The structure of monomeric unsolvated and weakly solvated (Me<Subscript>2</Subscript>Cu)Li and (Me<Subscript>2</Subscript>Cu)Cu

Density functional theory was used to study the structure of various isomers of (Me₂Cu)Li (1), (Me₂Cu)Cu (2), (Me₂Cu)Li · 2Me₂O (3), and (Me₂Cu)Cu · 2Me₂S (4) in the gas phase. Isomers of 1 and 3 were shown to be typical cuprates, whereas isomers of 2 and 4 should rather be treated as unsolvated and solvated methylcopper dimers, respectively. The reasons for the difference between structures 2, 4 and 1, 3 were considered. The energies of solvation of 1 by two dimethyl ether molecules (∼34 kcal/mol) and of 2 by two dimethyl sulfide molecules (∼36 kcal/mol) and the dissociation energies of all the compounds to the dimethylcuprate anion and the corresponding cation were calculated. The energies of solvation of 1 and 2 being almost equal, the transformation of 2 into 4 decreased the dissociation energy much more substantially than the transformation of 1 into 3.     

Einige Neue N,S-Substituierte 2-Nitrodienverbindungen Aus Reaktionen Von Mono(p-fluorarylthio)substituierten Dienen Mit Aminen

2-Nitrodiene compound 1 was stirred with p-fluorothiophenol for a long time and compound 3 was obtained. Compound 1 gave bis(thio)substituted 2-nitrodiene compound 4 and tris(thio)substituted compound 5 with 2 moles of p-fluorothiophenol in the presence of NaOH in ethanol. The compounds 9a–g have been prepared from 8a–g and 3. Compound 7 was obtained from the reaction of mono(thio)substituted 2-nitrodiene with morpholine. Compound 3 gives 11a–d in the reaction with piperidines in CH₂Cl₂ (or ether). Compound 13a–b have been obtained from the reaction of compound 3 with primary amines 12a–b. Compound 3 gives 15 and 16 in the reaction with 2,5-dimethylpiperazine in CH₂Cl₂.

     

Synthesis,crystal structure,redox behavior and DNA-binding properties of a series of copper(II) complexes with two new carboxamide derivatives

Four mononuclear copper(II) complexes of two new carboxamide derivatives formulated as [Cu(L¹)₂](ClO₄)₂ (1a), [Cu(L¹)₂](NO₃)₂ (1b), [Cu(L²)₂(H₂O)₂](ClO₄)₂ (2a), and [Cu(L²)₂(H₂O)](NO₃)₂ (2b) have been isolated in pure form from the reaction of L¹ and L² [where L¹ = N-(furan-2-ylmethyl)-2-pyridinecarboxamide and L² = N-(thiophen-2-ylmethyl)-2-pyridinecarboxamide] with copper(II) salts of perchlorate and nitrate. All the complexes were characterized by physicochemical and spectroscopic tools along with single-crystal X-ray diffraction studies. The structural analyses showed that 1 is monomeric of square planar geometry with copper(II) chelated by two L¹ ligands. Complex 2 differs in coordination geometry, being octahedral and distorted square pyramidal. Two L² ligands occupy the equatorial positions of the octahedral 2a and the basal sites of the pyramidal 2b, with water molecules that complete the coordination sphere in each case. Electrochemical studies using cyclic voltammetry showed a reversible redox behavior of the copper(II) in 1 and 2. The electronic spectroscopic behavior and the trend of one electron equivalent redox potential corresponding to a Cu^II/Cu^I couple have also been confirmed by density functional theory calculations. The spectroscopic and viscosity measurement study in tris–HCl buffer suggested an intercalative interaction of 1a and 2 with calf thymus DNA likely due to the stacking between the non-coordinated furan and thiophene chromophore with the base pairs of DNA.     

Synthesis and spectroscopic studies of new organotin(IV) complexes with tridentate N- and O-donor Schiff bases

The Schiff bases H₂L¹ and H₂L² have been prepared by the reaction of 2-amino-4-chlorophenol with pyrrole-2-carbaldehyde and 2-hydroxy-1-naphtaldehyde, respectively, and HL³ from reaction of 2-(aminomethyl)pyridine with 2-hydroxy-1-naphtaldehyde. Organotin complexes [SnPh₂(L¹)] (1), [SnPh₂(L²)] (2), [SnMe₂(L²)] (3) and [SnPhCl₂(L³)] (4) were synthesized from reaction of SnPh₂Cl₂ and SnMe₂Cl₂ with these Schiff bases. The synthesized complexes have been investigated by elemental analysis and FT-IR, ¹H NMR and ¹¹⁹Sn NMR spectroscopy. In complexes the Schiff bases are completely deprotonated and coordinated to tin as tridentate ligands via phenolic oxygen, pyrrolic, and imine nitrogens in 1, two phenolic oxygens and imine nitrogen in 2 and 3, and phenolic oxygen, imine and pyridine nitrogens in 4. The coordination number of tin in 1, 2, and 3 is five and in 4 is six.     

L-鼠李糖基(氨基)硫脲类化合物的合成

以L-鼠李糖为起始原料, 制备1-溴-2,3,4-三-O-乙酰基-β-L-吡喃型鼠李糖, 然后在甲苯中与Pb(SCN)₂作用, 得到中间体2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯(1). 利用2,3,4-三-O-乙酰基-α-L-吡喃型鼠李糖基异硫氰酸酯易发生亲核加成的性质, 在不同溶剂中, 与取代的苯并噻唑胺(2a～2f)、取代的苯并噻唑肼(2g～2l)、氧化和非氧化的哒嗪酮甲酰肼(2m, 2n)以及取代的嘧啶胺(2o, 2p)反应, 合成了16种新的(氨基)硫脲类化合物3a～3p. 所有化合物的结构均经IR, ¹H NMR, LC-MS和元素分析确证, 并对它们的生物活性做了初步测试.     

Titanium-Substituted Heteropolytungstates as Model Catalysts for Studying the Mechanisms of Selective Oxidation by Hydrogen Peroxide

The ³¹P NMR method shows that four forms of titanium(IV)-monosubstituted Keggin-type heteropolytungstate (Ti–HPA) exist in MeCN: the dimer (Bu₄N)₇[{PTiW₁₁O₃₉}₂OH] (in the abbreviated form, (PW₁₁Ti)₂OH or H1), its conjugate base (PW₁₁Ti)₂O (1), and two monomers, PW₁₁TiO (2) and PW₁₁TiOH (H2). The ratio between the forms depends on the concentrations of H⁺and H₂O. Dimer H1is produced from 2in MeCN when H⁺(1.5 mol) is added, and monomer H2is the key intermediate in this process. The catalytic activity of Ti–HPA in the oxidation of thioethers by H₂O₂correlates with their activity in peroxo complex formation and decreases in the order H2> H1> 2. The reaction of 2with H₂O₂in MeCN occurs slowly to form the inactive peroxo complex PW₁₁TiO₂(A). The addition of H₂O₂to H1and H2most likely results in the formation of the active hydroperoxo complex PW₁₁TiOOH (B). Complexes Aand Btransform into each other when H⁺or OH^–(1 mol) is added per 1 mol of Aor B, respectively. The activity of Btoward thioethers in the stoichiometric reaction is proven by ³¹PNMR and optical spectroscopy.     

Synergies of urushiol and its pechmann derivative compatible with paclitaxel anti-HepG2 activity

The paper investigated the synergistic inhibitory effects of 1 (triene urushiol), 2 (monoene urushiol), 3 (urushiol pechmann derivative) and paclitaxel on proliferation of human hepatocellular carcinoma cell line HepG2. The inhibitory rate of cell proliferation was detected by MTT assay after HepG2 cells were separately treated with compounds 1, 2 and 3 combined with paclitaxel at different concentrations for 72 h. The joint index analysis was used to examine whether those compatible drugs had synergistic effect. The results showed that compounds 1, 2 and 3 had significant inhibitory effect on the proliferation of HepG2 cells in a dose-dependent manner, and their half inhibitory concentrations IC₅₀ were 29.3, 55.5 and 27.1 μM respectively. The synergistic effect of compounds 1, 2 and 3 combined with paclitaxel significantly inhibited the proliferation of HepG2 cells in vitro.     

Acetoacetanilides in Heterocyclic Synthesis,Part 1: An Expeditious Synthesis of Thienopyridines and Other Fused Derivatives

3-Oxo-N-{4-[(pyrimidin-2-ylamino)sulfonyl]phenyl}butanamide 1 reacts with arylidinecyanothioacetamide in refluxing ethanolic TEA to give the pyridinethione 2 rather than thiopyrane 4. Compound 2 reacts with α-haloketones to give the s-alkylated derivatives 7a–e. Compound 7a–e undergoes cyclization into thieno[2,3-b]pyridine derivatives 8a–e. The saponification of 8a gives the amino acid 9, which affords 10 when refluxed in Ac₂O. The treatment of 10 with NH₄OAc/AcOH gives 11. Compound II is also obtained when 8e is refluxed in Ac₂O. The reaction of 8a with hydrazine hydrate gives 12 and with formamide gives 13. Compound 13 also is obtained from the reaction of 8e with triethylorthoformate. The acetylation of 8a with Ac₂O gives the amide derivative 14, which, on treatment with aromatic amines, affords 15a–c. Compounds 15a–c are cyclized with H₂SO₄ to 16a–c. Compound 16 is obtained also from the acetylation of compound 8c, d by Ac₂O. Reactions of compound 8e with CS₂ in refluxing dioxane afford 17. The diazotization and self-coupling of 8e give the pyridothienotriazine 18. Finally, the chloronation of compound 13 with POCl₃ affords the chloride derivative 19.     

Different coordination patterns for two related unsymmetrical compartmental ligands: crystal structures and IR analysis of [Cu(C21H21O2N3)(OH2)(ClO4)]ClO4·2H2O and [Zn2(C22H21O3N2)(C22H20O3N2)]ClO4

The crystal structures of the new complexes [Cu(HL1)(OH₂)(ClO₄)]ClO₄·2H₂O (1) and [Zn₂(HL2)(L2)]ClO₄ (2), derived from two related, phenol-based compartmental ligands, are described. Compound 2 constitutes the first report of a complex obtained from H₂L2. The metal compounds are structurally different; 2 is a dimer in which all the heteroatoms of the ligand take part in coordination, while 1 is mononuclear containing a pair of cis-oriented ligands that complete an “open” coordination sphere, in which the aldehyde group of HL1 is not involved. The protonation status of the central phenol groups of HL1 and H₂L2 are also dissimilar between the complexes. Infrared vibrational analyses of both complexes, as well as their respective ligands, were performed to connect the observed spectral features with the structural properties of the solids. While some distinctive bands shifted upon complexation, it was not possible to confirm involvement of the aromatic aldehyde group in coordination by this technique. ¹H NMR experiments involving 2 suggest that its particular protonation status is maintained upon dissolution in d₆-DMSO.     

Three cobalt coordination polymers based on bis(1,2,4-triazol-1-ylmethyl)benzene positional isomer ligands and thiocyanate

The reaction of three positional isomer ligands of bis(1,2,4-triazol-1-ylmethyl)benzene and Co(NCS)₂ gives three coordination polymers [Co(obtz)₂(NCS)₂] _n (1), [Co(mbtz)₂(NCS)₂] _n (2), and {[Co(bbtz)₂(NCS)₂]?·?2DMF} _n (3). Polymers 1 and 2 are comprised of similar 1-D double chains. In 1, each chain forms π–π stacking interactions with four adjacent chains (two above and two below) to extend to a 3-D supramolecular network. Polymer 3 is a neutral 2-D (4,4) network. The dangling NCS^? inserts into the window of adjacent layers in a mutual relationship and result in a 2-D?→?3-D polythreaded network in 3. The thermal stability and the diffuse reflectance UV-Vis spectroscopy of 1, 2, and 3 were measured.     

Synthesis,structural studies,and antibacterial activity of zinc,copper, and silver complexes derived from N′-(1-(pyrazin-2-yl)ethylidene)isonicotinohydrazide

The multidentate Schiff-base ligand N′-(1-(pyrazin-2-yl)ethylidene)isonicotinohydrazide (HL) has been prepared. Reaction with zinc, copper, and silver nitrate afford three complexes, [Zn(HL′)₂](NO₃)₂·3H₂O (1), {[Cu₂(L)₂(NO₃)(H₂O)₂]·NO₃}_n (2) and {[Ag₂(L)₂]·3H₂O}_n (3). These complexes have been characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. In 1, HL is a neutral tridentate ligand, whereas in 2 and 3, HL is a deprotonated tetradentate ligand. The hydrogen bonding interactions between NO₃^? and the host framework result in various supramolecular polymeric structures: a 2-D layer for 1 and 3-D network for 2 and 3. The antibacterial activities of these complexes have been investigated and the results indicate that 3 showed good antibacterial activities.     

Some diazinon analogues containing the 4-trifluoromethyl group

Summary Diazinon analogues were prepared containing trifluoromethyl in place of the 4-methyl group and methylthio (2 a), amino (2 b), dimethylamino (2 c), methylphenylamino (2 d), or isopropyl (2 e) in position 2 of the pyrimidine ring. The most active analogue (2 b) was less than half as insecticidal as Diazinon.

---

Einige Diazinon-Analoga mit einer 4-Trifluormethylgruppe

Zusammenfassung Es wurden Diazinon-Analoga hergestellt, die anstelle der 4-Methylgruppe die Trifluormethylgruppe und in 2-Position des Pyrimidin-Rings verschiedene Substituenten enthielten.2 a: 2-Methylthio-;2 b: 2-Amino;2 c: 2-Dimethylamino-;2 d: 2-Methylphenylamino-;2 e: 2-Isopropyl-. Das aktivste Analogon war2 b, das allerdings auch weniger als die Hälfte der insektiziden Wirkung des Diazinon aufwies.

     

N-Methylpyridinium Tosylate Catalysed Green Synthesis,X-Ray Studies and Antimicrobial Activities of Novel (E)-3-Amino-2-(e)-(3, 4-Dihydronaphthalen-1(2H)-Ylidene)Hydrazono)Thiazolidin-4-Ones

Abstract

3,4-Dihydro-2H-naphthalen-1-ones 1,on reaction with thiocarbohydrazide, afforded monothiocarbohydrazones 2, which, on condensation with chloroacetic acid in the presence of an ionic liquid and bromotrimethylsilane furnish (E)-3-amino-2-(E)-(3,4-dihydronaphthalen-1-(2H)-ylidene)hydrazono)thiazolidin-4-ones 3 in quantitative yields. Acetyl derivatives 5 were obtained from 3 with acetic anhydride. Monothiocarbohydrazones 2 on condensation with benzaldehyde yield azomethines 4. The structure of compounds 2–5 has been established by elemental analysis, IR, ¹H NMR, and mass spectral data. The structure of compound 3a has been further confirmed by X-ray crystallographic data. The compounds 2–5 were screened for antimicrobial activity. The thiazolidinones 3a and 3b showed maximum antimicrobial activities.     

Nouvelle Synthese Des 2-Thioxoethylphosphonates, 2- mercaptovinylphosphonates, 2-Phosphoryl-3-thioxopropanoates, 2-Thiomethylvinylphosphonates, 2-Thioethoxycarbonylmethylvinylphosphonates

The cyanomethylphosphonates 1 and the ethyl phosphoacetates 2 were reacted with some fluorophenylisothiocyanates to give the 2-thioxoethylphosphonates 3 in tautomeric equilibrium with the corresponding 2-mercaptovinylphosphonates 3 ′ and the 2-phosphoryl-3-thioxopropanoates 4 , respectively. Reaction of the cyanomethylphosphonates 1 with fluorophenylisothiocyanates in presence of methyliodide furnished the 2- thiometylvinylphosphonates 5 . The 2-mercaptovinylphosphonates 3 ′ reacted with ethyl chloroacetate in refluxing ethanol in the presence of triethylamine to give S-substitued derivatives 6 .     

Synthesis,crystal structure,spectroscopy, thermal properties and carbonic anhydrase activities of new metal(II) complexes with mefenamic acid and picoline derivatives

The mononuclear six metal(II) complexes ([Co(mef)₂(3-pic)₂(CH₃OH)₂] (1), [Ni(mef)₂(3-pic)₂(CH₃OH)₂] (2), [Cu(mef)₂(3-pic)₂] (3), [Co(mef)₂(4-pic)₂] (4), [Ni(mef)₂(4-pic)₂] (5), and [Cu(mef)₂(4-pic)₂] (6) with mefenamic acid and picoline ligands were synthesized, characterized, and their carbonic anhydrase inhibitory activities were evaluated. The six complexes were characterized by elemental analysis, FT-IR spectroscopy, and thermal analyses. The crystal structures of 1, 3, and 6 were determined by X-ray crystallography. The complexes have octahedral geometry. In 1, the mefenamato ligand behaved as monodentate whereas in 3 and 6, the mefenamato ligand acted as a bidentate ligand. Complexes 3 and 6 consist of the mefenamate and 4-picoline ligands. In 1, unlike the other complexes, methanol acted as a ligand and was involved in the coordination. Carbonic anhydrase I and II isoenzymes were purified from human erythrocytes. The in vitro effects of mefenamic acid, 3-picoline, 4-picoline, and the six metal(II) complexes on these isoenzymes were evaluated.     

Synthesis and Cation-Binding Properties of (1→6)-2,5-Anhydro-D-glucitol with 3,4-Di-O-Pentyl and Decyl Groups by Cyclopolymerization of 1,2:5,6-Dianhydro-D-mannitols

Abstract

The cyclopolymerizations of 1,2:5,6-dianhydro-3,4-di-O-pentyl-D-mannitol (1b) and 1,2:5,6-dianhydro-3,4-di-O-decyl-D-mannitol (1c) were carried out using BF₃OEt₂ and t-BuOK. All the resulting polymers consisted of cyclic constitutional units, i.e., the extent of cyclization was 100%. The polymer structures for the polymerization with t-BuOK were (1→6)-2,5-anhydro-3,4-di-O-pentyl-D-glucitol (2b) and (1→6)-2,5-anhydro-3,4-di-O-decyl-D-glucitol (2c), whereas those with BF₃O-decyl₂ comprised 2,5-anhydro-D-glucitols as major units along with other cyclic ones. These polymers were soluble in n-hexane, CHCl₃, and THF, but insoluble in water, which differs from the amphiphilic solubility of (1→6)-2,5-anhydro-3,4-di-O-methyl-D-glucitol (2a). The cation-binding properties of 2b and 2c were examined using alkali-metal picrates in order to compare them with those of 2a. The extraction yields for each cation decreased in the order of 2c < 2b < 2a. Every polymer exhibited a similar cation-binding selectivity in the order Cs⁺ > Rb⁺ > K⁺ ? Na⁺ > Li⁺. The ratio of K⁺ and Na⁺, K⁺/Na⁺, was 4.6 for 2a, 5.1 for 2b, and 7.1 for 2c in the increasing order 2a < 2b > 2c.     

Synthesis,characterization, interactions with DNA and bovine serum albumin (BSA), and antibacterial activity of cyclometalated iridium(III) complexes containing dithiocarbamate derivatives

Three mononuclear cyclometalated iridium(III) complexes having dithiocarbamate ligands, [Ir^III(2-C₆H₄py)₂(L)] (where 2-C₆H₄py?=?2-phenylpyridine; and L¹H?=?4-MePipzcdtH, L²H?=?MorphcdtH, and L³H?=?4-BzPipercdtH for 1, 2, and 3, respectively), were synthesized from [Ir(2-C₆H₄py)₂Cl]₂·1/4CH₂Cl₂ by displacing the two bridging chlorides with one dithiocarbamate ligand. The complexes were characterized using physicochemical and spectroscopic tools along with structural analysis of [Ir(2-C₆H₄py)₂(L²)] (2) by single crystal X-ray diffraction. Structural analysis of 2 showed a distorted octahedron in which the nitrogen donor of one 2-phenylpyridine and the carbon donor of another 2-phenylpyridine are in axial positions, trans to one another. Electrochemical analysis by cyclic voltammetry showed the irreversible two-electron equivalent reduction voltammograms of 1, 2, and 3 attributable to Ir(III) to Ir(I). Electronic characterizations of these complexes are consistent with significant delocalization of the sulfur electron density onto the empty metal d-orbital. The intercalative interaction of the complexes with calf thymus DNA was evaluated using absorption, fluorescence quenching, and viscosity measurements. The binding affinities of these complexes with bovine serum albumin were estimated in terms of quenching constants using the Stern–Volmer equation. Study of antibacterial activities of the complexes by agar disk diffusion against some species of pathogenic bacteria was also performed.     

Ruthenium(II) carbonyl complexes of P,P and P,O donor diphosphine ligands,Ph2P(CH2)nPPh2 and Ph2P(CH2)nP(O)Ph2, n = 2, 3 and their activities in catalytic transfer hydrogenation reactions

The polymeric precursor [RuCl₂(CO)₂]_n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl₂(CO)₂(?²-P∩P)] (1a, 1b) and [RuCl₂(CO)₂(?²-P∩O)] (1c, 1d), where P∩P: Ph₂P(CH₂)_nPPh₂, n = 2(a), 3(b); P∩O: Ph₂P(CH₂)_nP(O)Ph₂, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a–1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h^?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl₃ itself. Among 1a–1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.     

Spectroscopic,thermal and X-ray crystal structure studies of some bis-(pyrazine-2-carboxylato) nickel(II) complexes

Three nickel(II) complexes [Ni(PC)₂(H₂O)₂], 1, [Ni(PC)₂(TU)₂], 2 and [Ni(PC)₂(ABI)₂]· 2(H₂O), 3, PC?=?pyrazine-2-carboxylate, TU?=?thiourea and ABI?=?2-aminobenzimidazole, were synthesized and characterized by elemental analysis, IR spectroscopy and thermal analysis. The complexes were also investigated by single crystal X-ray diffraction analysis. Structures of the monomeric complexes showed nickel(II) chelated to two PC ions from an oxygen atom of carboxylate ion and the adjacent hetero nitrogen atom. The three complexes were crystallized in a monoclinic system with P2 ₁ /c space group for 1, while 2 and 3 had C2/c space groups. The structure of 1 showed two coordinated water molecules occupying the trans positions of a slightly elongated octahedron. The structure of 2 consisted of two PC ions and two thiourea molecules in trans positions. The structure of 3 was different and showed a highly distorted octahedron with two ABI molecules chelated to the nickel ion in cis positions through their hetero nitrogen atoms. Two water molecules of crystallisation were shown in the structure of 3.     

Reaction of Quinoline-5,8-Diones with Selected Charged Phosphorus Nucleophiles

Abstract

The redox reactivity of the two quinoline-5,8-dione derivatives—2-methyl-5,8-dioxo-5,8-dihydroquinoline-7-amine (2a) and N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acet-amide (2b)—has been demonstrated by their reaction with negatively charged three-coordinated phosphorus nucleophiles, such as R₂P-YM (1a–d, Y = O or lone pair; R = Ph, tBu, OCH₂CMe₂CH₂O, or EtO; M = Li or Na). 1a–d participated in single-electron transfer (SET) to 2a and 2b, generating the radical anions 3 and 4, respectively, together with short-lived phosphorus-centered radical intermediates of type R₂P(= Y)· (5). The radicals 5 dimerize to give R₂P(Y)–(Y)PR₂ (6). Both 3 and 4 are remarkably persistent with half-lives of more than 1 month in THF (tetrahydrofuran) at 300 K.