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1

Synthesis and characterization of aldamine condensed Schiff bases and their iron salts

Meng Chao, Gu Zheng, Wang Jianfa, Sui Jinyong, Hu Shaokai, Zhang Susu, Zhang Xiaoyi, Li Peiyao, Liu Wenjin, Hu Yifan

Polimery

|

2023

|

Vol. 68, nr 2

99--105

EN

Two types of long-chain conjugated Schiff bases and their iron salts were obtained by the coordination polycondensation of p-phenylenediamine with glyoxal or terephthalaldehyde. Elemental analysis and infrared spectroscopy (FTIR) were used to evaluate the chemical structure of the obtained poly(Schiff bases) and their salts. Thermal stability (TGA) and electrical conductivity were also investigated.

PL

W wyniku koordynacyjnej polikondensacji p-fenylenodiaminy z glioksalem lub aldehydem tereftalowym otrzymano dwa rodzaje długołańcuchowych sprzężonych zasad Schiffa oraz ich sole żelazowe. Do oceny struktury chemicznej otrzymanych zasad Schiffa i ich soli stosowano analizę elementarną i spektroskopię w podczerwieni (FTIR). Zbadano również stabilność termiczną (TGA) i przewodnictwo elektryczne.

2

Synteza i redukcja prochiralnych imin

Berniak T. A.

Wiadomości Chemiczne

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2016

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[Z] 70, 5-6

353--368

EN

Natural chemical compounds and their derivatives could be used for designing new classes of anticancer, antifungal or antiviral drugs. One of those compounds is gossypol, isolated from grains of wool. Gossypol’s derivatives can freely penetrate the blood-brain barrier (BBB). This basic review considers synthesis and reduction of prochiral imines. Gossypol derivatives belong to imines. Imines as unstable compounds, hydrolyze in contact with a small amount of water. There are substrates for preparation of oximes and its derivatives. In this article three methods of imines production are presented. There are: (a) reaction of aldehyde or ketones with primary amine, (b) addition of Grignard reagents to nitriles and (c) pyrolysis of alkyl azide. The first one is discussed in details with specific description of the mechanism of both steps: first stage - addition to form a hemiaminal, second one – dehydration with formation of imine. Many conditions such as acid power, value of pH reaction and environment (preferably anhydrous) have influence on the formation rate of imines and determine each of two stages, i.e. addition and dehydration. Furthermore, the imines-enamines tautomeric and stereochemical aspects with possible attack of nucleophile molecules to the carbon atom of the C=N bond from the Si or Re side of prochiral imines as well as potential ways of imines reductions to amines by using commonly used reducers (NaCNBH3) are discussed. Moreover, two new methods of reduction are presented: the first – with using trichlor acids catalyzed chiral Lewis’s bases and the second one – asymmetric hydrogenation of imines.

3

Zasady Schiffa : wybrane syntezy, reakcje i aktywność biologiczna

Nowicka A., Liszkiewicz H., Nawrocka W. P.

Wiadomości Chemiczne

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2014

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[Z] 68, 3-4

187--209

EN

Schiff bases are compounds with a functional group that contains a carbon- -nitrogen double bond with the nitrogen atom connected to an aryl or alkyl group. Schiff bases are condensation products of primary amines with carbonyl compound. Several studies showed that the presence of a lone pair of electrons on the nitrogen atom of the azomethine determine biological and chemical properties of imines. Schiff bases are generally excellent chelating agents, because of the special properties of C=N bond. Their metal complexes have been widely studied because they possess anticancer in vitro and herbicidal applications. Imines also have biological importance. Schiff bases are common enzymatic intermediates where an amine reacts with an aldehyde or ketone of a cofactor or a substrate. Imines have been reported for their biological properties such as antibacterial (E. coli, S. aureus), antifungal (C. albicans) activities. A large number of different Schiff bases are active against a wide range of protozoan (T. gypseum, P. viticola).

4

Ultrasonic Assisted Synthesis, Acoustical Property and Antibacterial Activity of Some Schiff Bases

Premalatha R., Santhi N.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 14, iss. 1

53--64

EN

An efficient, simple clean synthesis of Schiff bases of some 4-nitroaniline/ 2,4-dinitroaniline/ 3,4-dichloroaniline / 4-methoxy-3-nitro aniline with 3-bromo-4-fluorobenzaldehyde were done by an ultrasound irradiation method. The major advantages of ultra-sonication are short reaction time, operational simplicity, high yield, easy workup and environment friendly procedure. The isolated compounds obtained by ultrasound irradiation method were characterized by UV, IR and NMR spectral data. These acoustical parameters were determined. Furthermore their antibacterial activities are screened against certain strains of bacteria and showed significant anti-microbial activity.

5

Synthesis, Spectral Characterization and X – Ray Diffraction studies of some Pd(II) Complexes with Schiff bases

Shaikh J. A.

International Letters of Chemistry, Physics and Astronomy

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2014

|

Vol. 17, iss. 3

272--280

EN

The synthesis, spectroscopic and X – Ray Diffraction studies of some Pd(II) complexes with bidentate Schiff bases are reported here. These Schiff bases were derived by condensing aldehydes like 2-hydroxy-1-naphthaldehyde, 5-chloro salicyladehyde with amines like 4-nitro aniline, 4-methyl aniline and 4-methoxy aniline. The complexes were characterized on the basis of elemental analysis, molar conductivity, spectral (IR, 1H and electronic) as well as thermal analysis. All the Pd (II) complexes exhibit square planar geometry with 1:2 (metal : ligand) stoichiometry. The X- ray diffraction studies suggest monoclinic crystal system for these complexes.

6

Zasady Schiffa – interesujący zakres zastosowań w różnych dziedzinach nauki

Brodowska K., Łodyga-Chruścińska E.

Chemik

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2014

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Vol. 68, nr 2

129--134

PL

Kompleksy metali odgrywają istotną rolę zarówno w rolnictwie, jak również chemii farmaceutycznej i przemysłowej. Zasady Schiffa są produktami kondensacji pierwszorzędowych amin i związków karbonylowych. Związki te oraz ich kompleksy z metalami są coraz częściej stosowane jako katalizatory, polimery i barwniki. W artykule przedstawiono właściwości zasad Schiffa oraz korzyści wynikające z ich stosowania w różnych gałęziach przemysłu.

EN

Metal complexes play an important role in agriculture as well as industrial and pharmaceutical chemistry. Schiff bases are the condensation products of primary amines and carbonyl compounds. Schiff bases and their metal complexes are increasingly being used as catalysts, polymers and dyes. This paper reviews the properties of Schiff bases and benefits of their use in various branches of industry.

7

Selective Extraction of Copper(II) from Aqueous Solution by Using Schiff Bases

Aydin L., Sözcan S., Ziyadanogullari B., Temel H.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 9

1591-1600

EN

New [N,N'-bis-(salicylaldehydene)-1,2-bis-(m-aminophenoxy)eth ane] (MAS) and a common tetra dentate ligand N,N'-ethylenebis(salicylideneimine) (AS) for this study have been prepared, and the new ligand was characterized on the basis of microanalytical data, elemental analysis, UV-visible, IR, 1H NMR and 13C NMR spectra. Selective extraction of Cu(II) from aqueous solution by using N,N'-bis-(salicylalde hydene)-1,2-bis-(m-aminophenoxy)ethane and N,N'-ethylenebis(salicylideneimine) was studied. Separation of Cu(II) from other metal ions such as Cd(II), Pb(II), Ni(II), Co(II) in aqueous solutions of various pH values and complexing reagents (MAS, AS) was described. The separation factors for these metals using these reagents were reported and efficient methods for the separation of Cu(II) from other metal ions were proposed. From the loaded organic phase, Cu(II) stripping was carried out in one stage with different mineral acid solutions. The stripping efficiency was found to be quantitative in case of H2SO4 for MAS and HNO3, H2SO4, HCl for AS.

8

2'-Hydroxybenzylideneanilines and 2-Hydroxyazobenzenes. The Role of Intramolecular O–HźźźN Resonance Assisted Hydrogen Bonds

Majewska P., Rospenk M., Sobczyk L.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 5

709-721

EN

A short review on the effect of the OH groups in the ortho position on the liquid crystalline properties of benzylideneanilines and azobenzenes is presented. Numerous examples show that there are no general rules governing the behaviour of these compounds. How ever one finds most frequently a broadening of the existence range of mesophases both due to a decrease of freez ing temperature and an increase of the isotropisation temperature. In contrast, the presence of strongly polar groups such as –NO2 and –CN leads to a reverse be haviour that can be explained by as suming a strong pi-electron conjugation of these groups with the conjugate-chelatering formed by intramolecular O–HźźźN hydrogen bond. These rings are analyzed by us ing data related to the structure of molecules and infrared spectra in the region of the stretch ing ni(OH) and bend ing delta(OH) and gamma(OH) modes.

9

Synthesis, Spectroscopic and Structural Characterization of Trivalent Chromium, Manganese, Iron and Cobalt Complexes with Schiff Bases Derived from o-Vanillin

Tripathi N., Shalini, Sharma V. K.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 3

523-535

EN

A series of new coordination complexes in volving chromium(III), manganese(III), iron(III) and cobalt(III) with Schiff bases derived from condensation of o-vanillin with diamines viz. 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane or 1,2-dia - minobenzene and monoamines viz., p-methylaniline or p-methoxyaniline have been prepared and characterized by elmental analysis, spectral (IR, electronic, 1H NMR, FAB mass), magnetic susceptibility and electrical conductance measurements. The IR spectra suggest that o-VDAEH2, o-VDAPH2, o-VDABuH2 and o-VDABH2 are dibasic tetradentate ligands to wards all the four metals giving the complexes with composition [M(L)(H2O)X] (X = Cl, and OAc; LH2 = o-VDAEH2, o-VDAPH2, o-VDABuH2 and o-VDABH2) while o-VPMEAH and o-VPMAH are monobasic bidentate ligands towards the metals giving the complexes with composition [M(Lc)3] (LcH = o-VPMEAH and o-VPMAH). Various physicochemical data suggest a six coordinated octahedral geometry for all the complexes. Studies were conducted to investigate the inhibiting potential of the complexes synthesized and the ligands, against various fungal and bacterial strains.

10

Structural Characterization of Some New Coordination Compounds of Tin(II) with Schiff Bases of Sulpha Drugs

Maheshwari R., Sharma S., Bedi M., Varshney A.K.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 7

1361-1365

EN

Some new coordination compounds of tin(II) have been synthesized by the reaction of tin(II) methoxide with the Schiff bases prepared by condensation of aldehyde/ketones with sulpha drugs. These complexes have been characterized on the basis of elemental analysis, ultraviolet, infrared, 1H NMR and 119Sn NMR spectral studies. The analytical data of complexes indicate 1:2 metal ligand stoichiometry of the type of [ML2], where M = Sn(II). The ligands be haved as bidentate chelating agents and bonded to the metal ion through imines nitrogen and ox ygen atom of either moiety of ligand. The antibacterial activities of the ligands and their tin(II) coordination compounds have been screened in vitro against the o ga ism Escherichia coli, Staphylococus aureus, Prouteus mirabilis,and Bacillus thurengiensis.

11

Self-Assembly in Lanthanum Complexes of Salicylaldimines Derived from Biogenic Diamines

Pospieszna-Markiewicz I., Radecka-Paryzek W.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 6

1207-1212

EN

Lanthanum(III) chloride and nitrate appear to be effective template agents in the one-step synthesis of salicylaldimine complexes derived from salicylaldehyde and biogenic diamines putrescine or cadaverine. The potentially tetradentate N2O2 Schiff bases display a rare coordination pattern of salen-type complexes acting as neutral ligands us ing oxygens as do nor atoms with out in volving the nitrogen atoms in the coordination. The synthesis and characteriz tion of the new free salicylaldimine ligand derived from cadaverine was also carried out.

12

Fotoaktywność układów organicznych. Fotochromizm i fotoluminescencja 1,4-dihydropirydyn i zasad schiffa.

Lewanowicz A.

Prace Naukowe Wydziału Chemicznego Politechniki Wrocławskiej. Monografie

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2007

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Nr 4, nr 4

5-132

PL

W monografii przedstawiono wyniki badań dotyczące fotoaktywności dwóch rodzin związków organicznych: 1,4-dihydropirydyn i zasad Schiffa. Dyskusję nad fotoaktywnością zawężono tu do fotochromizmu i fotoluminescencji przedstawicieli tych rodzin: l-metylo-2,4,4,6-tetrafenylo-l,4-dihydropirydyny oraz N-trifenylometylosalicylidenoiminy. Badania, wspierane przewidywaniami teoretycznymi, były prowadzone różnymi technikami (optycznymi i nieoptycznymi) i metodami pomiarowymi. Ich wyniki, mające na celu określenie mechanizmu procesu fotochromowego, prezentują kilka aspektów energetyki procesów fotofizycznych i fotochemicznych, przedstawiają struktury i właściwości cząsteczek w stanie podstawowym i w niższych wzbudzonych stanach elektronowych.W wypadku 1,4-dihydropirydyn zanalizowano dynamikę kształtowania się indywiduów generowanych w trakcie reakcji oraz ustalono naturę niższych wzbudzonych stanów elektronowych, aktywnych w reakcjach fotochemicznych. Zaproponowano aspekt birodnikowy pierwszego etapu reakcji fotochemicznej, co - w połączeniu z międzycząsteczkowym transportem atomu wodoru ("kaskada wodorowa") - wyjaśniło mechanizm procesu fotochromowego l-metylo-2,4,4,6-tetrafenylo-l,4-dihydropirydyny. Podstawę potwierdzającą hipotezę "kaskady wodorowej" stanowiły: analiza widm w zakresie podczerwieni, kinetyka generacji i wybielania form barwnych, sygnały EPR kryształów tego związku oraz wyniki rentgenowskiej analizy strukturalnej. Badania strukturalne i widmo rozproszenia ramanowskiego były pomocne w dostrzeżeniu oddziaływania typu CR-tt, określanego jako słabe, międzycząsteczkowe wiązanie wodorowe. Mimo złożonej budowy i znacznych rozmiarów cząsteczki, uzyskano ustrukturo-wane widma fotoluminescencji w warunkach występowania efektu Szpolskiego, co umożliwiło określenie natury niższych wzbudzonych stanów elektronowych, zanalizowanie struktury wibronowej widm i scharakteryzowanie zachowań cząsteczki po wzbudzeniu w ograniczonej skali czasowej. W zasadach Schiffa poszukiwano m.in. odpowiedzi na pytanie, czy istotnie chinoidowa struktura cząsteczki jest odpowiedzialna za przemianę termochromową, czy też - jak w wypadku anili - o właściwościach termochromowych decyduje reakcja przeniesienia protonu w stanie podstawowym, o właściwościach zaś fotochromowych - reakcja przeniesienia protonu w stanie wzbudzonym. Dla luminezującej N-trifenylornetylosalicylidenoiminy, wykazującej również fotochromizm i termochromizm, zaproponowano hipotezę konformeru otwartego, ukształtowanego w stanie podstawowym, w niskich temperaturach, odpowiedzialnego za termochromizm. Pokazano, iż przemiana termochromowa jest odwracalna. Odwracalny jest także cykl generujący formę fotochromową. Zaproponowano schemat przemian związanych z generowaniem formy fotochromowej i wskazano na procesy eliminujące tę właściwość. W wieloetapowym mechanizmie przekształceń cząsteczki łączącym procesy fotofizyczne i fotochemiczne, zidentyfikowano aktywne wzbudzone stany elektronowe typu (n, pi) i ''3(n, pi).

EN

Photoactivity of two families of organic compounds; i.e. 1,4-dihydropyridines and Schiff bases, are presented. The photoactivity of l-methyl-2,4,4,6-tetraphenyl-l,4-dihydropyridine (DHP) and /V-triphenyl-methylsalicylideneimine (MSI) was also discussed. It was limited to their photochromism and to the photoluminescence. Different experimental techniques, i.e., optical and non-optical, were presented and supported by quantum-chemical calculations. The results revealed new ideas for energetic of the photo-physical and photochemical processes. The molecular structures and optically generated molecular forms of the compounds studied were proposed. Based on experimental results and theoretical considerations the mechanisms of photochromic behavior were suggested. For the first time it was demonstrated that an intermolecular hydrogen transfer process ("hydrogen cascade") induces photochromism of l-methyl-2,4,4,6-tetraphenyl-l,4-dihydropyridyne in the solid state. Hydrogen atom moves from the CH3 group to aromatic carbon atom therefore the intermolecular hydrogen transfer in the solid state over a distance of 2-3 A takes place. Two nonsymmetrical triplet biradical structures take part in the hydrogen cascade. Moreover, photomagnetism and photochromism are inseparable. The DHP is the first example of photochromic organic material that exhibits this novel feature. Additionally, the T-shape-type structure of DHP provides a clear evidence of the weak intermolecular hydrogen bond in DHP crystalline form. The hypothesis of the open and closed conformers in the ground state was helpful for explaning the complexity of photoactivity in N-triphenylmethylsalicylideneimine. Thermochromism has been interpreted as a result of geometry changes of chelate ring rather than the shift of the tautomeric equilibrium benzenoid-to-quinoid form. Both open and closed conformers of MSI were probably responsible for dual phosphorescence observed at low temperature in the Shpolskii matrix. The well resolved phosphorescence spectrum, related to the open form, is "stigmatized" by the activity of an C=N stretching mode of the imine part, similar to the C=0 stretching vibration in the case of carbonyl compounds. The dual fluorescence of MSI was identified at ambient temperature. The highly shifted Stokes fluorescence of proton transferred form, beside dual phosphorescence, was detected and analyzed at 77 K. The energy of the S1 (n, pi )-type state of MSI, which was active in photochemical reactions, was directly determined in the photoluminescence measurements. Both thermochromism and photochromism are reversible in MSI. General conclusion: the hydrogen transfer process initiates the photochromism in the organic compounds under discussion.

13

Synthesis of N-Arylamino(ferrocenyl)methylphosphinic Acids and Their Cholesteryl Esters

Lewkowski J., Karpowicz R.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 12

2097-2101

EN

The synthesis of N-arylamino(ferrocenyl)methylphosphinic acids by the action of hypo - phosphorous acid on anazomethine bond of ferrocenyl N-aryl Schiff bases is described. Ferrocenyl aminophosphinic acids obtained in this way have been converted into their cholesteryl esters by their reaction with cholesterol in the presence of DCC.

14

Influence of the smectic standart's polarity on their stability in mixtures with 4-decyloxybenzylidene-4'-alkyloxyanilines

Godzwon J., Sienkowska M. J., Galewski Z.

Scientific Bulletin. Physics / Lodz University of Technology

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2006

|

Vol. 26

29-37

EN

This paper describes synthesis and liquid crystalline properties of the homologous series of 4-decyloxybenzylidene-4'-alkyloxyanilines. On the basis of the polarization microscopy (POM, TOA) and the calorimetric (DSC) measurements a rich polymorphism has been detected. Investigated compounds have the following phases: nematic, smectic A, smectic C, smectic B, smectic I and smectic G. The presence of these mesophases has been confirmed by the miscibility method, using a mesophase reference 4-heptyloxybenzilidene-4'-pentyloaniline. Seven other smectic standarts with different polarity has been applied for search mesophase stability.

PL

W pracy przedstawiono wyniki badań właściwości ciekłokrystalicznych pełnego szeregu homologicznego 4-decykloksybenzylideno-4'-alkiloksyanilin. Metodami kalorymetrii DSC oraz mikroskopii polaryzacyjnej POM określono ilościowo parametry przejść fazowych oraz zidentyfikowano występujące mezofazy (w oparciu o metodę współmieszalności Sackmanna-Demusa). Zbadano pięć diagramów fazowych pochodnych badanego szeregu z wzorcem mezofaz, 4-heptyloksybenzylideno-4'-pentyloaniliną, które potwierdziły obecność sześciu mezofaz: N, SmA, SmC, SmB, SmI, i SmG. Zbadano również wpływ polarności wzorca (7 związków) na stabilność występujących mezofaz oraz na położenie punktów potrójnych pochodnej 4-decyloksybenzylideno-4'-propyloksyaniliny.

15

The Reaction of Tris(aminoethyl)amine with Rigid Aromatic Dialdehydes as a Convenient Tool for the Synthesis of Cryptands

Brzezik M., Jarosz M., Jurczak J.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 11

1825-1829

EN

Four bicyclic octaazacryptands and three triaza macrocyclic amines have been synthesized via the reaction of tris(aminoethyl)amine with six rigid aromatic dialdehydes, followed by reduction of the formed Schiff bases with sodium borohydride.

16

Synthesis and Characterization of a New 4-Methoxysalicyliden-p-aminoacetophenoneoxime and Its Complexes with Co(II), Cu(II) and Zn(II)

Tuna S., Canpolat E., Kaya M.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 10

1651-1656

EN

The novel Schiff base ligand, 4-methoxysalicyliden-p-aminoacetophenoneoxime (LH) was synthesized starting from p-aminoacetophenoneoxime and 4-methoxysalicylaldehyde. Mononuclear cobalt(II), copper(II) and zinc(II) complexes of the ligand have been prepared by using Co(II), Cu(II) and Zn(II) salt with a metal to ligand ratio of 1:2. The structures of the ligand and its complexes were identified by using elemental analyses, IR, 1H- and 13C-NMR spectra, magnetic susceptibility measurements, UV spectra and thermogravimetric analyses (TGA).

17

Synthesis and Antiproliferative Activity in vitro of New 2-Aminobenzimidazole Derivatives. Part 3 [1]. Reactions of 2-Arylideneaminobenzimidazole with Selected 1,3-Diketones

Nawrocka W., Sztuba B., Dryś A., Wietrzyk J., Kosendiak J., Opolski A.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 2

279-287

EN

A series of pyrimido[1,2-a]benzimidazole derivatives has been synthesized in the reactions of 2-aminobenzimidazole Schiff bases 1-6 with selected _-diketones; acetylacetone 7-12 or benzoylacetone 13-18. The structures 4, 7-18 were confirmed by the results of elemental analysis and their IR, 1H NMR and MS spectra. Compounds 4, 7-18 were examined for their antiproliferative activityin vitro against 3 cancer cell lines: P338 (mice leukemia), A549 (non-small cell lung carcinoma), SW707 (rectal adenocarcinoma), using SRB (sulphorhodamine B) or MTT (3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide) technique. The Schiff base 4 and tricyclic derivatives 9, 14, 16 exhibited the highest cytotoxic activity in vitro.

18

Synthesis and Characterization of Complexes of Isatin Schiff Base

Rafat F., Siddigi K. S., Siddiqi M. Y.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 4

663-670

EN

Complexes of Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) with Schiff bases derived from isatin and ethylenediamine (L1) or diethylenetriamine (L2) have been synthesized and characterized by microanalysis, IR, UV-Vis, 1H NMR, EPR and conductance measurements. Electrical conductance of the Fe(III) chelates indicated them to be 1:1 electrolyte whilst those of divalent metal ions are non-electrolytes in DMSO. On the basis of magnetic moment and spectral data a pseudooctahedral geometry has been suggested for all of the complexes. The EPR spectrum of [Cu(L1)Cl2] complex indicates a considerable exchange interaction in the solid state.

19

Studies on Mononuclear Chelates Derived from Substituted Schiff Bases Ligands (Part 8): Synthesis and Characterization of a New 5-Chlorosalicyliden-p-aminoacetophenoneoxime and Its Complexes with Co(II), Ni(II), Cu(II) and Zn(II)

Canpolat E.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 4

619-625

EN

Co(L)2, Ni(L)2, Cu(L)2 and Zn(L)2 were synthesized from p-aminoacetophenoneoxime and 5-chlorosalicylaldehyde and Co(AcO)2.4H2O or Ni(AcO)2.4H2O or Cu(AcO)2.H2O or Zn(AcO)2.2H2O in 1:2 molar ratio, employing a template approach. Based on elemental analyses, molar conductivity and magnetic susceptibility data, IR, 1H- and 13C-NMR and UV spectra, as well as thermal analyses (TG), a tetrahedral geometry for the complexes was determined. The data show that the ligand coordinates to the metal ion via -C=N- and -C-O- groups. All complexes are soluble in common organic solvents such as DMF and DMSO.

20

Studies on Mononuclear Chelates Derived from Substituted Schiff Bases Ligands (Part 1): Synthesis and Characterization of a New Salicyliden-p-aminoacetophenoneoxime and Its Complexes with Co(II), Ni(II), Cu(II) and Zn(II)

Canpolat E., Kaya M.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 6

959-965

EN

The new ligand salicyliden-p-aminoacetophenoneoxime (LH) was synthesized from p-aminoacetophenoneoxime and salicylaldehyde under reflux in absolute ethanol. Mononuclear complexes with a metal:ligand ratio of 1:2 have been prepared with Co2+, Ni2+, Cu2+ and Zn2+ salts. Their structures have been elucidated on the basis of IR, 1H- and 13C-NMR spectra, electronic spectra, elemental analyses, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses. According to the results, it is suggested that two ligands are coordinated to each metal atom by hydroxyl and the imino nitrogen to form high spin tetrahedral complexes with Co2+, Ni2+, Cu2+ and diamagnetic complex with Zn2+.