Synthesis and Single-crystal Structures of Two Copper(II) Complexes and One Iron(II) Complex Prepared by in situ Ligand Substitution at Room Temperature

Two hexa-coordinate copper(II) complexes formulated as [Cu(phen)(4-dmampy)₂(ClO₄)₂] and [Cu(bpy)(3-ampy)₂(ClO₄)₂] · 0.5CH₃OH · 0.5H₂O (phen = 1,10–phenanthroline bpy = 2,2′-bipyridine, 3-ampy = 3-aminopyridine, 4-dmampy = 4-dimethylaminopyridine), and one low-spin ferrous complex formulated as [Fe(dmbpy)₃](ClO₄)₂ · H₂O (dmbpy = 4,4′-dimethyl-2,2′-bipyridine), were synthesized by in situ ligand substitution at room temperature, and characterized by X-ray single-crystal diffraction. This is the first structural report where either 4-dmampy and phen molecules, or 3-ampy and bpy molecules, are located simultaneously around one metal center.     

Supramolecular frameworks composed of copper(II), zinc(II), and ferrous(II) complexes having 3-bromo or 3,8-dibromo-1,10-phenanthroline ligand with different molar ratios of metal and ligand

Abstract  

Three copper(II), one zinc(II), and one ferrous(II) complexes having 3-bromo or 3,8-dibromo-1,10-phenanthroline ligand with different metal/ligand molar ratios, formulated as [Cu(3-bromo-phen)(ClO₄)(C₃H₇NO)₂(H₂O)](ClO₄) (1), [Cu(3,8-dibromo-phen)(ClO₄)(C₃H₇NO)₂(H₂O)](ClO₄) (2), [Cu(3,8-dibromo-phen)(ClO₄)(H₂O)₃](ClO₄)(H₂O)₃ (3), [Zn(3,8-dibromo-phen)₂(H₂O)₂](ClO₄)₂(H₂O)₂ (4), and [Fe(3,8-dibromo-phen)₃](ClO₄)₂(H₂O)(CH₄O)(C₃H₆O)₂ (5) (phen = 1,10-phenanthroline), have been synthesized and characterized in this paper. X-ray single-crystal diffraction studies reveal the different crystallographic symmetry and packing fashions between neighboring phen rings in 1:1 Cu(II) complexes 1–3 due to the alteration of bromo substituent 1,10-phenanthroline ligands and coordinated or free solvent molecules. Additionally, in 1:2 Zn(II) and 1:3 Fe(II) complexes 4 and 5, continuous π–π stacking and alternating π–π and dimeric p–π stacking are found.     

A Polymeric Arched Chain and a Chair‐like M2L2‐Metallamacrocycle Crystal Engineered of [M(phen)]2+ (M = Cu,Cd; phen = 1,10‐Phenanthroline) Corner Units and the Bent Ligand 4,4′‐Dithiodipyridine

Self‐assembly of Cd(phen)²⁺ and Cu(phen)²⁺ (phen = 1,10‐phenanthroline) building blocks with the bent ligand 4,4′‐dithiodipyridine (dtdp) has been investigated. Both building blocks serve as corner units with constrained cis‐geometry. The arched chain coordination polymer [{Cd(phen)(μ‐dtdp)(dtdp)(H₂O)}(ClO₄)₂·2CH₃OH·1.5H₂O]_n ( 1 ) crystallised from a mixture of Cd(ClO₄)₂·H₂O, phen and dtdp in methanol. The reaction of [Cu(phen)(H₂O)₂](CF₃SO₃)₂ ( 2 ) with dtdp in an ethanol/water mixture yielded a chair‐like metallamacrocycle, [{Cu(phen)(CF₃SO₃)₂}₂(μ‐dtpd)₂] ( 3 ). The crystal structure of the precursor complex 2 is also reported.     

Three new binuclear copper(II) complexes with isonicotinic acid N-oxide: syntheses,crystal structures and properties

Three new copper(II) complexes with isonicotinic acid N-oxide (HL) and 1,10-phenanthroline (phen) as ligands, [Cu(L)(phen)(H₂O)]₂(NO₃)₂···2H₂O (1), [Cu(L)(phen)(H₂O)]₂(ClO₄)₂···2H₂O (2), and [Cu(L)(phen)Br]₂- [Cu(L)(phen)(H₂O)]₂Br₂···6H₂O (3) have been synthesized and structurally characterized. The structures of all three complexes feature a Cu₂ dimer formed by two Cu(II) ions interconnected by two bridging ligands. Each copper(II) ion has a distorted square pyramidal coordination geometry with elongated axial coordination by an aqua ligand or halogen anion. The isonicotinic acid N-oxide anion is bidentate, being coordinated to two Cu(II) ions through its N-O oxygen and one of its carboxylate oxygen atoms. Magnetic susceptibility measurements show a Curie–Weiss paramagnetic behavior characteristic of one unpaired electron for a copper(II) ion for all three complexes.     

Synthetic,structural and spectroscopic studies of complexes derived from the copper(II) perchlorate/fumaric acid/N,N′-chelates tertiary reaction systems

The synthetic investigation of the Cu(ClO₄)₂·6H₂O/fumaric acid (H₂fum)/N,N’-chelates (1,10-phen, 2,2′-bpy) tertiary reaction systems has yielded mononuclear, dinuclear and tetranuclear complexes, and three coordination polymers. The chemical and structural identity of the products depends on the solvent, the absence or presence of external hydroxides in the reaction mixtures and the N,N’-donor. Three fumarato(−2) complexes, i.e. compounds [Cu₂(fum)(phen)₄](ClO₄)₂·2H₂O (1·2H₂O), [Cu(fum)(phen)(H₂O)]_n (3) and [Cu₂(fum)(bpy)₂(H₂O)₂]_n(ClO₄)_2n (6), were isolated and structurally characterized, and four non-fumarato complexes, i.e. compounds [Cu₄(μ₃-ΟΗ)₂(μ₂-ΟΗ)₂(phen)₄(H₂O)₂](ClO₄)₄·2H₂O (2·2H₂O), [Cu(ClO₄)(phen) (MeCN)₂(H₂O)](ClO₄) (4), [Cu(ClO₄)(phen)(MeCN)₂]_n(ClO₄)_n (5) and [Cu(ClO₄)₂(bpy)(MeCN)₂] (7), were simultaneously obtained from the reaction systems investigated. The coordination versatility of the fumarato(−2) ligand is reflected to the three different coordination modes observed in 1·2H₂O, 3 and 6; the monodentate bridging μ₂-κO:κO′ mode in 3, the asymmetric chelating bridging μ₂-κO:κO′:κO′′:κO′′′ mode in 1·2H₂O and 3, and the syn,syn bridging μ₄-κO:κO′:κO′′:κO′′′ mode in 6. The crystal structures of the complexes are stabilized by intra- and inter-molecular hydrogen bonding and π–π stacking interactions leading to interesting supramolecular architectures. Characteristic IR bands of the complexes are discussed in terms of the known structures, and the coordination modes of the fum²⁻ ligands.     

Synthesis, crystal structure, spectroscopic and photoluminescence studies of manganese(II), cobalt(II), cadmium(II), zinc(II) and copper(II) complexes with a pyrazole derived Schiff base ligand

Varying coordination modes of the Schiff base ligand H₂L [5-methyl-1-H-pyrazole-3-carboxylic acid (1-pyridin-2-yl-ethylidene)-hydrazide] towards different metal centers are reported with the syntheses and characterization of four mononuclear Mn(II), Co(II), Cd(II) and Zn(II) complexes, [Mn(H₂L)(H₂O)₂](ClO₄)₂(MeOH) (1), [Co(H₂L)(NCS)₂] (2), [Cd(H₂L)(H₂O)₂](ClO₄)₂ (3) and [Zn(H₂L)(H₂O)₂](ClO₄)₂ (4), and a binuclear Cu(II) complex, [Cu₂(L)₂](ClO₄)₂ (5). In the complexes 1-4 the neutral ligand serves as a 3N,2O donor where the pyridine ring N, two azomethine N and two carbohydrazine oxygen atoms are coordinatively active, leaving the pyrazole-N atoms inactive. In the case of complex 5, each ligand molecule behaves as a 4N,O donor utilizing the pyridine N, one azomethine N, the nitrogen atom proximal to the azomethine of the remaining pendant arm and one pyrazole-N atom to one metal center and the carbohydrazide oxygen atom to the second metal center. The complexes 1-4 are pentagonal bipyramidal in geometry. In each case, the ligand molecule spans the equatorial plane while the apical positions are occupied by water molecules in 1, 3 and 4 and two N bonded thiocyanate ions in 2. In complex 5, the two Cu(II) centers have almost square pyramidal geometry (τ = 0.05 for Cu1 and 0.013 for Cu2). Four N atoms from a ligand molecule form the basal plane and the carbohydrazide oxygen atom of a second ligand molecule sits in the apex of the square pyramid. All the complexes have been X-ray crystallographically characterized. The Zn(II) and Cd(II) complexes show considerable fluorescence emission while the remaining complexes and the ligand molecule are fluorescent silent.     

Copper(II)–manganese(II) complexes of 3,3′-(1,3-propanediyldiimine)bis-(3-methyl-2-butanone)dioxime with superoxide dismutase-like activity

Novel mononuclear [Cu(HPnAO)H₂O]ClO₄ (2), homodinuclear [Cu(PnAO)Cu(phen)(H₂O)₂](ClO₄)₂ (3), homotrinuclear [Cu₃(PnAO)₂(H₂O)₂](ClO₄)₂ (4) and heterodinuclear [Cu(PnAO)Mn(phen)₂(H₂O)](ClO₄)₂ (5) complexes have been prepared from 3,3-(1,3-propanediyldiimine)bis-(3-methyl-2-butanone)dioxime (H₂PnAO) and characterized by elemental analyses, magnetic moments, i.r., u.v.–vis., and by mass spectral studies. The geometry of the metal chelates is discussed with the help of magnetic and spectroscopic measurements. I.r. spectra show that the ligand acts in a tetradentate manner and coordinates through the (C=N) and (N—H) groups. The elemental analyses, stoichiometry and the spectroscopic data of the complexes indicate that the copper(II) ions are coordinated by the ligand dianion. The heterodinuclear complex (5) displays in vitro ability to scavenge superoxide radicals produced by the xanthine–xanthine oxidase (XXO) system, using nitroblue tetrazolium as an indicator. The complex also supports aerobic growth of Escherichia coli (sodA ^– sodB ^–) in vivo in minimal media, indicating that complex (5) is a speculative potent SOD-mimic.     

Ni(II), Pd(II), Cu(II) And Zn(II) complexes with N-(2-Pyridyl)Carbonylaniline (L), Syntheses and X-Ray Crystal structures of [Cu(L)2(H2O)2](No3)2, [Cu(L)2(H2O)2](Clo4)2 and [Zn(L)2(H2O)2](Clo4)2

Reaction of the N-(2-pyridyl)carbonylaniline ligand (L) with Cu(NO₃)₂, Cu(ClO₄)₂, Zn(ClO₄)₂, Ni(NO₃)₂ and PdCl₂ gives complexes with stoichiometry [Cu(L)₂(H₂O)₂](NO₃)₂, [Cu(L)₂(H₂O)₂](ClO₄)₂, [Zn(L)₂(H₂O)₂] (ClO₄)_2, [Ni(L)₂(H₂O)Cl](NO₃) and PdLCl₂. The new complexes were characterized by elemental analyses and infrared spectra. The crystal structures of [Cu(L)₂(H₂O)₂](NO₃)₂, [Cu(L)₂(H₂O)₂](ClO₄)₂, and [Zn(L)₂(H₂O)₂](ClO₄)₂ were determined by X-ray crystallography. The cation complexes [M(L)₂(H₂O)₂] contain copper(II) and zinc(II) with distorted octahedral geometry with two N-(2-pyridyl)carbonylaniline (L) ligands occupying the equatorial sites. The hexa-coordinated metal atoms are bonded to two pyridinic nitrogens, two carbonyl oxygens and two water molecules occupying the axial sites. Both the coordinated water molecules and uncoordinated amide NH groups of the N-(2-pyridyl)carbonylaniline (L) ligands are involved in hydrogen bonding, resulting in infinite hydrogen-bonded chains running in one and two-dimensions.     

Syntheses,Structures, and Properties of Lanthanide Supramolecular Complexes with 1, 10‐Phenanthroline and Terminal Amino Acids with Different Chain Lengths

Four lanthanide supramolecular coordination compounds, [Eu(gly)₂(phen)₂(H₂O)₂](ClO₄)₃(phen)₄ · H₂O ( 1 ), [Eu₂(APA)₆(phen)₂](ClO₄)₆(phen)₄ · 3H₂O ( 2 ), [Tb₂(ABA)₄(phen)₄](ClO₄)₆(phen)₄ ( 3 ), and [Eu₂(AHA)₄(phen)₄](ClO₄)₆(phen)₂ · 2H₂O · 2C₂H₅OH ( 4 ) (gly = glycine, APA = 3‐aminopropionic acid, ABA = 4‐aminobutanoic acid, AHA = 6‐aminohexanoic acid, phen = 1, 10‐phenanthroline), were synthesized and characterized by single crystal X‐ray diffraction. Compound 1 has a 2‐D supramolecular layered structure of mononuclear coordination cations and free phen molecules connected via hydrogen bonding and π‐π stacking interactions. 2 forms a 3‐D supramolecular network by hydrogen bonding between binuclear coordination cations and free phen molecules, between coordination cations and lattice water molecules, and π‐π stacking interactions between free phen molecules. Compounds 3 and 4 form 2‐D supramolecular structures with π‐π stacking between coordinating phen molecules, and between free phen molecules hydrogen‐bonded to the binuclear coordination cations. The high‐resolution emission spectra show only one Eu³⁺ ion site in the title complexes. The aqueous solutions of the title complexes are all photochromic with the color of the solution changing from yellow to green when irradiated by mercury lamp. During the decoloration process, they return to yellow color.     

Polyazamacrocycles VI. Homo-trimetallic copper(II) and nickel(II) complexes with a new tri-cavity macrocycle

Summary A new tri-cavity decaaza macrocycle (TCM) has been synthesised by the condensation of tetra(aminopropyl)-cyclam with diethanolamine. The new macrocyclic ligand forms tri-nuclear complexes, [Cu₃(TCM)(H₂O)₂]-(ClO₄)₆ and [Ni₃(TCM)(H₂O)₂](ClO₄)₆.     

Synthesis and characterization of new organocobaloxime derivatives with asymmetric dioxime ligands

New organocobaloxime derivatives of the types [Co(HL)₂(All)X], [CoL₂(All)XB₂F₄] and [CoL₂(All)X(Cu(phen))₂](ClO₄)₂ [H₂L¹ = 4-(4-chlorophenylamino)biphenylglyoxime and H₂L² = 4-(naphthyl-1-amino)biphenylglyoxime; phen = 1,10-phenanthroline; All = Allyl; X = H₂O, py (pyridine), APy (acetylpyridine)] were synthesized and characterized by elemental analysis, molar conductance, FT-IR, ¹H NMR and magnetic susceptibility measurements. Trinuclear complexes {CoL₂(All)X[Cu(phen)]₂}(ClO₄)₂ have planar N-donor heterocyclic base [1,10-phenanthroline (phen)]. The IR spectra indicated that the complexes coordinate through the N atom of the oxime group of each ligand. The magnetic susceptibilities of the complexes indicated that they are diamagnetic (low-spin d ⁶ octahedral) except trinuclear complex which show a subnormal magnetic moment.     

Syntheses and Characterization of a New One-Dimensional Polymer Containing (µ-Thiocyanate)(bpy)Lead(II) Molecule and New Mixed-Anion Lead (II) Complexes: Crystal Structures of [Pb(bpy)(SCN)2] n (byp = 2,2'-Bipyridine) and [Pb(phen)2(NO3)0.7(ClO4)0.3](ClO4) (phen = 1,10-Phenanthroline)

Complexes [Pb(bpy)(SCN)₂] _n (bpy = 2,2′-bipyridine), [Pb (phen)₂(NO₃)_0.7(ClO₄)_0.3](ClO₄), Pb(phen)₂(SCN)-(NO₃), and Pb(phen)₂(SCN)(ClO₄) (phen = 1,10-phenanthroline)], have been synthesized using a direct reaction between Pb(NO₃)₂ and ligands. The complexes have been isolated and characterized by IR-spectra and CHN-elemental analysis. The structures of [Pb(bpy)(SCN)₂] _n and [Pb(phen)₂(NO₃)_0.7(ClO₄)_0.3](ClO₄) have been confirmed by X-ray crystallography. The single crystal X-ray crystallography of a new one-dimensional complex of Pb(II) with 2,2′-bipyridine, [Pb(bpy)(SCN)₂] _n , shows the complex to be polymeric as a result of thiocyanate ligand bridging. The Pb atom being in a unsymmetrical eight-coordinate, N₄S₄, environment and the arrangement of the 2,2′-bipyridine, thiocyanate anion suggest a gap in coordination geometry around the Pb(II) ion, occupied possibly by a stereoactive lone pair of electrons on lead (II) and the coordination around atoms is hemi-directed. There is a π-π interaction between the aromatic rings of the interchains in [Pb(bpy)(SCN)₂] _n , this stacking causes the complex to be more stable. An attempt to isolate single crystals of Pb(phen)₂(NO₃)(ClO₄) from water led to the isolation of [Pb(phen)₂(NO₃)_0.7(ClO₄)_0.3](ClO₄). The single crystal X-ray study shows the complex to be monomeric. The Pb atom lies in an unsymmetrical six-coordinate, N₄O₂, environment and the arrangement of the 1,10-phenanthrolines, suggest a gap in coordination geometry around the Pb(II) ion, occupied possibly by a stereoactive lone pair of electrons on lead (II) and the coordination around atoms is hemi-directed.     

Novel Platinum(II) Complexes with Dipyridyl Containing Chelating Ligands and their Products with the Model Nucleobases 1‐Methylthymine and 1‐Methyluracil

The reactions of [Pt(dpma)(H₂O)₂]²⁺ (dpma = 2,2′‐dipyridylmethylamine) and [Pt(dpk)(H₂O)₂]²⁺ (dpk = 2,2′‐dipyridylketone) with the model nucleobases 1‐methylthymine (1‐MeT) and 1‐methyluracil (1‐MeU) were studied. Reaction products were characterized by ¹⁹⁵Pt NMR spectroscopy and by X‐ray structure analysis. The symmetric dpma and dpk diaqua complexes form dinuclear complexes with 1‐methylthymine, acting as secondary bridging ligand via its N3 and O4 donor atoms. [Pt₂(dpma)₂(1‐MeT)₂](ClO₄)₂ · H₂O ( 5 ) and [Pt₂(dpk)(dpk · H₂O)(1‐MeT)₂](PF₆)₂ · 4 H₂O ( 6 ) both show a head‐to‐head arrangement. Biological tests show a significant in vitro antitumor activity of [Pt(dpk)Cl₂] against the human glioma cell line U 87.     

Characterization of copper(II) coordination compounds of 5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine: the crystal structure of diaquatetrakis(5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine-N3)-copper(II) hexafluorophosphate

Copper(II) coordination compounds of several CuA₂ salts (A = PF₆, BF₄, ClO₄, CF₃SO₃ or NO₃) with 5,7-dimethyl[1,2,4]triazolo[1,5-a]pyrimidine (dmtp) as a ligand have been studied. The crystal structure of [Cu(dmtp)₄(H₂O)₂](PF₆)₂ is described. This compound is monoclinic, space group P2₁/c, a = 11.826(2) Å, b = 9.463(2) Å, c = 17.673(3) Å, β = 97.50(1)°, Z = 2, d_calc. = 1.66 Mg m⁻³, and has been refined to a final discrepancy factor (R) of 0.0382 based on 2316 reflections. The structure consists of PF⁻₆ anions and centrosymmetric mononuclear [Cu(dmtp)₄(H₂O)₂]²⁺ cations, Cu₂₊ being coordinated by four equatorial N(3)-bonded dmtp molecules with CuN = 2.019 and 2.050 Å, and by two axial water molecules with CuO = 2.650 Å. The water molecules form intramolecular hydrogen bonds with the dmtp N(4) atoms.     

Synthesis,structure and in vitro antiproliferative activities of oxamido‐bridged dicopper(II) complexes: A comparative study of experimental evidence and molecular docking of DNA/protein binding

Two μ‐oxamido‐bridged dicopper(II) complexes, namely [Cu₂(hmpoxd)(H₂O)(phen)](ClO₄) ( 1 ) and [Cu₂(papo)(H₂O)(phen)](ClO₄)·2H₂O ( 2 ), where H₃hmpoxd and H₃papo represent N‐(2‐hydroxy‐5‐methylphenyl)‐N′‐[3‐(dimethylamino)propyl]oxamide and N‐(2‐hydroxylphenyl)‐N′‐(3‐aminopropyl)oxamide, respectively, and phen represents 1,10‐phenanthroline, were synthesized. Single‐crystal X‐ray crystallography and other methods revealed that the two copper(II) ions in complex 1 are bridged by the cis‐hmpoxd^3? with Cu···Cu separation of 5.1896(7) Å, in which the inner (Cu1) and outer (Cu2) copper(II) atoms are located in square‐planar and square‐pyramidal geometries, respectively. To evaluate the effects of bridging ligand hydrophobicity on DNA/protein binding and potential anticancer activities, comparative studies of the reactivity towards herring sperm DNA and protein bovine serum albumin (BSA) as well as cytotoxicity of complex 1 with our previously reported complex 2 were conducted theoretically and experimentally. The results indicate that the two complexes can interact interactively with DNA, and bind to BSA via the binding sites Trp213 for 1 and Trp134 for 2 . Interestingly, the in vitro anticancer activities and DNA/protein binding affinities consistently follow the order of 1 > 2 .     

Synthesis and magnetism of 6-nitrobenzimidazolate and imidazolate-bridged copper(II) complexes

Summary Four new trinuclear copper(II) complexes, [Cu(phen)-(NBzIm)] (ClO₄) (1), [Cu(bpy)(NBzIm)](ClO₄) (2), [Cu-(Me₂-bpy)(NBzIm)](Ac)·1/2H₂O (3) and [Cu(Me₂-bpy)-(Im)](ClO₄)·1/2H₂O (4) (phen = 1, 10-phenanthroline, bpy = 2,2-bipyridine, NBzIm = 6-nitrobenzimidazolate ion, Im=imidazolate ion) have been prepared and characterized by variable temperature magnetic susceptibility measurements. A weak antiferromagnetic spin exchange interaction operates between copper(II) ions, exchange integrals evaluated as J =-23.82 cm^-1 for (1); and J=-21.91 cm^-1 for (2).     

Supramolecular architectures constructed by lanthanum, amino acids and 1,10-phenanthroline via non-covalent bond interactions

Three supramolecular lanthanum coordination compounds of amino acids, with 1,10-phenanthroline (phen), [La₂(APA)₆(phen)₂(H₂O)₂](ClO₄)₆(phen)₄·2H₂O (1), [La₂(ABA)₆(phen)₂(H₂O)₂](ClO₄)₆ (phen)₆·4H₂O (2), and [La₂(AHA)₄(phen)₄](ClO₄)₆(phen)₄·2H₂O (3) (APA=3-aminopropionic acid; ABA=4-aminobutanoic acid; AHA=6-aminohexanoic acid) were synthesized and characterized by single crystal X-ray diffraction. The results show that the three coordination compounds are all composed of binuclear coordination cations built by metal-ligand coordination. Through hydrogen bonding and π-π stacking interactions, complex 1 forms a two-dimensional supramolecular sheet structure extending in the (001) plane, complex 2 forms a three-dimensional supramolecular network with many cavities occupied by ClO₄⁻ and lattice H₂O molecules, and complex 3 forms a two-dimensional supramolecular lamellar structure in the (100) plane.     

Synthesis and crystal structure of two copper complexes with one-dimensional chain structures bridged by bipyridine ligands

Two copper complexes {[Cu(phen)(azpy)(H₂O)(ClO₄)](ClO₄)}_n1 (phen=1,10-phenthroline, azpy=4,4′-azobispyridine) and {[Cu(phen)(bpe)(H₂O)(ClO₄)](ClO₄)}_n2 (bpe=trans-1,2-bis(4-pyridyl)ethylene), have been synthesized and characterized. The X-ray analysis reveals that copper ion has distorted square pyramidal coordination environments in the complexes 1 and 2. The copper is coordinated by two N atoms of phen, two N atoms from two bridging ligand azpy in 1 and from two bridging ligand bpe in 2, one O atom of coordinated water. Due to Jahn Teller distortion the sixth site in 1 and 2 is occupied by one O atom from one perchlorate anion. Copper ions are linked to each other through bridging ligand azpy in 1 and bridging ligand bpe in 2 to form one-dimensional chain. Variable-temperature magnetic susceptibility studies show that there is a weak antiferromagnetic interaction between the Copper ions in 1 and 2.     

Synthesis,Crystal Structures and Properties of Tetrametallic Complexes: [M2(phen)4(FCA)2](ClO4)2·(H2O)2 (M=Zn or Co,phen=1,10‐phenanthroline,FCA=anion of 3‐ferrocenyl‐2‐crotonic acid)

Two new complexes [Zn₂(phen)₄(FCA)₂](ClO₄)₂·(H₂O)₂ ( 1 ) and [Co₂(phen)₄ (FCA)₂](ClO₄)₂·(H₂O)₂ (2) (FCA=anion of 3‐ferrocenyl‐2‐crotonic acid, phen=1,10‐phenanthroline) have been synthesized, and characterized by elemental analysis, IR, UV‐Vis spectra, thermal analyses, and single‐crystal X‐ray diffraction. Two M(II) (M=Zn or Co) ions are bridged by two FCA anions with syn‐anti bridging ligands, leading to dimeric cores, [M₂(phen)₄(FCA)₂]²⁺, and each M(II) ion is six‐coordinated in a distorted octahedral geometry by two chelate phen ligands and two μ₂‐carboxylate oxygen atoms from two FCA groups. The M(II)…M(II) intradimer distances are 0.4391 and 0.4462 nm in 1 and 2 , respectively. Electrochemical properties of the complexes have been discussed.     

Co(II), Cu(II) and Zn(II) dinuclear complexes of a polypodal ligand containing phenolate and pyridyl donor groups

Acetate and perchlorate dinuclear metal complexes of Co(II), Cu(II) and Zn(II) with the cresolate polypodal ligand having mixed phenolate and pyridyl pendant functionalities, H₃L, have been synthesized. The complexes were characterized by microanalysis, LSI mass spectrometry, IR, UV–Vis spectroscopy, magnetic studies and conductivity measurements. Crystal structures of H₃L, [Cu₂(HL)(OAc)(H₂O)₂](OAc)·1.5H₂O and [Zn₂L(CH₃OH)₃](ClO₄)CH₃OH·2H₂O complexes, have been also determined.