Synthesis, spectroscopic studies and electrochemistry of palladium (II) macrocyclic complexes derived from a new tetraazahalogen substituted ligands by template method and their antimicrobial and pesticidal activities

A new series of Pd(II) macrocyclic complexes have been synthesized by template condensation of bis(benzil)4-chloro 1,2-phenylenediamine (ML1) and bis(benzil)4-fluro 1,2-phenylenediamine (ML2) respectively, with appropriate diamine i.e. 1,2-phenylenediamine, 4-chloro 1,2-phenylenediamine and 4-fluro 1,2-phenylenediamine in the presence of PdCl2 to form complexes of the type [Pd(C40H26N4ClF)]Cl2, [Pd(C40H27N4X)]Cl2 and [Pd(C40H26N4X2)]Cl2, where X=Cl, F. The complexes have been characterized with the help of elemental analysis, IR, 1H NMR, electronic spectra, conductance measurement, magnetic susceptibility, cyclic voltammetry and X-ray powder diffraction studies. On the basis of these studies a square planar geometry has been proposed around the metal ion. The newly synthesized ligands and their complexes have been screened for antimicrobial and pesticidal activities. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substance with pesticidal activity and promising antimicrobial activity.     

Synthesis and cytotoxicity studies of novel anion‐exchanged Titanocene Y derivatives

Starting from the potential anticancer drug candidate Titanocene Y {bis‐[(4‐methoxybenzyl)cyclopentadienyl]titanium(IV) dichloride}, anion exchange experiments were performed using silver malonate (1a) or silver cyclobutane‐1,1‐malonate (1b) in order to yield bis‐[(4‐methoxy‐benzyl)cyclopentadienyl] titanium(IV) malonate (2a) and bis‐[(4‐methoxy‐benzyl)cyclopentadienyl] titanium(IV) cyclobutane‐1,1‐malonate (2b). In addition, Titanocene Y was reacted with salicylic acid (3a) or 3,5‐dinitro‐salicylic acid (3b) in the presence of diethylamine to synthesize bis‐[(4‐methoxy‐benzyl)cyclopentadienyl] titanium(IV) salicylate (4a) or bis‐[(4‐methoxy‐benzyl)cyclopentadienyl] titanium(IV) 3,5‐dinitro‐salicylate (4b). These titanocenes had their cytotoxicity investigated through preliminary in vitro testing on the LLC‐PK (pig kidney epithelial) cell line in an MTT‐based assay in order to determine their IC50 values. Titanocenes 2a–b and 4a were found to have IC50 values of 74 ( ± 13) µM , 18 ( ± 5) µM and 49 ( ± 11) µM on the LLC‐PK cell line, while compound 4b was found to have lost all its cytotoxic activity on this cell line. Copyright © 2010 John Wiley & Sons, Ltd.     

Syntheses and characterization of Ru(III) with chelating containing ONNO donor quadridentate Schiff bases

Complexes of ruthenium(III) with N,N'-disalicylidene-l,2-phenylenediamine (H2dsp), N,N'-disalicylidene-3,4-diaminotoluene (H2dst), 4-nitro-N,N'-disalicylidene-1,2-phenylenediamine (H2ndsp) and N,N'-disalicylidene ethylenediamine (H2salen) have been prepared and characterized by elemental analysis, molar conductivity, spectral methods (mid-infrared, 1H NMR and UV-vis spectra) and simultaneous thermal analysis (TG and DTG) techniques. The molar conductance measurements proved that all these complexes are non-electrolytes. The electronic spectra measurements were used to infer the structures. The IR spectra of the ligands and their complexes are used to identify the type of bonding. The kinetic thermodynamic parameters such as: E*, DeltaH*, DeltaS* and DeltaG* are estimated from the DTG curves. The four ligands and their complexes have been studied for their possible biological antifungal activity.     

2-fluoro-3-nitroaniline and 2-fluoro-1,3-phenylenediamine

2-Fluoro-3-nitroaniline (I), erroneously reported in the literature, has been synthesized by partial reduction of 2-fluoro-1,3-dinitrobenzene (II). Total reduction of (II) gives 2-fluoro-1,3-phenylenediamine (V). The NMR parameters of 1-fluoro-2,4-dinitrobenzene (IV), 2-fluoro-5-nitroaniline (III) and compounds (I), (II) and (V) are reported.     

柄型金属有机化合物(Ⅳ)——四甲基二硅桥连取代环戊二烯基钛和锆化合物的合成及催化乙烯聚合

四甲基二硅桥连取代环戊二烯基配体相继与丁基锂及MCl₄·2THF作用,生成四甲基二硅桥连取代环戊二烯基钛和锆化合物(Me₂SiSiMe₂)(C₅H₄R)(C₅H₄R')MCl₂[R=H,R'=t-Bu,M=Ti(1),Zr(2),Hf(3);R=H,R'=Me,M=Ti(4);R=R'=Me,M=Ti(5),Zr(6)].通过元素分析、MS和¹HNMR谱表征了化合物的分子结构,并通过X射线衍射分析测定了化合物1的晶体结构.研究了在甲基铝氧烷(MAO)的助催化下,化合物1-3和6对乙烯聚合的催化性能。     

Synthesis and spectroscopic studies of complexes of zinc(II) with N2O2 donor groups

Complexes of zinc(II) with N,N'-disalicylidene-1,2-phenylenediamine (H2dsp), N,N'-disalicylidene-3,4-diaminotoluene (H2dst), 4-nitro-N,N'-disalicylidene-1,2-phenylenediamine (H2ndsp) and N,N'-disalicylidene ethylenediamine (H2salen) have been prepared and characterized by elemental analysis, electronic, IR, 1H NMR and thermal studies. TG studies show that all complexes decomposed in one step. Kinetic and thermodynamic parameters were computed from the thermal decomposition data. The activation energy of complexes lies 60-87 kJ mol(-1) range.     

一些单立方烷化合物MFe_3S_4(S_2CNR_2)_5(M=Mo,W)的~1H NMR研究

本文报道了一些单立方烷化合物MFe_3S_4(S_2CNR_2)_5(M=Mo,W;R_2=Me_2,Et_2,C_4H_8,OC_4H_8,C_5H_(10))的~1H NMR谱研究,结果表明与铁原子相连的配体的α-H产生了相当大的各向同性位移,它随温度升高而减少,基本上服从居里定律。本文还讨论了化合物中的配体间交换反应以及簇骼中金属原子间耦合作用对配体的NMR的影响。     

Microwave‐assisted synthesis,spectroscopy and biological aspects of binuclear titanocene chelates of isatin‐2,3‐bis(thiosemicarbazones)

The reactions of bis(cyclopentadienyl)titanium(IV) chloride with a new class of bis(thiosemicarbazones) (H₂L), derived by condensing isatin with different N(4)‐substituted thiosemicarbazides, have been studied both by a conventional stirring method and also using microwave technology. Binuclear products of type [{(η⁵‐C₅H₅)₂TiCl} ₂(L)] have been isolated in both cases. Tentative structural conclusions are drawn for the reaction products based upon analysis, electrical conductance, magnetic moment and spectral (UV‐visible, IR, ¹H NMR and ¹³C NMR) data. FAB mass spectra of these compounds were also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the ligands and complexes against various fungal, viral and bacterial strains. Copyright © 2008 John Wiley & Sons, Ltd.     

A study of the reaction of Se(IV) with 3,4-diaminobenzoic acid and 4-bromo-1, 2-phenylenediamine

The condensation reactions of Se(IV) with 3,4-diaminobenzoic acid and 4-bromo-1,2-phenylenediamine have been studied by means of UV spectra and kinetic investigations. A mechanism for the formation of 2,1,3-benzoselenadiazole in acidic medium is proposed. The influence of substitution at C(4) in 1,2-phenylenediamine on the reactivity of the system is discussed.     

大取代茂钼化合物的合成与结构分析

利用芳基锂与6,6-二烷基富烯发生加成反应,制得大取代环戊二烯基负离子.用六羰基钼配位,合成出13个钼-钼双核及5个钼-卤素单核羰基化合物.研究了其IR、^1HNMR、^95MoNMR.测定了[(CH~3)~2C(m-CH~3C~6H~4]Mo(CO)~3Br(1)的晶体结构.该晶体属于单余晶系,晶胞参数为a=1.175(3),b=1.4196(2),c=1.1894(4)nm,β=118.03(2)°,Ⅴ=1.75134nm^3.Z=4,D~0=1.733g/cm^3,F(000)=904,μ=30.0cm^-1,R=0.039,R~W=0.050,空间群为P2~1/α.     

Inclusion complexes of the antitumour metallocenes Cp(2)MCl(2) (M = Mo, Ti) with cucurbit[n]urils

The encapsulation of the aquated forms of molybdocene dichloride and titanocene dichloride by cucurbit[n]uril (Q[n], where n = 7 and 8) at different pD values has been studied by (1)H NMR spectroscopy and molecular modelling. (1)H NMR titration experiments indicate that both metallocenes form 1 : 1 host-guest complexes with both Q[7] and Q[8]. In these complexes, both the cyclopentadienyl ligands and metal centre are positioned deep within the cucurbituril cavity. In vitro cell proliferation studies using the cancer cell lines MCF-7 and 2008 showed that the encapsulated molybdocene complex was more active than the corresponding free metallocene, with GI(50) values of 210 and 400 muM respectively. However, unexpectedly the encapsulation of Cp(2)MoCl(2(aq))at pD 7 catalysed significant degradation of the cucurbituril framework in the presence of oxygen. Encapsulation of Cp(2)TiCl(2(aq)) by Q[7] greatly slowed the protonolysis of the cyclopentadienyl ligands in aqueous phosphate buffer (pD 7), while encapsulation in Q[8] only slightly retarded the hydrolytic degradation of the metallocene.     

New triorganotin (IV) derivatives of dipeptides as models for metal-protein interactions: synthesis, structural characterization and biological studies

New non-electrolytic triorganotin(IV) derivatives of dipeptides with general formulae R3Sn(HL), where R = Ph and HL = monoanion of glycylisoleucine (H2L-1), valylvaline (H2L-2), alanylvaline (H2L-3), leucylalanine (H2L-4), leucylleucine (H2L-5); R = n-Bu and HL = monoanion of glycylisoleucine (H2L-1) and leucylalanine (H2L-4); and R = Me and HL = monoanion of leucylalanine (H2L-4) have been synthesized and characterized on the basis of infrared, multinuclear 1H, 13C and 119Sn NMR and 119Sn M?ssbauer spectroscopic studies. These investigations suggest that all the ligands in R3Sn(HL) act as monoanionic bidentates coordinating through the COO- and NH2 groups. The 119Sn M?ssbauer studies, together with the NMR data, indicate that, for these polymeric derivatives, the polyhedron around tin in R3Sn(HL) is a trigonal-bipyramid with the three organic groups in the equatorial positions, while the axial positions are occupied by a carboxylic oxygen and the amino nitrogen atom from the adjacent molecule. The anti-inflammatory and cardiovascular activities and toxicity of all these compounds have been determined. Four of the complexes have also been screened against some of the chosen bacterial and fungal strains. The Ph3Sn(IV) compounds exhibit better anti-inflammatory and cardiovascular activities in comparison to the Me3Sn(IV) and n-Bu3Sn(IV) analogues. n-Bu3Sn(Gly-Ile) and Ph3Sn(Ala-Val) exhibit good antibacterial activity against all the chosen strains.     

Synthesis and characterization of N-[2-P(i-Pr)2-4-methylphenyl]2- (PNP) pincer tin(IV) and tin(II) complexes

N-[2-P(i-Pr)(2)-4-methylphenyl](2)(-) (PNP) pincer complexes of tin(IV) and tin(II), [(PNP)SnCl(3)] (2) and [(PNP)SnN(SiMe(3))(2)] (3), respectively, were prepared and characterized by X-ray diffraction, solution and solid state NMR spectroscopy, and (119)Sn M?ssbauer spectroscopy. Furthermore, (119)Sn cross polarization magic angle spinning NMR spectroscopic data of [Sn(NMe(2))(2)](2) are reported. Compound 2 is surprisingly stable toward air, but attempts to substitute chloride ligands caused decomposition.     

Synthesis of ONO-Ligated Tetrylenes Based on 2,6-bis(2-Hydroxyphenyl)pyridines: Influence of Ligand Sterics on the Structure of the Products

A series of novel tetrylenes based on three 2,6-bis(2-hydroxyphenyl)pyridines 4 a – 4 c have been obtained by the reaction of Lappert's tetrylenes E[N(SiMe₃)₂]₂ (E=Ge, Sn) with corresponding tridentate pyridine-linked phenol-based ligands. It was found that the structure of the ligand and the size of the atom of the group 14 element drastically affect the structure of the reaction product. Ligand 4 c with a bulky tert-butyl group leads to monomeric tetrylenes, while ligands with less bulky groups lead to bis-ligand derivatives of M(IV) (M=Ge, Sn) and a coordination polymer. Also, derivatives of germanium (IV) and tin (IV) were obtained by the metathesis reaction of MCl₄ (M=Ge, Sn) with lithium phenoxides. The compositions and structures of the novel compounds were established by elemental analysis and ¹H, ¹³C, ¹¹⁹Sn ( 5 – 7 ), ¹H DOSY ( 6 ) NMR spectroscopy, in the solid state by X-ray diffraction analysis (germylene 10 , stannylene 6 , Ge⁴⁺ compound 8 , Sn⁴⁺ compound 7 ) and ¹¹⁹Sn Mössbauer spectrum of tin complex 6 . All the synthesized tetrylenes are monomeric. Tetrylenes 6 and 10 were characterized by cyclic voltammetry. A study of the redox behavior of 6 , 10 by cyclic voltammetry on a glassy carbon working electrode in acetonitrile solution of 0.1 M Bu₄NPF₆ as a supporting electrolyte showed that these compounds can be both oxidized and reduced electrochemically in the accessible potential range.     

Synthesis, reactivity, spectroscopic characterization, X-ray structures, PGSE, and NOE NMR studies of (eta5-C5Me5)-rhodium and -iridium derivatives containing bis(pyrazolyl)alkane ligands

Rhodium(III) and iridium(III) complexes containing bis(pyrazolyl)methane ligands (pz = pyrazole, L' in general; specifically, L1 = H2C(pz)2, L2 = H2C(pzMe2)2, L3 = H2C(pz4Me)2, L4 = Me2C(pz)2), have been prepared in a study exploring the reactivity of these ligands toward [Cp*MCl(mu-Cl)]2 dimers (M = Rh, Ir; Cp* = pentamethylcyclopentadienyl). When the reaction was carried out in acetone solution, complexes of the type [Cp*M(L')Cl]Cl were obtained. However, when L1 and L2 ligands have been employed with excess [Cp*MCl(mu-Cl)]2, the formation of [Cp*M(L')Cl][Cp*MCl3] species has been observed. PGSE NMR measurements have been carried out for these complexes, in which the counterion is a cyclopentadienyl metal complex, in CD2Cl2 as a function of the concentration. The hydrodynamic radius (rH) and, consequently, the hydrodynamic volume (VH) of all the species have been determined from the measured translational self-diffusion coefficients (Dt), indicating the predominance of ion pairs in solution. NOE measurements and X-ray single-crystal studies suggest that the [Cp*MCl3]- approaches the cation, orienting the three Cl-legs of the "piano-stool" toward the CH2 moieties of the bis(pyrazolyl)methane ligands. The reaction of 1 equiv of [Cp*M(L')Cl]Cl or [Cp*M(L')Cl][Cp*MCl3] with 1 equiv of AgX (X = ClO4 or CF3SO3) in CH2Cl2 allows the generation of [Cp*M(L')Cl]X, whereas the reaction of 1 equiv of [Cp*M(L')Cl] with 2 equiv of AgX yields the dicationic complexes [Cp*M(L')(H2O)][X]2, where single water molecules are directly bonded to the metal atoms. The solid-state structures of a number of complexes were confirmed by X-ray crystallographic studies. The reaction of [Cp*Ir(L')(H2O)][X]2 with ammonium formate in water or acetone solution allows the generation of the hydride species [Cp*Ir(L')H][X].     

Group 4 Metallocene Catalysts with Hapto‐Flexible Cyclopentadienyl‐Aryl Ligand

Catalytic precursors Ti(IV) and Zr(IV) complexes bearing cyclopentadienyl and substituted cyclopentadienyl anionic ligands, bonded to phenyl or substituted phenyl through an isopropylidene bridge have been utilized in the polymerization of propene and styrene and in ethylene‐styrene copolymerization. In the presence of trichloro[(1,2,3,4,5‐η)‐1‐(1‐methyl‐1‐phenylethyl)‐2,4‐cyclopentadien‐1‐yl]titanium (LTiCl₃) we have obtained either partially isotactic (chain‐end type) or atactic poly‐(propylene), and either atactic or syndiotactic polystyrene depending on the reaction temperature. [1‐Methyl‐1‐naphthylethyl‐2‐inden‐1‐yl]titanium(IV) behaves like (LTiCl₃) in styrene polymerization, while it affords metal‐controlled partially isotactic poly(propylene), as well as the corresponding zirconium compounds. The experimental data are tentatively explained by the temperature dependence of coordination of the bridged aryl group of the ligand.     

Spectral studies of complexes of nickel(II) with tetradentate schiff bases having N2O2 donor groups

Complexes of nickel(II) of N,N'-disalicylidene-1,2-phenylenediamine (H2dsp), N,N'-disalicylidene-3,4-diaminotoluene (H2dst), 4-nitro-N,N'-disalicylidene-1,2-phenylenediamine (H2ndsp) and N,N'-disalicylidene ethylenediamine (H2salen) have been prepared and characterised by elemental analysis, electronic, IR, magnetic susceptibility measurement, 1H NMR and thermal studies. TG studies show that the Ni(dsp) and Ni(salen) complex decomposed in one step and Ni(dst) and Ni(ndsp) complex in two steps. Kinetic and thermodynamic parameters were computed from the thermal decomposition data. The activation energy of either one step decomposition or two step decomposition of complexes lies 72-95 kJ mol(-1) range.     

Versatile scorpionates and new developments in the denticity changes of NNCp hybrid scorpionate/cyclopentadienyl ligands in Sc and Y compounds: from kappa1-Neta5-Cp to kappa2-NNeta5-Cp

Reaction of hybrid scorpionate/cyclopentadienyl ligands in the form of the lithium derivatives [Li(bpzcp)(THF)] [bpzcp=2,2-bis(3,5-dimethylpyrazol-1-yl)-1,1-diphenylethylcyclopentadienyl], [Li(bpztcp)(THF)] [bpztcp=2,2-bis(3,5-dimethylpyrazol-1-yl)-1-tert-butylethylcyclopentadienyl], and the in situ-generated "Li(bpzpcp)" [bpzpcp=2,2-bis(3,5-dimethylpyrazol-1-yl)-1-phenylethylcyclopentadienyl] with MCl3(THF)3 afforded the group 3 halide compounds [MCl2(bpzcp)(THF)] (M=Sc, 1; Y, 2), [MCl2(bpztcp)(THF)] (M=Sc, 3; Y, 4), and [MCl2(bpzpcp)(THF)] (M=Sc, 5; Y, 6). The H2O adduct of 4, [YCl2(bpztcp)(H2O)] (7), was formed when a solution of 4 was allowed to stand at room temperature in the presence of moisture. Complexes 1-7 adopt a pseudo-octahedral structure with heteroscorpionate ligands kappa2-NNeta5-Cp coordinated to the metal through the cyclopentadienyl group and two imino nitrogens of pyrazole rings. The alkyl heteroscorpionate scandium and yttrium complexes recently reported by our group, [M(CH2SiMe3)2(bpzcp)], react with 2,6-dimethylphenol and 3,5-dimethylphenol to give the bis(aryloxide) derivatives [M(OAr)2(bpzcp)] (M=Sc, OAr=2,6-dimethylphenoxide, 8; M=Y, OAr=2,6-dimethylphenoxide, 9; M=Y, OAr=3,5-dimethylphenoxide, 10). Complex 9 underwent an interesting hydrolysis process to give the tetranuclear complex [{Y(bpzcp)}(micro-OH)2(micro3-OH){Y(OAr)2}]2 (11). Variable-temperature 1H NMR experiments on 9 and 10 revealed a rapid fluxional exchange between coordinated and noncoordinated pyrazolyl rings, producing interconversion between the two enantiomers in which the scorpionate ligand can be coordinated in a kappa1-Neta5-Cp form. The structures of the complexes were determined by spectroscopic methods and the X-ray crystal structures of 2, 7, and 11 were also established. Complexes 1 and 2 are active olefin polymerization catalysts after activation with methylaluminoxane. These compounds gave atactic polystyrenes with narrow molecular weight distribution (Mn/Mw 1.26-1.91) and with low molecular weights.     

Synthetic,Structural and Biological Studies on Divalent Tin Complexes of Sixteen to Twenty-Four Membered Tetraaza Macrocycles

A new series of 16- to 24-membered macrocycles of tin(II) containing tetraaza groups has been prepared by the template condensation reaction of glutaric acid and phthalic acid with 1,2-phenylenediamine, 2,6-diaminopyridine, and diethylenetriamine in 1:2:2 molar ratios. The reaction products were characterized by elemental analyses, molecular weight determinations, infrared, 1 H NMR, 119 Sn NMR, and mass spectral studies. X-ray powder diffraction spectrum of one representative compound also has been reported. The hexacoordinated state for tin has been confirmed by spectral studies. An octahedral geometry for these complexes has been proposed as the binding sites are the nitrogen atoms of the macrocycle. The formulation of the complexes as [Sn(N 4 MaC n )Cl 2 ] (where N 4 MaCn represent the ligand molecule and n = 1 to 6 has been established on the basis of the chemical composition. All of the complexes are monomeric. The ligands and their complexes also have been screened for their antimicrobial activities and the results are discussed.     

双(二吡啶胺)配体的二维和三维超分子配位聚合物的合成与晶体结构

从含4,4'-二吡啶胺结构单元的双(二吡啶胺) 桥联配体出发,采用溶剂热法合成了两个结构新颖的配位聚合物：[CdL1Br2]n?7.5nH2O (L1 = N,N,N′,N′-四(4-吡啶)-1,4-苯二胺) (1)和[Cu2L2(μ1,1,3-SCN)2]n?nMeOH (L2 = N,N-二(2-吡啶)-N',N'-二(4-吡啶)-1,4-苯二胺) (2),对它们进行了元素分析、红外光谱等表征,并用X-射线单晶衍射测定了其晶体结构。单晶测试结果显示,配合物1中配体L1的四个吡啶N原子均参与配位,桥联了4个Cd原子,每个Cd原子与四个吡啶 N 原子和两个溴配位,形成六配位的八面体构型。通过这些配位作用,最终形成包含 Kagome 结构的三维超分子网络。配合物2 是由一维柱状 {Cu(SCN)}n 链通过 L2 桥联生成的二维结构。有趣的是,L2中具有螯合能力的2,2'-二吡啶胺单元并未参与配位,只有4,4'-二吡啶胺单元中的两个吡啶N原子分别与一个 Cu(I) 配位,连接了相邻两条平行的{Cu(SCN)}n 链,生成二维结构。