Complexes of palladium(II) with cis- and trans-1,2-bis(dimethylarsino)ethylene

1969 ◽  
Vol 47 (14) ◽  
pp. 2699-2706 ◽  
Author(s):  
G. J. Erskine
Keyword(s):  
Metal Ion ◽  
Room Temperature ◽  
Analytical Data ◽  
Far Infrared ◽  
Bridging Ligand ◽  
Dimeric Complexes ◽  
Square Planar ◽  
Temperature Irradiation ◽  
Cis And Trans ◽  
Cis Isomer

Palladium(II) complexes of cis- and trans-1,2-bis(dimethylarsino)ethylene, 1 and 2, respectively, in the metal: ligand ratios 1:1 and 1:2 are described. Their structures are discussed in terms of nuclear magnetic resonance, infrared, conductivity, and analytical data, and by comparison with the corresponding platinum(II) complexes (1). The cis-isomer, cis-ED, is a strong chelating ligand and forms the complexes Pd(cis-ED)X2, 9 (X = Cl−, Br−), and Pd(cis-ED)2X2•3H2O, 8 (X = Cl−, Br−, ClO4−, PF6−). The trans-isomer, trans-ED is a bridging ligand and forms the dimeric complexes, [Pd(trans-ED)X2]2, 10 (X = Cl−, Br−), and Pd2(trans-ED)4X4•3H2O, 7 (X = Cl−, Br−, ClO4−, PF6−). All these complexes contain 4-coordinate, square planar palladium(II). The anhydrous form of 7 (X = Cl−) shows evidence for a Pd—Cl bond, suggesting 5-coordination in the solid state. Room temperature irradiation (with ultraviolet light) of 7 (X = Cl−), in non-aqueous solvents, causes isomerization of the ligand and the formation of complex 8 (X = Cl−). No change occurs under these conditions in aqueous solutions. Contrary to the original suggestion for the corresponding platinum(II) derivative, 10 (M = Pt(II), ref. 1) far infrared evidence supports a cis-configuration about the metal ion rather than the trans-configuration, 6.

Metal Ion Complexes of Aromatic Amino Acids

1966 ◽  
Vol 21 (6) ◽  
pp. 522-526 ◽  
Author(s):  
J. Smith Decker ◽  
Herschel Frye
Keyword(s):  
Metal Ion ◽  
Analytical Data ◽  
Aromatic Amino Acids ◽  
Chlorobenzoic Acid ◽  
Solubility In Water ◽  
Nonpolar Solvents ◽  
Aminobenzoic Acids ◽  
Square Planar ◽  
Coordinated Water ◽  
Infrared Data

This study has shown that certain ring substitutions on aminobenzoic acids are possible without greatly affecting the favorable chelating properties of the parent ligand. It was also shown that para substitution of methyl groups yields more stable complexes than does ortho substitution relative to the amino group. Meta substitution of chlorine enhances chelate formation and yields very insoluble complexes in yields approaching one hundred per cent.Based on carbon-hydrogen analyses and other analytical data, the structures have been determined as square planar ones in which the ligand functions as a bidentate. Some water is usually incorporated in the crystal lattice, and occasionally a complex will contain one or more molecules of coordinated water. The variable amount of water in some compound crystals makes the carbonhydrogen data less exact and tends to obscure interpretation of at least some of the infrared data. Lack of solubility in water and in other polar and nonpolar solvents increases the difficulty of both infrared and ultraviolet-visible analyses; in every case potassium bromide tablets were made and were used in both infrared and ultraviolet-visible spectrophotometers; evidence obtained through study of the ultraviolet-visible data are not presented here, but there substantiate the data obtained by the other methods.With the ligands and metal cations used, fifty-five compounds were possible; forty-four of these were actually prepared and isolated, and of these, thirty-five were shown to be coordination complexes. Twenty-seven of these complexes were previously unreported including all the compounds reported for 3,5-dimethylanthranilic acid, 2-amino-4-chlorobenzoic acid, and 6-amino-3-methylbenzoic acid.

Synthese von Silicium-Phosphor-Ringen - Struktur eines cis-2.2.4.4-Tetrakis(silylamino)-1.3-diphospha-2.4-disilacyclobutans / Synthesis of Silicon-Phosphorus-Rings - Structure of a cis-2,2,4,4-Tetrakis(silylamino)-1,3-diphospha-2,4-disilacyclobutane

1983 ◽  
Vol 38 (12) ◽  
pp. 1557-1562 ◽  
Author(s):  
Uwe Klingebiel ◽  
Norbert Vater ◽  
William Clegg ◽  
Martin Haase ◽  
George M. Sheldrick
Keyword(s):  
Crystal Structure ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Molar Ratio ◽  
Trans Isomers ◽  
Cis And Trans Isomers ◽  
Cis And Trans ◽  
By Products ◽  
Cis Isomer

Fluorosilylphosphanes of the type R2SiFPHR′ (R = CHMe2, CMe3, NMeSiMe3; R′ = H, C6H5; 1-4) are obtained in the reaction of difluorosilanes with lithiated phosphanes in a molar ratio 1:1. Diphosphasilanes (5, 6) and a difluorosilylphosphane (7) are isolated as by-products. 1-4 react with n-C4H9Li to give cyclic silylphosphanes, LiF, and C4H10 (8-11). Dilithiated 5 reacts with F2PN(CMe3)SiMe3 to form of a four-membered SiP3-ring 12. The 31P NMR spectra of 9 and 11 show signal coalescence for the cis-and trans-isomers at room temperature. The crystal structure of the cis-isomer of 11 has been determined. The substituted ring 13 is prepared in the reaction of lithiated 9 and Me2SiF2

Complexes of Di-2-pyridyl ketone. II. Some chelated nickel(II) products of metal-promoted reactions at the ketones

1970 ◽  
Vol 23 (10) ◽  
pp. 1997 ◽  
Author(s):  
MC Feller ◽  
R Robson
Keyword(s):  
Aqueous Solution ◽  
Spectral Data ◽  
Metal Ion ◽  
Room Temperature ◽  
Cyanide Ion ◽  
Nickel Ion ◽  
Square Planar ◽  
Ligand Fields ◽  
Solid Complexes

From reactions in aqueous solution between nickel(11) nitrate, di-2-pyridyl ketone (DPK), and the reagents MeNH2, NH3, pyrazole ( C3H4N2) , HS03-,PhNHNH2, and 82-, solid complexes with the following stoicheiometries were isolated: Ni(DPK)z(MeNH2)2(N03)z(H2O)x (x: = 1, 0), Ni(DPK)z(NH~)(H2O)(NO3)3, K~(DPK)z(C3H4NZ)2(NO3)Z(H2O)y(y = 3, O), Ni(DPK)Z(HSO4)Z(HZO), Ni(DPK)2- (PhNHNH2)2(N03)2, and Ni(DPK)2(H2O)2S. Magnetic and spectral data indicate pseudo-octahedral ligand fields in all cases. Except in the cases Ni(DPK)2(H20)2S and Ni(DPK)2(PhNHNH2)2(NO3)2, for which the evidence is ambiguous, elementary compositions and i.r. spectra indicate that the added nucleophile, HX, has condensed with at least one of the two DPK units per nickel ion, yielding tridentate products, (C5H4N)2(OH)X. I n the complexes of stoicheiometry Ni(DPK)2(C3H4N2)2(N03)2 and N~(DPK)z(M~NH~)z(NO~)Z both DPK units per nickel ion have condensed with the nucleophile yielding products bound to the cation as tridentate N3 ligands. U.V. spectral observations in aqueous solution indicate that with the reagents MeNH2, NH3, C ~ H ~ N Z , and HS03- attack upon DPK occurs slowly, if a t all, in the absence of nickel(11) a t room temperature, but in the presence of nickel(11) much more rapid condensation occurs. These reactions constitute new types of metal-ion promoted condensation. With cyanide ion as the nucleophile, attack occurs not a t the ketone but a t nickel yielding [Si(DPK)2]2+[Ni(CN)4]z- in w-hich the cation is octahedral, the anion square-planar, and some cyanide units are bridging.

scholarly journals Copper (II) Acylhydrazinates. Their Synthesis and Characterization

2001 ◽  
Vol 8 (3) ◽  
pp. 171-177 ◽  
Author(s):  
Zahid H. Chohan ◽  
M. A. Farooq ◽  
Claudiu T. Supuran
Keyword(s):  
Escherichia Coli ◽  
Schiff Bases ◽  
Metal Ion ◽  
Bacterial Species ◽  
Analytical Data ◽  
Synthesis And Characterization ◽  
Tetradentate Ligand ◽  
Base Function ◽  
Enolic Form ◽  
Square Planar

Acylhydrazine derived furanyl and thienyl Schiff bases and their Cu(II) complexes have been prepared and characterized on the basis of their physical, spectral and analytical data. The preferred enolic form of the Schiff base function as a tetradentate ligand during coordination to the metal ion yielding a square planar complex. The Schiff bases and their complexes with different anions were tested for their antibacterial activity against bacterial species such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa andKlebsiella pneumonae.

scholarly journals The First Metal Complexes of 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione: Preparation, Physical and Spectroscopic Studies, and Preliminary Antimicrobial Properties

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Sahar I. Mostafa ◽  
Constantina Papatriantafyllopoulou ◽  
Spyros P. Perlepes ◽  
Nick Hadjiliadis
Keyword(s):  
Metal Ion ◽  
Room Temperature ◽  
Free Ligand ◽  
Antimicrobial Properties ◽  
Spectroscopic Studies ◽  
Ligand Field ◽  
Square Planar ◽  
Elemental Analyses ◽  
Bidentate Chelate

The new complexes[M2O5L2(H2O)2]⋅H2O (M=Mo,1;M=W,2),[RuL2(H2O)2]⋅H2O (3),[ML3]⋅xH2O (M=Rh,x=2,4;M=Ir,x=1,5),[RhL2(PPh3)2](ClO4)⋅2H2O (6),[PdL2]⋅2H2O (7),[PdL(phen)]Cl⋅H2O (8),[Re⁡OL2(PPh3)]Cl (9)and[UO2L2] (10)are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligandL−is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino group as donor atoms. Oxobridged dinuclear(1, 2)and various mononuclear(3–10)structures are assigned for the complexes in the solid state. The metal ion coordination geometries are octahedral(1–6, 9, 10)or square planar(7, 8). The free ligand LH and complexes1,4,7, and8were assayed in vitro for antimicrobial activity against two bacterial and two fungal cultures.

Isotopic Studies of the Metal–Ligand Bond. Part III. The Far Infrared Spectra of Some Tetragonal Diamine Complexes of Cobalt(II) and Nickel(II): Studies of the Metal–Nitrogen Bond, as a Function of Metal Ion and of Spin State

1973 ◽  
Vol 51 (10) ◽  
pp. 1567-1581 ◽  
Author(s):  
A. B. P. Lever ◽  
Elvio Mantovani
Keyword(s):  
Infrared Spectra ◽  
Metal Ion ◽  
Far Infrared ◽  
Geometric Factors ◽  
Square Planar ◽  
Isotopic Studies ◽  
First Time ◽  
Far Infrared Spectra ◽  
Metal Ligand ◽  
Nitrogen Bond

The far infrared spectra of 35 complexes of the formula M(diamine)2X2 are reported where M = Co(II) and Ni(II), X = Cl−, Br−, I−, NO3−, SCN−, ClO4−, and AgI2− and the diamine is ethylenediamine or its N,N-symmetric or antisymmetrically substituted dimethyl or diethyl derivative. Isotopic substitution studies with 62Ni and with 2H are carried out with eleven characteristic complexes and assignments for the metal–nitrogen modes in both octahedral and square planar complexes so deduced. In most cases the appropriate number of metal–ligand modes, based on symmetry considerations, are observed. The variations in observed M—N frequencies are discussed in terms of the electronic and geometric factors previously utilized for the corresponding copper(II) complexes. In complexes containing the asymmetric ligands, stretching vibrations arising from the two types of metal–nitrogen bond can be separately identified. Isotopic studies of pairs of complexes containing the same ligand and metal ion but with the latter in alternate spin states are reported here for the first time. All of the cobalt(II) complexes and several of the nickel(II) complexes are reported here for the first time.

Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

1985 ◽  
Vol 50 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Jana Podlahová ◽  
Josef Šilha ◽  
Jaroslav Podlaha
Keyword(s):  
Metal Ion ◽  
Carboxyl Groups ◽  
Complex Solution ◽  
Square Planar ◽  
Weak Complexes ◽  
Carboxylic Groups ◽  
Uv Visible ◽  
The Stability ◽  
Tetrahedral Complexes ◽  
Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

scholarly journals High-Pressure Spectroscopy Study of Zn(IO3)2 Using Far-Infrared Synchrotron Radiation

Crystals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Akun Liang ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Ibraheem Yousef ◽  
Catalin Popescu ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Transitions ◽  
Synchrotron Radiation ◽  
Infrared Radiation ◽  
Room Temperature ◽  
Far Infrared ◽  
Low Pressure ◽  
Pressure Response ◽  
Spectroscopy Study ◽  
Far Infrared Radiation

We report the first high-pressure spectroscopy study on Zn(IO3)2 using synchrotron far-infrared radiation. Spectroscopy was conducted up to pressures of 17 GPa at room temperature. Twenty-five phonons were identified below 600 cm−1 for the initial monoclinic low-pressure polymorph of Zn(IO3)2. The pressure response of the modes with wavenumbers above 150 cm−1 has been characterized, with modes exhibiting non-linear responses and frequency discontinuities that have been proposed to be related to the existence of phase transitions. Analysis of the high-pressure spectra acquired on compression indicates that Zn(IO3)2 undergoes subtle phase transitions around 3 and 8 GPa, followed by a more drastic transition around 13 GPa.

Complexes of hybrid ligands. The synthesis of a thioanisole-substituted fluoro-alcohol and its complexes with Pd2+ and Pt2+; the structure of a palladium(II) complex containing alkoxide, phosphine, thioether, and chloride donors

1987 ◽  
Vol 65 (4) ◽  
pp. 798-803 ◽  
Author(s):  
René T. Boeré ◽  
David E. Esser ◽  
Christopher J. Willis ◽  
Douglas W. Stephan ◽  
Taras W. Obal
Keyword(s):  
Least Squares ◽  
Dihedral Angle ◽  
Chelate Ring ◽  
Monoclinic Space Group ◽  
Structural Determination ◽  
Bond Lengths ◽  
Square Planar ◽  
Planar Molecules ◽  
Hybrid Ligands ◽  
Cis And Trans

The compound 2-thioanisole-1,1,1,3,3,3-hexafluoro-2-propanol, CH3S—C6H4—C(CF3)2OH, HL2, has been prepared, and shown to act (in the ionized form) as a hybrid, chelating, ligand. Neutral bis-complexes M(L2)2 are formed with Pd2+ and Pt2+; the former reacts with PdCl42− to give the Cl-bridged dinuclear complex (L2)Pd(μ-Cl)2Pd(L2), which may in turn be cleaved by PPh3 or PPh2Me to give PdCl(L2)(PR3).A complete structural determination has been made for PdCl(L2)(PPh2Me); C23H20ClF6OPPdS. Crystals are monoclinic, space group P21/n, a = 15.526(5), b = 12.966(9), c = 12.900(8) Å, β = 101.84°, V = 2542(2) Å3, Z = 4. Least-squares refinement on F of 198 variables using 2801 observations converged at R1 = 0.0434, R2 = 0.0559. The complex consists of discrete square-planar molecules with phosphine and alkoxide trans-disposed. Bond lengths are Pd—O, 2.053(3); Pd—P, 2.242(1); Pd—Cl, 2.323(2); Pd—S, 2.252(2) Å. In the six-membered chelate ring, all atoms with the exception of Pd are close to coplanarity; there is a dihedral angle of 127.9° between the O—Pd—S plane and that of the aromatic ring.Multinuclear nmr measurements are used to show that both cis- and trans-forms of complexes PdCl(L2)(PR3) are present in solution, with inversion at coordinated sulfur occurring much more rapidly in the latter.

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