Showing papers in "Journal of Coordination Chemistry in 2007"
TL;DR: Schiff base complexes of cobalt, nickel, copper, and zinc with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, 1H- and 13C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses as discussed by the authors.
Abstract: Schiff-base complexes of cobalt(II), nickel(II), copper(II) and, zinc(II) with 3-ethoxysalicyliden-p-aminoacetophenoneoxime (HL) were prepared and characterized on the basis of elemental analyses, IR, 1H- and 13C-NMR, electronic spectra, magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses (TGA). A tetrahedral geometry has been assigned to the complexes.
96 citations
TL;DR: Two ternary copper(II) complexes with substituted aroylhydrazones have been synthesized and their crystal structures and spectroscopic properties have been studied.
Abstract: Two ternary copper(II) complexes [Cu(L1)(py)] (1) and [Cu(L2)(Himdz] · CH3OH (2) with substituted aroylhydrazones, 5-bromo-salicylaldehyde-3,5-dimethoxy-benzoylhydrazone (H2L1) and 5-bromo-salicylaldehyde-p-methyl-benzoylhydrazone (H2L2), pyridine (py) and imidazole (Himdz), have been synthesized. Their crystal structures and spectroscopic properties have been studied. In each complex, the metal is in a square-planar N2O2 coordination formed by the phenolate-O, the imine-N and the deprotonated amide-O atoms of L2−, and the sp2 N atom of the neutral heterocycle. In the solid state, 1 exists as a centrosymmetric dimer due to very weak apical coordination of the metal bound phenolate-O. Complex 2 has no such apical coordination and exists as a monomer. Self-assembly via C–H ··· O, N–H ··· O and O–H ··· N interaction leads to a one-dimensional chain arrangement; other non-covalent interactions such as C–H ··· π and π ··· π are not involved.
72 citations
TL;DR: In this article, the formation of mixed chloro-hydroxo complexes, [PdCl p (OH) q ]2−, has been investigated at three chloride concentrations, 1.0, 0.5 and 0.2
Abstract: Complex formation of Pd(II) with chloride and hydroxide has been investigated by spectrophotometry at 25°C and ionic strength 1.0 M. For the chloride complexes [PdCl n (H2O)4− n ]2− n (n = 0–4), the formation constants, β n , have been determined and the values are: log β1 = 4.47, log β2 = 7.80, log β3 = 10.18 and log β4 = 11.53. The formation of mixed chloro-hydroxo complexes, [PdCl p (OH) q ]2−, has been investigated at three chloride concentrations, 1.0, 0.5 and 0.2 M over the pHc range 4–12. The average values determined for the formation constants, β pq , where p and q refer to the number of chloride and hydroxide ions in the complex, are: log β31 = 16.48, log β22 = 20.63, log β13 = 24.02 and log β04 = 26.23. Molar absorption spectra for all the complexes in question have been obtained.
61 citations
TL;DR: In this paper, six new Schiff-base complexes were synthesized by reactions of hydrated lanthanide nitrates with H2L (H2L) and characterized by elemental analysis, DTA-TG, IR, UV and luminescence spectra.
Abstract: Six new lanthanide Schiff-base complexes were synthesized by reactions of hydrated lanthanide nitrates with H2L (H2L = N,N′-bis(salicylidene)-1,2-cyclohexanediamine) and characterized by elemental analysis, DTA–TG, IR, UV and luminescence spectra. The microanalyses and spectroscopic analyses indicate a 1D polymeric structure with the formula of [Ln(H2L)(NO3)3(MeOH)2] n [Ln = La (1), Ce (2), Pr (3), Sm (4), Gd (5) & Dy (6)]. The fluorescence spectrum of complex 4 exhibited Sm3+ centered, Schiff-base sensitized orange fluorescence, indicating that energy levels of the triplet state of H2L match closely to the lowest excited state (4G5/2) of Sm3+ ion.
47 citations
TL;DR: A few pincer-type ligands, such as 1,3-bis(2′-benzimidazolyl)benzene (L1), 2,6-bis (2′)-benzymidazolel)pyridine (L2 ), and their N-alkylated derivatives were prepared and characterized by IR and 1H NMR spectroscopy as mentioned in this paper.
Abstract: A few pincer-type ligands, 1,3-bis(2′-benzimidazolyl)benzene (L1 ), 2,6-bis(2′-benzimidazolyl)pyridine (L2 ), and their N-alkylated derivatives were prepared and characterized by IR and 1H NMR spectroscopy. The N-alkylated benzimidazolyl ligands, 2,6-bis(N-benzylbenzimidazolyl)pyridine (L3 ), 2,6-bis(N-allylbenzimidazolyl)pyridine (L4 ), and 1,3-bis(N-allylbenzimidazolyl)benzene (L5 ) form 1 : 1 complexes with copper nitrate. X-ray diffraction showed that [Cu(NO3)(MeOH)(L4 )](NO3) (7) and [Cu(NO3)2(L3 )] (8) are mononuclear complexes, whereas [Cu(NO3)2(L5 )] · 2DMF (9) exhibits one-dimensional zigzag motif. The chain consists of mutually bridged Cu(NO3)2 and L5 ligand. Crystal data: 7, triclinic, , a = 9.035(3) A, b = 11.149(4) A, c = 14.664(5) A, α = 104.856(5)°, β = 99.635(5)°, γ = 99.409(5)°, V = 1374.2(8) A3, Z = 2, and R 1 = 0.0666, wR 2 = 0.1753; 8, monoclinic, Cc, a = 12.979(5) A, b = 14.343(5) A, c = 16.966(6) A, β = 109.958(6)°, V = 2968.9(18) A3, Z = 4, and R 1 = 0.0582, wR 2 = 0.1352; 9, monocl...
43 citations
TL;DR: A potentially tridentate bishydrazone derived from isatin was prepared by condensing isatin monohydrazone and salicylaldehyde as discussed by the authors, and the ligand and metal complexes have been characterized on the basis of elemental analyses, molar conductance values, magnetic susceptibility data, NMR, UV-visible, IR and EPR spectral studies.
Abstract: A potentially tridentate bishydrazone derived from isatin was prepared by condensing isatin monohydrazone and salicylaldehyde. This ligand is versatile in forming a series of copper(II) complexes in the presence of different coordinating anions. The ligand and metal complexes have been characterized on the basis of elemental analyses, molar conductance values, magnetic susceptibility data, NMR, UV-visible, IR and EPR spectral studies wherever possible and applicable. The spectral studies reveal that the bishydrazone is monobasic tridentate, coordinating through the deprotonated phenolate oxygen, azomethine nitrogen and carbonyl group of the isatin moiety. Analytical data indicate that the complexes possess 1 : 1 metal–ligand ratio. Molar conductance values support the non-electrolytic nature of the complexes and the complexes have been formulated as [Cu(IBS)X]; where X = Cl−, Br−, , OAc−, or and HIBS = [(2-hydroxybenzaldehyde)-3-isatin]-bishydrazone. Based on the electronic spectral data, and magnetic mom...
36 citations
TL;DR: In this article, a one-dimensional coordination polymer [Co(μ 1,3-NCS)2(npdo)2] n (npdo = 4-nitropyridine N-oxide) has been synthesized and structurally determined by X-ray crystallography.
Abstract: A one-dimensional coordination polymer [Co(μ 1,3-NCS)2(npdo)2] n (npdo = 4-nitropyridine N-oxide) has been synthesized and structurally determined by X-ray crystallography. The complex crystallizes in the orthorhombic space group of Pbcn with a = 22.688(5) A, b = 7.2636(17) A, c = 10.299(2) A. Adjacent Co(II) ions are coordinated by two μ 1,3-SCN− bridging ligands, forming a one-dimensional chain along the c axis and the npdo coordinates to Co(II) ion as a terminal ligand. The thermal variation of the magnetic moments of the complex reflects the antiferromagnetic interaction between the bridged Co(II) ions above 20 K and the ferromagnetic transition or the strong short-range spin interaction below 20 K.
34 citations
TL;DR: In this article, two diastereoisomers, Me8[14]ane (LA and LB) and Cd(NO3)2, were shown to undergo axial ligand substitution reactions with KSCN, KNO2, KCl, KBr and KI, in the ratio of 1':'2 to yield white solid products corresponding to molecular formula.
Abstract: Reactions of two diastereoisomers of 3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecanes, Me8[14]ane (LA and LB) with Cd(NO3)2 in methanol produced trans-[CdL(NO3)2] (L = LA or LB). However, the third diastereoisomer, Me8[14]ane (LC) did not react with Cd(NO3)2. Trans-[CdLB(NO3)2] undergoes axial ligand substitution reactions with KSCN, KNO2, KCl, KBr and KI, in the ratio of 1 : 2 to yield white solid products corresponding to molecular formula [CdLBX2] where X = NCS−, , Cl−, Br− or I−. Characterization has been carried out on the basis of elemental analysis, IR, UV-visible and 1H-, 13C- and 113Cd-NMR spectroscopy, as well as by magnetic moment and conductivity measurement. These complexes show different electrolytic behaviours in different solvents. In chloroform, they are noneletrolytic indicating that both anions coordinate to cadmium(II) with retention of original molecular formula [CdLBX2]; their 1 : 2 electrolytic nature in water reveals the formation of diaquo complexes [C...
32 citations
TL;DR: In this paper, a polymeric chain was constructed by weak interchain hydrogen bonds, which formed a three-dimensional network, in which the zinc and cadmium atoms were six coordinate with two trans cyanide−nitrogen and four hydet-en N atoms in a distorted octahedron arrangement; the palladium atoms in 1 and 2 were four coordinate with four cyanide-C atoms in square planar arrangement.
Abstract: The novel heteronuclear compounds [Zn(hydet-en)2Pd(CN)4] (1) and [Cd(hydet-en)2Pd(CN)4] (2) {hydet-en: N-(2-hydroxyethyl-ethylenediamine)} have been synthesized and characterized by elemental analyses and IR spectra. The crystal structures of 1 and 2 have been determined by X-ray diffraction. Structural analysis shows that both compounds have shown a polymeric chain, in which the Zn(II)/Pd(II) and Cd(II)/Pd(II) centres are linked by two CN groups. Both zinc and cadmium atoms are six coordinate with two trans cyanide–nitrogen and four hydet-en N atoms in a distorted octahedron arrangement; the palladium atoms in 1 and 2 are four coordinate with four cyanide-C atoms in a square planar arrangement. The chains in both compounds are connected through weak interchain hydrogen bonds, N–H ··· O, N–H ··· N and O–H ··· N, thereby forming a three-dimensional network.
32 citations
TL;DR: A selection of reports that highlight very recent progress in mechanistic investigations of coordination chemistry is presented in this paper, where solvent exchange, ligand substitution, redox reactions, some reactions of nitric oxide and a few other reactions, whose mechanisms have been scrutinised, are covered.
Abstract: Detailed kinetics studies of reactions of coordination compounds in solution have been invaluable in determining the relevant reaction mechanisms. A selection of reports that highlights very recent progress in mechanistic investigations of coordination chemistry is presented. The methods and techniques employed in pursuit of these mechanistic goals are referred to mostly through the latest authoritative reports. Reactions chosen for inclusion are classified according to the comprehensive table of contents. In summary, solvent exchange, ligand substitution, redox reactions, some reactions of nitric oxide and a few other reactions, whose mechanisms have been scrutinised, are covered.
31 citations
TL;DR: In this paper, six bismuth(III) complexes containing dithio-ligands formulated as (R2NCS2)3Bi [R2 NCS2M]3Bi] and (R 2NCS 2M 2BiI]2 ] were obtained by reactions of halides with dithiocarbamate ligands in 1 or 1/3 stoichiometry.
Abstract: Six bismuth(III) complexes containing dithio-ligands formulated as (R2NCS2)3Bi [R2NCS2M = Me2NCS2Na, C4H8NCS2Na, Bz2NCS2Na] and [(R2NCS2)2BiI]2 [R2NCS2M = C5H10NCS2Na, n Bu2NCS2Na, OC4H8NCS2Na] have been obtained by reactions of bismuth(III) halides with dithiocarbamate ligands in 1 : 2 or 1 : 3 stoichiometry All compounds were characterized by elemental and IR analyses The crystal structures of complexes 1 and 4 have been determined by X-ray single crystal diffraction The structure analyses reveal that BiIII in complex 1 adopts a distorted pentagonal–pyramidal coordination, due to its stereochemically active lone pair of electrons A long Bi · S contact of 3218 (3) A leads to dimeric associations of molecules in the crystal structure The structure of complex 4 is six-coordination with a distorted octahedral configuration Intramolecular S · S weak interactions contribute to the stability and lead to a one-dimensional chain structure
TL;DR: In this paper, the synthesis, characterization, microbiological activity and electrochemical properties of the Schiff-base ligands A1-A5 and their Cd(II) and Cu-II metal complexes are reported.
Abstract: Synthesis, characterization, microbiological activity and electrochemical properties of the Schiff-base ligands A1–A5 and their Cd(II) and Cu(II) metal complexes are reported. The ligands and their complexes have been characterized by elemental analysis, FT–IR, UV–Vis, 1H- and 13C-NMR, mass spectra, magnetic susceptibility and conductance measurements. In the complexes, all the ligands are bidentate, the oxygen in the ortho position and azomethine nitrogen atoms of the ligands coordinate to the metal ions. The keto-enol tautomeric forms of the Schiff-base ligands A1–A5 have been investigated in polar and non-polar organic solvents. Antimicrobial activity of the ligands and metal complexes were tested using the disc diffusion method and the chosen strains include Bacillus megaterium and Candida tropicalis. The electrochemical properties of the ligands A1–A5 and their Cu(II) metal complexes have been investigated at different scan rates (100–500 mV s−1) in DMSO.
TL;DR: In this article, the photochemical reaction of metal carbonyls with salicylaldehyde ethanesulfonyl hydrazone (Hsalesh) was used to synthesize a tridentate ligand.
Abstract: The new complexes, M(CO)5(Hsalesh) (M = Cr (1), Mo (2), W (3)), Re(CO)4Br(Hsalesh) (4) and Mn(CO)3(Hsalesh) (5) have been synthesized by the photochemical reaction of metal carbonyls M(CO)6 (M = Cr, Mo, W), Re(CO)5Br, and Mn(CO)3Cp with salicylaldehyde ethanesulfonyl hydrazone (Hsalesh). The complexes have been characterized by elemental analysis, EI mass spectrometry, FT-IR and 1H NMR spectroscopy. The spectroscopic studies show that Hsalesh behaves as a monodentate ligand coordinating via imine N donor atom in M(CO)5(Hsalesh) (M = Cr, Mo, W) and Re(CO)4Br(Hsalesh) and as a tridentate ligand in Mn(CO)3(salesh).
TL;DR: In this article, a novel macrocyclic ligand called [H4L] has been synthesized by a multistep process and all metal complexes have been characterized by elemental analysis, IR, 1H NMR, 13C NMR and U.V.Visible spectroscopy.
Abstract: A novel macrocycle 1,16-diaza-7,10-diamino-6,11-dioxo-1,17-bis[2′-hydroxy-5′-aminobenzyl]-piperazine-4,12-cyclododecadiene, [H4L] has been synthesized by a multistep process. The interaction of 5-amino salicylic acid, piperazine and formaldehyde in ethanol gave PC-1, which was reduced into a chloro-derivative PC-2. PC-2 by reacting with ethylenediamine gave a new macrocyclic ligand titled [H4L]. Its binuclear complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ions have also been synthesized. The ligand and all metal complexes have been characterized by elemental analysis, IR, 1H NMR, 13C NMR and U.V.Visible spectroscopy. Molar conductance and magnetic moment measurements have also been determined. Microanalytical data revealed 1 : 2 molar ratio of ligand to metal in all the complexes. The spectral and magnetic data indicate that Mn(II), Co(II), Ni(II) complexes show octahedral geometry with two water molecules while Cu(II) and Zn(II) complexes exhibit square planar and tetrahedral environments, resp...
TL;DR: A series of binuclear ferro- and antiferromagnetic Cu(2+) chelates of structurally broadly varied Schiff bases (derived from o-tosylamino(hydroxyl)benzaldehydes and monoalkylated o-phenylenediamine, o-aminophenol, O-aminothiophenol, 1,2-diaminobenzimidazole, 1-aminobenzemidazoline-2-thione) has been prepared The tautomerism of the ligands and
Abstract: A series of novel binuclear ferro- and antiferromagnetic Cu(2+) chelates of structurally broadly varied Schiff bases (derived from o-tosylamino(hydroxyl)benzaldehydes and monoalkylated o-phenylenediamine, o-aminophenol, o-aminothiophenol, 1,2-diaminobenzimidazole, 1-aminobenzimidazoline-2-thione) and β-diketimines (derived from 2,6-di-i-Pr-aniline) has been prepared The tautomerism of the ligands and structureof their copper complexes have been studied with the use of IR, 1H NMR EPR and EXAFS spectroscopy Molecular and crystal structure of a β-diketimine copper dimer has been determined by X-ray crystallography The magnetic measurements (2–300 K) performed for all the complexes showed that the ferro- and antiferromagnetic character of the exchange interaction depends both on the structure of the coordination site (origin of the ligating centers) and the structure of the ligands (in particular, on the type of the cycle annelated to the bridging fragment) Whereas S-binding metal chelates 13 (X = NTs, Y
TL;DR: Several cis-dioxomolybdenum complexes of two tridentate ONS chelating ligands H 2L1 and H2L2 (obtained by condensation of S-benzyl and S-methyl dithiocarbazates with 2-hydroxyacetophenone) have been prepared and characterized as discussed by the authors.
Abstract: Several cis-dioxomolybdenum complexes of two tridentate ONS chelating ligands H2L1 and H2L2 (obtained by condensation of S-benzyl and S-methyl dithiocarbazates with 2-hydroxyacetophenone) have been prepared and characterized. Complexes 1 and 2 are found to be of the form MoO2 (CH3OH) L1 · CH3OH and MoO2L, respectively, (where L2– = dianion of H2L1 and H2L2). The sixth coordination site of the complexes acts as a binding site for various neutral monodentate Lewis bases, B, forming complexes 3–10 of the type MoO2LB (where B = γ-picoline, imidazole, thiophene, THF). The complexes were characterized by elemental analyses, various spectroscopic techniques, (UV-Vis, IR and 1H NMR), measurement of magnetic susceptibility at room temperature, molar conductivity in solution and by cyclic voltammetry. Two of the complexes MoO2(CH3OH) L1 · CH3OH (1) and MoO2L1(imz) (5) were structurally characterized by single crystal X-ray diffraction. Oxo abstruction reactions of 1 and 5 led to formation of oxomolybdenum(IV) compl...
TL;DR: In this article, three complexes, Na4[DyIII(dtpa)(H2O)]2,·· 16H 2O, Na3[dyIII (nta)2,3.5H 2, have been synthesized in aqueous solution and characterized by FT-IR, elemental analyses, TG-DTA and single-crystal X-ray diffraction.
Abstract: Three complexes, Na4[DyIII(dtpa)(H2O)]2 · 16H2O, Na[DyIII(edta)(H2O)3] · 3.25H2O and Na3[DyIII (nta)2(H2O)] · 5.5H2O, have been synthesized in aqueous solution and characterized by FT–IR, elemental analyses, TG–DTA and single-crystal X-ray diffraction. Na4[DyIII(dtpa)(H2O)]2 · 16H2O crystallizes in the monoclinic system with P21/n space group, a = 18.158(10) A, b = 14.968(9) A, c = 20.769(12) A, β = 108.552(9)°, V = 5351(5) A3, Z = 4, M = 1517.87 g mol−1, D c = 1.879 g cm−3, μ = 2.914 mm−1, F(000) = 3032, and its structure is refined to R 1(F) = 0.0500 for 9384 observed reflections [I > 2σ(I)]. Na[DyIII(edta)(H2O)3] · 3.25H2O crystallizes in the orthorhombic system with Fdd2 space group, a = 19.338(7) A, b = 35.378(13) A, c = 12.137(5) A, β = 90°, V = 8303(5) A3, Z = 16, M = 586.31 g mol−1, D c = 1.876 g cm−3, μ = 3.690 mm−1, F(000) = 4632, and its structure is refined to R 1(F) = 0.0307 for 4027 observed reflections [I > 2σ(I)]. Na3[DyIII(nta)2(H2O)] · 5.5H2O crystallizes in the orthorhombic system with ...
TL;DR: In this article, two isomorphous one-dimensional chain complexes Co(NCS)2(Him)2 (1) and Mn( NCS) 2 (Him's=imidazole) have been prepared and characterized structurally.
Abstract: Two isomorphous one-dimensional chain complexes Co(NCS)2(Him)2 (1) and Mn(NCS)2(Him)2 (2) (Him = imidazole) have been prepared and characterized structurally. Both 1 and 2 crystallize in the monoclinic system, space group P21/n, and the structures consist of one-dimensional polymeric chains in which metal ions are bridged by two thiocyanate groups bonding in end-to-end fashion. Both 1 and 2 exhibit two-dimensional sheet structures with N–H ··· S hydrogen bonds and three-dimensional supramolecular network structure with π ··· π stacking interactions. IR spectra indicate the presence of bridging thiocyanate groups in both 1 and 2, confirmed by their structures. The variable temperature magnetic susceptibility, measured in the 2–300 K range, indicates weak antiferromagnetic exchange interactions in complex 2.
TL;DR: The reaction between dpktch and CdCl2 in refluxing acetonitrile gave [CdCl 2(η3-dpktch] in good yield as mentioned in this paper.
Abstract: The reaction between dpktch and CdCl2 in refluxing acetonitrile gave [CdCl2(η3-dpktch)] in good yield. Spectroscopic measurements divulge the coordination of dpktch and the elemental analysis confirmed its formulation. Optical measurements in N,N-dimethylformamide (dmf) and dimethylsulfoxide (DMSO) in the absence and presence of a proton donor/acceptor disclosed two highly sensitivity interlocked intra-ligand-charge-transfer transitions (ILCT) that are sensitive to their surroundings. Under basic conditions, a low-energy electronic transition with an extinction coefficient of 17,400 ± 2000 M−1cm−1 appeared at ∼403 nm and a peak minimum appeared at 326 nm. Under acidic conditions, a high energy electronic transition with extinction coefficient of 13,500 ± 2000 M−1cm−1 appeared at ∼330 nm and a shoulder appeared at ∼400 nm. The addition of an acid to a dmf solution of [CdCl2(η3-dpktch)] caused the disappearance of the low energy absorption band at 403 nm and a peak maximum appeared at 330 nm. The reverse wa...
TL;DR: In this article, triorganotin(IV) pyrazolinates have been synthesized by the reaction of R3SnCl with the sodium salt of pyrazoline in anhydrous benzene, and newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement as well as spectral studies.
Abstract: Triorganotin(IV) pyrazolinates of the type R3Sn(C15H12N2O · X) [where C15H12N2O · X = 3(2′-hydroxyphenyl)-5(4-X-phenyl)pyrazoline {where X = H (a); CH3 (b); OCH3 (c); Cl (d) and R = Me, Pr n and Ph}] have been synthesized by the reaction of R3SnCl with the sodium salt of pyrazolines in a 1 : 1 molar ratio, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement as well as spectral studies [IR and multinuclear NMR (1H, 13C and 119Sn)]. The bidentate behaviour of the ligands was confirmed by IR, 1H and 13C NMR spectral data. Trigonal bipyramidal structure around tin(IV) atom for R3Sn(C15H12N2O · X) has been suggested. The free pyrazoline and a few triorganotin(IV) pyrazolinates have also been screened for their antibacterial and antifungal activities. Some triorganotin(IV) pyrazolinates exhibit higher antibacterial and antifungal effects than free pyrazoline and some of the antibiotics.
TL;DR: In this paper, the authors have shown that Ru3+ is a cage-like dimer consisting of two inversion-related ligands and two Ru 3+ atoms, bridged by a pair of inversion related Ru-N (azodye) bonds.
Abstract: Five bis-[5-(4′-R-phenylazo)-8-hydroxyquinoline] ruthenium complexes [RuLn · Cl2 · OH2]; where Ln = 5-(4′-R-phenylazo)-8-hydroxyquinolinol, R = OCH3 (n = 1), CH3(2), H(3), Cl(4), NO2(5), have been prepared and characterized on the basis of elemental analyses, IR, 1H NMR, ESR, thermal analysis and magnetic susceptibility measurements. The data show that these complexes exist in trans-isomeric solid form. Two inversion-related ligands and two Ru3+ atoms form a cage-like dimer. Both ligands of the dimer are bridged by a pair of inversion-related Ru–N (azodye) bonds. The octahedral coordination geometry of Ru3+ is made up of an N of pyridine, the deprotonated quinoline O atom, one of the azodye N atoms, two chlorides and one water. The ligands in the dimer are stacked over one another. In the solid state of azo-8-hydroxyquinoline, the dimers have inter-and intramolecular hydrogen bonds. Interactions between the ligands and the metal are discussed. The azo group was involved in chelation for all the prepared c...
TL;DR: In this paper, the preparation and characterization of zinc complexes of formula ZnL2X2 (X = Cl and Br), with L n-propyl substituted derivatives, are described.
Abstract: The preparation and characterization of zinc complexes of formula ZnL2X2 (X = Cl and Br), with L = 1,3-diazinane-2-thione (Diaz), 1,3-diazipane-2-thione (Diap), imidazolidine-2-thione (Imt) and its methyl and n-propyl substituted derivatives, are described. The complexes dichlorobis(1-methylimidazolidine-2-thione-S)-zinc(II) (1) and dichlorobis(1-propylimidazolidine-2-thione-S)-zinc(II) (2) have been characterized by single-crystal X-ray methods. Both complexes adopt distorted tetrahedral geometry. Only intramolecular hydrogen bonding interactions are observed in 1 and 2. Solution and solid state 13C NMR show a significant shift of the C=S carbon resonance of the ligands, while other resonances are relatively unaffected, indicating that most likely the solid state structure is maintained in solution. Antimicrobial activity studies of the free ligands and their complexes show that ligands exhibit substantial antibacterial activities compared to the complexes.
TL;DR: The reaction of Cd(NO3)2··· 4H2O with NH4SCN and pca (pca) in CH3OH gave complexes of the type [Cd(SCN)2(pca)] n (2) as mentioned in this paper.
Abstract: The reaction of Cd(NO3)2 · 4H2O with NH4SCN and dpa (dpa = 2,2′-dipyridylamine) in CH3OH afforded the complex [Cd(SCN)2(dpa)] n (1), while reaction of Cd(NO3)2 · 4H2O with NH4SCN and pca (pca = 2,2′-dipicolylamine) in CH3OH gave complexes of the type [Cd(SCN)2(pca)] n (2). The reaction of Cd(NO3)2 · 4H2O with NH4SCN, H2ox (H2ox = oxalic acid) and amp (amp = 2-aminopyridine) in CH3OH gave complexes of the type {[Cd(NCS)2(ox)](Hamp)2} n (3). Their IR spectra have been recorded and their structures determined. Complex 1 shows 1-D polymeric double-stranded chains with bridging thiocyanato groups. The double-stranded linear chains in 1 have eight-membered rings and close-pack to form the 3-D structures through C–H · S hydrogen bonding and π–π interactions. In the pseudo {CdN5S} octahedral complex 2, the nitrogen containing ligands occupy amine and pyridyl groups of the fac-pca ligand and two nitrogen atoms and one sulfur atom from the two bridging and one monodentate NCS− ligands, forming the 1-D polymeric hel...
TL;DR: In this article, a trigonal bipyramidal structure around tin(IV) for R2SnCl(C15H12N2O· X) is suggested.
Abstract: Chlorodiorganotin(IV)pyrazolinates of the type R2SnCl(C15H12N2O · X) [where C15H12N2O · X = 3(2′-Hydroxyphenyl)-5(4-X-phenyl)pyrazoline {where X = H (a); CH3 (b); OCH3 (c); Cl (d) and R = Me, Pr n and Ph}] have been synthesized by reaction of R2SnCl2 with the sodium salt of pyrazolines in 1 : 1 molar ratio, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement and spectral studies [IR and multinuclear NMR (1H, 13C and 119Sn)]. The bidentate behavior of the ligands was confirmed by IR, 1H and 13C NMR spectral data. Trigonal bipyramidal structure around tin(IV) for R2SnCl(C15H12N2O · X) is suggested. The free pyrazoline and some chlorodiorganotin(IV) pyrazolinates have been screened for their antibacterial and antifungal activities. Some chlorodiorganotin(IV) pyrazolinates exhibit higher antibacterial and antifungal effect than free pyrazoline and some antibiotics.
TL;DR: In this paper, a variety of coordination modes between crown ether and metal ions are presented, including coordination modes for the crown ether, the crown ion, and the metal ion's coordination modes.
Abstract: Complexes involving the perchlorate, chloride, bromide or iodide salts of the heavy group 2 elements, calcium, strontium or barium, and either 15-crown-5 or 18-crown-6 have been synthesized and their X-ray crystal structures determined. A variety of coordination modes are presented between the crown ether and metal ions.
TL;DR: In this paper, the mutual ligand arrangement in binuclear lanthanoid complexes of the type [Gu2Ln(μ-H)]2, [Gu 2Ln (μ-Cl)2Li(THF)2, where Gu is a substituted guanidinato ligand, is quantitatively analyzed based on the ligand solid angle approach.
Abstract: Mutual ligand arrangement in binuclear lanthanoid complexes of the type [Gu2Ln(μ-H)]2, [Gu2Ln(μ-Cl)]2, and Gu2Ln(μ-Cl)2Li(THF)2, where Gu is a substituted guanidinato ligand, is quantitatively analyzed based on the ligand solid angle approach. In complexes of Nd, Sm, and Gd the Gu ligands shield up to 87% of the metal and the bidentate ligands on opposite metal centers are in the eclipsed arrangement; in complexes of lanthanoids with smaller ionic radii Y, Yb, and Lu the Gu ligands shield over 88.3% of the metal surface and their staggered conformation is observed. The ligand solid angle approach is illustrated and its application to describing multidentate ligands is demonstrated. §Dedicated to Professor Georgy A. Domrachev on the occasion of his 70th birthday
TL;DR: In this article, Schiff-base complexes of stoichiometry MAB, MAB2 or MA2B2 have been detected in the Co(II, Ni(II), Cu(II) and Zn(II)-o-vanillin [A]-L-valine (val), L-glutamine (gln) and L-histidine (his)(B) systems.
Abstract: In solution Schiff-base complexes of stoichiometry MAB, MAB2 or MA2B2 have been detected in the Co(II), Ni(II), Cu(II) and Zn(II)-o-vanillin (o-van) [A]-L-valine (val), L-glutamine (gln) and L-histidine (his)(B) systems. The results suggest that in the M-o-van-val/gln systems, the Schiff-base ligand (AB) is tridentate in M(AB) complexes, while (AB) is tetradentate in his systems. MAB2 species can be represented as M(AB)(B), where the mode of coordination of (AB) would be similar to that in the M(AB) species. The MA2B2 complex can be represented as M(AB)2, where (AB) is tridentate in all the systems. The stabilities of complexes follow the Irwin–Williams order of stability. MAB complexes were isolated and conformed by characterization data. Conductance studies indicate that all complexes are non-ionic. Magnetic susceptibility and electronic spectral data suggest a tetrahedral structure in Co(II) and Ni(II)-o-van-val/gln and Ni(II)-o-van-his systems and square-planar structure in Co(II)-o-van-his and Cu(II)...
TL;DR: The mixed ligand complexes [M(bpy)(phen-dione)](PF6)2 have been synthesized and characterized by elemental analysis, IR, 1H NMR and electronic absorption spectroscopies as mentioned in this paper.
Abstract: The novel mixed ligand complexes [M(bpy)(phen-dione)](PF6)2 (M = Zn(II), Cd(II) and Hg(II), bpy = 2,2′-bipyridine and phen-dione = 1,10-phenanthroline-5,6-dione) have been synthesized and characterized by elemental analysis, IR, 1H NMR and electronic absorption spectroscopies. The ν(C=O) of coordinated phen-dione in these complexes are very similar to the free phen-dione ligand showing that phen-dione is not coordinated to metal ion from its C=O sites. Absorption spectra of the complexes show two absorption bands for intraligand transitions. These absorption bands show dependence to the dielectric constant of solvent. These complexes exhibit an intensive fluorescence band around 535 nm in DMF when the excitation wavelength is 260 nm at room temperature. The fluorescence intensity of these complexes is larger than that of the free ligand.
TL;DR: In this article, three ophthalate (pht) lead(II) complexes were synthesized and characterized by elemental analyses, IR, 1H NMR, and 13C NMR spectroscopy.
Abstract: Three new o-phthalate (pht) lead(II) complexes were synthesized and characterized by elemental analyses, IR, 1H NMR, and 13C NMR spectroscopy. Single crystal X-ray structural analysis of [Pb(pht)(H2O)] n shows the complex to be a novel 2D chain polymer as a result of phthalate bridging. Coordination number of Pb(II) is eight, PbO8, with a “stereo-chemically active” electron lone pair, and the coordination sphere is hemidirected. Packing of this compound in the solid state via π–π stacking and hydrogen bonding is discussed.
TL;DR: In this article, a novel vic-dioxime ligand with a thiourea moiety, (4E,5E)-1,3-bis{4-[(4-bromophenylamino)methylene]phenyl}-2-thiooxaimidazoline-4,5-dione dioxime (4) (bmdH2) has been synthesized from N,N′-bis.
Abstract: A novel vic-dioxime ligand with a thiourea moiety, (4E,5E)-1,3-bis{4-[(4-bromophenylamino)methylene]phenyl}-2-thiooxaimidazoline-4,5-dione dioxime (4) (bmdH2) has been synthesized from N,N′-bis{4-[(4-bromophenylamino)methylene]phenyl}thiourea and (E,E)-dichloroglyoxime. The bmdH2 ligand (4) forms transition metal complexes [M(bmdH)2] with a metal : ligand ratio of 1 : 2 with M = Ni(II), Co(II), and Cu(II). The mononuclear Ni(II), Co(II) and Cu(II) complexes, [Ni(bmdH)2] (5), [Co(bmdH)2] (6) and [Cu(bmdH)2] (7) have the metal ions coordinated through the two N,N atoms, as do most vic-dioximes. Elemental analyses, molar conductivity, magnetic susceptibility, IR, 1H NMR spectra, and UV-Visible spectroscopy were used to elucidate the structures of the ligand and its complexes. Conductivity measurements have shown that the mononuclear complexes are non-electrolytes. In addition, the ligands and metal complexes were screened for antibacterial and antifungal activities by agar well diffusion techniques using DMF...