4-b]quinoline substituted N-acylhydrazones 6(a–t) were synthesized from 2-chloro-6-methylquinoline-3-carbaldehyde (1) in four steps. 2-Chloro-6-methylquinoline-3-carbaldehyde (1) afforded 6-methyl-1H-pyrazolo[3,4-b]quinoline (2), which upon N-alkylation yielded 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetate (3). The hydrazinolysis of 3 followed by the condensation of resulting 2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazide (4) with aromatic aldehydes gave N-acylhydrazones 6(a–t). Structures of the synthesized compounds were established by readily available techniques such as FT-IR, NMR and mass spectral studies. The stereochemical behavior of 6(a–t) was studied in dimethyl sulfoxide-d6 solvent by means of 1H NMR and 13C NMR techniques at room temperature. NMR spectra revealed the presence of N’-(benzylidene)-2-(6-methyl-1H-pyrazolo[3,4-b]quinolin-1-yl)acetohydrazides as a mixture of two conformers, i.e., E(C=N)(N-N) synperiplanar and E(C=N)(N-N)antiperiplanar at room temperature in DMSO-d6. The ratio of both conformers was also calculated and E(C=N) (N-N) syn-periplanar conformer was established to be in higher percentage in equilibrium with the E(C=N) (N-N)anti-periplanar form.


2020 ◽  
Vol 32 (9) ◽  
pp. 2356-2364
Author(s):  
ASMA A. ALOTHMAN ◽  
MUNIRAH D. ALBAQAMI ◽  
RAZAN A. ALSHGARI

A series of Cu(II), Ni(II) and Co(II) azo chelates (AZC1-AZC3) of 7-((3-phenyl-4,5-dihydroisoxazol-5-yl)methyl)quinolin-8-ol have been designed and obtained. Thermal measurements, molar conductance, magnetic moment, elemental analyses, spectral (IR, UV-Vis, 1H and 13C NMR, ESR, mass) were used to characterize insulated solid complexes. The metal complexes were assumed to be non-electrolytic by molar conductance values. Thermal properties and decomposition kinetics of the metal chelates are investigated using Coats-Redfern method. The kinetic parameters like activation energy (E*), pre-exponential factor (A) and entropy of activation (ΔS*) were quantified. Results of spectral studies of mass and TGA data confirmed the octahedral geometry for all chelates. Finally, the synthesized metalcomplexes were tested for their in vitro antimicrobial efficacy.


2020 ◽  
Vol 17 (11) ◽  
pp. 832-836
Author(s):  
Manijeh Nematpour ◽  
Hossein Fasihi Dastjerdi ◽  
Mehdi Jahani ◽  
Sayyed Abbas Tabatabai

A simple and appropriate procedure for the synthesis of quinazoline-2,4(1H,3H)-dione derivatives from isocyanides, aniline and isocyanate via the Cu-catalyzed intramolecular C-H activation reaction is reported. The advantages of this method are one-pot conditions, accessible starting materials- catalyst, high yield of products, and short reaction times. The structures are confirmed spectroscopically (1H- and 13C-NMR, IR and EI-MS) and by elemental analyses.


2002 ◽  
Vol 8 (6) ◽  
pp. 347-353 ◽  
Author(s):  
Ashu Chaudhary ◽  
D. P. Jaroli ◽  
R. V. Singh

Some antifertility inhibitors of 18 to 24-membered tetraazamacrocyclic complexes of iron(II) and manganese(II) have been synthesised by the template condensation using 1,3-phenylenediamine with malonic acid, succinic acid, glutaric acid and adipic acid. The reaction proceed smoothly to completion. The complexes were characterized by elemental analyses, molecular weight determinations, infrared, electronic, magnetic moment, mössbaur and mass spectral studies. The elemental analyses are consistent with the formation of the complexes [M(N4Ln)Cl2] (M = Fe(lI) or Mn(II)). All these complexes are stable and monomeric in nature as indicated by the molecular weight determinations. The spectral studies confirm the octahedral geometry around the central metal atom. The complexes have been screened in vitro against a number of fungi and bacteria to assess their growth inhibiting potential. The testicular sperm density and testicular sperm morphology, sperm motility, density of cauda epididymal spermatozoa and fertility in mating trials and biochemical parameters of reproductive organs have been examined and discussed.


2010 ◽  
Vol 6 (3) ◽  
pp. 1120-1133
Author(s):  
F. Rehman ◽  
M. Bhardwaj ◽  
U.K. Jetley

Co(II) complex of 5-chloro-2,4-dihydroxy butyrophenoneoxime (CDHBOX) was synthesized from 5-chloro-2,4-dihydroxy butyrophenoneoxime by using standard protocol, and characterized by elemental analyses, melting point determination and spectral data. The ML2 (metal/ligand) stoichiometry of the complex was determined by spectrophotometric and potentiometric studies, and mass spectral data. The value of stability constant of the complex was found to be 6.94x 108 while its standard free energy of formation is 12.155 kcal/mol at 27ºC. Beer’s law is obeyed in the concentration range 2-15 ppm of Co. The value of molar extinction coefficient and sensitivity as per Sandell’s scale were found to 3.35x 103 L.mol-1cm-1and 0.017 μg Co/cm2 respectively. The value of activation energy and the Arrhenius constant Arrhenius constant were found as 4.949 kjmol-1, 74.39. The IR studies reveal that the phenolic proton is lost on complexation and the oxygen of the phenolic (–OH) and nitrogen of the oximino (=NOH) groups coordinate with Co(II) ion. The electronic spectra and magnetic susceptibility measurement indicate that the complex is paramagnetic and tetrahedral in nature. The antimicrobial activity of different concentrations of ligand and its Co(II)-complex  has been evaluated against Curvularia lunata, Fusarium oxysporum and Alternaria alternata fungi  and Streproproteus, Staph, Escherchia coli, Klebsella, and pseudomonas bacteria. The results indicated that the ligand (CDHBOX) and its Co(II) complex have good anti-microbial properties. 


2013 ◽  
Vol 11 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Gunasekaran Raja ◽  
Chinnasamy Jayabalakrishnan

AbstractA series of new ruthenium(II) complexes were synthesized with Schiff bases derived from salicylaldehyde / o-hydroxyacetophenone/ o-vanillin / 2-hydroxy-1-naphthaldehyde with thiosemicarbazide and acetyl furan. They are characterized by elemental analysis, IR, electronic, 1H NMR, 13C NMR and mass spectral studies. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). Four of these complexes were tested for its binding with CT-DNA using absorption spectroscopic studies and two of these complexes exhibit efficient DNA cleavage activity.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Har Lal Singh ◽  
Jangbhadur Singh

New series of organotin(IV) complexes and Schiff bases derived from amino acids have been designed and synthesized from condensation of1H-indole-2,3-dione, 5-chloro-1H-indole-2,3-dione, andα-amino acids (phenylalanine, isoleucine, and glycine). All compounds are characterized by elemental analyses, molar conductance measurements, and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance (1H,13C, and119Sn NMR) spectral studies. The results suggest that Schiff bases behave as monobasic bidentate ligands and coordinate with dibutyltin(IV) in octahedral geometry according to the general formula [Bu2Sn(L)2]. Elemental analyses and NMR spectral data of the ligands with their dibutyltin(IV) complexes agree with their proposed distorted octahedral structures. Few representative compounds are tested for their in vitro antibacterial activity against Gram-positive (B. cereus,Staphylococcusspp.) and Gram-negative (E. coli,Klebsiellaspp.) bacteria. The results show that the dibutyltin complexes are more reactive with respect to their corresponding Schiff base ligands.


2005 ◽  
Vol 2005 (6) ◽  
pp. 352-355 ◽  
Author(s):  
Rajendra Singh Ghadwal ◽  
Ram C. Mehrotra ◽  
Anirudh Singh

Reaction of VO(OPri)3 with two equivalents of N-phenyldiethanolamine (PhDEAH2) yields a homometallic complex [VO(PhDEA)(PhDEAH)] 1, which reacts with a number of metal alkoxides to afford heterobimetallic oxovanadium(V) complexes of the types [VO(PhDEA)2{M(OR)n-1}] [where PhDEA = C6H5N(CH2CH2O–)2], [M =: Al (n = 3, R = Pri) 2; Al (n = 3, R = But) 3; Ti (n = 4, R = Pri) 4; Zr (n = 4, R = Pri) 5; Nb (n = 5, R = Pri) 6; Ta (n = 5, R = Pri) 7. The derivative [VO(PhDEA)(OSiPh3)] 8 has been prepared by the equimolar interaction of [VO(PhDEA)(OPri)] with Ph3SiOH. All of these complexes have been characterised by spectroscopic (IR; 1H, 13C, 27Al and 51V NMR) studies, elemental analyses, and molecular weight measurements. The derivative 2 has also been characterised by FAB mass spectral studies, which supports for its monomeric nature.


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