Tricaesium tris(oxalato‐κ2O1,O2)chromate(III) dihydrate

The title compound, Cs₃[Cr(C₂O₄)₃]·2H₂O, has been synthesized for the first time and the spatial arrangement of the cations and anions is compared with those of the other members of the alkali metal series. The structure is built up of alternating layers of either the d or l enantiomers of [Cr(oxalate)₃]³⁻. Of note is that the distribution of the [Cr(oxalate)₃]³⁻ enantiomers in the Li⁺, K⁺ and Rb⁺ tris(oxalato)chromates differs from those of the Na⁺ and Cs⁺ tris(oxalato)chromates, and also differs within the corresponding BEDT‐TTF [bis(ethylenedithio)tetrathiafulvalene] conducting salts. The use of tris(oxalato)chromate anions in the crystal engineering of BEDT‐TTF salts is discussed, wherein the salts can be paramagnetic superconductors, semiconductors or metallic proton conductors, depending on whether the counter‐cation is NH₄⁺, H₃O⁺, Li⁺, Na⁺, K⁺, Rb⁺ or Cs⁺. These materials can also be superconducting or semiconducting, depending on the spatial distribution of the d and l enantiomers of [Cr(oxalate)₃]³⁻.     

Selective complexation of alkali metal ions and nanotubular cyclopeptides: a DFT study

A density functional theory based on interaction of alkali metal cations (Li⁺, Na⁺, K⁺, Rb⁺ and Cs⁺) with cyclic peptides constructed from 3 or 4 alanine molecule (CyAla3 and CyAla4), has been investigated using mixed basis set (C, H, O, Li⁺, Na⁺ and K⁺ using 6-31+G(d), and the heavier cations: Rb⁺ and Cs⁺ using LANL2DZ). The minimum energy structures, binding energies, and various thermodynamic parameters of free ligands and their metal cations complexes have been determined with B3LYP and CAM-B3LYP functionals. The order of interaction energies were found to be Li⁺ > K⁺ > Na⁺ > Rb⁺ > Cs⁺ and Li⁺ > Na⁺ > K⁺ ? Rb⁺ > Cs⁺, calculated at CAM-B3LYP level for the M/CyAla3 and M/CyAla4 complexes, respectively. Their selectivity trend shows that the highest cation selectivity for Li⁺ over other alkali metal ions has been achieved on the basis of thermodynamic analysis. The main types of driving force host–guest interactions are investigated, the electron-donating O offers lone pair electrons to the contacting LP* of alkali metal cations.     

An Imine‐Based Molecular Cage with Distinct Binding Sites for Small and Large Alkali Metal Cations

The synthesis of a cylindrical, imine‐based cage composed of two trimeric metallamacrocycles is described. The cage acts as a heterotopic receptor for alkali metal cations. The small cations Li⁺, Na⁺, and K⁺ bind to the outside of the cage with good selectivity for Li⁺, whereas the larger cations Rb⁺ and Cs⁺ are bound inside the cage to form unusual π complexes with a good selectivity for Cs⁺. Negative heterotopic cooperativity between the two binding sites is observed. The complexation of Cs⁺ is associated with a color change, which enables the cage to be used as a specific sensor for Cs⁺.     

Tris(2,2′‐bipyridine)ruthenium Derivatives with Multiple Viologen Acceptors: Quadratic Dependence of Photocatalytic H2 Evolution Rate on the Local Concentration of the Acceptor Site

Three Ru(bpy)₃²⁺ derivatives tethered to multiple viologen acceptors, [Ru(bpy)₂(4,4′‐MV2)]⁶⁺, [Ru(bpy)₂(4,4′‐MV4)]¹⁰⁺, and [Ru(bpy)(4,4′‐MV4)₂]¹⁸⁺ [bpy=2,2′‐bipyridine, 4,4′‐MV2=4‐ethoxycarbonyl‐4′‐(N‐G₁‐carbamoyl)‐2,2′‐bipyridine, and 4,4′‐MV4=4,4′‐bis(N‐G₁‐carbamoyl)‐2,2′‐bipyridine, where G₁=Asp(NHG₂)‐NHG₂ and G₂=‐(CH₂)₂‐N⁺C₅H₄‐C₅H₄N⁺‐CH₃] were prepared as “photo‐charge separators (PCSs)”. Photoirradiation of these complexes in the presence of a sacrificial electron donor (EDTA) results in storage of electrons per PCS values of 1.3, 2.7, and 4.6, respectively. Their applications in the photochemical H₂ evolution from water in the presence of a colloidal Pt H₂‐evolving catalyst were investigated, and are discussed along with those reported for [Ru(bpy)₂(5,5′‐MV4)]¹⁰⁺, [Ru(4,4′‐MV4)₃]²⁶⁺, and [Ru(5,5′‐MV4)₃]²⁶⁺ (Inorg. Chem. Front. 2016 , 3, 671–680). The PCSs with high dimerization constants (K_d=10⁵–10⁶ m ^?1) are superior in driving H₂ evolution at pH 5.0, whereas those with lower K_d values (10³–10⁴ m ^?1) are superior at pH 7.0, where K_d=[(MV⁺)₂]/[MV^{+ .} ]². The (MV⁺)₂ site can drive H₂ evolution only at pH 5.0 as a result of its 0.15 eV lower driving force for H₂ evolution relative to MV^{+ .} , whereas the PCSs with lower K_d values exhibit higher performance at pH 7.0 owing to the higher population of free MV^{+ .} . Importantly, the rate of electron charging over the PCSs is linear to the apparent H₂ evolution rate, and shows an intriguing quadratic dependence on the number of MV²⁺ units per PCS.     

Nanoscale Metal–Organic Layers for Deeply Penetrating X‐ray‐Induced Photodynamic Therapy

We report the rational design of metal–organic layers (MOLs) that are built from [Hf₆O₄(OH)₄(HCO₂)₆] secondary building units (SBUs) and Ir[bpy(ppy)₂]⁺‐ or [Ru(bpy)₃]²⁺‐derived tricarboxylate ligands (Hf‐BPY‐Ir or Hf‐BPY‐Ru; bpy=2,2′‐bipyridine, ppy=2‐phenylpyridine) and their applications in X‐ray‐induced photodynamic therapy (X‐PDT) of colon cancer. Heavy Hf atoms in the SBUs efficiently absorb X‐rays and transfer energy to Ir[bpy(ppy)₂]⁺ or [Ru(bpy)₃]²⁺ moieties to induce PDT by generating reactive oxygen species (ROS). The ability of X‐rays to penetrate deeply into tissue and efficient ROS diffusion through ultrathin 2D MOLs (ca. 1.2 nm) enable highly effective X‐PDT to afford superb anticancer efficacy.     

Intermetallic Competition in the Fragmentation of Trimetallic Au–Zn–Alkali Complexes

Cationization is a valuable tool to enable mass spectrometric studies on neutral transition‐metal complexes (e.g., homogenous catalysts). However, knowledge of potential impacts on the molecular structure and catalytic reactivity induced by the cationization is indispensable to extract information about the neutral complex. In this study, we cationize a bimetallic complex [AuZnCl₃] with alkali metal ions (M⁺) and investigate the charged adducts [AuZnCl₃M]⁺ by electrospray ionization mass spectrometry (ESI‐MS). Infrared multiple photon dissociation (IR‐MPD) in combination with density functional theory (DFT) calculations reveal a μ³ binding motif of all alkali ions to the three chlorido ligands. The cationization induces a reorientation of the organic backbone. Collision‐induced dissociation (CID) studies reveal switches of fragmentation channels by the alkali ion and by the CID amplitude. The Li⁺ and Na⁺ adducts prefer the sole loss of ZnCl₂, whereas the K⁺, Rb⁺, and Cs⁺ adducts preferably split off MCl₂ZnCl. Calculated energetics along the fragmentation coordinate profiles allow us to interpret the experimental findings to a level of subtle details. The Zn²⁺ cation wins the competition for the nitrogen coordination sites against K⁺, Rb⁺, and Cs⁺ , but it loses against Li⁺ and Na⁺ in a remarkable deviation from a naive hard and soft acids and bases (HSAB) concept. The computations indicate expulsion of MCl₂ZnCl rather than of MCl and ZnCl₂.     

Spectrophotometric studies of alkali and alkali earth metal ions complexes of mono amino derivative of calix[4]arene

The synthesis and complexive abilities of 5,11,17-tris(tert-butyl)-23 amino-25,26,27,28-tetra-propoxycalix[4]arene towards alkali cations Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺ and alkali earth cations Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺ in methanol-chloroform mixture have been evaluated at 25°C, using UV-Vis spectrophotometric techniques. The results showed that the ligand is capable to complex with all the cations by 1: 1 metal to ligand ratios. The selectivity presented considering the calculated formation constants are in the order Li⁺ > Na⁺ > K⁺ > Rb⁺ > Cs⁺ and Mg²⁺ > Ca²⁺ > Sr²⁺ > Ba²⁺ with the ligand.     

Cation transport at 25°c from binary Na+Mn+, Cs+Mn+ and Sr2+Mn+ nitrate mixtures in a H2OCHCl3H2O liquid membrane system containing a series of macrocyclic carriers

Cation fluxes from binary mixtures of either Na⁺, Cs⁺ or Sr²⁺ with other alkali metal cations, alkaline earth metal cations, and Pb²⁺ through a H₂OCHCl³H₂O bulk liquid membrane system containing one of several macrocyclic carriers have been determined Nitrate salts were used in all cases. The most selective transport of Na⁺ over all other cations studied was found with the carrier cryptand [2.2.1]. Selective transport of Na⁺ relative to Li⁺, Cs⁺ and the alkaline earth cations was found with cryptand [2.2.2B] and cryptand [2.2.2D]. The ligands 21-crown-7 and dibenzo-24-crown-8 showed selective transport of Cs⁺ over the second cation in all cases. Several macrocycles showed selectivity for Sr²⁺ over the second cation with the macrocycle 1,10-diaza-18-crown-6 showing the highest selectivity for this cation of all ligands studied. Relative fluxes from binary cation mixtures are rationalized in terms of macrocycle cavity size, donor atom type and ring substituents.     

一种基于硫杂杯[4]芳烃的高效银离子载体

合成了基于下缘含有酰肼基团的硫杂杯芳烃衍生物的银离子载体1,其核磁研究证实硫杂杯芳烃以1,3-交替构象存在,并且通过非竞争萃取实验和竞争萃取实验研究了它对碱金属和过渡金属离子（Li⁺, Na⁺, K⁺, Cs⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ and Ag⁺）的键合能力和选择性。实验结果表明：将酰肼基团引入1,3-交替构象的硫杂杯芳烃骨架的下缘可以提高其对Ag⁺的键合能力和选择性,同时,对Cu²⁺的萃取能力较弱,对碱金属离子和其它的重金属离子几乎没有萃取能力。进一步的核磁滴定和电喷雾质谱实验显示化合物1与银离子形成配合物的配合计量比为1：1,由此推断主要由“N-Ag⁺”配位键以及硫杂杯芳烃骨架的协同作用构成了化合物1与银离子的配合模式。     

Synthesis and adsorption investigations of zeolites MCM-22 and MCM-49 modified by alkali metal cations

Ion exchange was made on MCM-22 and MCM-49 zeolites with different Si/Al molar ratios, with Li⁺, Na⁺, K⁺, and Cs⁺ ions and the study of the influence of alkali metal cations on CO₂ adsorption properties was performed. The degree of ion-exchange decreased for larger cations (Cs⁺) apparently due to steric hindrances. The exchange with different cations led to a decrease in the surface area and the micropore volume. Our study shows that the adsorption capacity of the tested zeolites depends significantly on the nature and the concentration of the charge-compensating cations. The highest CO₂ adsorption capacity was obtained on the MWW zeolites with the lowest Si/Al molar ratio and the Li⁺ or K⁺ cations.     

Factors Influence Complexing Selectivity of Lariat Crown Ethers Toward Alkali Metal Ions in Electrospray Ionization Mass Spectrometry

The selectivity of eight lariat crown ethers in the sym‐dibenzo‐16‐crown‐5 series toward alkali metal ions was studied with electrospray ionization mass spectrometry under different conditions. With the exception of 2g , which is equally selective toward Na⁺ and Li⁺, all other lariat crown ethers show the best selectivity toward Li⁺ in methanol. Factors that influence the selectivity include the water content, counterions, nature of the side arms, and the externally added cations. Iodide gives the best Na⁺ selectivity with R_I > R_Br > R_Cl. Increased water content profoundly increases the Na⁺ selectivity when the side arm is hydrophilic and the steric hindrance is small. Externally added cations (Cs⁺ and/or Rb⁺) enhance the Na⁺ selectivity by exchanging the smaller Li⁺ from the cavity.     

Synthesis of a Calix[4]crown‐6 Cone Conformer‐Based Oligomer and its Metal Cation Extraction Abilities

A new calixcrown‐6 oligomer 5 was synthesized by reacting a 1,3‐distal di‐amino derivative of cone p‐tert‐butylcalix[4]crown‐6 with malonyl dichloride. Extraction studies with precursor monomers 2 and 3 and oligomer 5 showed differences in their metal cation extraction behavior and selectivity. Precursors monomers 2 and 3 were selective for Hg²⁺; whereas, oligomer 5 showed high affinity towards both alkali (Li⁺, Na⁺, K⁺, and Cs⁺) and heavy metal cations (Cu²⁺, Cd²⁺, Hg²⁺ and Pb²⁺).     

Two‐Photon Chemistry in Ruthenium 2,2′‐Bipyridyl‐Functionalized Single‐Wall Carbon Nanotubes

Ruthenium polypyridyl complexes are widely used as light harvesters in dye‐sensitized solar cells. Since one of the potential applications of single‐wall carbon nanotubes (SWCNTs) and their derived materials is their use as active components in organic and hybrid solar cells, the study of the photochemistry of SWCNTs with tethered ruthenium polypyridyl complexes is important. A water‐soluble ruthenium tris(bipyridyl) complex linked through peptidic bonds to SWCNTs (Ru‐SWCNTs) was prepared by radical addition of thiol‐terminated SWCNT to a terminal C?C double bond of a bipyridyl ligand of the ruthenium tris(bipyridyl) complex. The resulting macromolecular Ru‐SWCNT (≈500 nm, 15.6 % ruthenium complex content) was water‐soluble and was characterized by using TEM, thermogravimetric analysis, chemical analysis, and optical spectroscopy. The emission of Ru‐SWCNT is 1.6 times weaker than that of a mixture of [Ru(bpy)₃]²⁺ and SWCNT of similar concentration. Time‐resolved absorption optical spectroscopy allows the detection of the [Ru(bpy)₃]²⁺‐excited triplet and [Ru(bpy)₃]⁺. The laser flash studies reveal that Ru‐SWCNT exhibits an unprecedented two‐photon process that is enabled by the semiconducting properties of the SWCNT. Thus, the effect of the excitation wavelength and laser power on the transient spectra indicate that upon excitation of two [Ru(bpy)₃]²⁺ complexes of Ru‐SWCNT, a disproportionation process occurs leading to delayed formation of [Ru(bpy)₃]⁺ and the performance of the SWCNT as a semiconductor. This two‐photon delayed [Ru(bpy)₃]⁺ generation is not observed in the photolysis of [Ru(bpy)₃]³⁺; SWCNT acts as an electron wire or electron relay in the disproportionation of two [Ru(bpy)₃]²⁺ triplets in a process that illustrates that the SWCNT plays a key role in the process. We propose a mechanism for this two‐photon disproportionation compatible with i) the need for high laser flux, ii) the long lifetime of the [Ru(bpy)₃]²⁺ triplets, iii) the semiconducting properties of the SWNT, and iv) the energy of the HOMO/LUMO levels involved.     

Affinity capillary electrophoresis and density functional theory study of noncovalent interactions of cyclic peptide [Gly6]‐antamanide with small cations

ACE and density functional theory were employed to study the noncovalent interactions of cyclic decapeptide glycine‐6‐antamanide ([Gly⁶]AA), synthetic derivative of native antamanide (AA) peptide from the deadly poisonous fungus Amanita phalloides , with small cations (Li⁺, Rb⁺, Cs⁺, NH₄⁺, and Ca²⁺) in methanol. The strength of these interactions was quantified by the apparent stability constants of the appropriate complexes determined by ACE. The stability constants were calculated using the nonlinear regression analysis of the dependence of the effective electrophoretic mobility of [Gly⁶]AA on the concentration of the above ions in the BGE (methanolic solution of 20 mM chloroacetic acid, 10 mM Tris, pH_MeOH 7.8, containing 0–70 mM concentrations of the above ions added in the form of chlorides). Prior to stability constant calculation, the effective mobilities measured at actual temperature inside the capillary and at variable ionic strength of the BGEs were corrected to the values corresponding to the reference temperature of 25°C and to the constant ionic strength of 10 mM. From the above ions, Rb⁺ and Cs⁺ cations interacted weakly with [Gly⁶]AA but no interactions of [Gly⁶]AA with univalent Li⁺ and NH₄⁺ ions and divalent Ca²⁺ ion were observed. The apparent stability constants of [Gly⁶]AA‐Rb⁺ and [Gly⁶]AA‐Cs⁺ complexes were found to be equal to 13 ± 4 and 22 ± 3 L/mol, respectively. The structural characteristics of these complexes, such as position of the Rb⁺ and Cs⁺ ions in the cavity of the [Gly⁶]AA molecule and the interatomic distances within these complexes, were obtained by the density functional theory calculations.     

Polymerization of acrylamide photoinitiated by tris(2,2′‐bipyridine)ruthenium(II)–amine in aqueous solution: Effect of the amine structure

The photopolymerization of acrylamide (AA) initiated by the metallic complex tris(2,2′‐bipyridine)ruthenium(II) [Ru(bpy)₃⁺²] in the presence of aliphatic and aromatic amines as co‐initiators was investigated in aqueous solution. Aromatic amines, which are good quenchers of the emission of the metal‐to‐ligand‐charge‐transfer excited state of the complex, are more effective co‐initiators than those that do not quench the luminescence of Ru(bpy)₃⁺², such as aliphatic amines and aniline. Laser‐flash photolysis experiments show the presence of the reduced form of the complex, Ru(bpy)₃⁺¹, for all the amines investigated. For aliphatic amines, the yield of Ru(bpy)₃⁺¹ increases with temperature, and on the basis of these experiments, a metal‐centered excited state is proposed as the reactive intermediate in the reaction with these amines. The decay of the transient Ru(bpy)₃⁺¹ is faster in the presence of AA. This may be understood by an electron‐transfer process from Ru(bpy)₃⁺¹ to AA, regenerating Ru(bpy)₃⁺² and producing the radical anion of AA. It is proposed that this radical anion protonates in a fast process to give the neutral AA radical, initiating in this way the polymerization chain. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4265–4273, 2001     

Tetrahedral [Tt4]4– Zintl Anions Through Solution Chemistry: Syntheses and Crystal Structures of the Ammoniates Rb4Sn4·2NH3, Cs4Sn4·2NH3, and Rb4Pb4·2NH3

The crystalline isotypic solvates Rb₄Sn₄·2NH₃, Cs₄Sn₄·2NH₃, and Rb₄Pb₄·2NH₃ have been synthesized using the direct reduction of elemental tin or tetraphenyltin, respectively, with heavier alkali metals or the dissolution of the binary phase RbPb in liquid ammonia. These compounds contain the cluster ions [Sn₄]^4– or [Pb₄]^4– respectively. This is the first time that[Tt₄]^4– ions (Tt = tetrels) are detected as result of a solution reaction. The accommodation of the ammonia molecules, which build up ion‐dipole interactions to alkali metal cations, requires some modifications of the crystal structures compared to the binary phases RbSn, CsSn, and RbPb. The tetrahedral [Tt₄]^4– anions have a slightly lower coordination by Rb⁺ or Cs⁺ cations and, furthermore, the intercluster distances show a remarkable increase.     

Host-guest complexes of the Beer-Can-cryptand: prediction of ion selectivity by quantum chemical calculations XI

Abstract

Based on DFT calculations (B3LYP/LANL2DZp) and the application of model equations, as well as a comparison of M-N-donor length with an unstrained reference ([M(solvent)₆]ⁿ⁺), the selectivity of the alkali and alkaline earth cations (Li⁺ – Cs⁺ and Be²⁺ – Ba²⁺) for the recently synthesized cryptand bis-triazacyclononane tris-pyridyl N₉-azacryptand (Beer-Can) was investigated. The host can bind the alkali cation K⁺ best, followed by the alkaline earth cations Ca²⁺ and Sr²⁺, and by Na⁺ and Ba²⁺. This selectivity pattern is identical to the selectivity of the Lehn-type cryptand [phen.phen.phen], which suggests a similar cavity size. The good flexibility of the Beer-Can is provided by the aza-crown-like top and bottom of the “can,” and the pyridines on the “can-wall.”     

A Dinuclear Ruthenium(II) Complex as a One‐ and Two‐Photon Luminescent Probe for Biological Cu2+ Detection

A new dinuclear Ru^II polypyridyl complex, [(bpy)₂Ru(H₂bpip)Ru(bpy)₂]⁴⁺ ( RuH₂bpip , bpy=2,2‐bipyridine, H₂bpip=2,6‐pyridyl(imidazo[4,5‐f][1,10]phenanthroline), was developed to act as a one‐ and two‐photon luminescent probe for biological Cu²⁺ detection. This Ru^II complex shows a significant two‐photon absorption cross section (400 GM) and displays a remarkable one‐ and two‐photon luminescence switch in the presence of Cu²⁺ ions. Importantly, RuH₂bpip can selectively recognise Cu²⁺ in aqueous media in the presence of other abundant cellular cations (such as Na⁺, K⁺, Mg²⁺, and Ca²⁺), trace metal ions in organisms (such as Zn²⁺, Ag⁺, Fe³⁺, Fe²⁺, Ni²⁺, Mn²⁺, and Co²⁺), prevalent toxic metal ions in the environment (such as Cd²⁺, Hg²⁺, and Cr³⁺), and amino acids, with high sensitivity (detection limit≤3.33×10^?8 M ) and a rapid response time (≤15 s). The biological applications of RuH₂bpip were also evaluated and it was found to exhibit low cytotoxicity, good water solubility, and membrane permeability; RuH₂bpip was, therefore, employed as a sensing probe for the detection of Cu²⁺ in living cells and zebrafish.     

Drei Alkalimetall‐Erbium‐Thiophosphate: Von der Schichtstruktur bei KEr[P2S7] zur dreidimensionalen Vernetzung in NaEr[P2S6] und Cs3Er5[PS4]6

Three Alkali‐Metal Erbium Thiophosphates: From the Layered Structure of KEr[P₂S₇] to the Three‐Dimensional Cross‐Linkage in NaEr[P₂S₆] and Cs₃Er₅[PS₄]₆ The three alkali‐metal erbium thiophosphates NaEr[P₂S₆], KEr[P₂S₇], and Cs₃Er₅[PS₄] show a small selection of the broad variety of thiophosphate units: from ortho‐thiophosphate [PS₄]^3? and pyro‐thiophosphate [S₃P–S–PS₃]^4? with phosphorus in the oxidation state +V to the [S₃P–PS₃]^3? anion with a phosphorus‐phosphorus bond (d(P–P) = 221 pm) and tetravalent phosphorus. In spite of all differences, a whole string of structural communities can be shown, in particular for coordination and three‐dimensional linkage as well as for the phosphorus‐sulfur distances (d(P–S) = 200 – 213 pm). So all three compounds exhibit eightfold coordinated Er³⁺ cations and comparably high‐coordinated alkali‐metal cations (CN(Na⁺) = 8, CN(K⁺) = 9+1, and CN(Cs⁺) ≈ 10). NaEr[P₂S₆] crystallizes triclinically ( ; a = 685.72(5), b = 707.86(5), c = 910.98(7) pm, α = 87.423(4), β = 87.635(4), γ = 88.157(4)°; Z = 2) in the shape of rods, as well as monoclinic KEr[P₂S₇] (P2₁/c; a = 950.48(7), b = 1223.06(9), c = 894.21(6) pm, β = 90.132(4)°; Z = 4). The crystal structure of Cs₃Er₅[PS₄] can also be described monoclinically (C2/c; a = 1597.74(11), b = 1295.03(9), c = 2065.26(15) pm, β = 103.278(4)°; Z = 4), but it emerges as irregular bricks. All crystals show the common pale pink colour typical for transparent erbium(III) compounds.     

Synthesis, characterization and liquid–liquid extraction properties of new methoxyaminobiphenylglyoxime derivatives and their complexes with some transition metals

In this study, three new aminobiphenylglyoximes, [L¹H₂] N-(2-methoxy)aminobiphenylglyoxime, [L²H₂] N-(3-methoxy)aminobiphenylglyoxime and L[³H₂] N-(4-methoxy)aminobiphenylglyoxime have been synthesized by the reaction of (E,E)-4′-biphenylchloroglyoxime with 2-Methoxyaniline, 3-Methoxyaniline and 4-Methoxyaniline in absolute ethanol. The preparation Ni^II, Co^II and Cu^II complexes of these ligands are described. The ligands and their complexes were characterized by elemental analyses, IR, mass, H¹ and ¹³C NMR spectra, thermogravimetric analyses (t.g.a) and magnetic susceptibility measurements. Ligands complexing properties were studied by the liquid–liquid extraction of selected alkali (Li⁺, Na⁺, K⁺, Cs⁺) and transition metals (Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺). It has been observed that all ligands show a high affinity to Cu²⁺ ions, whereas almost no affinity to alkali metals. The extraction equilibrium constants (K _ex) for complexes of ligands with Cu²⁺ metal picrates between dichloromethane and water have been determined at 25°C.