Bidentate Chelating Fashion Research Articles

New 3- hydrazonoindolin-2-one Cd(II) complexes with amino pyridine ligands, Synthesis, Characterization and biological activity evaluation

This research includes synthesis and characterization of some of Cd(II) complexes with (3-hydrazonoindolin-2-one)(HZI) ligand and amino pyridine ligands. 
 Treatment equialmolar of CdCl2.2.5H2O and (HZI) ligand with two moles of n-aminopyridine (n-amp) (n:2,3,4) ligands afford a tetrahedral complexes of the type [Cd(HZI)(n-amp)2]Cl2, where (HZI) ligand behaves as a bidentate chelating fashion through the N atom of azomethine group and O atom of carbonyl group. Whereas the (n-amp)(n: 2,3,4) was bonded monodentate mode through the N atom of heterocyclic ring.
 The prepared complexes have been characterized by molar conductivity, elemental analysis, infrared spectra and 1H-NMR and 13C-NMR spectra.
 Also the evaluation of biological activity of the prepared complexes against two types of gram positive bacteria (Staphylococcus Epidermidis and Staphylococcus aureus) and (Citrobacer Freundii) and gram negative, all prepared complexes showed activity against Staphylococcus aureus more than amikacin, while the [Cd(HZI)(3-amp)2]Cl2 complex showed high activity against Staphylococcus Epidermidis and Citrobacter freundii more than another prepared complexes

New 3- hydrazonoindolin-2-one Cd(II) complexes with amino pyridine ligands, Synthesis, Characterization and biological activity evaluation

This research includes synthesis and characterization of some of Cd(II) complexes with (3-hydrazonoindolin-2-one)(HZI) ligand and amino pyridine ligands. 
 Treatment equialmolar of CdCl2.2.5H2O and (HZI) ligand with two moles of n-aminopyridine (n-amp) (n:2,3,4) ligands afford a tetrahedral complexes of the type [Cd(HZI)(n-amp)2]Cl2, where (HZI) ligand behaves as a bidentate chelating fashion through the N atom of azomethine group and O atom of carbonyl group. Whereas the (n-amp)(n: 2,3,4) was bonded monodentate mode through the N atom of heterocyclic ring.
 The prepared complexes have been characterized by molar conductivity, elemental analysis, infrared spectra and 1H-NMR and 13C-NMR spectra.
 Also the evaluation of biological activity of the prepared complexes against two types of gram positive bacteria (Staphylococcus Epidermidis and Staphylococcus aureus) and (Citrobacer Freundii) and gram negative, all prepared complexes showed activity against Staphylococcus aureus more than amikacin, while the [Cd(HZI)(3-amp)2]Cl2 complex showed high activity against Staphylococcus Epidermidis and Citrobacter freundii more than another prepared complexes
 
 http://dx.doi.org/10.25130/tjps.25.2020.028

Synthesis, characterization and anticancer studies of bis-(N-methyl-1-phenyldithiocarbamato) Cu(II), Zn(II), and Pt(II) complexes: single crystal X-ray structure of the copper complex

Cu(II), Pt(II), and Zn(II) complexes of N-methyl-1-phenyldithiocarbamate were synthesized and characterized by FTIR, NMR, UV-visible spectroscopy and elemental analysis. The complexes were formulated as [Cu(L)2], [Zn(L)2] and [Pt(L)2] (where L = N-methyl-1-phenyldithio­carbamate) in which two molecules of the ligands coordinate to the metal ions in a bidentate chelating fashion. This is confirmed by elemental analysis and the presence of strong single bands at 952, 951, and 955 cm−1 for Cu(II), Pt(II), and Zn(II) complexes, respectively, in the FTIR spectra. The electronic spectra of Pt(II) and Cu(II) complexes are consistent with four-coordinate square planar geometry. Single crystal X-ray of [Cu(N-mpDTC)2] confirmed square planar structural arrangement (CuS4) in which the ligands are asymmetrically bonded to the Cu(II) ion building a centrosymmetric monomer entity. The S-Cu-S bite angle is 77.95° (3) whereas the intramolecular N–C bond length is 1.318 Å and trans S11-Cu-S1 = S21-Cu-S2 is 180°, which are consistent with reported copper thiolates in square planar environment. In vitro antiproliferative activity of the complexes against three human cancer cell lines showed that the zinc complex has better activity compared to Cu and Pt complexes, with IC50 values of 14.28, 22.74 and 20.10 μM against TK10, UACC62, and MC7 cell lines, respectively.

Iron(II) Bis-α-Benzyldioximate Complexes with 3- and 4-Pyridine Hemiacetals as Axial Ligands: Synthesis, Structure, and Physicochemical Properties

The coordination compounds [Fe(DfgH)2(HL1)2] and [Fe(DfgH)2(HL2)2], where DfgH = is the α-benzyldioxime monoanion, HL1 = 3-pyridine hemiacetals: methoxy(pyridin-3-yl)methanol (I), ethoxy(pyridin-3-yl)methanol (II); HL2 = 4-pyridine hemiacetal: methoxy(pyridin-4-yl)methanol (III), ethoxy(pyridin-4-yl)methanol (IV), and propoxy(pyridin-4-yl)methanol (V), were synthesized and studied by X-ray diffraction and IR and Mossbayer spectrosopy. According to X-ray diffration data (CIF files CCDC 1578217–1578221 for I–V, respectively), all of these Fe(II) complexes are molecular. The metal coordination polyhedron is an octahedron formed by four equatorial nitrogen atoms of two monodeprotonated α-benzyldioxime residues coordinated in the bidentate chelating fashion and by two axial nitrogen atoms of two neutral 3- or 4-pyridine hemiacetal molecules coordinated in the monodentate fashion. The DfgH– ligands in complexes I–V are joined by intramolecular O–H···O hydrogen bonds to form a pseudomacrocyclic system. The ligands HL1 and HL2 are generated in the reaction of the corresponding alcohols with 3- or 4-pyridinecarboxaldehyde. The IR and Mossbauer spectra of the products were studied. The Mossbauer spectral parameters of compounds I–V correspond to low-spin iron(II) ions.

A first report on the crystal structure of hydrazine based solid solution precursor, Mn0.61Zn0.39(OOCCH[dbnd]NNH2)2(H2O)2

A novel mixed metal complex, [Mn0.61Zn0.39(OOCCHNNH2)2(H2O)2] has been synthesized and characterized by hydrazine and metal analyses, CHN analyses, infrared spectra, simultaneous TG-DTA and single crystal X-ray diffraction studies. The structure of the complex has been determined by X-ray single crystal study which clearly reveals that the octahedral site is occupied by two metal ions (viz., Mn and Zn) around which two hydrazoneglyoxylate ligands (OOCCHNNH2) coordinate in a bidentate chelating fashion. Two water molecules occupy the remaining two other sites of a slightly distorted octahedron with C2 axis of symmetry. The infrared spectrum reveals the monodentate coordination behavior of carboxylate ions and coordination of water molecules. The simultaneous TG-DTA traces are in accordance with the formation of mixed metal oxide (spinel oxide) as an end product. The high resolution scanning electron microscopy (HRSEM) images show the presence of irregularly shaped agglomerated particles of sub-micron size. The zeta potential value for mixed metal oxide is −33.1mV, which indicates the stability of the oxide.

Syntheses, Structural Characterization, Reactivity, and Theoretical Studies on Some Heteroligand Oxoperoxotungstate(VI)

White microcrystalline diamagnetic oxoperoxotungstate(VI) complexes K[WO(O2 ) 2F]·H2O, K2 [WO(O2 )2(CO3 )]·H2O, [WO(O2 )(SO4 )(H2O)2] have been synthesized from reaction of Na2WO4 ·2H2O with aqueous HF, solid KHCO3 , aqueous H2SO4 (W:F− 1:3; W: CO3 2 − 1:1; and W: SO4 2 − 1:3), and an excess of 30% H2O2 at pH 7.5–8. Precipitation was completed by the addition of precooled acetone. The occurrence of terminal WO and triangular bidentate O2 2 −(C 2 v ) in the synthesized compounds was ascertained from IR spectra. The IR spectra also suggested that the F− and SO4 2 − ions in K[WO(O2 ) 2F]·H2O and [WO(O2 )(SO4 )(H2O)2] were bonded to the WO +4 center in monodentate manner, while CO3 2 − ion in K2 [WO(O2 )2(CO3 )]·H2O binds the metal center in bidentate chelating fashion. The complex [WO(O2 )(SO4 )(H2O)2] is stable upto 110°C. The water molecule in [WO(O2 )(SO4 )(H2O)2] is coordinated to the WO +4 center, whereas it occurs as water of crystallization in the corresponding peroxo(fluoro) and peroxo(carbonato) compounds. Mass spectra of the compounds are in good agreement with the molecular formulae of the complexes. K2 [WO(O2 )2(CO3 )]·H2O acts as an oxidant for bromide in the aqueous-phase bromination of organic substrates to the corresponding bromo-organics, and the complex also oxidizes Hantzsch-1,4-dihydropyridine to the corresponding pyridine derivative in excellent yield at room temperature. Density functional theory computation was carried out to compute the frequencies of relevant vibrational modes and electronic properties, and the results are in agreement with the experimentally obtained data.

Syntheses and characterization of two novel tetranuclear lead(II) clusters self-assembled by hydrogen bonded interactions.

BackgroundThe usage of polynuclear metal clusters as secondary building units (SBU’s) in designing of metal organic frameworks (MOF’s) is a field of current interest. These metal clusters have attracted a great deal of attention not only due to their interesting structural topologies but also due to promising physical and chemical properties. In this regard various d,f block (transition and lanthanide) metal clusters have been widely investigated so far. Less attention is paid to construction of heavy p-block Pb(II) clusters.ResultsTwo mixed ligand Pb(II) clusters have been synthesized with bipy(2,2’-Bipyridine), phen(1,10-Phenanthroline), quin (8-Hydroxy quinolinate) and 5-tpc (5-chloro thiophene 2-carboxylate). They have been characterized by elemental analysis, IR, TGA and X-ray crystallography. X-ray diffraction analysis reveals that the complexes [Pb4(quin)4(bipy)2(5-tpc)4] (1) and [Pb4(quin) 4(phen) 2(5-tpc)4] (2) are tetranuclear. The complexes show a slight variation in unit cell parameters, due to the replacement of bipy and the phen ligands. Both complexes contain two types of Pb(II) ions which differ in the coordination geometry around the Pb(II) ion.ConclusionsIn both complexes the four lead ions Pb1,Pb2, Pb1i and Pb2i lie on the same plane bridged by the 5-tpc anions. Pb1 and Pb2 of both complexes contain a 5-tpc and quin coordinated in a bidentate chelating bridging fashion. In addition the Pb2 and Pb2i ions alone contain a bipy and phen in a bidentate chelating fashion in (1) and (2) respectively. An additional notable feature in both of these complexes are the bridging ability of the quin oxygen which forms a network of coordination bonds in between the four Pb(II) ions. In both complexes the individual units are self-assembled by C-H---Cl/C-H---S hydrogen bonding interactions to generate 2-D aggregates.

Hydroxylation of azomethine carbon: isolation of complexes of η5 and η6-cyclic hydrocarbon platinum group metals with a new Schiff-base ligand

A new Schiff base, (pyridin-2-yl)-N-(3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-yl)methanimine, (L), was synthesized. Reaction of [(η6-arene)Ru(µ-Cl)Cl]2 and [Cp*M(µ-Cl)Cl]2 (M = Rh and Ir) with one equivalent of L in the presence of NH4PF6 in methanol yielded dinuclear complexes, [(η6-arene)2Ru2(L-OH)Cl](PF6)2 {arene = C6H6 (1), p-iPrC6H4Me (p-cymene) (2) and C6Me6 (3)}, and [Cp*2M2(L-OH)Cl](PF6)2 [M = Rh (4) and Ir (5)], respectively, leading to the formation of five new chiral complexes with –OH on the azomethine carbon. L is a pentadentate ligand where one of the metal centers is coordinated to two nitrogen atoms in a bidentate chelating fashion while the other metal is bonded tridentate to three nitrogen atoms. Although the ligand is neutral before coordination, after complexation it is anionic (uni-negative) with negative charge on the azo nitrogen {see the structures: N(5) in 2[PF6]2 and N(3) for 4[PF6]2}. The complexes have been characterized by various spectroscopic methods including infrared and 1H NMR and the molecular structures of the representative complexes are established by single-crystal X-ray diffraction studies.

Explorations of New Second-Order Nonlinear Optical Materials in the KI-MII -IV-O Systems

Explorations of new second-order nonlinear optical (NLO) materials in the K(I)-M(II) -I(V)-O systems led to four novel mixed metal iodates, namely, K(2)M(IO(3))(4)(H(2)O)(2) (M = Mn, Co, Zn, Mg). The four compounds are isostructural and crystallize in space group I2 which is in the chiral and polar crystal class 2. Their structure features zero-dimensional {M(IO(3))(4)(H(2)O)(2)}(2-) anions that are separated by K(+) cations. The M(II) centers are ligated by two aqua ligands in trans fashion and four monodentate iodate anions. The K(+) cation is eight-coordinated by two iodate anions in bidentate chelating fashion and four other iodates in a unidentate fashion. Second harmonic generation (SHG) measurements indicate that K(2)Zn(IO(3))(4)(H(2)O)(2) and K(2)Mg(IO(3))(4)(H(2)O)(2) display moderate SHG responses that are approximately 2.3 and 1.4 times of KH(2)PO(4) (KDP), respectively, and they are also phase-matchable. The SHG response of K(2)Co(IO(3))(4)(H(2)O)(2) is much weaker (about 0.3 x KDP), and no obvious SHG signal was detected for K(2)Mn(IO(3))(4)(H(2)O)(2). Results of optical property calculations for the Zn and Mg phases revealed SHG responses of approximately 5.3 and 4.7 times of KDP, respectively, the order of Zn > Mg is in good agreement with the experiment data.

Fac-[N,N′-Bis(3-chloro-2-fluorobenzylidene)ethylenediamine]bromidotricarbonylrhenium(I)

In the title compound, [ReBr(C16H12Cl2F2N2)(CO)3], the Re atom is in a slightly distorted octa­hedral coordination environment with the three carbonyl ligands having a fac configuration. The diimine ligand is equatorial and is bonded to the Re centre in an N,N′-bidentate chelating fashion, with a bite angle of 77.7 (2)°. The dihedral angle between the two benzene rings is 88.7 (6)°. In the crystal structure, there are F⋯O [2.856 (9) Å], Cl⋯C [3.150 (8) Å] and O⋯C [2.984 (10) Å] contacts which are shorter than the sum of the van der Waals radii for these atoms. In addition, symmetry-related mol­ecules are linked via inter­molecular C—H⋯O, C—H⋯Br and the F⋯O inter­actions into one-dimensional chains extending along the a axis. The crystal structure is further stabilized by inter­molecular π–π inter­actions [centroid–centroid distance = 3.571 (5) Å].

New Organically Templated Ln(III)−Cu(I) Heteronuclear Sulfite Bromides

Two novel organically templated 3d−4f mixed metal sulfites, namely, [H2pip][Ln4Cu4(SO3)8Br2(H2O)6] (Ln = Eu, 1; Gd, 2; pip = piperazine) have been synthesized and structurally characterized. Compounds 1 and 2 are isostructural and feature a 2D inorganic anion layer of [Ln4Cu4(SO3)8Br2(H2O)6]2−. Among two unique lanthanide(III) ions in the asymmetric unit, one is eight coordinated by seven oxygen atoms from six sulfite groups (five of them in unidentate fashion and one in bidentate chelating fashion) and an aqua ligand; the other one is eight-coordinated by six oxygen atoms from five sulfite groups (four of them in unidentate fashion and one in bidentate chelating fashion) and two aqua ligands. Cu(1) is four coordinated by two S and one O from three SO32− anions, as well as a Br anion, and Cu(2) is three coordinated by one S and one O atom from two SO32− anions, as well as a Br anion. The Ln(III) ions and Cu(I) ions are interconnected by sulfite anions and Br anions to form a layered structure. The piperazine molecules are located at the interlayer spaces. Magnetic properties for both compounds were also studied.

Bis(dithiobenzoato-κ2S,S′)bis(tetrahydrofuran-κO)magnesium(II)

The title compound, [Mg(C7H5S2)2(C4H8O)2], was obtained by the reaction of PhMgBr with an excess of CS2. The magnesium(II) cation is six-coordinated by two dithio­benzoate ligands coordinating through their S atoms in a bidentate chelating fashion and two O atoms from two tetra­hydro­furan ligands, in a distorted octa­hedral geometry.

Homoleptic Alkaline Earth Metal Bis(trifluoromethanesulfonyl)imide Complex Compounds Obtained from an Ionic Liquid

The first homoleptic alkaline earth bis(trifluoromethanesulfonyl)imide (Tf2N) complexes [mppyr]2[Ca(Tf2N)4], [mppyr]2[Sr(Tf2N)4], and [mppyr][Ba(Tf2N)3] were crystallized from a solution of the respective alkaline earth bis(trifluoromethanesulfonyl)imide and the ionic liquid [mppyr][Tf2N] (mppyr = 1,1-N-methyl-N-propylpyrrolidinium). In the calcium and strontium compounds, the alkaline earth metal (AE) is coordinated by four bidentately chelating Tf2N ligands to form isolated (distorted) square antiprismatic [AE(Tf2N)4]2- complexes which are separated by N-methyl-N-propylpyrrolidinium cations. In contrast, the barium compound, [mppyr][Ba(Tf2N)3], forms an extended structure. Here the alkaline earth cation is surrounded by six oxygen atoms belonging to three Tf2N- anions which coordinate in a bidentate chelating fashion. Three further oxygen atoms of the same ligands are linking the Ba2+ cations to infinite (infinity)(1)[Ba(Tf2N)3] chains.

Bis(piperidine-1-dithiocarbamato-κ2S,S′)palladium(II)

In the title centrosymmetric complex, [Pd(C6H10NS2)2], the PdII atom has a square-planar environment with two dithio­carbamate ligands coordinating through their S atoms in a bidentate chelating fashion.

Versatility in the binding of 2-pyrazinecarboxylate with iron. Synthesis, structure and magnetic properties of iron(ii) and iron(iii) complexes

The synthesis and characterization of two new iron(II) complexes, [Fe(pca)2(py)2].py (1) and {[Fe(pca)2(H2O)].H2O}n (2) and one new iron(III) complex, Na2{[Fe(pca)()]2O}.2H2O.2CH3CN (3) (pca- stands for 2-pyrazinecarboxylate), are reported. Complex 1 is obtained from the reaction of iron powder with 2-pyrazinecarboxylic acid. The reaction of Fe(ClO4)3.10H2O with Hpca in the presence of 3 equiv. of Bu4NOH yields 2, whereas the presence of NaOH yields 3. The molecular structure of 1 contains an iron(II) ion with a pseudo-octahedral environment resulting from the coordination of two pca- ligands in a bidentate chelating fashion and two pyridine molecules; pi-pi stacking interactions between pyridine and pyrazine rings lead to a one-dimensional chain. Complex 2 is an iron(II) coordination polymer with an infinite zig-zag motif and an Fe...Fe separation of 7.1 A. In 2, the pi-pi stacking interactions involving the pyrazine rings and the strong hydrogen bonds between the coordinated water molecule and the carboxylate oxygens of two pca- ligands result in a three-dimensional network structure. Complex 3 consists of an anionic micro-oxo-bridged diiron(III) core with two crystallographically distinct iron(iii) ions; the negative charge is compensated by two sodium cations. Complex 3 is assembled in a three dimensional network structure through coordination of Na(I) and hydrogen bond interactions. Temperature dependent magnetic susceptibility and Mössbauer spectroscopic studies indicate that 1 and 2 have similar magnetic properties. Both complexes are paramagnetic above 12 K, whereas antiferromagnetic ordering is observed below 12 K. The magnetic properties of reveal strong intramolecular antiferromagnetic interactions between the two iron(III) ions with a J value of -221 cm(-1); no long range intermolecular magnetic coupling is observed between 295 and 4.2 K.

H 2en] 2{La 2M(SO 4) 6(H 2O) 2} ( M=Co, Ni): First organically templated 3 d–4 f mixed metal sulfates

The first organically templated 3 d–4 f mixed metal sulfates, [H 2en] 2{La 2 M(SO 4) 6(H 2O) 2} ( M=Co 1, Ni 2) have been synthesized and structurally determined from non-merohedrally twinned crystals. The two compounds are isostructural and their structures feature a three-dimensional anionic network formed by the lanthanum(III) and nickel(II) ions bridged by sulfate anions. The La(III) ions in both compounds are 10-coordinated by four sulfate anions in bidentate chelating fashion, and two sulfate anions in a unidentate fashion. The transition metal(II) ion is octahedrally coordinated by six oxygens from four sulfate anions and two aqua ligands. The doubly protonated enthylenediamine cations are located at the tunnels formed by 8-membered rings (four La and four sulfate anions).

N,N′-Bis(2,4-dimethylbenzene)-2,3-dimethyl-1,4-diazabuta-1,3-diene]-fac-tricarbonyl(trifluoroacetato)rhenium(I)

In the title compound, [Re(CF3COO)(C20H24N2)(CO)3], the Re atom has a distorted octahedral configuration. The 1,4-di­aza­buta­diene part of the donor ligand and two carbonyl groups occupy the equatorial plane of the complex, with the third carbonyl ligand and the tri­fluoro­acetate group in the axial positions. The equatorial di­imine ligand is bound to the Re center in an N,N′-bidentate chelating fashion, leading to a five-membered ReN2C2 chelate ring with an N—Re—N bite angle of 73.4 (2)°.

Synthesis, Characterization and Some Properties of Oxoperoxo Complexes of Molybdenum with 2-Hydroxy-1-naphthaldehyde Isonicotinoylhydrazone

Abstract The peroxo complexes [MoO(O2) (ihnpy)].2H2O(1) (H2ihnpy=2-hydroxy-1-naphthaldehyde isonicotinoylhydrazone), K[MoO(O2)2 (Hihnpy)](2), K(Mo2O2(O2)4 (Hihnpy) (H2O)2](3), the oxo complexes [MoO2 (ihnpyH)-(HSO4)](4) and [MoO2 (ihnpy)].2H2O(5) have been prepared and characterized by elemental analyses, molar conductance, IR and IH NMR spectroscopic studies. On the basis of the spectroscopic evidence, H2 ihnpy coordinates to the molybdenum centre in the enol form in a bridging fashion in complexes (1) and (5) through the phenolic oxygen, enolic oxygen, azomethine nitrogen and pyridyl nitrogen atoms. In the complexes (2) and (3), H2 ihnpy coordinates to the molybdenum centre in the keto form as a monobasic bidentate ligand through the phenolic oxygen and azomethine nitrogen atoms. Peroxide is coordinated to the metal centre in a bidentate chelating fashion in the complexes (1), (2) and (3). The molecular oxoperoxo complex (1) on reaction with SO2 yielded the complex [MoO2. (ihnpyH) (HSO4)] (4) in which t...

Reactivity of the cyclic tetranuclear complex [Pd 4(μ- o-C 6H 4) 2(μ-O 2CMe) 4(μ-SPr i2) 2

Bridge splitting reactions of the cyclic tetranuclear complex, [Pd 4(μ-o-C 6H 4) 2(μ-O 2CMe) 4(μ-SPr i 2) 2], with neutral and anionic ligands afforded a variety of dinuclear palladium(II) complexes. In addition to the common one bridging o-phenylene ligand, the products contained different bridging ligands depending upon the ligand used. Dpm (Ph 2PCH 2PPh 2) or btmp (PhCH 2SCH 2PPh 2) acted as bidentate bridging ligands to give [Pd 2(μ-o- C 6H 4)(O 2CMe) 2(μ-L 2) 2] (L 2 = dpm, btmp). In contrast, Me 2bpy (4,4′-dimethyl-2,2′-bipyridyl) behaved as a bidentate chelating ligand to afford a cationic complex bearing the μ-acetato ligand, [Pd 2(μ- o-C 6H 4)(μ- O 2CMe)(Me 2bpy) 2](MeCO 2). In the case of Tl(acac), the acac ligand coordinated in a bidentate chelating fashion to yield a μ-sulfide complex, [Pd 2(μ- o-C 6H 4))(acac- O, O′) 2 (μ-SPr i 2)]. This complex further reacted with 3,5-lutidine to give [Pd 2(μ- o-C 6H 4))(acac- O, O′) 2(3,5-lut) 2 ]. Complexes obtained here were characterized by means of elemental analyses, NMR and IR spectroscopies.