Synthesis and characterization of manganese(IV) and ruthenium(III) complexes derived from bis (2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone

Bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone(naohH₄) interacts with manganese(II) acetate in methanol followed by addition of KOH giving [Mn^IV(naoh)(H₂O)₂]. Activated ruthenium(III) chloride reacts with naohH₄ in methanol yielding [Ru^III(naohH₄)Cl(H₂O)Cl₂]. The replacement of aquo by heterocyclic nitrogen donor in these complexes has been observed when the reaction is carried out in presence of heterocyclic nitrogen donors such as pyridine(py), 3-picoline(3-pic) or 4-picoline(4-pic). The molar conductance values in DMF for these complexes suggest non-electrolytic nature. Magnetic moment values suggest +4 oxidation state for manganese in its complexes, however, ruthenium(III) complexes are paramagnetic with one unpaired electron. Electronic spectral studies suggest six coordinate metal ions. IR spectra reveal that naohH₄ coordinates in enol-form and keto-form to manganese and ruthenium, respectively. ESR and cyclic voltammetric studies of the complexes have also been reported.     

Synthesis and characterization of molybdenum(V,VI) complexes derived from bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone

Monometallic molybdenum(VI) complexes [MoO₂(CH₂LH₂)]?·?H₂O (1), [Mo₂O₄(CH₂LH₂)₂(A)₂] (A?=?py (2), 2-pic (3), 3-pic (4) and 4-pic (5)) and molybdenum(V) complexes [Mo(CH₂LH₂)(inh)]?·?H₂O (6) and [Mo(CH₂LH₂)(slh)] (7) of bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH₂LH₄) have been synthesized and characterized by various physico-chemical and spectroscopic studies. The compositions of the complexes have been established by elemental analyses and molecular weight determination. The structural assessment of the complexes has been done on the basis of data obtained from molar conductances, magnetic moment studies, electronic, infrared, electron paramagnetic resonance (EPR), proton nuclear magnetic resonance, and ¹³C proton nuclear magnetic resonance spectroscopic studies. The molar conductance values for the complexes in DMSO suggest that they are non-electrolytes. The magnetic moment values for 6 and 7 correspond to one unpaired electron while the remaining complexes are diamagnetic. Complexes 1, 6, and 7 have six-coordinate octahedral stereochemistry around molybdenum, while 2–5 are eight-coordinate dodecahedral around the metal centers. EPR spectral features suggest that 7 is less symmetrical than 6.     

Synthesis and spectral studies on heterobimetallic complexes of manganese and ruthenium derived from N-(2-hydroxynaphthalen-1-yl)methylenebenzoylhydrazide

The complex [Mn^IV(napbh)₂] (napbhH₂ = N-(2-hydroxynaphthalen-1-yl)methylenebenzoylhydrazide) reacts with activated ruthenium(III) chloride in methanol in 1 : 1.2 molar ratio under reflux, giving heterobimetallic complexes, [Mn^IV(napbh)₂Ru^IIICl₃(H₂O)] · [Ru^III(napbhH)Cl₂(H₂O)] reacts with Mn(OAc)₂·4H₂O in methanol in 1 : 1.2 molar ratio under reflux to give [Ru^III(napbhH)Cl₂(H₂O)Mn^II(OAc)₂]. Replacement of aquo in these heterobimetallic complexes has been observed when the reactions are carried out in the presence of pyridine (py), 3-picoline (3-pic), or 4-picoline (4-pic). The molar conductances for these complexes in DMF indicates 1 : 1 electrolytes. Magnetic moment values suggest that these heterobimetallic complexes contain Mn^IV and Ru^III or Ru^III and Mn^II in the same structural unit. Electronic spectral studies suggest six coordinate metal ions. IR spectra reveal that the napbhH₂ ligand coordinates in its enol form to Mn^IV and bridges to Ru^III and in the keto form to Ru^III and bridging to Mn^II.     

Synthesis and spectral studies of nickel(II) complexes derived from disalicylaldehyde oxaloyldihydrazone

The mononuclear nickel(II) complex [Ni(H₂slox)(H₂O)₃] (1) and polymeric dinuclear complexes [Ni₂(slox)(A₄)] {A = H₂O (2), py (3), 2-pic (4), 3-pic (5) and 4-pic (6)} and the discrete binuclear complexes [Ni₂(slox)(NN)₃] {NN = bpy (7) and phen (8)} have been synthesized from disalicylaldehyde oxaloyldihydrazone (H₄slox) in methanol. All of the complexes are nonelectrolytes. Complexes 1, 7, and 8 are paramagnetic while binuclear 2–6 possess anomalously low μ _eff value, indicating considerable metal–metal interaction. Discrete binuclear 7 and 8 have no interaction between the two nickel(II) ions. The anomalously low magnetic moment values in 2–6 are explained as metal–metal interaction via phenoxide bridge. Such metal–metal interactions are less in 7 and 8 due to coordination of bipyridine and phenanthroline molecules which do not allow phenoxide bridging. The dihydrazone coordinates to the metal center as a dibasic tridentate ligand in keto-enol form in staggered configuration in 1, while in the remaining complexes the dihydrazone is tetrabasic hexadentate in enol form in anticis configuration. The metal center has a tetragonally distorted octahedral stereochemistry.     

Synthesis,characterization, reactivity,and antifungal activity of chlorobis(2,4-dinitrophenoxo) monooxovanadium(V)

[VOCl(OC₆H₃(NO₂)₂-2,4)₂] (1) has been synthesized by the reaction of VOCl₃ with bimolar amounts of Me₃SiOC₆H₃(NO₂)₂-2,4 in toluene and characterized by elemental analyses, molar conductance, infrared (IR), ¹H and ¹³C NMR and mass spectral, and thermal studies. Molecular modeling dynamics of the complex suggests tetrahedral geometry around vanadium. The reaction of 1 with sodium alkoxides, NaOR (OR?=?OMe (methoxy); OEt (ethoxy), OBuⁿ(n-butoxy); OPrⁱ (isopropoxy); and OAmⁱ(isoamyloxy)) afforded mixed alkoxo–phenoxo complexes, [VO(OR)(OC₆H₃(NO₂)₂-2,4)₂] authenticated by physicochemical and IR spectral studies. The antifungal activities of the ligand and complexes against three fungi, namely Aspergillus niger, Byssachlamys fulva, and Mucor circinelloides have been assayed by the minimum inhibitory concentration method. The complexes have improved antifungal activity compared to free ligand.     

Synthesis and characterization of heterobimetallic Ni(II)–Zn(II) complexes from bis(2-hydroxy-1 -naphthaldehyde)succinoyldihydrazone

Monometallic zinc(II) and nickel(II) complexes, [Zn(H₂nsh)(H₂O)] (1) and [Ni(H₂nsh)(H₂O)₂] (2), have been synthesized in methanol by template method from bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone (H₄nsh). Reaction of monometallic complexes with alternate metal(II) acetates as a transmetallator in 1 : 3 molar ratio resulted in the formation of heterobimetallic complexes [NiZn(nsh)(A)₃] and [ZnNi(nsh)(A′)₂] (A = H₂O (3), py (4), 2-pic (5), 3-pic (6), 4-pic (7)), (A′ = H₂O (8), py (9), 2-pic (10), 3-pic (11), and 4-pic (12)). The complexes have been characterized by elemental analyzes, mass spectra, molar conductance, magnetic moments, electronic, EPR, and IR spectroscopies. All of the complexes are non-electrolytes. Monometallic zinc(II) is diamagnetic while monometallic nickel(II) complex and all heterobimetallic complexes are paramagnetic. The metal centers in heterobimetallic complexes are tethered by dihydrazone and naphthoxo bridging. Zinc(II) is square pyramidal; nickel(II) is six-coordinate distorted octahedral except [ZnNi(nsh)(A)₂], in which nickel(II) has square-pyramidal geometry. The displacement of metal center in monometallic complexes by metal ion has been observed in the resulting heterobimetallic complexes.     

Synthesis,characterization, antimicrobial,DNA binding,and oxidative cleavage activities of Cu(II) and Co(II) complexes with 2-(2-hydroxybenzylideneamino)isoindoline-1,3-dione

(E)-2-(2-hydroxybenzylideneamino)isoindoline-1,3-dione (Hbid) was prepared by condensation of N-aminophthalimide and salicylaldehyde and characterized by elemental analysis, IR, ¹H-NMR, and mass spectral studies. Mononuclear complexes [(phen)Cu^II(μ-Hbid)₂H₂O] (1), [(phen)Co^II(Cl)₂(μ-Hbid)]6H₂O (2) (phen?=?1,10-phenanthroline) and binuclear complexes [Cu^II(μ-Hbid)]₂ (3), and [Co^II(μ-Hbid)]₂ (4) with Hbid were prepared and characterized by elemental analysis, IR, UV-Vis, molar conductance, and thermogravimetric (TG) techniques. DNA-binding properties of 1–4 were investigated by UV spectroscopy, fluorescence spectroscopy, and viscosity measurements. The results suggest that 1 and 2 bind to DNA by partial intercalation, whereas 3 and 4 find different groove-binding sites. The cleavage of these complexes with super coiled pUC19 has been studied using gel electrophoresis; all the complexes displayed chemical nuclease activity in the absence and presence of H₂O₂ via an oxidative mechanism. Complexes 1–4 inhibit the growth of both Gram-positive and Gram-negative bacteria.     

Syntheses,characterizations, and antimicrobial activities of binuclear ruthenium(III) complexes containing 2-substituted benzimidazole derivatives

Binuclear ruthenium(III) complexes [RuX₃L]₂?·?nH₂O (X?=?Cl, L?=?L¹, L², L³; n?=?1, L⁴ and L⁵, X?=?Br; L?=?L³), [RuX₃L_1.5]₂?·?nH₂O (X?=?Br, L?=?L¹; n?=?0, L⁴; n?=?6 and L⁵; n?=?10), and [RuX₃L₂]₂ (X?=?Br, L?=?L²) have been isolated by treatment of hydrated RuX₃ (X?=?Cl/Br) in acetone with 2-(2′-aminophenylbenzimidazole) (L¹), 2-(3′-aminophenylbenzimidazole) (L²), 2-[(3′-N-salicylidinephenyl)benzimidazole] (L³), 2-(3′-pyridylbenzimidazole) (L⁴), and 2-(4′-pyridylbenzimidazole) (L⁵) in acetone. The complexes were characterized by elemental analysis, conductivity and magnetic susceptibility measurements, IR, electronic, EPR, and mass spectral studies. The complexes were dimeric; based on analytical and spectral studies, an octahedral geometry was proposed for the complexes. The synthesized complexes were screened against Gram-positive and Gram-negative bacteria and fungi.     

Synthesis and characterization of mixed ligand complexes of cobalt(II) with some nitrogen and sulfur donors

Mixed ligand complexes of Co(II) with nitrogen and sulfur donors, Co(OPD)(S–S) · 2H₂O and Co(OPD)(S–S)L₂ [OPD = o-phenylenediamine; S–S = 1,1-dicyanoethylene-2,2-dithiolate (i-MNT^2?) or 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED^2?); L = pyridine (py), α-picoline (α-pic), β-picoline (β-pic), or γ-picoline (γ-pic)], have been isolated and characterized by analytical data, molar conductance, magnetic susceptibility, electronic, and infrared spectral studies. The molar conductance data reveal non-electrolytes in DMF. Magnetic moment values suggest low-spin and high-spin complexes. The electronic spectral studies suggest distorted octahedral stereochemistry around Co(II) in these complexes. Infrared spectral studies suggest bidentate chelating behavior of i-MNT^2?, CED^2?, or OPD while other ligands are unidentate in their complexes.     

Molybdenum(VI), (V) and (IV) complexes with chiral benzoin thiosemicarbazone

The chiral (ONS) dianionic Schiff base ligand benzoin thiosemicarbazone (H₂L) reacts with MoO₂(acac)₂ to give the polymeric complex [(MoO₂L) _n ] (1) (Type 1). The reaction of MoO₂L with pyridine (py), 3-picoline (3-pic) or 4-picoline (4-pic) gives [Mo^VIO₂LD] (D = py, 3-pic or 4-pic) (Type 1). Further, the reaction of [MoO₂L] or [MoO₂LD] with PPh₃ or reaction of [MoO₂L] with PPh₃ (plus bpy or phen, D) in the presence of donor reagents D gives [Mo^IVOL] or [Mo^IVOLD] (Type 2). On the other hand, the reaction of [MoO₂L] with hydrazides (zdhH₃) such as benzoylhydrazine (bhH₃), isonicotinoylhydrazine (inhH₃), nicotinoylhydrazine (nhH₃), salicyloylhydrazine (slhH₃) and thiosemicarbazide (tscH₃) produced non-oxo–diazenido complexes [MoL(zdh)] (Type 3). The complexes have been characterized by elemental analyses, molar conductance, magnetic moment, electronic, i.r. and e.s.r. spectroscopic measurements.     

DNA-binding and cleavage activity of polypyridyl ruthenium(II) complexes

Polypyridyl ruthenium(II) complexes [Ru^II(3-bptpy)(dmphen)Cl]ClO₄ (1), [Ru^II(3-cptpy)(dmphen)Cl]ClO₄ (2), [Ru^II(2-tptpy)(dmphen)Cl]ClO₄ (3), and [Ru^II(9-atpy)(dmphen)Cl]ClO₄ (4) {where 3-bptpy?=?4′-(3-bromophenyl)-2,2′:6′,2″-terpyridine, 3-cptpy?=?4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine, 2-tptpy?=?4′-(2-thiophenyl)-2,2′:6′,2″-terpyridine, 9-atpy?=?4′-(9-anthryl)-2,2′:6′,2″-terpyridine, dmphen?=?2,9-dimethyl-1,10-phenanthroline} have been synthesized and characterized. The DNA-binding properties of the complexes with Herring Sperm DNA have been investigated by absorption titration and viscosity measurements. The ability of complexes to break the pUC19 DNA has been checked by gel electrophoresis. The experimental results suggest that all the complexes bind DNA via partial intercalation. The results also show that the order of DNA-binding affinities of the complexes is 4?<?3?<?2?<?1, confirming that planarity of the ligand in a complex is very important for DNA-binding.     

A study on synthesis and thermal,spectral and biological properties of carboxylato-Mg(II) and carboxylato-Cu(II) complexes with bioactive ligands

Summary Synthesis, elemental (CHN), spectral (FTIR), thermogravimetry (TG), differential thermal analysis (DTA) and complexometric titration have been applied to the investigation of the thermal behavior and structure of the complexes: Mg(ac)₂(mpc)₃·3H₂O(I), Mg(Clac)₂(mpc)₂·3H₂O(II), Mg(Cl₂ac)₂(mpc)₂·3H₂O(III), Mg(Cl₃ac)₂(mpc)₂·3H₂O(IV) and [Cu(ac)₂(mpc)]₂·3H₂O(V) (ac=CH₃COO^-, Clac=ClCH₂COO^-, Cl₂ac=Cl₂CHCOO^-, Cl₃ac=Cl₃CCOO^- and mpc=methyl-3-pyridyl carbamate). Thermal decomposition of these complexes is a multi-stage processes. The composition of the complexes and the solid state intermediate and resultant products of thermolysis had been identified by means of elemental analysis and complexometric titration. The possible scheme of decomposition of the complexes is suggested. Heating the complexes first resulted in a release of water molecules. The TG results show that the loss of the volatile ligand (mpc) occurs in one step for complexes II, IV and V, and in two steps for complexes I and III. The final solid product of thermal decomposition was MgO or CuO. The thermal stability of the complexes can be ordered in the sequence: I=II<IV<III<V. Mpc was coordinated to Mg(II) or Cu(II) through the nitrogen atom of its heterocyclic ring. IR data suggest to a unidentate coordination of carboxylates to magnesium or copper n complexes I-V. The preliminary studies have shown that the complexes do have antimicrobial activities against bacteria, yeasts and/or fungi. The highest antimicrobial activities were manifested by the complex V.     

Three Cu(II) (R)-2-chloromandelato complexes generated from dipyridyl-type ligands with different spacer lengths: syntheses,crystal structures,and ferroelectric properties

Three Cu(II) complexes, Cu₂(bpy)(H₂O)(Clma)₂ (1), Cu₂(bpe)(H₂O)₂(Clma)₂ (2), and Cu(bpp)(Clma) (3), were synthesized (HClma = (R)-2-Chloromandelic acid, bpy?=?4,4′-dipyridine, bpe?=?1,2-di(4-pyridyl)ethylene, bpp?=?1,3-di(4-pyridyl)propane). Complexes 1, 2, and 3 are constructed from 1-D coordination arrays generated from Cu₂(H₂O)(Clma)₂, Cu₂(H₂O)₂(Clma)₂, and Cu₂(Clma)₂ moieties and linked through bpy, bpe, and bpp co-ligands, respectively. 1 and 2 are assembled into 3-D supramolecular networks via O–H?O hydrogen bonds with topology of (6³)(6⁹·8) and (4¹²·6³), respectively, and 3 is assembled into a 3-D architecture through C–H?O hydrogen bonds with topology of (4³·6³)(4³)(4⁴·6⁵·8)(4⁶·6⁶·8³). Compounds 1, 2, and 3 crystallized in acentric space groups P2₁, P1, and P2₁, which exhibit significant ferroelectricity (remnant polarization Pr?=?0.008?μC?cm^?2, coercive field Ec?=?21.4?kV?cm^?1, the spontaneous saturation polarization Ps?=?0.167?μC?cm^?2 for 1, Pr?=?0.183?μC?cm^?2, Ec?=?1.69?kV?cm^?1, and Ps?=?0.021 μC?cm^?2 for 3). Results from infrared and thermal analyses are also discussed.     

Synthesis,spectroscopic, and thermal analyses of trinuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with some sulfa derivatives

New bi- and trihomonuclear Mn(II), Co(II), Ni(II), and Zn(II) complexes with sulfa-guanidine Schiff bases have been synthesized for potential chemotherapeutic use. The complexes are characterized using elemental and thermal (TGA) analyses, mass spectra (MS), molar conductance, IR, ¹H-NMR, UV-Vis, and electron spin resonance (ESR) spectra as well as magnetic moment measurements. The low molar conductance values denote non-electrolytes. The thermal behavior of these chelates shows that the hydrated complexes lose water of hydration in the first step followed by loss of coordinated water followed immediately by decomposition of the anions and ligands in subsequent steps. IR and ¹H-NMR data reveal that ligands are coordinated to the metal ions by two or three bidentate centers via the enol form of the carbonyl C=O group, enolic sulfonamide S(O)OH, and the nitrogen of azomethine. The UV-Vis and ESR spectra as well as magnetic moment data reveal that formation of octahedral [Mn₂L¹(AcO)₂(H₂O)₆] (1), [Co₂(L¹)₂(H₂O)₈] (2), [Ni₂L¹(AcO)₂(H₂O)₆] (3), [Mn₃L²(AcO)₃(H₂O)₉] (5), [Co₃L²(AcO)₃(H₂O)₉] · 4H₂O (6), [Ni₃L²(AcO)₃(H₂O)₉] · 7H₂O (7), [Mn₃L³(AcO)₃(H₂O)₆] (9), [Co₂(HL³)₂(H₂O)₈] · 4H₂O (10), [Ni₃L³(AcO)₃(H₂O)₉] (11), [Mn₃L⁴(AcO)₃(H₂O)₉] · H₂O (13), [Co₂(HL⁴)₂(H₂O)₈] · 5H₂O (14), and [Ni₃L⁴(AcO)₃(H₂O)₉] (15) while [Zn₂L¹(AcO)₂(H₂O)₂] (4), [Zn₃L²(AcO)₃(H₂O)₃] · 2H₂O (8), [Zn₃L³(AcO)₃(H₂O)₃] · 3H₂O (12), and [Zn₃L⁴(AcO)₃(H₂O)₃] · 2H₂O (16) are tetrahedral. The electron spray ionization (ESI) MS of the complexes showed isotope ion peaks of [M]⁺ and fragments supporting the formulation.     

Synthesis,crystal structures,and fluorescence properties of (RS)-2-methylglutarato Zn(II), Cd(II) complexes

Reactions of fresh M(OH)₂ (M = Zn²⁺, Cd²⁺) precipitate and (RS)-2-methylglutaric acid (H₂MGL), 2,2′-bipyridine (bipy), or 1,10-phenanthroline (phen) in aqueous solution at 50°C afforded four new metal–organic complexes [Zn₂(bipy)₂(H₂O)₂(MGL)₂] (1), [Zn₂(phen)₂(H₂O)(MGL)₂] (2), [Cd(bipy)(H₂O)(MGL)] · 3H₂O (3), and [Cd(phen)(H₂O)(MGL)] · 2H₂O (4), which were characterized by single crystal X-ray diffraction, IR spectra, TG/DTA analysis as well as fluorescence spectra. In 1, the [Zn(bipy)(H₂O)]²⁺ moieties are linked by R- and S-2-methylglutarate anions to build up the centrosymmetric dinuclear [Zn₂(bipy)₂(H₂O)₂(MGL)₂] molecules. In 2, the 1-D ribbon-like chains [Zn₂(phen)₂(H₂O)(MGL)₂] _n can be visualized as from centrosymmetric dinuclear [Zn₂(phen)₂(H₂O)₂(MGL)₂] units sharing common aqua ligands. Both 3 and 4 exhibit 1-D chains resulting from [Cd(bipy)(H₂O)]²⁺ and [Cd(phen)(H₂O)]²⁺, respectively, bridged alternately by R- and S-2-methylglutarate anions in bis-chelating fashion. The intermolecular and interchain π···π stacking interactions form supramolecular assemblies in 1 and 1-D chains in 2–4 into 2-D layers. The hydrogen bonded lattice H₂O molecules are sandwiched between 2-D layers in 3 and 4. Fluorescence spectra of 1–4 exhibit LLCT π → π* transitions.     

Syntheses,crystal structures,and spectral properties of Mn(II) and Co(II) complexes with 3-(p-chlorophenyl)- 4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole

Two new complexes, trans-[MnL₂(NCS)₂] (1) and trans-[CoL₂(H₂O)(EtOH)](ClO₄)₂?·?H₂O (2) with asymmetrical triaryltriazole ligands [L?=?3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole], have been synthesized and characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray diffraction. In the complexes each L adopts a chelating bidentate mode via the nitrogen of pyridyl and triazole. Both complexes have a similar distorted octahedral core with two NCS^? ions in the trans position in 1, while one H₂O and one EtOH are present in the axial sites in 2.     

Mono and dinuclear copper(II) naproxenato complexes containing 3-picoline and 4-picoline: synthesis,structure, properties,catechol oxidase,and antimicrobial activities

Mononuclear and dinuclear copper(II) complexes [Cu₂(μ-nap)₄(3-pic)₂] (1) and [Cu(nap)₂(H₂O)(4-pic)₂] (2) have been synthesized in the presence of 3-picoline and 4-picoline. Two complexes were characterized by FT-IR, UV–vis spectroscopic methods and their thermal stabilities were determined by TG/DTA/DTG techniques. The crystal structures of 1 and 2 were established by X-ray analysis. X-ray structure analysis has shown that copper(II) has a distorted square-pyramidal geometry. Naproxenate is a bridging ligand in 1 and monodentate in 2. Two complexes have shown catalytic activity on oxidation of 3,5-di-tert-butylcatechol to 3,5-di-tert-butylquinone exhibiting saturation kinetics at high substrate concentrations. The complexes were also screened for antimicrobial activity against pathogenic bacteria and fungi. The complexes exhibited antimicrobial activity against Entrococcus faecalis and Candida albicans.     

Synthesis,spectral characterization,anticancer and antibacterial studies of cyclodiphosph(V)azane derivatives and their copper(II) complexes

The new cyclodiphosph(V)azane derivatives (1,3-dimethyl-2,4-dioxo-2',4'-bis(2,4-bis(dimethylaminopropylimino)cyclodiphosph(V)azane (H₂L¹) (1,3-dimethyl-2,4-dioxo-2',4'-bis(2,4-bis(dimethylaminoethylimino)cyclodiphosph(V)azane (H₂L²) and (1,3-dimethyl-2,4-dioxo-2'-(dimethylaminoethylimino)-4'-(dimethylaminopropyl-imino)cyclodiphosph(V)azane (H₂L³) containing four active coordination centers (NNNN) and their Cu(II) complexes have been synthesized and characterized by elemental analyses, spectroscopic methods, molar conductance as well as thermal and magnetic measurements. The UV–Vis and mass spectra of the ligands and their Cu(II) complexes were also recorded. The copper(II) complexes were found to have magnetic moments of 1.58–1.69 B. M. corresponding to one unpaired electron. The possible geometries of the complexes were assigned on the basis of EPR, electronic, and infrared spectral studies. The absence of water molecules in all complexes was supported by thermal studies. All the thermal decomposition processes ended with the formation of CuO. The kinetic and thermodynamic parameters have been calculated. The ligand (H₂L³) and its Cu(II) complexes were screened for their anticancer studies against human breast cancer cell lines MCF-7 and minimum inhibitory concentration was calculated. The screening was extended to the antibacterial activity using Kirby–Bauer single disk susceptibility test for all compounds.     

Synthesis,spectroscopic (IR,electronic, FAB-mass,and PXRD), magnetic,and antimicrobial studies of new iron(III) complexes containing Schiff bases and substituted benzoxazole ligands

Mixed ligand complexes of iron(III), [Fe(sb)₂(py)Cl]?·?2H₂O (1–9) [where sbH?=?Schiff bases (derived from condensation of 2-aminopyridine (sapH), 2-aminophenol (saphH), o-toluidine (o-smabH), aminobenzene (sabH), p-toluidine (p-smabH), 3-nitroaniline (snabH), and anthranilic acid (saaH) with salicylaldehyde and substituted (mercapto-)benzimidazole (mbzH), {2-(o-hydroxyphenyl)}benzoxazole, (pboxH)], have been synthesized by the interactions of iron(III) chloride with corresponding ligands in 1?:?2 molar ratio in refluxing pyridine. These complexes have been characterized by elemental analyses, melting points, spectral, and magnetic studies. Powder X-ray diffraction studies of some representative complexes are also reported herein. The antibacterial and antifungal activities of the free ligands and their iron(III) complexes were found in vitro. The complexes showed good antibacterial and antifungal effect to some bacteria and fungi. Two standard antibiotics (chloromphenicol and terbinafine) were used for comparison with these complexes.     

Three novel octacyanomolybdate(IV)–M(II) [M = Mn and Cu] bimetallic assemblies: crystal structures and magnetic properties

Synthesis, structure characterization, and magnetic properties of three novel cyano-bridged complexes {[Mn^II(bpy)(DMF)₂]₂[Mo^IV(CN)₈]·1.5H₂O} _n (1), [Cu^II(L)]₂[Mo^IV(CN)₈]·6.75H₂O (2), and [Mn^II(bpy)₂]₄[Mo^IV(CN)₈]₂·4MeOH·4H₂O (3) (where DMF = N,N′-dimethylformamide; bpy = 2,2-bipyridine and L = 1,3,6,8,11,14-hexaazatricyclo[12.2.1.1^8,11]octadecane) have been studied. The X-ray single-crystal structure reveals that 1 is a cyanide-bridged 1D infinite chain with the alternating of Mn^II(bpy)(DMF)₂ and Mo^IV(CN)₈ moieties. The neighboring chains interact with each other by hydrogen bonding to form a sheet-like network, and the layers further extend to a 3D network due to the face-to-face π···π stack interactions. For 2, the Mo^IV center adopts a distorted square antiprism coordination environment, while the Cu^II center adopts a distorted square pyramidal geometry. The weak Mo–CN···Cu interactions between neighboring molecules lead to a 2D network structure of 2. For 3, basic structural unit is centrosymmetric and contains four Mn^II centers bridged by two octacyanomolybdate(IV). Here, their magnetic properties have also been studied. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.