- Synthesis, characterization and extraction studies of a new vic-dioxime and its complexes containing bis(diazacrown ether) moieties
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A new vicinal dioxime ligand containing bis(diazadioxa-12-crown-4 ethoxy) units (H2L) has been synthesized by the reaction of cyanogendi-N-oxide with 3,4-bis(2-{10-[(4-methylphenyl)sulfonyl]-1,7-dioxa-4,10-diazacyclododecan-4-yl}ethoxy)aniline, which was prepared by the reduction of 4-[(4-methlyphenyl)sulfonyl]-10-[2-((4-nitro-2-{2-[10-phenylsulfonyl)-1,7-dioxa-4,10-diazacyclododecan-4-yl]ethoxy}phenoxy)ethyl]-1,7dioxa-4,10-diazacyclododecan. A mononuclear nickel(II) and copper(II) complexes with a metal:ligand ratio of 1:2 for H2L were also synthesized. The mononuclear cobalt(III) complex of H2L has been isolated with L′ = pyridine, together with chlorine as an axial ligand. In addition, a cobalt(III) complex containing the BF2+ bridge macrocycle was synthesized using a precursor hydrogen-bridged cobalt(III) complex via the template effect. The extraction abilities of 1, 3, 6 and 10 were also evaluated in 1,2-dichloroethane by using several alkali (Li+, Na+, K+, Cs+) and transition metal picrates such as Ag+, Pb2+, Cd2+, Cu2+, Zn2+. The structure of the dioximes and their complexes are proposed according to elemental analyses, 1H and 13C NMR, FT-IR UV-Vis and mass spectra.
- Bilgin, Ahmet,Ertem, Beytullah,A?in, Fatma Din?,G?k, Ya?ar,Karslio?lu, Selami
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- Synthesis, conformational studies, and inclusion properties of tris[(2- pyridylmethyl)oxy]hexahomotrioxacalix[3]arenes
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O-Alkylation of the flexible macrocycle 1 with 2-(chloromethyl)pyridine in the presence of Cs2CO3 resulted in the preferential formation of partial-cone-2. The cone-to-partial-cone ratio of 2 increased in the presence of K2CO3, and led to almost equal in the presence of NaH. The template effect of the alkali metal cations plays an important role in this O- alkylation reaction. The structural characterization of these products is also discussed. The two-phase solvent extraction data indicated that tris[(2- pyridylmethyl)oxy]hexahomotrioxacalix[3]arenes 2 show moderate extractability for n-butylammonium ion and high extractability for Ag+. The 1H NMR titration of cone-2 with AgSO3CF3 clearly demonstrates that a 1:1 complex is formed, which is stable on the NMR time scale. Thus, the synergism of cyclophane moiety and two or three lower-rim side chains with pyridyl groups play a significant role on the complexation of tris[(2-pyridylmethyl)oxy] derivatives cone-2 and partial-cone-2 with Ag+ ion and n-butylammonium ion.
- Yamato, Takehiko,Haraguchi, Mitsuteru,Nishikawa, Jun-Ichi,Ide, Seiji,Tsuzuki, Hirohisa
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- Synthesis of metal-free and metallophthalocyanines containing 18- and 21-membered macrocycles with mixed donor atoms and their metal-ion binding properties
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This paper describes the synthesis of a series of metal-free phthalocyanines and metallophthalocyanines peripherally substituted by macrocycles of different ring sizes with the same donor atom sets. The effects of varying ring size of the macrocycle on the spectroscopic and metal ion binding properties of phthalocyanines were examined. For these purposes, electronic absorption properties for metal-free phthalocyanines and metallophthalocyanines were studied in dimethylformamide and tetrahydrofuran. The liquid-liquid extraction of metal picrates such as Ag(I), Hg(II), Cd(II), Zn(II), Cu(II), Ni(II), Pb(II), and Co(II) from the aqueous phase to the organic phase was carried out using metallophthalocyanines. All new compounds were characterized using several spectroscopic techniques.
- G?k, Halil Zeki
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p. 750 - 763
(2015/08/06)
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- Synthesis, crystal structure investigation, DFT analyses and antimicrobial studies of silver(i) complexes with N,N,N′,N′′-tetrakis(2- hydroxyethyl/propyl) ethylenediamine and tris(2-hydroxyethyl)amine
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The synthesis, crystal structures, DFT and antimicrobial studies of three novel complexes of silver: [Ag(THEEN)]2(PIC)2 (1), [Ag(THPEN)]2(PIC)2 (2) and [Ag(TEAH3) 2](PIC) (3), have been reported in the present work, where THEEN/THPEN (N,N,N′,N′′-tetrakis(2-hydroxyethyl/propyl) ethylenediamine) are tetrapodal ligands and TEAH3 (tris(2-hydroxyethyl)amine) is a tripodal ligand. Complexes (1) and (2) are dinuclear, whereas (3) is mononuclear. Complex (1) adopted a see-saw geometry with coordination number four, whereas (2) and (3) are five coordinated. Complex (2) acquired distorted square-pyramidal geometry, whereas complex (3) acquired distorted trigonal-bipyramidal geometry. Extensive hydrogen bonding interactions have been found in all three complexes. The primary coordination sphere of the newly synthesized silver(i) complexes has been optimized, structural parameters have been calculated and the energy gaps of the frontier orbitals have been predicted with the B3LYP/6-31G/LANL2DZ level of theory. Structural parameters from the crystallographic and DFT studies are in good agreement with each other. The relatively smaller calculated HOMO-LUMO energy gaps (HLG) suggest charge transfer transitions. Antimicrobial studies have been performed with the new silver(i) complexes against gram +ve bacteria (Staphylococcus aureus), gram -ve bacteria (Serratia marcescens, Sphingobium japonicum and Stenotrophomonas maltophilia) and fungal species (Candida albicans, Aspergillus niger and Saccharomyces cerevisiae). Dinuclear complexes (1) and (2) exhibited remarkable results. All the synthesized silver(i) complexes have been proven to be better antibacterial and antifungal agents, even than their standard drugs (ciprofloxacin and fluconazole) and can be used as effective antimicrobial agents and potential drugs in the future.
- Kumar, Rakesh,Obrai, Sangeeta,Kaur, Amanpreet,Hundal, Maninder Singh,Meehnian, Harmanpreet,Jana, Asim Kumar
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p. 1186 - 1198
(2014/03/21)
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- Synthesis and characterization of some mixed-ligand picrate complexes of nickel(II) involving heterocyclic nitrogen donors
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The present communication describes the synthesis of some mixed-ligand hexacoordinated picrato complexes of nickel(II) of the composition [Ni(PA)2(L-L)2], where PAH = picric acid and L-L = 2-aminoben-zothiazole (ABZT), 2-(2′-aminophenyl)benzothiazole (2′-AMPHBZT), 2-(3′-aminophenyl)benzothiazole (3′-AMPHBZT), bipyridine (bpy), o-phenanthroline (phen) or 2,6-bis(benzimidazyl)pyridine (BBZLPY). These complexes were obtained by the interaction of nickel(II) picrate with the corresponding ligands L-L in methanol. The resulting compounds have been characterized by elemental analyses, magnetic, molar conductance and decomposition temperature measurements, electron spin resonance, infrared and electronic spectral studies. All the complexes are thermally stable and behave as non-electrolytes. An octahedral structure has been tentatively proposed for these complexes.
- Maurya,Sharma,Roy
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p. 683 - 698
(2008/10/08)
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- Synthesis, magnetic and spectral studies of Co(II) picrate complexes with heterocyclic nitrogen donors
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New mixed-ligand picrate complexes of cobalt(II), formed by interaction of cobalt(II) picrate with 2-aminobenzothiazole (ABZT), 2-(2'- aminophenyl)benzothiazole (2'-AMPHBZT), 2-(3'-aminophenyl)benzothiazole(3'- AMPHBZT), bipyridyl(Bipy), o-phenonthroline (Phen), and 2,6- bis(benzimidazole-2'yl)pyridine(BBZLY) are described. The complexes have been characterised by elemental analyses, molar conductances, magnetic and decomposition temperature measurements, electron spin resonance, infrared and electronic spectral studies. They have the composition [Co(PA)2(L-L)2], where L - L= ABZT, 2'-AMPHBZT, 3'AMPHBZT, Bipy, Phen or BBZLY. A trans octahedral structure has been tentatively proposed for these complexes.
- Maurya,Sharma
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p. 509 - 513
(2007/10/03)
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- Molecular Design of Crown Ethers. 3. Extraction of Alkaline Earth and Heavy Metal Picrates with 14- to 17-Crown-5 and 17- to 22-Crown-6
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The solvents extraction of alkaline earth and heavy metal picrates with a series of ring-contracted and ring-enlarged crown ethers has been carried out in order to reveal the effects of methylene-chain lenght upon cation-binding ability.Compared with the parent 3m-crown-m, the ring contracted crown ethers and their sila analogues possess limited extractabilities, often as low as those for the corresponding glymes.On the other hand, the ring-enlarged crown ethers, in general, show gradual, but not drastic, decreases in extractability for most cations with increasing methylene-chain lenght.Interestingly, the extractabilities for Ag+, Tl+, and Ba2+ do not decreases monotonously with ring expansion; in particilar 16-crown-5 is a better extractants for Ag+ than 15-crown-5 and even than 18-crown-6.Effects of cation hydration upon extractability and the limitations of solvent extraction technique are also discussed.
- Inoue, Yoshihisa,Ouchi, Mikio,Hakushi, Tadao
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p. 525 - 530
(2007/10/02)
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