Synthesis,crystal structures,and biological activity of oxovanadium(V) complexes with similar tridentate hydrazone ligands

Two new oxovanadium(V) complexes, [VOL¹(OEt)(EtOH)] (1) and [VOL²(OMe)(MeOH)] (2), were prepared by reaction of [VO(acac)₂] (where acac?=?acetylacetonate) with N′-(3-bromo-2-hydroxybenzylidene)-4-methylbenzohydrazide (H₂L¹) in ethanol and N′-(3-bromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide (H₂L²) in methanol, respectively. Crystal and molecular structures of the complexes were determined by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. The V ions have octahedral coordination. Thermal stability and the inhibition of urease of the complexes were studied.     

Steric and electronic effects of N -coordinated NC − and NCS− on NiS2PN: synthesis,spectral and single crystal X-ray structural studies on N,N ′-di- n -butyldithiocarbamate complexes of nickel(II) with phosphorus and nitrogen donor ligands

Planar nickel(II) complexes involving N,N′-dibutyldithiocarbamate, such as [Ni(bu₂dtc)(PPh₃)(NC)] (1) and [Ni(bu₂dtc)(PPh₃)(NCS)] (2) (where bu₂dtc = N,N′-dibutyldithiocarbamate anion) have been prepared, characterized by electronic, IR and NMR spectra and their structures determined by single crystal X-ray crystallography. Cyclic voltammetric characterizations of the complexes are also reported. IR spectra of the two complexes indicate the isobidentate coordination (ν_c-s ? 1095 cm^?1 without splitting) of the dithiocarbamate moiety. The important stretching mode characteristic of the thioureide bond (ν_C–N) occurs at higher wave numbers compared to that of the parent dithiocarbamate complex [Ni(bu₂dtc)₂]. The electronic spectra of 1 and 2 show signature bands at 426 nm and 478 nm, respectively. NMR spectra show large ³¹P chemical shifts in both compounds and the most important N¹³CS₂ chemical shift appears at 204.86 ppm and 203.23 ppm for 1 and 2, respectively. The CV studies clearly show the presence of reduced electron density on the nickel ions in mixed-ligand complexes 1 and 2 compared to the parent dithiocarbamate. Single crystal X-ray structure studies show that 2 crystallizes as a new triclinic polymorph, whose molecular structure closely resembles that of the previously reported monoclinic form. Both complexes contain a planar NiS₂PN chromophore in keeping with the observed diamagnetism. In both complexes the Ni-S distances are significantly different. The thioureide C–N distances of the complexes are shorter than those observed in the parent [Ni(bu₂dtc)₂]. The two compounds allow comparison of the influence of NCS^? in place of NC^?.     

哒嗪酮类α1-肾上腺素受体拮抗剂的合成和生物活性研究

将苯(氧)乙胺和苯氧烷胺类α₁-肾上腺素受体拮抗剂中的苯(氧)乙胺、苯氧烷胺片段引入哒嗪酮类化合物中, 设计、合成了30个新的含哒嗪酮环的α₁-肾上腺素受体拮抗剂. 所有新化合物的结构均经¹H NMR, IR, HRMS确证. 生物活性测试表明28个目标物对α₁-肾上腺素受体有较好的拮抗作用(pA₂＞6.00), 化合物6o, 6p, 6q, 6v, 6x, 6y, 10c, 10d的pA₂值＞7.00.     

Synthesis,structure and antiproliferative activity of dinuclear ruthenium arene complexes with differently coordinated thiosemicarbazones

A series of di‐nuclear ruthenium arene complexes with TSC ligands ([(η⁶‐p‐cymene)Ru(N¹,S‐TSC)]₂Cl₂, A‐type, 1 and 2 ) and their corresponding analogues ([(η⁶‐p‐cymene)Ru(N²,S‐TSC)]₂Cl₂, B‐type, 3 and 4 ), in which TSCs act as different coordination mode, have been synthesized and structurally characterized by a variety of physical methods. The molecular structures of 1 , 3 and 4 were determined using single‐crystal X‐ray diffraction analysis. The Gibbs free energy of the two examples of the two types of complexes ( 1 and 3 ) and bonding order in their single‐crystals were discussed using density functional theory (DFT) calculations. The compounds were further evaluated for their in vitro antiproliferative activities against several cancerous and HEK‐293 T noncancerous cell lines, and the results indicate that B‐type complexes show stronger cytotoxicity than A‐type complexes. Furthermore, the interactions of the compounds with DNA were investigated by electrophoretic mobility spectrometry studies.     

Syntheses,structural determination,and binding studies of binuclear nine-coordinate (MnH)4[Ho 2 III (Dtpa)2] · 12H2O and polynuclear nine-coordinate {(MnH)[HoIII(Egta)] · 3H2O} n

Two novel rare earth metal coordination compounds, (MnH)₄[Ho ^III₂ (Dtpa)₂] · 12H₂O (I) (Mn = methylamine, H₅Dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaaceticacid) and {(MnH)[Ho^III(Egta)] · 3H₂O} _n (II) (H₄Egta = ethyleneglycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) have been successfully synthesized through direct heating reflux and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction techniques (CIF files CCDC nos. 890878 (I) and 1457061 (II)). Complex I shapes a binuclear nine-coordinate structure with distorted tricapped trigonal prismatic conformation and crystallizes in the triclinic crystal system with space group P1?. The central Ho³⁺ ion is coordinated by three nitrogens and six oxygens from two octadentate Dtpa ligands. The cell dimensions are as follows: a = 9.8420(10), b = 12.1319(13), c = 13.2931(15) Å, α = 89.223(2)°, β = 68.4280(10)°, γ = 72.1280(10)° and V = 1396.0(3) ų. Complex II adopts a polynuclear nine-coordinate structure with pseudo-monocapped square antiprismatic conformation and crystallizes in the monoclinic crystal system with space group C2/c. The central Ho³⁺ ion is coordinated by two nitrogens and seven oxygens from two octadentate Egta ligands. The crystal data are as follows: a = 38.4755(13), b =13.5569(5), c = 8.7343(3) Å, β = 100.135(3)° and V = 4484.8(3) ų.

     

Interaction of Mn(acac)3 with Asymmetrical Schiff Base Ligands containing an Amido Group

Interaction of asymmetrical Schiff base ligands H₃Lⁿ [where H₃Lⁿ are substituted 3–aza–4–(2–hydroxyphenyl)–N– (2–hydroxyphenyl)but–3–enamide] with Mn(acac)₃ (acac = acetylacetonate) has been investigated. Two different type of manganese(III) complexes have been obtained depending on the nature of the substituents on the ligand. We have found that ligands containing donor substituents drives to the formation of two different kinds of complexes from the same reaction: Mn(Lⁿ)(H₂O)_x ( 1a–5a ) and [Mn(HLⁿ)(acac)](H₂O)_y ( 1b–5b ) (where Lⁿ and HLⁿ signify the ligand in its trianionic and dianionic form, respectively). However, when the substituents are electron withdrawing or poor donor only compounds of the type [Mn(HLⁿ)(acac)](H₂O)_y ( 6–10 ) are obtained. All these compounds have been characterized by elemental analyses, IR and ¹H NMR spectroscopy, FAB mass spectrometry, magnetic measurements and molar conductivities. The electrochemical behaviour of these complexes has also been studied.     

Vapochromic Ionic Liquids from Metal–Chelate Complexes Exhibiting Reversible Changes in Color,Thermal, and Magnetic Properties

Vapor‐ and gas‐responsive ionic liquids (ILs) comprised of cationic metal‐chelate complexes and bis(trifluoromethanesulfonyl)imide (Tf₂N) have been prepared, namely, [Cu(acac)(BuMe₃en)][Tf₂N] ( 1 a ), [Cu(Bu‐acac)(BuMe₃en)][Tf₂N] ( 1 b ), [Cu(C₁₂‐acac)(Me₄en)][Tf₂N] ( 1 c ), [Cu(acac)(Me₄en)][Tf₂N] ( 1 d ), and [Ni(acac)(BuMe₃en)][Tf₂N] ( 2 a ) (acac=acetylacetonate, Bu‐acac=3‐butyl‐2,4‐pentanedionate, C₁₂‐acac=3‐dodecyl‐2,4‐pentanedionate, BuMe₃en=N‐butyl‐N,N′,N′‐tetramethylethylenediamine, and Me₄en=N,N,N′,N′‐trimethylethylenediamine). These ILs exhibited reversible changes in color, thermal properties, and magnetic properties in response to organic vapors and gases. The Cu^II‐containing ILs are purple and turn blue‐purple to green when exposed to organic vapors, such as acetonitrile, methanol, and DMSO, or ammonia gas. The color change is based on the coordination of the vapor molecules to the cation, and the resultant colors depend on the coordination strength (donor number, DN) of the vapor molecules. The vapor absorption caused changes in the melting points and viscosities, leading to alteration in the phase behaviors. The IL with a long alkyl chain ( 1 d ) transitioned from a purple solid to a brown liquid at its melting point. The Ni^II‐containing IL ( 2 a ) is a dark red diamagnetic liquid, which turned into a green paramagnetic liquid by absorbing vapors with high DN. Based on the equilibrium shift from four‐ to six‐coordinated species, the liquid exhibited thermochromism and temperature‐dependent magnetic susceptibility after absorbing methanol.     

Mono‐ and Binuclear Rhodium and Platinum Complexes of 1, 3, 5‐Trimethyl‐1, 3, 5‐triaza‐2σ3λ3‐phosphorin‐4, 6‐dionyloxy‐substituted Calix[4]arenes

The reaction behaviour of 1, 3, 5‐triaza‐2σ³λ³‐phosphorin‐4, 6‐dionyloxy‐substituted calix[4]arenes towards mono‐ and binuclear rhodium and platinum complexes was investigated. Special attention was directed to structure and dynamic behaviour of the products in solution and in the solid state. Depending on the molar ratio of the reactands, the reaction of the tetrakis(triazaphosphorindionyloxy)‐substituted calix[4]arene ( 4 ) and its tert‐butyl‐derivative ( 1 ) with [(cod)RhCl]₂ yielded the mono‐ and disubstituted binuclear rhodium complexes 2 , 3 , and 5 . In all cases, a C₂‐symmetrical structure was proved in solution, apparently caused by a fast intramolecular exchange process between cone conformation and 1, 3‐alternating conformation. The X‐ray crystal structure determination of 5 confirmed [(calixarene)RhCl]₂‐coordination through two opposite phosphorus atoms with a P ⃜P separation of 345 pm. The complex displays crystallographic inversion symmetry, and the Rh₂Cl₂ core is thus exactly planar. Reaction of 1 and of the bis(triazaphosphorindionyloxy)‐bis(methoxy)‐substituted tert‐butyl‐calix‐[4]arene ( 7 ) with (cod)Rh(acac) in equimolar ratio and subsequent reaction with HBF₄ led to the expected cationic monorhodium complexes 5 and 8 , involving 1, 3‐alternating P‐Rh‐P‐coordination. The cone conformation in solution was proved by NMR spectroscopy and characteristic values of the ¹J(PRh) coupling constants in the ³¹P‐NMR‐spectra. Reaction of equimolar amounts of 4 with (cod)Rh(acac) or (nbd)Rh(acac) led, by substitution of the labile coordinated acetylacetonato and after addition of HBF₄, to the corresponding mononuclear cationic complexes 9 and 10 . Only two of the four phosphorus atoms in 9 and 10 are coordinated to the central metal atom. Displacement of either cycloocta‐1, 5‐diene or norbornadiene was not observed. For both compounds, the cone conformation was proved by NMR spectroscopy. Reaction of 4 with (cod)PtCl₂ led to the PtCl₂‐complex ( 11 ). As for all compounds mentioned above, only two phosphorus atoms of the ligand coordinate to platinum, while two phosphorus atoms remain uncoordinated (proved by δ³¹P and characteristic values of ¹J(PPt)). NMR‐spectroscopic evidence was found for the existence of the cone conformation in the cis‐configuration of 11 .     

Synthesis,antitubercular evaluation and molecular docking studies of phthalimide bearing 1,2,3-triazoles

In a search for safer and potent antitubercular agents, here a library of newly substituted dioxoisoindolinylmethyl-triazolyl-N-phenylacetamide derivatives (5a–l) has been synthesized via click chemistry approach. All synthesized compounds were evaluated for their antitubercular activity against Mycobacterium tuberculosis H₃₇Rv (MTB). Among the screened compounds, 5d, 5e, 5h, and 5l showed good antitubercular activity. The compounds 5d and 5l have shown very effective antitubercular activity against Mycobacterium tuberculosis H₃₇Rv (MTB) with MIC 12.5?μg/mL. All the newly synthesized compounds were thoroughly characterized by ¹H NMR, ¹³C NMR, and HRMS spectral data. We further performed exploratory docking studies on the crystal structure of Mycobacterium tuberculosis enoyl reductase to demonstrate the mechanism of antitubercular activity.     

Infrared spectral studies on the stability of some binuclear transition metal—Schiff base complexes

Some di-Schiff bases like N,N′-o-phenylene-bis-salicylaldimine (DSB₁), N,N′-m-phenylene-bis-salicylaldimine (DSB₂) and N,N′-p-phenylene-bis-salicylaldimine (DSB₃) have been synthesized by the condensation of salicylaldehyde with o-, m- and p-phenylenediamines, respectively. The synthesized complexes of Cu(II), Ni(II) and Co(II) with these ligands have been assigned their molecular structure on the basis of their elemental analyses, molecular weight determination, magnetic measurements, electronic spectra, molar volume and infrared spectral studies. The nature of bonding between metal ion and Schiff bases is studied by i.r. spectrophotometry. The shift in the band position of the groups involved in coordination has been utilized to estimate the coordination bond lengths. The value of the coordination bond length of Cu(II) complexes is shorter than the corresponding values for Ni(II) and Co(II) complexes.     

Synthesis,structure, cytotoxic activities,and DNA-binding of 1-D copper(II) and zinc(II) coordination polymers

Two 1-D coordination polymers have been synthesized and identified as [Zn(ox)(en)] _n (H₂O)_{2 n} (1) and [Cu₂(dmeo)(N₃)₂] _n (2), where en represents diaminoethane, ox and dmeo stand for dianions of oxalic acid and N,N′-bis[2-(dimethylamino)ethyl]oxamide, respectively. Polymer 1 was characterized by elemental analysis, molar conductance measurement, IR and electronic spectra, and single-crystal X-ray diffraction. Polymer 1 consists of 1-D chains bridged by oxalate. The Zn^II can be described as a distorted octahedral environment and the Zn^II···Zn^II separation through the μ-oxalato-bridge is 5.5420(9)?Å. Hydrogen bonds assemble the coordination polymers to a 3-D supermolecular structure. The crystal structure of 2 has been reported previously. However, the bioactivities were not studied. The DNA-binding properties and cytotoxic activities of the two coordination polymers are investigated. The results suggest that the two polymers interact with HS-DNA in groove binding with binding affinity following the order of 1?>?2, which is consistent with their anticancer activities.     

Spectroscopic,electrochemical and X-ray crystallographic properties of a novel palladium(II) complex of thioamide deprotonated di-2-pyridyl ketone thiosemicarbazone (dpktsc-H)−

The reaction between di-2-pyridyl ketone thiosemicarbazone (dpktsc) and PdCl₂(CH₃CN)₂, generated in situ from the reaction between PdCl₂ and CH₃CN, gave the unprecedented [Pd₂Cl₃(κ⁵-N_py,N_im,S,N_py,N_am-dpktsc-H)]·2CH₃CN (1) complex (py = pyridine, im = imine and am = amide). The identity of 1 was confirmed via its elemental analysis and spectroscopic properties. Infrared and ¹H-NMR spectra confirmed the coordination of (dpktsc-H)^? to the palladium ions. The electronic absorption spectra measured in dmso and dmf and density functional theory (DFT) calculations revealed metal-to-ligand charge-transfer (MLCT), d–d and intra-ligand charge-transfer (ILCT) electronic transitions. X-ray structural analysis on a crystal of [Pd₂Cl₃(κ⁵-N_py,N_im,S,N_py,N_am-dpktsc-H)]·H₂O (2) grown from dmf solution of 1 confirmed its formulation and showed the solid-state structure contains a web of molecules locked via a network of non-covalent interactions. Electrochemical measurements on 1 in dmf revealed metal- and ligand-based redox processes. In contrast to the electrochemical decomposition of uncoordinated dpktsc, coordinated (dpktsc-H)^? in 1 does not undergo electrochemical decomposition. Electrochemical titrations of 1 with p-toluenesulfonic acid monohydrate (p-TSOH) revealed electro-catalytic proton reduction. Over-potential (η) of 180 mV for the H₂ evolution was observed and is comparable to several molecular electro-catalysts for proton reduction. Controlled-potential electrolysis confirmed the electro-catalytic proton reduction by the Pd-complex. Electrochemical reactions of CO₂ in the presence of 1 exhibited a proton dependence, and metal- and ligand-based electrochemical reaction.     

Preparation and structural,spectroscopic, thermal,and electrochemical characterizations of iron(III) compounds containing dipicolinate and 2-aminopyrimidine or acridine

Two new iron(III) compounds, (Hamp)[Fe(pydc)₂]?·?2H₂O (1) and (Hacr)[Fe(pydc)₂]?·?2H₂O (2) (pydc^2??=?pyridine-2,6-dicarboxylic acid, amp?=?2-aminopyrimidine, acr?=?acridine), have been hydrothermally synthesized. Both compounds were characterized by spectroscopic methods (IR, UV/Vis), and their molecular and crystal structures were determined by X-ray crystal structure analysis and their thermal stability by thermogravimetric analysis/differential thermal analysis (TGA/DTA) methods. Compound 1 consists of Hamp⁺ cation and [Fe(pydc)₂]^? anion and 2 consists of Hacr⁺ cation and [Fe(pydc)₂]^? anion. Crystallographic characterization revealed an octahedron as a coordination polyhedron for the complex anion in 1 and 2 and the same O,N,O′-chelated coordination mode of pyridine-2,6-dicarboxylate. The crystal structures of 1 and 2 are stabilized by a complicated network of hydrogen bonds between the crystallization water molecules, counter ion, and carboxylates of pydc^2?. Thermogravimetric (TG) analyses of the two compounds were carried out to examine their thermal stabilities. Cyclic voltammetric response of bare glassy carbon electrode surface in 0.10?mol?L^?1 phosphate buffer containing 1 and 2 at different pH values indicated that they have the same voltammograms at all pH values and the electrochemical behavior of 1 and 2 has not been affected by different ion pairs. The formal potential of the solutions of 1 and 2 at the glassy carbon electrode surface was also pH-dependent with a slope of ?57.0?mV/pH unit at 25°C. This shows that the number of electrons and protons involved in the electrode process is equal.     

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.     

Synthesis and biological activity evaluation of new thiazolidinone-diclofenac hybrid molecules

Abstract

A novel series of [2-(2,6-dichlorophenylamino)-phenyl]-acetic acid N`-3-(substituted)-4-thiazolidin-5-ylidenemethyl-hydrazide derivatives has been designed and synthesized. The structures of synthesized compounds were confirmed by their <sup>1</sup>H NMR, <sup>13</sup>C NMR and LCMS spectroscopic data. Target compounds were screened for their in vitro anticancer activity according to US NCI protocols, in vitro trypanocidal activity toward Trypanosoma brucei brucei (Tbb) and evaluated for anti-inflammatory activity on the carrageenan edema model in rats. Biological screening data led to identification of compounds 3.3 ([2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid N`-(4-oxo-2-thioxo-thiazolidin-5-ylidenemethyl)-hydrazide) and 3.7 ([2-(2,6-dichloro-phenylamino)-phenyl]-acetic acid N`-(4-oxo-2-thioxo-3-(3-trifluoromethylphenyl)thiazolidin-5-ylidenemethyl)-hydrazide) which demonstrated moderate antitumor activity on the non-small-cell lung cancer NCI-H522 and colon cancer HCT-116 cell lines. Several hit compounds (3.2, 3.4) exhibited the promising and significant inhibition growth of the parasites at micromolar concentrations (IC₅₀ values of 4.8 and 7.06?μM, respectively). The synthesized compounds also demonstrated considerable anti-inflammatory effect comparable to the reference non-steroidal anti-inflammatory drugs (NSAIDs) diclofenac sodium or ketorolac tromethamine.     

Crystal-field splitting in the M11,111 spectra of Co(II) compounds

We have analyzed part of the M_11,111 absorption spectra of the compounds CoF₂, CoCl₂, CoBr₂, Co(acac)₂ as due to the crystal-field splitting of a ⁴G state arising from the configuration 3p⁵3d⁸.     

Pressure Effects in the Solvolysis of Benzyl Chlorides

Rates of solvolysis of benzyl chloride and of substituted benzyl chlorides have been measured in an acetone-water mixture (acetone mole fraction 0.147) at pressures ranging from atmospheric to 1 kbar. Pressure studies have also been made for p-methyl benzyl chloride in various acetone-water mixtures. Measurements have also been made of the partial molar volumes of the reactants. The plots of log k against pressure are fitted to a second-degree polynomial in P, and values of ΔV^? and (δΔV^//δP)_T are obtained. The ΔV^? values are all negative, having values ranging from ?18 to ?24 cc/mole. The results are interpreted on the view that the mechanisms are S_N2(1), i.e. are towards the S_N1 end of the S_N2 spectrum of behavior. The ΔV^? values steadily become more negative in the series p? CH₃, H, p? Cl, pNO₂, and this is interpreted in terms of the greater spreading of positive charge in the p? CH₃ case and in terms of greater S_N2(2) character in the p? NO₂ case. The ΔV^? values go through a minimum as the solvent composition is varied, a result that is related to the existence of a corresponding maximum in the partial molar volumes of the reactant. The (δΔV^?/δP)_T values show a negative correlation with ΔV^?, suggesting, as expected, that the more compact activated complexes are the least compressible.     

Synthesis and characterization of the [Cu(Cin2bda)2]ClO4 and [Cu(Ncin2bda)2]ClO4 complexes: Crystal structure of [Cu(Ncin2bda)2]ClO4

Two copper(I) complexes [Cu(Cin₂bda)₂]ClO₄ (I) and [Cu(Ncin₂bda)₂]ClO₄ (II) have been prepared by the reaction of the ligands N²,N²′-bis(3-phenylallylidene)biphenyl-2,2′-diamine (L¹) and N²,N²′-bis[3-(2-nitrophenyl)allylidene]biphenyl-2,2′-diamine (L²) and copper(I) salt. These compounds were characterized by CHN analyses, ¹H NMR, IR, and UV-Vis spectroscopy. The C=N stretching frequency in the copper(I) complexes shows a shift to a lower frequency relative to the free ligand due to the coordination of the nitrogen atoms. The crystal and molecular structure of II was determined by X-ray single-crystal crystallography. The coordination polyhedron about the copper(I) center in the complex is best described as a distorted tetrahedron. A quasireversible redox behavior was observed for complexes I and II. The article is published in the original.     

Vinylmetallics as ligands : VII. Acetylacetonatobis(η2-vinylsilane)rhodium(I) complexes

Complexes of the type, [(acac)Rh(ViSiR₃)₂] and [(acac)Rh(Vi₂SiR₂)], are readily prepared by displacement of ethylene from [(acac)Rh(C₂H₄)₂]. The compounds, which are less reactive to air than similar carbon analogues, have been characterized by ¹H and ¹³C NMR. The ¹³C NMR results suggest that the vinylsilane ligands function as better π-acceptors than do similar carbon analogues, and that dπpπ interactions between the silicon atom and the double bond are decreased upon coordination of the vinylsilane.     

Synthesis,structure, DNA-binding,and cytotoxic activities of N-(5-chloro-2-hydroxyphenyl)-N′-[3-(2-hydroxyethylamino)propyl]oxamide and its dicopper(II) complex

A dissymmetrical N,N′-bis(substituted)oxamide, N-(5-chloro-2-hydroxyphenyl)-N′[3-(2-hydroxyethylamino)propyl]oxamide (H₃oxpep), and its dicopper(II) complex, [Cu₂(oxpep)(phen)]ClO₄ (1) (phen?=?1,10-phenanthroline), were synthesized. The crystal structure of 1 was determined by single-crystal X-ray diffraction. In 1, Cu1 and Cu2 are bridged by cis-oxpep^3? with Cu?···?Cu separation of 5.2007(6)?Å. Cu1 is in a distorted square-pyramidal environment, while Cu2 has a square-planar coordination geometry. The 3-D supramolecular structure of 1 is formed through π–π stackings and hydrogen bonds. The DNA-binding properties and cytotoxic activities of the two compounds were investigated. The results suggest that the two compounds can interact with HS-DNA by intercalation with binding affinities following the order 1?>?H₃oxpep, which is consistent with their anticancer activities.