Bidentate Ethylenediamine Research Articles

Crystal Field Splitting Energy (Δo) and Racah Parameters (B) of Some Metal-Saccharine and Metal-Saccharine-Ethylenediamine Complexes

[M(sac)2(H2O)4].2H2O [sac = saccharinato anion, M = Fe(II), Co(II), Ni(II), and Cu(II)], and [M(sac)2(en)2].2H2O [sac = saccharinato anion, en = ethylenediamine, M = Fe(II), Co(II), Ni(II) and Cu(II)] were prepared in an aqueous medium. The compounds are crystalline of different colors and are ambiently stable. By examining their physico-chemical properties and relevant literature, the metal(II) ions in both [M(sac)2(H2O)4].2H2O and [M(sac)2(en)2].2H2O complexes are octahedrally coordinated. In the former by four neutral H2O molecules and two monoanionic sac ligands while in later, the octahedral sites fulfilled by two neutral bidentate ethylenediamine molecules and two monoanionic sac ligands. Splitting of the crystal field (Δo) and Racah parameter (B) of two sets of complexes [M(sac)2(H2O)4].2H2O and [M(sac)2(en)2].2H2O are estimated from their electronic spectra using Tanabe-Sugano diagram of Co(II) and Ni(II) complexes while Δo values of Fe(II) and Cu(II) derivatives are calculated directly from their absorption maxima. Our experimental results show that for the studied ligands and the divalent transition metal ions, the Δo values vary according to the following order: Cu(II) > Fe(II) > Co(II) > Ni(II). Dhaka Univ. J. Sci. 71(1): 6-12, 2023 (Jan)

Efficient Copper(I) Extraction by Ethylenediamine from Stable Catenane Complexes

AbstractA new demetallation method for Cu(I)‐bound catenanes that contain a strong binding bis(phenanthroline) cavity using the bidentate ethylenediamine is reported. Cu(I) extraction using the organic diamine is mild, convenient and efficient, and the metal can be removed from the kinetically stable catenane complexes in various solvents within 5 minutes, offering an alternative strategy to the use of toxic cyanide in competing for the Cu(I) coordination.

Tuning of Cr-Cr Magnetic Exchange through Chalcogenide Linkers in Cr2 Molecular Dimers.

A set of three Cr-dimer compounds, Cr2Q2(en)4X2 (Q: S, Se; X: Br, Cl; en: ethylenediamine), with monoatomic chalcogenide bridges have been synthesized via a single-step solvothermal route. Chalcogenide linkers mediate magnetic exchange between Cr3+ centers, while bidentate ethylenediamine ligands complete the distorted octahedral coordination of Cr centers. Unlike the compounds previously reported, none of the chalcogenide atoms are connected to extra ligands. Magnetic susceptibility studies indicate antiferromagnetic coupling between Cr3+ centers, which are moderate in Cr2Se2(en)4X2 and stronger in Cr2S2(en)4Cl2. Fitting the magnetic data requires a biquadratic exchange term. High-frequency EPR spectra showing characteristic signals due to coupled S = 1 spin states could be interpreted in terms of the "giant spin" Hamiltonian. A fourth compound, Cr2Se8(en)4, has a single diatomic Se bridge connecting the two Cr3+ centers and shows weak ferromagnetic exchange interactions. This work demonstrates the tunability in strength and type of exchange interactions between metal centers by manipulating the interatomic distances and number of bridging chalcogenide linkers.

A unique copper coordination structure with both mono- and bi-dentate ethylenediamine ligands

A new crystal structure achieving penta-coordination using exclusively ethylenediamine ligands is discovered and characterized.

(μ-Methylenediphosphonato-κ4 O,O':O'',O''')bis[(ethyl-ene-diamine-κ2 N,N')palladium(II)] tetra-hydrate.

The title compound, [Pd2(C2H8N2)2(CH2O6P2)]·4H2O, comprises of a binuclear mol-ecule (point group symmetry 2), with a twofold rotation axis running through the central C atom of the methyl-enedi-phospho-nate (MDP) anion. The PdII atom has a square-planar coordination environment defined by the N atoms of a bidentate ethyl-enedi-amine (en) ligand and two O atoms of the bridging MDP anion. In the crystal structure, metal complexes are arranged in layers parallel (001) and are sandwiched between layers containing disordered water mol-ecules of crystallization. Extensive intra-layer hydrogen bonds of the type N-H⋯O in the metal complex layer and O-H⋯O in the water layer, as well as O-H⋯O hydrogen bonds between the two types of layers, lead to the formation a three-dimensional network structure. The two lattice water mol-ecules are each equally disordered over two positions.

Systematic pH-specific synthesis and structure transformations in binary-ternary In(III) assemblies with hydroxycarboxylic DPOT and aliphatic-aromatic chelators

Driven by the need to generate hybrid In(III)-(O,N) luminescent materials containing appropriately configured organic ligands, binary-ternary In(III) metal-organic systems involving the multidentate organic ligand DPOT, ethylenediamine (en) and phenanthroline (phen) were investigated under pH-specific conditions. The arisen materials [In2(C11H13N2O9)2](CH6N3)4·7H2O(1), [In3(C11H13N2O9)2(C2H8N2)2](C2H9N2)·4H2O(2), [In2(C11H13N2O9)2](CH6N3)6(Cl)2·6H2O(3), and [In2(C11H13N2O9)(C12H8N2)2(Cl)(H2O)]·7.5H2O(4) were characterized by analytical, spectroscopic (FT-IR, 13C-MAS NMR, luminescence) techniques, TGA and X-ray crystallography. The binary materials 1 and 3 exhibit dinuclear alkoxido-bridged In2O2 cores, with the fully-deprotonated organic ligand spanning both centers. Introduction of bidentate ethylenediamine leads to ternary trinuclear species 2, whereas phen introduction in 4 leads to a dinuclear asymmetric assembly, incorporating a chloride ion and a water molecule. Chemical transformations among 1–4 provide mechanistic insight into the nature of chelators, dictating nuclearity, coordination, composition and lattice-specific luminescence. The collective physicochemical properties in 1–4 present well-defined 1D-3D structural architecture-dimensionality and spectroscopic property correlations, pointing out criteria based on which synthon design, custom architecture and photoactivity are interwoven into the future development of In(III)-containing metal-organic hybrid materials.

Crystal structure of penta-kis-(ethyl-enedi-amine-κ(2) N,N')lanthanum(III) trichloride-ethylene-diamine-dichloromethane (1/1/1).

We report here the crystal structure of a ten-coordinate lanthanum(III) metal coordinated by five bidentate ethyl-enedi-amine ligands, [La(C2H8N2)5]Cl3·C2H8N2·CH2Cl2. One free ethyl-enedi-amine mol-ecule and three Cl(-) anions are also located in the asymmetric unit. The overall structure is held together by an extensive hydrogen-bonding network between the Cl(-) anions and the NH groups on the metal-bound ethyl-enedi-amine ligands. The free ethyl-enedi-amine mol-ecule is held in an ordered position by additional hydrogen bonds involving both the chlorides and -NH groups on the metal-bound ligands. One highly disordered mol-ecule of di-chloro-methane is located on an inversion center; however, all attempts to model this disorder were unsuccessful. The electron density in this space was removed using the BYPASS procedure [van der Sluis & Spek (1990 ▶). Acta Cryst. A46, 194-201].

The First Tetradentate μ‐1κ2:2κ2‐Sn2Se6 Ligand to a Lanthanide(III) Center: Solvothermal Syntheses and Characterizations of Lanthanide Selenidostannate Polymers with Tetraethylenepentamine as a Second Ligand

AbstractNovel lanthanide selenidostannate polymers containing the soft‐base Sn2Se6 ligand, (H3O)n[La(tepa)(μ‐1κ2:2κ2‐Sn2Se6)]n (1), [{Nd(tepa)(μ‐OH)}2(μ‐1κ:2κ‐Sn2Se6)]n (2), and [{Gd(tepa)(μ‐OH)}2(μ‐1κ:2κ‐Sn2Se6)]n·nH2O (3) (tepa = tetraethylenepentamine) were prepared by treating lanthanide oxides with Sn and Se using pentadentate polyamine tepa as a second ligand under solvothermal conditions. In 1, the La3+ ion is coordinated by a tepa ligand to form an unsaturated [La(tepa)]3+ unit, and the [Sn2Se6]4– anion acts as a tetradentate bridging ligand with four terminal Se atoms to connect the [La(tepa)]3+ units into a coordination polymeric anion [La(tepa)(μ‐1κ2:2κ2‐Sn2Se6)–]n. The μ‐1κ2Se1,Se2:2κ2Se5,Se6 bridging mode in 1 is a new coordination mode for the Sn2Se6 unit to LnIII centers. In 2 and 3, the lanthanide ion is coordinated by a tepa ligand, and two [Ln(tepa)]3+ (Ln = Nd, Gd) ions are joined by two μ‐OH bridges to form dinuclear cations. Behaving as a bidentate μ‐Sn2Se6 ligand with the trans‐terminal Se atoms, the Sn2Se6 units connect the [{Ln(tepa)(μ‐OH)}2]4+ cations into neutral coordination polymers [{Ln(tepa)(μ‐OH)}2(μ‐Sn2Se6)]n. The coordination modes μ‐1κ2Se1,Se2:2κ2Se5,Se6 in 1 and μ‐1κSe1:2κSe5 in 2 and 3 are related to the metal size of the lanthanide(III) ions. In addition, as an ethylenepolyamine with higher denticity, the pentadentate tepa exhibits a significantly different influence on the structures of the solvothermally synthesized Ln selenidostannates compared to the bidentate ethylenediamine and tridentate diethylenetriamine. Compounds 1–3 are semiconductors with well‐defined band gaps of 1.95–2.34 eV.

Synthesis, characterization and anti proliferative effect of [Au(en) 2]Cl 3 and [Au(N- propyl-en) 2]Cl 3 on human cancer cell lines

Two Au(III) complexes of the type [Au(en) 2]Cl 3 ( 2a) and [Au(N-pr-en) 2]Cl 3 ( 3a) were synthesized by reacting Auric acid (HAuCl 4·3H 2O) with 2 equiv. ethylenediamine (en) or N-alkyl substituted ethylenediamine ligands. This metallodrug was characterized by various analytical and spectroscopic techniques such as elemental analysis, UV–Vis, Far-IR, 1H NMR and solution 13C as well as solid 13C and 15N NMR. Potentiality of [Au(en) 2]Cl 3 and [Au(N-pr-en) 2]Cl 3 as an anti-cancer agent were investigated by measuring some relevant physicochemical and biochemical properties such as stability of Au-N bonds by vibrational stretching from Far IR as well as cytotoxicity and stomach cancer cell inhibiting effect, respectively. The solid-state 15N NMR chemical shift shows that the ligand is strongly bound to gold(III) centre via N atoms. The computational study of 2a shows that the gold coordination sphere adopts distorted square planar geometry with bidentate ethylenediamine ligands acting as a tetradentate chelate. While stable in the solution state, the in vitro biological studies performed with these compounds 2a in solution showed higher activity towards the inhibitory effects of the human cancer cell lines such as prostate cancer (PC-3) and gastric carcinoma (SGC-7901) than that of the N-substituted gold(III) complex ( 3a). Cytotoxicity of the new compounds has also been estimated in PC-3 and SGC-7901 cells.

Fabrication of tubular ZnO by vesicle–template fusion

Zinc oxide microtubes were synthesized by hydrothermal method. The cooperation activities of surfactant cetyltrimethylammonium bromide (CTAB) and bidentate ethylenediamine ligand were found to be appropriate for the formation of final tubes. The morphologies and structures of the samples were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). A possible vesicle-template elongating fusion mechanism was proposed and discussed.

Complexes of ligands derived from 1,8-dihydroxynaphthalene. Synthesis and crystal structures of a palladium and a copper complex

A simplified synthesis has been elaborated for 2,7-diacetyl-1,8-dihydroxy-3,6-dimethylnaphthalene, H2daddn, whose di-Schiff base derivatives in principle offer binuclear metal complexes with potentially useful geometrical features; only mono-Schiff base products, however, are formed upon condensation with the mono-primary amines 2-aminomethylpyridine, 2-aminoethylpyridine or N,N-dimethylethylenediamine in either metal-free reactions or in the presence of Pd2+ or Cu2+. The X-ray crystal structures of two metal derivatives of H2daddn have been determined. Crystals of [PdL(N3)](in which L is the monoanion formed by proton loss from a phenolic group in the mono-Schiff base from H2daddn and 2-aminoethylpyridine) are monoclinic, space group P21/c, with a= 11.220(1), b= 12.910(2), c= 14.521(2)A and β= 92.540(9)°; at convergence R= 0.030 for 3398 reflections [I > 2σ(I)]. The Pd is essentially square planar with one N3– ligand, L acting as a tridentate chelating ligand which has a pronounced fold. The intact phenolic OH is hydrogen-bonded to the adjacent deprotonated and co-ordinated phenoxy centre. Crystals of [Cu(daddn)(en)]·MeOH (en = ethylenediamine) are orthorhombic, space group Pbca, with a= 14.515(2), b= 16.596(3) and c= 16.406(3)A; at convergence R= 0.046 for 1158 reflections [I > 3σ(I)]. An approximately square O2N2 arrangement around the Cu is provided by a bidentate daddn2– on one side and a bidentate ethylenediamine on the other; the molecules are present in pairs in which a phenoxide atom in one molecule is weakly bonded [Cu ⋯ O 2.848(12)A] to the Cu in its neighbour.

Ba(en)4]2 As4Te6, das erste Telluridoarsenat / [Ba(en)4]2 As4Te6, the First Telluridoarsenate

The new compound [Ba(en)4]2As4Te6 has been prepared by reaction of appropriate mixtures of the elements in dry ethylenediamine. It crystallizes in the monoclinic system, space group P21/n with a = 1776.0(6) pm, b = 1459.9(6) pm, c = 1000.0(4) pm, β = 101.8(1)°. The As4Te6 4- anion forms a six-membered ring As4Te2 of chair conformation, in which two As-As groups are bridged by Te atom s. A t each As atom a further exocyclic Te neighbour is bonded in the equatorial position. The Ba2+ cation is eight-coordinated by the bidentate ethylenediamine ligand.

Ab initio MO calculations on stabilities and binding energies of bidentate ethylene diamine with ions (Na +, Li +, and H +)

Geometrical relaxations and binding energies of the complexes of ions (Na +, Li +, and H +) and bidentate ethylene diamine were studied by using an ab initio MO method, and are compared with those of the monodentate form of ethylene diamine and methylamine. Computed 6-31G * binding energies of Na + and Li + ions with bidentate ethylene diamines are 42.3 and 66.3 kcal/mol, which are larger than those with monodentate form of ethylene diamine by 9.9 and 19.7 kcal/mol, respectively. These energies (9.9 and 19.7 kcal/mol) correspond to the cyclization stabilization, i.e. binding energies due to the second NH 2 addition. Morokuma's energy decomposition analyses were performed to analyze the interaction energy components. Larger binding energies of Li + and amines are due to the larger contribution of electrostatic stabilization; smaller contribution of polarization stabilization cancels the increase of electron-exchange destabilization. Proton affinity of bidentate ethylene diamine, computed at the level of Hartree—Fock MO theory with the 6-31G * basis set, was smaller than that of monodentate ethylene diamine, in contrast to the experimental findings. Third-order Møller—Plesset perturbation calculations with the 6-31G ** basis set (in the model system) suggest the importance of the electron correlation contribution in the proton affinity computations of bidentate ethylene diamine.

Reactions of [Zn{S2P(OR)2}2] with nitrogen bases and the single-crystal X-ray structures of [Zn{S2P(OPri)2}2]·H2NCH2CH2NH2and [Zn{S2P(OPri)2}2]·NC5H5

The adducts [Zn{S2P(OR)2}2]·L [L = H2NCH2CH2NH2(en), MeHNCH2CH2NHMe (dmen), Me2NCH2CH2NMe2(tmen), 2,2′-bipyridyl,1,10-phenanthroline,2,9-dimethyl-1,10-phenanthroline, or pyridine; R = Et or Pri] and the ionic compounds [Zn(en)3][S2P(OR)2]2 and [Zn(dmen)][S2P(OR)2]2 have been isolated by treating [Zn{S2P(OR)2}2] with L in the appropriate stoicheiometry. The crystal structures of [Zn{S2P(OPri)2}2]·en (1) and [Zn{S2P(OPri)2}2]·py (2) have been determined: (1), monoclinic, space group P21/c, with a= 13.402(8), b= 16.470(9), c= 12.294(7)Å, β= 99.0(1)°, and Z= 4; (2), monoclinic, space group P21/n with a= 21.28(1), b= 8.35(1), c= 16.27(1)Å, β= 99.5(1)°, and Z= 4. Diffractometer data were collected for both crystals [of which 1 340 (1) and 1 940 (2) were above background] and both structures were refined to R 0.073. In (1) the zinc atom is four-co-ordinate forming two Zn–N bonds [2.077(13) and 1.922(16)Å] to the bidentate ethylenediamine molecule and two Zn–S bonds [2.292(5) and 2.331(5)Å] to the monodentate dithiophosphate ligands. In (2) the zinc atom is five-co-ordinate being bonded to pyridine [Zn–N 2.015(12)Å], and to two bidentate dithiophosphate ligands. One ligand is bonded to the metal more symmetrically [Zn–S 2.502(4) and 2.358(4)Å] than the other [Zn–S 2.269(4) and 3.032(4)Å]. The 31P n.m.r. spectra of a number of these compounds have been examined. A correlation between the positions of the resonances and the mode of bonding of the [S2P(OR)2]– groups to the metal has been established.

Ab initio MO calculations on binding energies and stabilities of Na + with ethylene diamine

Binding energies and stabilities of Na + with bidentate ethylene diamine were studied using ab initio MO calculations with a 6-31G * basis set. The computed results for bidentate ethylene diamine were compared with those for two (monodentate) CH 3NH 2 molecules.

Reactions of Metal Complexes with Carbohydrates. Synthesis and Structure of (2-[(2-Aminoethyl)amino]-2-deoxy-l-sorbose)(ethylenediamine)nickel(II) Dichloride Hemi Methanol Solvate: [Ni(en)(l-sor-en)]Cl2·1/2CH3OH (en=ethylenediamine and sor=sorbose)

Abstract The synthesis and crystal structure of the complex [Ni(en)(l-sor-en)]Cl2·1/2CH3OH which was derived from the reaction of tris(ethylenediamine)nickel(II) dichloride dihydrate with l-sorbose are described. Crystal-lographic details for the complex are follows: space group C2 (monoclinic); a=17.862(2) Å, b=8.212(1) Å, c=12.644(2) Å, β=90.89(1)°; Z=4; Dcalcd=1.53 gcm−3. The structure was solved by heavy atom methods, and the structure parameters including almost all hydrogen atoms were refined by least-squares methods. The final R factor was 0.032 for 2680 independent reflections. The nickel atom is octahedrally coordinated with a bidentate ethylenediamine and a tetradentate glycosylamine ligand of l-sor-en. l-Sorbose moiety adopts the six-membered α-2C5 chair conformation. In addition to the synthesis and structure of this complex, we report the results of absorption and circular dichroism spectroscopy.

The crystal and molecular structure of bis(ethylenediamine) copper(II) selenocyanate

The crystal structure of [Cu(en)2](SeCN)2 was solved by the heavy atom method and refined by the least squares method using the full matrix and anisotropic thermal parameters to a value of R = 0.063 for 660 observed reflections. The crystals are triclinic , with a space group of P1 and lattice parameters of a = 6.660(2), b = 9.360(2), c = 7.754(2) . 10-10 m, α = 129.22(2), β = 109.87(2) and γ = 92.38(2)°, Z = 1. The structure consists of discrete molecules that are centrosymmetric. The Cu(II) atom occupies a special position at the centre of symmetry and is coordinated by 4 nitrogen atoms from two bidentate ethylenediamine molecules: C-N 1.999(8) and 2.033(8) . 10-10 m and angle N1-Cu-N2, 84.1(3)°. The selenium atom in the SeCN group completes this square planar arrangement to form a deformed octahedron along the longer Cu...Se distance of 3.263(2) . 10-10 m. The ethylenediamine molecule has a non-symmetrical gauche arrangement with the carbon atoms C1 and C2 + 0.542 and -0.095 . 10-10 m above and below the N1-Cu-N2 coordination plane, respectively.

Coordination chemistry of 7,9-disubstituted 6-oxopurine metal compounds. 4. Platinum(II) coordination at N(1). Molecular and crystal structure of [(ethylenediamine)bis(7,9-dimethylhypoxanthine)platinum(II)] hexafluorophosphate

The preparation and molecular and crystal structure of the complex [(ethylenediamine)bis(7,9,-dimethylhypoxanthine)platinum(II)] hexafluorophosphate, [Pt(C 2H 8N 2)(C 7H 8N 4O) 2] (PF 6) 2, are reported. The complex crystallizes in the monoclinic system, space group C2/c, with a = 12.334(2)Å, b = 10.256(2)Å, c = 22.339(3)Å, β = 101.31(1)°, V = 2771.0Å 3, Z = 4, D measd = 2.087(3) g cm −3, D calc = 2.094 g cm −3. Intensities for 3992 symmetry-averaged reflections were collected in the θ-2 o scan mode on an automated diffractometer employing graphite-monochromatized MoKα radiation. The structure was solved by standard heavy-atom Patterson and Fourier methods. Full matrix least-squares refinement led to a final R value of 0.051. Both the ethylenediamine chelate and the PF 6 − anion are disordered. The primary coordination sphere about the Pt(II) center is approximately square planar with the bidentate ethylenediamine ligand and the N(1) atoms [Pt(II) − N(1) = 2.020(5)Å] of two 7,9-dimethylhypoxanthine bases (related by a crystallographic twofold axis of symmetry) occupying the four coordination sites. The exocyclic O(6) carbonyl oxygen atoms of the two 7,9-dimethylhypoxanthine ligands participate in intracomplex hydrogen bonding with the amino groups of the ethylenediamine chelate [ N(ethylenediamine) ⋯ O(6) = 2.89( )Å]. The observed Pt ⋯ O(6) intramolecular distances of 3.074(6)Å are similar to those found in other Pt(II) N(1)-bound 6-oxopurine complexes and in several Pt(II) N(3)-bound cytosine systems.

Notizen: Gezielte Synthese von Sulfinato-O–und -S-Komplexen einiger Übergangsmetalle, XVIII1 Synthese eines Sulfinato-O-Komplexes und Ionisationsisomerie bei Palladium(II)2 / Directed Synthesis of Sulfinato-O and -S Complexes of Some Transition Metals, XVIII1. Synthesis of a Sulfinato-O Complex and Ionization Isomerism with Palladium(II)2

The sulfinato-O complex (p-CH3C6H4S(O)O)2Pd(en) (2a) and its ionization isomer, the ionic compound [Pd(en)2][p-CH3C6H4SO2]2 (2b), are obtained from 1 by ligand addition in dependence of the nature of the solvent. 2 a, b can be transformed into each other reversibly. For 2 a two structural models are discussed. The pseudooctahedral configuration with two bidentate ethylene diamine and two sulfinato-O ligands in trans position seems to be more likely.

The colour isomerism and structure of some copper co-ordination compounds. Part XIV. The crystal structure of chloroaquobis(ethylenediamine)copper(II) chloride

The crystal structure of the monohydrate of bis(ethylenediamine)copper(II) has been determined by three-dimensional X-ray methods. The complex ion is octahedral, the ligands being the two bidentate ethylenediamine molecules, the water molecule, and one of the chloride ions.