Synthesis and antimicrobial evaluation of coordination compounds containing 2,2′-bis(3-aminopyridyl) diselenide as ligand

The reaction between 2,2′-bis(3-aminopyridyl) diselenide (L) and metal transition salts results in the formation of molecular or cluster complexes. The structural elucidation of the synthesized complexes [CuCl₂(L)] ( 1 ), [Cu(3-NH₂PySeO₂)₂]·2H₂O ( 2 ), [Cu₄(3-NH₂PySe)₄]·dimethylformamide ( 3 ), [CoCl₂(L)] ( 4 ), [ZnCl₂(L)] ( 5 ), and [Ag₆(3-NH₂PySe)₆] ( 6 ) demonstrates the coordination of nitrogen atoms to Cu^II, Co^II, and Zn^II, and that of the selenium atoms to Cu^I and Ag^I, which agrees with Pearson’s hard and soft acids and bases (HSAB) theory. Furthermore, the oxidation of selenium with the formation of 3-aminopyridylseleninate [3-NH₂PySeO₂]⁻ bonded to the copper atom was observed in complex 2 . The antimicrobial action of complexes 1 , 2 , 4 , and 5 was evaluated against Mycobacterium fortuitum, Mycobacterium massiliense, and Mycobacterium abscessus. It was observed that all these complexes have potential antimicrobial activity compared with the free ligand and metal salts used in the synthesis.     

Synthesis,structure, and physico-chemical properties of 3-methyl and 3,3-dimethyl derivatives of l-(4′,4′-dimethyl-2′,6′-dioxocyclohex-1′-yl)-3,4-dihydroisoquinoline

3,3-Dimethyl- and 3-methyl-1-(4,4-dimethyl-2,6-dioxocyclohex-1-yl)-3,4-dihydroisoquinolines have been synthesized. Crystal and molecular structures of the 3,3-dimethyl derivative have been determined. In the crystalline state this compound exists as a tautomeric form where a hydrogen atom is located at the N atom of the dihydroisoquinoline fragment of the molecule. The tautomeric equilibrium does not shift noticeably in solutions, as shown by IR, UV, and NMR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 331–336, February, 1993.     

Synthesis and structures of 4,5-dimethyl-1,3-bis(pyridin-2-ylmethyl)-1H-imidazolium chloride and 1,1′-bis(pyridin-2-ylmethyl)-2,2′-bis(4,5-dimethylimidazole)

4,5-Dimethyl-1,3-bis(pyridin-2-ylmethyl)-1H-imidazolium chloride (1) was synthesized and characterized by IR and NMR spectroscopy and X-ray diffraction. An attempt to prepare the free tridentate N-heterocyclic carbene pincer ligand by the reaction of 1 with KN(SiMe₃)₂ resulted in the formation of 1,1′-bis(pyridin-2-ylmethyl)-2,2′-bis(4,5-dimethylimidazole) as a product of dimerization of the target carbene followed by the rearrangement accompanied by the elimination of dipyridylethane.

     

Preparation,structures, and properties of nickel complexes containing 2,6-bis[4′,4′-dimethyloxazolin-2′-yl]pyridine,a pincer ligand

Five- and six-coordinate nickel complexes [(Dm-Pybox)NiCl₂], [(Dm-Pybox)Ni(H₂O)Cl₂], [(Dm-Pybox)Ni(H₂O)₂Cl]Cl (2a), and [(Dm-Pybox)Ni(MeOH)₂Cl]Cl (2b), where Dm-Pybox is 2,6-bis[4′,4′-dimethyloxazolin-2′-yl]pyridine, have been isolated and structurally characterized by single crystal X-ray diffraction. The solid state structures of 2a and 2b feature different modes of non-covalent interactions, C–H?Cl, C–H?O and O–H?Cl interactions. Spectroscopic and analytical methods, UV–vis and thermogravimetric analyses were done to further investigate chemical properties of the complexes.     

Synthesis and Crystal Structure of(p-{2-[p-(5′-Phenyl-1′,3′,4′-oxadiazole-2′-yl)-phenyl]-vinyl}-phenyl)-di-p-tolyl-amine

The crystal of the title compound (C36H29N3O,Mr = 519.62) has been prepared and structurally determined by X-ray single-crystal diffraction. It crystallizes in triclinic P ī space group with the crystal cell parameters: a = 12.544(4), b = 14.112(4), c = 17.770(5)A, α = 96.150(6), β = 106.112(5), γ = 107.156(5)°, V = 2825.7(14) ?3, Z = 4, Dc = 1.221g/cm3, μ(MoKα) = 0.074 mm-1 , F(000) = 1096,the final R = 0.0747 and wR = 0.1632 for 4713 observed reflections with I >2σ(I). The E-stereochemistry of the title compound can be confirmed by the result of the X-ray diffraction analysis.     

The synthesis and structural analysis of cis -β-{(1,6-di(2′-pyridyl)(2,5-dibenzyl-2,5-diazahexane O(1,2-diazahexane))(1,2-benzoquinone diimine))ruthenium(II)} and related complexes

Several isomers are possible when N₄-tetradentate ligands coordinate to form metal complexes. Here we report the synthesis and structural analysis of cis-β-{[1,6-di(2′-pyridyl)(2,5-dibenzyl-2,5-diazahexane)(1,2-benzoquinone diimine)]ruthenium(II)} formed exclusively from the β-precusor, β-{[1,6-di(2′-pyridyl)(2,5-dibenzyl-2,5-diazahexane) (dimethylsulfoxide)chloride] ruthenium(II)} hexaflourophosphate. Ruthenium(II) complexes synthesised from 1,6-di(2′-pyridyl)-2,5-dibenzyl-2,5-diazahexane, produce only two isomers which can be separated by recrystallisation into α- and β-[Ru(picenbz₂)(dmso)Cl]PF₆ (where picenbz₂ is 1,6-di(2′-pyridyl)-2,5-dibenzyl-2,5-diazahexane). The distinctively different proton NMR spectra of the isomers are an especially convenient feature with which to assess separation. Isomeric structure of the precursor, α or β, is conserved upon coordination of a bidentate ligand, such as benzene-1,2-diamine, 4,5-dimethyl-benzene-1,2-diamine, naphthalene-2,3-diamine, 2,2′-bipyridine, 1,10-phenanthroline or dipyrido[3,2-d:2′3′-f] quinoxaline, to produce complexes of the type α- or β-[Ru(picenbz₂)(bidentate)](PF₆)₂. The synthesis, separation and characterisation of the α- and β-precursors and the α- and β-[Ru(picenbz₂)(bidentate)](PF₆)₂ complexes are reported. Moreover, the crystal structures have been determined for β-[Ru(picenbz₂)(dmso)Cl]PF₆.0.5H₂O (C₃₀H₃₇N₄O_1.5F₆PSClRu); it is triclinic, space group P 1, a?=?9.987, b?=?12.883, c?=?14.287?Å, α?=?72.11, β?=?78.65, γ?=?88.39° and Z?=?2 and β-[Ru(picenbz₂)(bqdi)](PF₆)₂, (C₃₄H₃₈N₆F₁₂P₂Ru) which is triclinic, space group P 1, with a?=?10.129, b?=?10.338, c?=?19.587?Å, α?=?104.42, β?=?93.36, γ?=?92.00° and Z?=?2. The structures were determined at room temperature and refined by least-squares methods to R?=?0.044 for 5109 and R?=?0.075 for 3057 non-zero diffractometer data, respectively, for the dmso and bqdi species above.     

MK-10 clay catalyzed,one pot,three component and efficient synthesis of novel 4-(2′,5′-disubstituted-1′H-indol-3′-yl)-2,6-bis(2″,5″-disubstituted-1″H-indol-3″-yl)pyridine-3,5-dicarbonitrile under conventional and microwave irradiation

Abstract

A series of title compounds were synthesized via a one pot, multicomponent reaction of 2,5-disubstituted indole 3-carboxaldehydes, 3-cyanoacetyl indoles, and ammonium acetate under microwave irradiation and conventional method in a short time to afford the corresponding products in high yields. It is an ideal, efficient, and environmental benign reaction. The structures of products thus obtained are confirmed by their melting point, IR, ¹HNMR, and mass spectral data.     

Synthesis of 3-(3′-Acetyl-5′-aroyl-1′,3′,4′-oxadiazolyl-2′)-chromones

A general method has been proposed for synthesizing 3-(3-acetyl-5-aroyl-1,3,4-oxadiazolyl-2)-chromones that has been based on conversion of 3-formylchromones to acylhydrazones and of theacylhydrazones into the heterocyclic chromones.     

Cadmium(II) complexes containing 2,2′-dimethyl-4,4′-bithiazole ligand: synthesis,characterization, and crystal structure

Mononuclear and coordination polymer compounds of 2,2′-dimethyl-4,4′-bithiazole (dm4bt) ligand have been prepared by metallation of dm4bt with Cd(NO₃)₂ · 4H₂O and CdCl₂ · H₂O. The compounds were characterized by IR, ¹H NMR, UV–Vis spectroscopy, and X-ray crystallography. The structural study of [Cd(dm4bt)₂(NO₃)₂] · H₂O (1) shows that the complex is a monomeric seven-coordinate (CdN₄O₃) cadmium(II)-bithiazole system with two bidentate dm4bt and mono and bidentate nitrates. The structure of [Cd(dm4bt)Cl₂] _n (2) is a distorted octahedral environment around the cadmium(II) (CdN₂Cl₄) forming a 1-D coordination polymer as a result of bridging by two chlorides and 2-D structure from π–π stacking interactions.     

Crystallographic and computational study of the structure of copper(II) 2,2′-bis(2-oxidobenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl

The reaction of M(OAc)₂ with 2,2′-bis(2-hydroxybenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl (H₂L1) allows the synthesis of 2,2′-bis(2-oxidobenzylideneamino)-4,4′-dimethyl-1,1′-biphenyl complexes of Cu(II) (CuL1), Co(II) (CoL1) and Ni(II) (NiL1) that were characterized by elemental analysis, FTIR spectroscopy and for CuL1 also by X-ray crystallography verifying a tetradentate binding mode of L1 via an (ONNO) motif of the two phenolic oxygen atoms and two azomethine nitrogen atoms. Recrystallization from a solvent mixture of dichloromethane and methanol promotes the formation of methanol adducts. Different binding modes of the methanol–complex were investigated using density functional theory calculations and binding energies, and thermodynamic data of the interaction are reported. The results show that the favored interaction occurs when the methanol molecule acts as a Lewis acid weakly binding via an O–H···O hydrogen bridge to a phenoxide moiety leading to an elongation of the respective M–O bond.

     

Synthesis of 4,4′-Bis[4-(2,5-dioxo-2,5-dihydro-1H-pyrroll-1-yl)-phenylcarbonylamino]-3,3′-dichlorodiphenylmethane and 1,4-Bis{2-[4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-phenylcarbonyloxy]ethoxy}benzene

Russian Journal of Organic Chemistry - 4,4′-Bis[4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)phenylcarbonylamino]-3,3′-dichlorodiphenylme-thane has been obtained by the reaction of...     

Synthesis of (−)-(4R,5R)-4,5-bis[di-3′-(2′,6′-dimethoxypyridyl)phosphinomethyl]-2,2-dimethyl-1,3-dioxolane and its application in the Rh-catalyzed asymmetric hydrogenation reactions

The chiral ligand (−)-(4R,5R)-4,5-bis[di-3′-(2′,6′-dimethoxypyridyl)phosphinomethyl]-2,2-dimethyl-1,3-dioxolane 3 [(R,R)-Py*-DIOP] was synthesized via a key intermediate bis[3-(2,6-dimethoxypyridyl)]phosphine-borane 9. The asymmetric hydrogenation of prochiral olefins was investigated using a rhodium catalyst containing 3. For the hydrogenation of amidoacrylic acids, enols and itaconic acid, while the enantioselectivity of [Rh-(R,R)-Py*-DIOP] was similar to that of [Rh-(R,R)-DIOP] the absolute configurations of the products from the two catalyst systems were found to be opposite.     

Synthesis and crystal structure of nickel(Ⅱ) and zinc(Ⅱ) complexes with 2,4-bis(3,5-dimethylpyrazol-1-yl)-6-methoxyl-1,3,5-triazine

2,4-Bis(3,5-dimethylpyrazol-1-yl)-6-methoxyl-1,3,5-triazine(bpt) has been synthesized by using a new, simple and general method with high yields. Reactions of bpt with Ni(CIO4)2 · 6H2O and Zn(CIO4)2 · 6H2O in methanol gave mononuclear complex [Ni(bpt)2] · (CIO4)2 · H2O and ternary complex [Zn(mpt)2(dmp)](CIO4)2 respectively, where mpt (2,4-dimethoxy-6-(3,5-dimethyl-pyrazol-1-yl)-1,3,5-triazine) and dmp(3,5-dimethylpyrazole) are the alcoholysis products of bpt in the presence of Zn2+ ion. A possible mechanism for this catalytic reaction was proposed. X-ray crystal structure for ligand bpt, Ni and Zn complexes are reported. The protonated form of the ligand bpt crystallizes as its perchlorate salt including one molecule of water, [Hbpt · H2O · CIO4]. The proton is located on one pyrazole N-atom. [Hbpt ?H2O ?CIO4], in which [Hbpt]+ is in cis-cis conformation, are packed in slipped stacks of approximately parallel layers. The π-π overlap interactions between the non-protonized pyrazoles of the adjace     

Theoretical studies on the rotamers and dynamic behaviors of ethyl-5-acetyl-4-(3′,4′-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3-carboxylate

The potential energy surfaces of ethyl-5-acetyl-4-(3′,4′-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3-carboxylate have been explored by density functional theory B3LYP with 6-31G* basis set method. All minima and maxima points have a flat boat conformation and the aryl ring lies above the 1,4-dihydropyridine ring. Therefore, the rotation of aryl, acetyl, and carboethoxy groups do not cause a major conformational change in this compound. However, the orientations of carbonyl groups and the distortion from planarity of dihydropyridine ring have been changed. Intramolecular H-contacts involving CH-groups as proton donors have also been investigated. Comparative analysis of the results indicates that the barrier to rotation for aryl group is smaller than that of the carbonyl groups. In addition, the barriers to rotation for the carbonyl and aryl groups of the corresponding pyridine, i.e., ethyl-5-acetyl-4-(3′,4′-dimethoxyphenyl)-2,6-dimethyl-pyridine-3-carboxylate, have also been computed by a similar basis set to investigate the effect of aromaticity of the dihydropyridine ring on the these parameters.     

Transition metal(II) complexes of 1-(α-hydroxynaphthyl)-2-(3′-methyl-5′-mercapto-1′,2′,4′-triazole)-2-aza-ethane

Summary Binuclear metal complexes of the type [M(HMTE)-(H₂O)₂]₂, where HMTE=1-(-hydroxynaphthyl)-2-(3-methyl-5-mercapto-1,2,4-triazolc)2-aza-ethane and M-Cu^II, Co^II, Ni^II and Mn^II have been prepared and characterized. An octahedral geometry around the metals is proposed. The complexes have been screened as possible fungicides.     

Assembly of a new Keggin polyoxometalate-templated complex using flexible 1,2-bis(imidazol-1′-yl)ethane ligand

A new compound, [{Cu^I(bim)}₄{SiW₁₂O₄₀}] (1) (bim?=?1,2-bis(imidazol-1′-yl)ethane), was hydrothermally synthesized and characterized by elemental analyses, IR, TG, and single-crystal X-ray diffraction. Compound 1 is an infinite 1-D chain composed of Cu-bim coordination polymers and [α-SiW₁₂O₄₀]^4? polyanions. The electrochemical and electrocatalytic behaviors of 1-modified carbon paste electrode (1-CPE) have been studied.     

Cobalt(II) porphyrin axially coordinated with 2′-(pyridin-4-yl)-5′-(pyridin-2-yl)-1′-(pyridin-2-ylmethyl)-2′,4′-dihydro-1′H-pyrrolo[3′,4′ : 1,2](C60-Ih)[5,6]fullerene: formation,chemical structure,and spectroscopic properties

Construction of new effective photovoltaic devices based on organic dyes has important implications for modern and future technologies. In this article, we studied the equilibrium, the rate, and the spectral manifestation of the reaction of [(2,3,7,8,12,18-hexamethyl,13,17-diethyl,5-(2-pyridyl)porphyrinato)cobalt(II)]–[2′-(pyridin-4-yl)-5′-(pyridin-2-yl)-1′-(pyridin-2-ylmethyl)-2′,4′-dihydro-1′H-pyrrolo[3′,4′ : 1,2](C₆₀-I_h)[5,6]fullerene] triad formation as well as its spectral properties and photo electrochemical behavior. The cobalt porphyrin–pyridyl-substituted fullerene mixtures in toluene are self-assembling systems due to axial donor–acceptor binding between Co of the porphyrin complex and N-pyridyl of the substituted fullerene. The formation rate constant, k^298K, and the stability constant, K^298K, of donor–acceptor triad formed by coordination of two substituted fullerene molecules to Co porphyrin are (44.4 ± 0.8) mol L^?1 s^?1 and (56 ± 16)×10⁷ L² mol^?2, respectively. Modification of the titanium electrode coated with the natural oxide film was carried out using the porphyrin–fullerene triad and its individual components. Photopotential and photocurrent density of the system with modified electrode were studied. The obtained results are of interest for creating porphyrin-based donor–acceptor systems as components in organic photovoltaics.     

Synthesis,characterization, and investigations of antimicrobial activity of 6,6-dimethyl-3-aryl-3′,4′,6,7-tetrahydro-1′H,3H-spiro[benzofuran-2,2′-naphthalene]-1′,4(5H)-dione

Chalcone-like compounds 3a–l, 2-(benzylidene)-3,4-dihydronaphthalen-1(2H)-one, were synthesized from the addition of different benzaldehyde derivatives (2a–l) to 1,2,3,4-tetrahydro-1-napthalone (1) in basic medium. Mn(OAc)₃-mediated addition of dimedone (4) to chalcone-like compounds gave the spirobenzofuran derivatives (5a-l), 6,6-dimethyl-3-aryl-3′,4′,6,7-tetrahydro-1′H,3H-spiro[benzofuran-2,2′-naphthalene]-1′,4 (5H)-dione, in good yields. The structures of synthesized compounds 5a–l were elucidated on basis of spectral data (NMR, IR) and elemental analysis. In addition, their antibacterial activities were screened against some human pathogenic microorganisms.