Copper(II) complexes of 2-(pyrrolidinomethyl)- and 2-(3-pyrrolinomethyl)pyridine N-oxides

Summary This title pyridine N-oxides have been prepared and their copper(II) complexes isolated as perchlorate, tetrafluoroborate and nitrate salts. The ligands coordinatevia both the pyridine N-oxide oxygen and the amine nitrogen to give bis(ligand) complexes for the perchlorate and tetrafluoroborate salts. The nitrate solids have [CuL(NO₃)₂] stoichiometry with monodentate nitrato-ligands. The spectral properties of these complexes are compared to those of N-alkyl-and N,N-dialkyl2-picolinamine N-oxides as well as other 2-substituted pyridine N-oxides.NATO Fellow on leave from Istanbul Medical Faculty, Istanbul University.     

2-Amino-3-picolineN-oxide complexes formed from various copper(II) Salts

Summary Copper(II) complexes of 2-amino-3-picolineN-oxide (3 MA) have been isolated as perchlorate, tetrafluoroborate, nitrate, chloride and bromide salts, and characterized by spectral methods (i.e., i.r., u.v.-vis and e.s.r.). Variation of the ligand to copper(II) salt ratio yielded solids having the following empirical formulas: Cu(3 MA)₄X₂ (X = ClO₄, BF₄ or NO₃), Cu(3 MA)₂X₂ (X = NO₃, Cl or Br) and Cu(3 MA)X₂ (X = Cl). In addition, a deprotonated ligand complex, Cu(3 MA-H)₂, was prepared by treating an aqueous slurry of Cu(3 MA)₄(ClO₄)₂ with NaOH. This complex is considered to be square planar, but does associate to form a dimer in nonpolar solvents such as CHCl₃. The complexes involving coordinated anions appear to be polymeric and to contain halogen orN-oxide oxygen bridging ligands.     

Copper(II) complexes of thiosemicarbazones derived from 2-acetylpyridine and its n-oxide

A series of Cu(II) complexes of the thiosemicarbazone, 3-azabicyclo[3.2.2]-nonene-3-thiocarboxylic acid 2-[1-(2-pyridinyl)ethylidene]hydrazide(HL) and the corresponding N-oxide (HLO) have been prepared and characterized. Both ligands undergo deprotonation and appear to coordinate via the thione sulfur, the imine nitrogen and the pyridyl nitrogen (or N-oxide oxygen). A single anionic ligand such as Cl^?, Br^?, NCS^? and N^?₃ completes the bonding to the Cu(II) center of these 4-coordinate complexes. When the complexes are prepared using Cu(II) perchlorate, the solids isolated contain a neutral thiosemicarbazone ligand as well as the deprotonated ligand. The solids are primarily characterized by IR, electronic and electron spin resonance spectroscopy. In addition, electronic and ESR spectra of their chloroform solutions were recorded. Most of the solids (except the nitrates) were unaltered upon dissolution. Simulation of the solution ESR spectra was used to estimate the coupling constants of the various coordinated nuclei.     

2-amino-4,6-lutidineN-oxide complexes formed from various copper(II) salts

Summary Copper(II) complexes of 2-amino-4,6-lutidineN-oxide (4,6DMAH) have been isolated as tetrafluoroborate, nitrate, chloride and bromide salts, and characterized by spectral methods (i.e., i.r., u.v.-vis. and e.s.r.). Variation of the ligand-to-copper(II) ratio yielded solids having the following empirical formulae: [Cu(4,6DMAH)₄]X₂ (X=BF₄), [Cu(4,6DMAH)₂X₂] (X=NO₃, Cl) and [Cu(4,6DMAH)X₂] (X=Br). In addition, a deprotonated ligand complex, Cu(4,6DMA)₂, was prepared using copper(II) acetate. The Sigand usually binds to the copper(II) centresvia theN-oxide oxygen and only the deprotonated ligand coordinatesvia the exocyclic nitrogen as well as the TV-oxide oxygen. The complexes involving coordinated anions and at least two ligands are monomeric while Cu(4,6DMAH)Br₂ is polymeric. The ring substituents affect either the stoichiometry or the stereochemistry of these solids when compared to less sterically demanding 2-aminopyridineN-oxides.     

2-Amino-5-picoline N-oxide complexes formed from various copper(II) salts

Copper(II) complexes with 2-amino-5-picoline N-oxide (2am5PicO = L), CuL₄X₂(X = ClO₄, BF₄, and NO₃), CuL₂X₂ (X = Cl, Br) and CuLX₂ (X = Cl) have been isolated and characterized using spectral methods (i.e. IR, UV-vis and ESR). Coordination occurs via the N-oxide oxygen exclusively with the amine functional group showing only slight tendency to involve itself in hydrogen bonding to the anions. The halide complexes involve the halide ions in the coordination spheres while the polyatomic anions are not bound directly to copper. The latter compounds have monomeric, 4-coordinate CuO₄ chromophores while the former solids are apparently polymeric. Evidence for N-oxide bridging ligands in the CuL₂X₂ solids and halogen bridging in the CuLX₂ solid is presented.     

Copper(II) complexes of 4-chloro,3-methyl,5-phenylisoxazole

4-chloro,3-methyl,5-phenylisoxazole copper(II) complexes of the type Cu(L)X₂(X = Cl, Br, NO₃) and Cu(L)₂(ClO₄)₂ have been prepared and studied by the IR, electronic, paramagnetic resonance spectroscopy and molar conductivity values. The ligand acts as monodentate N-bonded except to the nitrate derivative where this behaves as bridging bidentate. The halide complexes are tetrahedral, while the nitrate and perchlorate derivatives are square planar.     

Complexes of Cu(II) and Co(II) with NN′-bis-8-quinolylethylenediamine

This article describes some complexes of Cu(II) and Co(II with NN′-bis-8-quinolylethylenediamine ligand (nn′). All the compounds are of stoichiometry [MX₂(nn′)] (M = Cu or Co; X = Cl^?, Br^?, I^?, NO^?₃ or SCN^?). The electronic spectra are consistent with distorted octahedral geometry around the ions, indicating the four coordination of the nn′ ligand. Magnetic susceptibility measurements down to 100 K show antiferromagnetic interactions in all the Cu(II) compounds demonstrating the existence of the ionic and bridging X group. Infrared spectra show the presence of ionic and bridging nitrate in the [M(NO₃)₂(nn′)] (M = Co or Cu) compounds and ionic and bridging NCS group in the [Cu(NCS)₂(nn′)] compound.     

两个含双(3,5－二甲吡唑基)甲烷配体的铅(II)配合物的合成与结构表征

Reactions of lead（Ⅱ） nitrate or perchlorate with bis（3,5-dimethylpyrazolyl）methane （dmpzm）, produced two new Pb（Ⅱ） chelated complexes [Pb（dmpzm）2X2] （X=NO3^- 1, ClO4^- 2）. Both compounds were structurally characterized by elemental analysis, IR spectroscopy, thermal analysis, and single crystal X-ray diffraction. Both compounds are mononuclear with a distorted square antiprismatic PbN4O4 coordination geometry incorporating a pair of O,O＇-bidentate anions and N,N＇-bidentate dmpzm ligands. In the crystals of 1 or 2, the methyl or methylene groups of dmpzm ligand interact with the oxygen atoms of nitrates or perchlorates to afford intra- and intermolecular hydrogen bonding, thereby forming a two-dimensional network 1 or a three-dimensional structure 2.     

Cobalt(II) and copper(II) complexes of 3-amino-5-methylisoxazole

Summary Cobalt(II) and copper(II) halide, nitrate, thiocyanate and perchlorate complexes of 3-amino-5-methylisoxazole (3-AMI) have been prepared and characterized by means of magnetic, spectroscopic and molar conductivity measurements. In Cu(3-AMI)₂X₂ compounds (X = Cl, Br, N02) the 3-AMI ligand is bridging and bidentate [N (ring), O(bonded)]. In the other derivatives it is monodentate [N(ring) bonded]. All cobalt(II) complexes have an octahedral stereochemistry, if the Co(3-AMI)₂X₂ derivatives (X = Cl, Br), which are tetrahedral, are excluded. Copper(II) complexes have generally a distorted square pyramidal stereochemistry in the solid state and in solution.     

Ni(II) complexes with 8-aminoquinoline derivatives

Some Ni(II) complexes with 5,7-dicloro-8-aminoquinoline (dcaq), 5,7-dibromo-8-aminoquinoline(dbaq) and 5,7-diiodo-8-aminoquinoline(diaq) are described. The compounds are of stoichiometry NiL₂X₂(L= dcaq, dbaq, diaq; X= NO^?₃ and L= dbaq; X= Cl^?, Br^?, I^?, NCS^?) and NiLX₂·H₂O(L= dcaq, diaq; X= Cl^?). The electronic spectra and magnetic susceptibility data at room temperature, are consistent with octahedral geometry for the Ni(II) in each compound. I.r. spectra show the presence of ionic and bridging nitrate groups in the compounds NiL₂(NO₃)₂(L= dcaq, dbaq, diaq) and we assign them polymeric structures. Polymeric structures with bridging chloride are proposed for the compounds NiLCl₂·H₂O(L= dcaq, diaq) and monomeric octahedral structures for NiL₂X₂(L= dbaq; X= Cl, Br, I, NCS).     

Transition Metal Complexes of Dis(thiosemicarbazone): Synthesis and Spectral,and Antifungal Studies

Mn(II), Co(II), Ni(II), and Cu(II) complexes have been synthesized with benzil bis(thiosemicarbazone) (L) and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, thermogravimetric studies, infrared (IR), electronic, and electron paramagnetic resonance (eEPR) spectral studies. The molar conductance measurements of the complexes in DMF correspond to the non-electrolytic nature of the complexes. Thus these complexes may be formulated as [M(L)X₂] (where M = Mn(II), Co(II), Ni(II), Cu(II) and X = Cl^? and NO₃ ^?). On the basis of IR, electronic, and EPR spectral studies, an octahedral geometry has been assigned for Mn(II), Co(II), and Ni(II) complexes, whereas a tetragonal geometry for the Cu(II) complexes is presumed. The free ligand and its metal complexes were tested against the phytopathogenic fungi (i.e., Rhizoctonia baticola, Alternaria alternata) in vitro.     

EPR Study of some Copper(II) Coordination Compounds with substituted Biguanides. III

Copper(II) coordination compounds with p-chlorphenylbiguanide of the type: [Cu(Cl-PhBig)₂]X₂ and [Cu(Cl–PhBig)X₂] with X =Cl^?, Br^? NO₃, OH^?, NCS^?, NCO^?, N₃, have been studied by EPR spectroscopy using polycrytalline powders and solutions in DMF. The parameters of the EPR spectra have been used to estimate molecular orbital coefficient, in these compounds and to discuss details of the chemical bonding.     

Cobalt(II) complexes of 1,2-(diimino-4′-antipyrinyl)ethane and 4-N-(4′-antipyrylmethylidene)aminoantipyrine

Cobalt(II) complexes of the Schiff bases 1,2-(diimino-4-antipyrinyl)ethane (GA) and 4-N-(4-antipyrylmethylidene)aminoantipyrine (AA) have been prepared and characterised by elemental analysis, electrical conductance in non-aqueous solvents, i.r. and electronic spectra, as well as by magnetic susceptibility measurements. The complexes have the general formulae [Co(GA)X]X (X = ClO^– ₄ or NO₃ ^–), [Co(GA)X₂] (X = Cl^–, Br^– or I^–), [Co(AA)₂]X₂ (X = ClO₄ ^–, NO₃ ^–, Br^– or I^–) and [Co(AA)Cl₂]. GA acts as a neutral tetradentate ligand, coordinating through both carbonyl oxygens and both azomethine nitrogens. In the perchlorate and nitrate complexes of GA one anion is coordinated in a bidentate fashion, whereas in the halide complexes both anions are coordinated to the metal, generating an octahedral geometry around the Co ion. AA acts as a neutral bidentate ligand, coordinating through the carbonyl oxygen derived from the aldehydic moiety and the azomethine nitrogen. Both anions remain ionic in the perchlorate, nitrate, bromide and iodide complexes of AA, whereas both anions are coordinated to the metal ion in the chloride complex, resulting tetrahedral geometry around the Co ion.     

Synthesis,spectroscopic studies,and antibacterial activities of 14-membered tetraazamacrocyclic complexes of divalent transition metal ions

A new series of macrocyclic complexes, [M(C₄₈H₃₂N₄)X₂], where M?=?Co(II),?Ni(II),?Cu(II), and Zn(II); X?=?Cl^?,?NO₃ ^?,?CH₃COO^?, have been synthesized by condensation of 1,8-diaminonaphthalene and benzil, in the presence of divalent metal salts in methanolic medium. The complexes have been characterized by elemental analyses, conductance measurements, magnetic measurements, and electronic, NMR, IR, and MS spectral studies. The low value of molar conductance indicates the presence of non-electrolytes. A distorted octahedral geometry is proposed for the complexes. The metal complexes were also tested for their in vitro antibacterial activities against some bacterial strains and compared with the standard antibiotic Ciprofloxacin. Some tested complexes show good antibacterial activities against some bacterial strains.     

Nickel(II) and copper(II) complexes of 2,5-dimethyl-1,3,4-thiadiazole

Summary Nickel(II) and copper(II) complexes of 2,5-dimethyl-1,3,4-thiadiazole Ni(DTZ)X₂ (X = Cl or Br) and M(DTZ)₂X₂ (M = Ni, X = 1 or N03; M = Cu, X = Cl, Br or NO₃) have been prepared. The i.r. spectra show that in all the complexes the ligand is N,N- or N-bonded to the metal while the sulfur atom does not participate in coordination, and that the halide ions are coordinated forming terminal M-X bonds. The NO ₃ ^- group is coordinated in both the nitrato complexes. Magnetic moments of 3.07–3.29 B.M. for the nickel(II) and 1.86–1.92 B.M. for the copper(II) complexes were observed. The Ni(DTZ)X₂ complexes have a pseudo-tetrahedral [N₂X₂] coordination with N,N-bridging ligand molecules. The Ni(DTZ)₂X₂ and Cu(DTZ)₂X₂ complexes, with predominantly monodentate ligand, involve six-coordinate metal atoms with strong equatorial [N₂X₂] bonds and weaker axial bonds.Author to whom all correspondence should be directed.     

Synthesis, spectral and thermal studies of new copper (II) complexes with 1,2-di(imino-2-aminomethylpyridil)ethane

New copper (II) complexes of Schiff bases with 1,2-di(imino-2-aminomethylpyridil)ethane with the general composition CuLX _m (H₂O) _x , [L = Schiff base, X = Cl^?, Br^?, NO₃ ^?, ClO₄ ^?, CH₃COO^?, m = 2; X = SO₄ ^2?, m = 1] were prepared by template synthesis. The complexes were characterized by elemental analysis, conductivity measurements, magnetic moments, IR, UV–VIS and EPR spectra. The thermal behavior of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC). Infrared spectra of all complexes are in good agreement with the coordination of a neutral tetradentate N₄ ligand to the cooper (II) through azomethinic and pyridinic nitrogen. Magnetic, EPR and electronic spectral studies show a monomeric distorted octahedral geometry for all Cu(II) complexes. Conductance measurements suggest the non-electrolytic nature of the compounds, except for copper (II) nitrate and perchlorate complexes which are 1:2 electrolytes. Heats of decomposition, ΔH, associated with the exothermal effects were also determined.     

Mass, EPR, IR and electronic spectroscopic studies on newly synthesized macrocyclic ligand and its transition metal complexes

Manganese(II), cobalt(II), nickel(II) and copper(II) complexes have been synthesized with a new tetradentate ligand viz. 1,3,7,9-tetraaza-2,4,8,10-tetraketo-6,12-diphenyl-cyclododecane (L) and characterized by the elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, ¹H NMR, IR, electronic and EPR spectral studies. The molar conductance measurements of the complexes in DMF correspond to be nonelectrolytic nature for Mn(II), Co(II) and Cu(II) while 1:2 electrolytes for Ni(II) complexes. Thus, these complexes may be formulated as [M(L)X₂] and [Ni(L)]X₂ (where M = Mn(II), Co(II) and Cu(II) and X = Cl⁻ and NO₃⁻).On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Mn(II) and Co(II) complexes, square-planar for Ni(II) whereas tetragonal for Cu(II) complexes. The ligand and its complexes were also evaluated against the growth of bacteria and pathogenic fungi in vitro.     

New structures in the bi­pyridine–copper(II) nitrate–methanol system: [(bpy)2Cu(NO3)]NO3·CH3OH and [(bpy)2Cu(NO3)]NO3

Reaction of 2,2′‐bi­pyridine (bpy) and copper(II) nitrate in methanol results in two complexes, namely light‐blue bis(2,2′‐bi­pyridine)­nitrato­copper(II) nitrate methanol solvate, [Cu(NO₃)(C₁₀H₈N₂)₂]NO₃·CH₃OH, (I), which is unstable in air, and the product of its decomposition, catena‐poly­[[[bis(2,2′‐bi­pyridine)copper(II)]‐μ‐nitrato‐O:O′] nitrate], {[Cu(NO₃)(C₁₀H₈N₂)₂]NO₃}_n, (II). The crystal structures of both compounds were determined from one crystal at room temperature. Later, the structure of (I) was redetermined at low temperature. In (I) and (II), the Cu atom is coordinated by two bpy and one or two nitrate ions, respectively. The second nitrate ion in (I), along with the methanol solvent mol­ecule, is found in the outer coordination sphere, not bonded to Cu. The nitrate in (I) is chelating, while in (II), it bridges (bpy)₂Cu complexes, forming a one‐dimensional chain structure. The Cu cation in (II) lies on a twofold axis and the uncoordinated NO₃^? ion is located close to a twofold axis and is therefore disordered. Compound (I) converts into (II) upon loss of solvent.     

Bonding modes of nitrite and nitrate in palladium(II) and platinum(II) complexes

The crystal structures of the well-known complexes, [(Me₄en)M(II)X₂] (Me₄en?=?N,N,N??,N??-tetramethylethylenediamine; M(II)?=?Pd(II) or Pt(II); X ^??=?NO₂ ^? or NO₃ ^?) have been determined. For [(Me₄en)Pd(NO₂)₂] and [(Me₄en)Pt(NO₂)₂], the nitrite anion acts as a monodentate N-donor ligand in the solid state. In contrast, for [(Me₄en)Pd(ONO₂)(O₂NO)], the two nitrate anions act as a monodentate O-donor (ONO₂) and a bidentate O,O??-donor (O₂NO). Recrystallization of [(Me₄en)Pt(NO₃)₂] from Me₂SO yields the Me₂SO adduct with a monodentate O-donor nitrate and a counteranionic nitrate, [(Me₄en)Pt(ONO₂)(S-Me₂SO)](NO₃). The solution behavior of these complexes, including the equilibrium between coordinated and free Me₂SO, has been investigated.     

Synthesis and Structure of Copper(II) Nitrate Complexes with 2, 6‐Bis(pyrazolyl)pyridine

Three mononuclear copper(II) complexes of copper nitrate with 2, 6‐bis(pyrazol‐1‐yl)pyridine ( bPzPy ) and 2, 6‐bis(3′,5′‐dimethylpyrazol‐1‐yl)pyridine ( bdmPzPy ), [Cu(bPzPy)(NO₃)₂] ( 1 ), [Cu(bPzPy)(H₂O)(NO₃)₂] ( 2 ) and [Cu(bdmPzPy)(NO₃)₂] ( 3 ) were synthesized by the reaction of copper nitrate with the ligand in ethanol solution. The complexes have been characterized through analytical, spectroscopic and EPR measurements. Single crystal X‐ray structure analysis of complexes 1 and 2 revealed a five‐coordinate copper atom in 1 , whereas 2 contains a six‐coordinate (4+2) Cu^II ion with molecular units acting as supramolecular nodes. These neutral nodes are connected through O–H ··· O(nitrate) hydrogen bonds to give couples of parallel linear strips assembled in 1D‐chains in a zipper‐like motif.