Tin(IV) complexes of 2‐benzoylpyridine N(4)‐phenyl‐thiosemicarbazone: spectral characterization,structural studies and antifungal activity

Three tin(IV) complexes of 2‐benzoylpyridine N(4)‐phenylthiosemicarbazone (H2Bz4Ph) were prepared: [Sn(L)Cl₃] (1), [BuSn(L)Cl₂] (2) and [(Bu)₂Sn(L)Cl] (3), in which L stands for the anionic ligand formed upon complexation with deprotonation and release of HCl. The complexes were characterized by a number of spectroscopic techniques. The crystal structures of H2Bz4Ph and complex 3 were determined. The antifungal activity of the ligand and its tin(IV) complexes was tested against Candida albicans. The thiosemicarbazone proved to be more active than the tin(IV) complexes. Copyright © 2003 John Wiley & Sons, Ltd.     

Two Lanthanide(III) Complexes based on the Schiff Base N,N′‐Bis(salicylidene)‐1,5‐diamino‐3‐oxapentane: Synthesis,Characterization, DNA‐binding Properties,and Antioxidation

The Schiff base N,N′‐bis(salicylidene)‐1,5‐diamino‐3‐oxapentane (H₂L) and its lanthanide(III) complexes, PrL(NO₃)(DMF)(H₂O) ( 1 ) and Ho₂L₂(NO₃)₂ · 2H₂O ( 2 ), were synthesized and characterized by physicochemical and spectroscopic methods. Single crystal X‐ray structure analysis revealed that complex 1 is a discrete mononuclear species. The Pr^III ion is nine‐coordinate, forming a distorted capped square antiprismatic arrangement. Complex 2 is a centrosymmetric dinuclear neutral entity in which the Ho^III ion is eight‐coordinate with distorted square antiprismatic arrangement. The DNA‐binding properties of H₂L and its Ln^III complexes were investigated by spectrophotometric methods and viscosity measurements. The results suggest that the ligand H₂L and its Ln^III complexes both connect to DNA in a groove binding mode; the complexes bind more strongly to DNA than the ligand. Moreover, the antioxidant activities of the Ln^III complexes were in vitro determined by superoxide and hydroxyl radical scavenging methods, which indicate that complexes 1 and 2 have OH ^· and O₂^{– ·} radical scavenging activity.     

Synthesis,Characterization, and Antibacterial Activities of Organotin(IV) Complexes with 2‐Acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone (HAPCT)

The reaction of 2‐acetylpyridine‐N(4)‐cyclohexylthiosemicarbazone [(HAPCT), ( 1 )] ligand with organotin(IV) chloride(s) afforded the five new organotin(IV) complexes: [MeSnCl₂(APCT)] ( 2 ), [BuSnCl₂(APCT)] ( 3 ), [PhSnCl₂(APCT)] ( 4 ), [Me₂SnCl(APCT)] ( 5 ), and [Ph₂SnCl(APCT)] ( 6 ). The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) have been synthesized and characterized by CHN analyses, molar conductivity, UV–vis, FT IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. The single crystal X‐ray diffraction studies indicated that [PhSnCl₂(APCT)] ( 4 ) is six coordinated and strongly adopts a distorted octahedral configuration with the coordination through pyridine‐N, azomethine‐N, and thiolato‐S atoms of the ligand. The compound crystallizes into a monoclinic lattice with the space group P21/n. The ligand ( 1 ) and its organotin(IV) complexes ( 2–6 ) were assayed for in vitro antibacterial activity against Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, and Salmonella typhi. The screening results have shown that the organotin(IV) complexes ( 2–6 ) have better antibacterial activity than the free ligand. Furthermore, it has been shown that the diphenyltin(IV) derivative ( 6 ) exhibits significantly better activities than the other organotin(IV) derivatives ( 2–5 ). © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:43–52, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21061     

Novel 13,14‐dimethyl‐5,8‐dioxa‐2,11,13,14‐tetraaza‐1,12‐diphosphabicyclo [10.1.1] tetradecane 1,12‐dioxide ligand and its Ni(II), Co(II), and Cu(II) complexes: Synthesis,characterization, antimicrobial,DNA cleavage,and computational studies

A novel diazadiphosphetidine ligand derived from the reaction of 2,4‐dichloro‐1,3‐dimethyl‐1,3,2,4‐diazadiphosphetidine‐2,4‐dioxide and 2,2′‐(ethane‐1,2‐diylbis[oxy])bis(ethan‐1‐amine) and its Ni(II), Cu(II), and Co(II) complexes have been synthesized, characterized by spectroscopic, elemental analyses, magnetic susceptibility, and conductivity methods, and screened for antimicrobial, DNA binding, and cleavage properties. Spectroscopic analysis and elemental analyses indicate the formula [M(H₂L)Cl₂] for the Cu(II), Co(II), Ni(II), and Zn(II) complexes and octahedral geometry for all the complexes. The non‐electrolytic nature of the complexes in dimethyl sulfoxide (DMSO) was confirmed by their molar conductance values, which are in the range 12.32–6.73 Ω^?1 cm² mol^?1. Computational studies have been carried out at the density functional theory (DFT)‐B3LYP/6‐31G(d) level of theory on the structural and spectroscopic properties of diazadiphosphetidine H₂L and its binuclear Cu(II), Co(II), Ni(II), and Zn(II) complexes. Six tautomers and geometrical isomers of the diazadiphosphetidine ligand were confirmed using semiempirical AM1 and DFT method from DMOL³ calculations. The copper complex had the best antibacterial activity against Staphylococcus aureus (ATCC 29213). DNA cleavage activities of the compounds, evaluated on pBR322 DNA by agarose gel electrophoresis in the presence and absence of an oxidant (H₂O₂) and a free‐radical scavenger (DMSO), indicated no activity for the ligand and moderate activity for the complexes, with the copper complex cleaving pBR322 DNA more efficiently in the presence of H₂O₂.     

Ligational behavior of thiosemicarbazone,semicarbazone and thiocarbohydrazone ligands towards VO(IV), Ce(III), Th(IV) and UO2(VI) ions: Synthesis,structural characterization and biological studies

Mono- and binuclear VO(IV), Ce(III), Th(IV) and UO₂(VI) complexes of thiosemicarbazone, semicarbazone and thiocarbohydrazone ligands derived from 4,6-diacetylresorcinol were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, UV–vis, ESR, ¹H NMR and mass spectra as well as conductivity and magnetic susceptibility measurements and thermal analyses. The thiosemicarbazone (H₄L¹) and the semicarbazone (H₄L²) ligands behave as dibasic pentadentate ligands in case of VO(IV) and UO₂(VI) complexes, tribasic pentadentate in case of Ce(III) complexes and monobasic pentadentate in case of Th(IV) complexes. However, the thiocarbohydrazone ligand (H₃L³) acts as a monobasic tridentate ligand in all complexes except the VO(IV) complex in which it acts as a dibasic tridentate ligand. The antibacterial and antifungal activities were also tested against Rhizobium bacteria and Fusarium-Oxysporium fungus. The metal complexes of H₄L¹ ligand showed a higher antibacterial effect than the free ligand while the other ligands (H₄L² and H₃L³) showed a higher effect than their metal complexes. The antifungal effect of all metal complexes is lower than the free ligands.     

Syntheses,characterization and biological studies of zinc(II), copper(II) and cobalt(II) complexes with Schiff base ligand derived from 2‐hydroxy‐1‐naphthaldehyde and selenomethionine

Novel zinc(II), copper(II), and cobalt(II) complexes of the Schiff base derived from 2‐hydroxy‐1‐naphthaldehyde and D, L ‐selenomethionine were synthesized and characterized by elemental analysis, IR, electronic spectra, conductance measurements, magnetic measurements and powder XRD. The analytical data showed the composition of the metal complex to be ML(H₂O), where L is the Schiff base ligand and M = Co(II), Cu(II) and Zn(II). IR results confirmed the tridentate binding of the Schiff base ligand involving azomethine nitrogen, naphthol oxygen and carboxylato oxygen atoms. ¹H NMR spectral data of lithium salt of the Schiff base ligand [Li(HL)] and ZnL(H₂O) agreed with the proposed structures. The conductivity values of complexes between 12.50 and 15.45 S cm² mol^?1 in DMF suggested the presence of non‐electrolyte species. The powder XRD studies indicated that Co(II) complex is amorphous, whereas Cu(II) and Zn(II) complexes are crystalline. The results of antibacterial and antifungal screening studies indicated that Li(HL) and its metal complexes are active, but CuL(H₂O) is most active among them. Copyright © 2010 John Wiley & Sons, Ltd.     

Lanthanide(III) Complexes of 4,10‐Bis(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecane‐1,7‐diacetic acid (trans‐H6do2a2p) in Solution and in the Solid State: Structural Studies Along the Series

Complexes of 4,10‐bis(phosphonomethyl)‐1,4,7,10‐tetraazacyclododecane‐1,7‐diacetic acid (trans‐H₆do2a2p, H₆ L ) with transition metal and lanthanide(III) ions were investigated. The stability constant values of the divalent and trivalent metal‐ion complexes are between the corresponding values of H₄dota and H₈dotp complexes, as a consequence of the ligand basicity. The solid‐state structures of the ligand and of nine lanthanide(III) complexes were determined by X‐ray diffraction. All the complexes are present as twisted‐square‐antiprismatic isomers and their structures can be divided into two series. The first one involves nona‐coordinated complexes of the large lanthanide(III) ions (Ce, Nd, Sm) with a coordinated water molecule. In the series of Sm, Eu, Tb, Dy, Er, Yb, the complexes are octa‐coordinated only by the ligand donor atoms and their coordination cages are more irregular. The formation kinetics and the acid‐assisted dissociation of several Ln^III–H₆ L complexes were investigated at different temperatures and compared with analogous data for complexes of other dota‐like ligands. The [Ce( L )(H₂O)]^3? complex is the most kinetically inert among complexes of the investigated lanthanide(III) ions (Ce, Eu, Gd, Yb). Among mixed phosphonate–acetate dota analogues, kinetic inertness of the cerium(III) complexes is increased with a higher number of phosphonate arms in the ligand, whereas the opposite is true for europium(III) complexes. According to the ¹H NMR spectroscopic pseudo‐contact shifts for the Ce–Eu and Tb–Yb series, the solution structures of the complexes reflect the structures of the [Ce(H L )(H₂O)]^2? and [Yb(H L )]^2? anions, respectively, found in the solid state. However, these solution NMR spectroscopic studies showed that there is no unambiguous relation between ³¹P/¹H lanthanide‐induced shift (LIS) values and coordination of water in the complexes; the values rather express a relative position of the central ions between the N₄ and O₄ planes.     

Copper(II) and Cadmium(II) Complexes Based on N,N‐Bis(3, 5‐dimethyl‐2‐hydroxybenzyl)‐N‐(2‐pyridylmethyl)amine Ligand: Syntheses,Structures, Magnetic,and Luminescent Properties

The reaction of the aryl‐oxide ligand H₂L [H₂L = N,N‐bis(3, 5‐dimethyl‐2‐hydroxybenzyl)‐N‐(2‐pyridylmethyl)amine] with CuSO₄ · 5H₂O, CuCl₂ · 2H₂O, CuBr₂, CdCl₂ · 2.5H₂O, and Cd(OAc)₂ · 2H₂O, respectively, under hydrothermal conditions gave the complexes [Cu(H₂L¹)₂] · SO₄ · 3CH₃OH ( 1 ), [Cu₂(H₂L²)₂Cl₄] ( 2 ), [Cu₂(H₂L²)₂Br₄] ( 3 ), [Cd₂(HL)₂Cl₂] ( 4 ), and [Cd₂(L)₂(CH₃COOH)₂] · H₂L ( 5 ), where H₂L¹ [H₂L¹ = 2, 4‐dimethyl‐6‐((pyridin‐2‐ylmethylamino)methyl)phenol] and H₂L² [H₂L² = 2‐(2, 4‐dimethyl‐6‐((pyridin‐2‐ylmethylamino)methyl)phenoxy)‐4, 6‐dimethylphenol] were derived from the solvothermal in situ metal/ligand reactions. These complexes were characterized by IR spectroscopy, elementary analysis, and X‐ray diffraction. A low‐temperature magnetic susceptibility measurement for the solid sample of 2 revealed antiferromagnetic interactions between two central copper(II) atoms. The emission property studies for complexes 4 and 5 indicated strong luminescence emission.     

Synthesis,spectral and antimicrobial studies of diorganotin(IV)3(2′‐hydroxyphenyl)‐5‐(4‐substituted phenyl) pyrazolinates

Diorganotin(IV) dipyrazolinates of the type R₂Sn(C₁₅H₁₂N₂OX)₂ [where C₁₅H₁₂N₂OX = 3(2′‐Hydroxyphenyl)‐5(4‐X‐phenyl)pyrazoline {where X = H ( a ); CH₃ ( b ); OCH₃ ( c ); Cl ( d ) and R = Me, Prⁿ and Ph}] have been synthesized by the reaction of R₂SnCl₂ with sodium salt of pyrazolines in 1:2 molar ratio, in anhydrous benzene. These newly synthesized derivatives have been characterized by elemental analysis (C, H, N, Cl and Sn), molecular weight measurement as well as spectral [IR and multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn)] studies. The bidentate behaviour of the pyrazoline ligands was confirmed by IR, ¹H and ¹³C NMR spectral data. A distorted trans‐octahedral structure around tin(IV) atom for R₂Sn(C₁₅H₁₂N₂OX)₂ has been suggested. The free pyrazoline and diorganotin(IV) dipyrazolinates have also been screened for their antibacterial and antifungal activities. Some diorganotin(IV) dipyrazolinates exhibit higher antibacterial and antifungal effect than free ligand and some of the antibiotics. Copyright © 2006 John Wiley & Sons, Ltd.     

Structural studies and biological activity evaluation of Pd(II), Pt(II) and Ru(II) complexes containing N‐phenyl,N`‐(3‐triazolyl)thiourea

[MCl(H₂L)(OH₂)]·1.5H₂O (M = Pd(II) ( 1 ) and Pt(II) ( 2 )) and [Ru(H₂L)₂(OH₂)₂]·3H₂O ( 3 ) (H₃L: N‐phenyl, N`‐(3‐triazolyl)thiourea) were synthesized, characterized and tested for their antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria. The thiourea derivative is coordinated to Mⁿ⁺ ions as a mono‐negatively N,S‐bidentate ligand via the enolization of C = S group and triazole N center. The density functional theory calculations reveal that presence of a water molecule in a trans position to triazole ring increased the stability of d⁸ metal ions complexes via the formation of strong Cl…NH intramolecular H‐bond. The cis‐Ru(II)‐isomer with two isoenergetically H₂L^? molecules are more stable than the trans‐analog. Coordination of H₃L to Ru(II) ion did not alter the toxicity of the free ligand, while the interaction with the d⁸ metal ions gave rise to inactive compounds.     

A new diaza‐18‐crown‐6 ligand containing two quinolin‐8‐ylmethyl side arms: Crystal structures and characterization of the ligand,the protonated ligand and its mononuclear barium(II) and dinuclear copper(II) complexes

A new 7,16‐bis(quinolin‐8‐ylmethyl)‐1,4,10,13‐tetraoxa‐7,16‐diazacyclooctadecane ligand, L, has been prepared and its crystal structure reported. In addition, the structure of the protonated ligand H₂L has been determined. H₂L is of interest because of interatomic interactions between the ligand and perchlorate ions. The mononuclear Ba(II) (Ba L ), and dinuclear Cu(II) (Cu₂L) complexes of L have been prepared and their crystal structures determined. Stability constants and other thermodynamic data valid in methanol at 23 or 25° for these and several other complexes of L have been obtained. Among the metal ions studied, L forms the most stable complex with Ba²⁺. In addition, L selectively binds Cu²⁺ over Ni²⁺ by about 3 orders of magnitude. Some of the complexes have been studied using nmr and uv‐vis spectroscopic techniques. Crystal data are given for L, space group, P2₁c, a = 8.8325(14) Å, b = 13.808(3) Å, c = 13.310(3) Å; β = 94.72(2)° Z=2, R = 0.0727; for H₂ L , space group, P2₁/c, a = 14.685(3) Å, b = 15.035(6) Å, c = 17.369(4) Å, β = 90.366(12)°, Z = 4, R = 0.0781; for Ba L , space group, Pbcn, a = 17.314(3) Å, b = 9.539(2) Å, c = 22.081(3) Å, Z = 4, R = 0.0354; and for Cu₂ L , space group, Cc, a = 19.762(2) Å, b = 14.413(2) Å, c = 14.935(2) Å, β = 98.753(12)°, Z = 4, R = 0.0564. Cu²⁺ forms a hydroxo‐bridged dinuclear complex with L while Ba²⁺ forms a mononuclear complex with L in which its two side arms are not involved in complexation.     

Molecular and Supramolecular Structures of 1‐Phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H2L) and its Complexes with Diphenyllead(IV) Chloride and Acetate

Reaction of 1‐phenyl‐4‐phenylacetyl‐2‐thiosemicarbazide (H₂L) with diphenyllead(IV) dichloride and acetate afforded the complexes [PbPh₂Cl₂(H₂L)₂] and [PbPh₂L]. The ligand and the complexes were characterized by elemental analyses, ¹H and ¹³C NMR spectroscopy and X‐ray crystallography. In the asymmetric unit of crystals of the ligand there are four independent molecules of H₂L and four molecules of water, which associate in the lattice as two independent sheets. The complex [PbPh₂Cl₂(H₂L)₂]·4MeOH has slightly distorted all‐trans octahedral geometry around the lead atom, and the fact that the ligand is S‐bound rather than O‐bound suggests that PbPh₂Cl₂ behaves as a “soft” Lewis acid. Hydrogen bonds involving NH groups, Cl atoms and MeOH molecules form a three‐dimensional supramolecular structure. In [PbPh₂L]·Me₂CO, the L^2? anion bridges between two metal centres, binding to one strongly via the N and S atoms and weakly via the O atom, and to the other via the O atom, thus creating polymeric chains along the b axis. The double deprotonation and metallation of H₂L induce significant changes in its configuration and lengthen the C‐S and C‐O bonds, suggesting an evolution of the dianion towards a thiol‐enol form.     

Adducts of bis(acetylacetonato)zinc(II) with 1,10‐phenanthroline and 2,2′‐bipyridine

In each of the zinc(II) complexes bis(acetylacetonato‐κ²O,O′)(1,10‐phenanthroline‐κ²N,N′)zinc(II), [Zn(C₅H₇O₂)₂(C₁₂H₈N₂)], (I), and bis(acetylacetonato‐κ²O,O′)(2,2′‐bipyridine‐κ²N,N′)zinc(II), [Zn(C₅H₇O₂)₂(C₁₀H₈N₂)], (II), the metal center has a distorted octahedral coordination geometry. Compound (I) has crystallographically imposed twofold symmetry, with Z′ = 0.5. The presence of a rigid phenanthroline group precludes intramolecular hydrogen bonding, whereas the rather flexible bipyridyl ligand is twisted to form an intramolecular C—H...O interaction [the chelated bipyridyl ligand is nonplanar, with the pyridyl rings inclined at an angle of 13.4 (1)°]. The two metal complexes are linked by dissimilar C—H...O interactions into one‐dimensional chains. The present study demonstrates the distinct effects of two commonly used ligands, viz. 1,10‐phenanthroline and 2,2′‐bipyridine, on the structures of metal complexes and their assembly.     

trans‐[1,3‐Bis(2,4,6‐trimethylphenyl)imidazolidin‐2‐ylidene]dichlorido(triphenylphosphine‐κP)palladium(II)

The title complex, [PdCl₂(C₂₁H₂₆N₂)(C₁₈H₁₅P)], shows slightly distorted square‐planar coordination around the Pd^II metal centre. The Pd—C bond distance between the N‐heterocyclic ligand and the metal atom is 2.028 (5) Å. The dihedral angle between the two trimethylphenyl ring planes is 36.9 (2)°.     

(2,2′‐Biquinoline‐κ2N,N′)dichloropalladium(II), ‐copper(II) and ‐zinc(II)

In the three title complexes, namely (2,2′‐biquinoline‐κ²N,N′)dichloro­palladium(II), [PdCl₂(C₁₈H₁₂N₂)], (I), and the corresponding copper(II), [CuCl₂(C₁₈H₁₂N₂)], (II), and zinc(II) complexes, [ZnCl₂(C₁₈H₁₂N₂)], (III), each metal atom is four‐coordinate and bonded by two N atoms of a 2,2′‐biquinoline molecule and two Cl atoms. The Pd^II atom has a distorted cis‐square‐planar coordination geometry, whereas the Cu^II and Zn^II atoms both have a distorted tetra­hedral geometry. The dihedral angles between the N—M—N and Cl—M—Cl planes are 14.53 (13), 65.42 (15) and 85.19 (9)° for (I), (II) and (III), respectively. The structure of (II) has twofold imposed symmetry.     

Synthesis,structure and cytotoxic activity of binuclear phenyltin(IV) complexes with N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand

Two new dinuclear phenyltin(IV) complexes derived from N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand, [2‐HOC₆H₄CH₂N(CS₂SnPh₃)CH₂]₂ ( 1 ) and [2‐HOC₆H₄CH₂N(CS₂SnClPh₂)CH₂]₂ ( 2 ) have been synthesized and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of complexes 1 and 2 were determined by X‐ray single crystal diffraction and show that the dithiocarbamate ligand is coordinated to the tin atom in the anisobidentate manner and the tin atom is five‐coordinated. The coordination geometry of tin atom is best described as an intermediate between trigonal bipyramidal and square pyramidal with τ‐values of 0.63 and 0.53, respectively. Intermolecular hydrogen bonds (O H···S and O H···Cl) in 1 and 2 connect neighboring molecules into a one‐dimensional supramolecular chain with the centrosymmetric cyclic motifs. Complex 1 has potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while complex 2 displays weak cytotoxic activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis,characterization, DFT modeling and biological studies of new Co(II), Ni(II) and Cu(II) 4,6-bis(4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile complexes

Three new metal complexes of 4,6-bis(4-chlorophenyl)-2-amino-1,2-dihydropyridine-3-carbinitrile (L) with Co(II), Ni(II) and Cu(II) were synthesized and characterized with physicochemical and spectroscopic techniques. The data suggest that (L) acts as a bidentate ligand bound to the divalent metal ions through amino N and carbinitrile N atoms having [M(L)₂(H₂O)₂]²⁺ formula (M = metal ions). The theoretical parameters, model structures, charges and molecular orbitals of all possible complexes have been determined using density functional theory. The energy gap of free ligand is ?E = 0.12565 eV, and this value is greater than energy gap of complexes, which indicates that the complexes are more reactive than free ligand. Also, ?E of Co(II) complex is lower than other complexes, which indicates that Co(II) complex is more reactive than Ni(II) and Cu(II) complexes. The antibacterial and antifungal activities of the ligand, metal salts and its complexes were tested against some microorganisms (bacteria and fungi). The complexes showed increased antibacterial and antifungal profile in comparison with the free ligand.     

Synthesis,Crystal Structure and Photoluminescence Property of Zinc(II), Cadmium(II), and Lead(II) Complexes with Bidentate Ligand: 1‐(1‐Imidazolyl)‐4‐(imidazol‐1‐ylmethyl)benzene (IIMB)

Assembly of bidentate ligand 1‐(1‐imidazolyl)‐4‐(imidazol‐1‐ylmethyl)benzene (IIMB) with varied metal salts of Zn^II, Cd^II and Pb^II provide three new complexes, [Zn(IIMB)₂](ClO₄)₂·2H₂O ( 1 ), [Cd(IIMB)₂(SCN)₂] ( 2 ) and [Pb(IIMB)₂(SCN)](SCN) ( 3 ). Single crystal X‐ray diffraction studies revealed that complexes 1 and 2 display a similar one‐dimensional double stranded chain structure, while complex 3 is a slight distorted rhombohedral grid network with (4,4) topology. The results indicate that the coordination geometry of the metal ion and the counter anion have great impact on the structure of the complexes. In addition, the photoluminescence properties of ligand IIMB and complexes 1 – 3 were studied in the solid state at room temperature.     

New Transition and Actinide Metal Complexes of 2‐Carboxy‐phenylhydrazo‐Benzoylacetone Ligand: Synthesis,Characterization and Biological Study

A new series of binary mononuclear complexes were prepared from the reaction of the hydrazone ligand, 2-carboxyphenylhydrazo-benzoylacetone (H2L), with the metal ions, Cd(II), Cu(II), Ni(II), Co(II), Th(IV) and UO2(VI). The binary Cu(II) complex of H2L was reacted with the ligands 1,10-phenanthroline or 2-aminopyridine to form mixed-ligand complexes. The binary complexes of Cu(II) and Ni(II) are suggested to have octahedral configurations. The Cd(II) and Co(II) complexes are suggested to have tetrahedral and/or square-planar geometries, respectively. The Th(IV) and UO2(VI) complexes are suggested to have octahedral and dodecahedral geometries, respectively. The mixed-ligand complexes have octahedral configurations. The structures of all complexes and the corresponding thermal products were elucidated by elemental analyses, conductance, IR and electronic absorption spectra, magnetic moments, 1H NMR and TG-DSC measurements as well as by mass spectroscopy. The ligand and some of the metal complexes were found to activate the enzyme pectinlyase.     

Synthesis and characterization of oxovanadium(IV), vanadium(IV) and oxovanadium(V) complexes of tetradentate Schiff bases. Attempted preparation of vanadium-carbon bonded compounds through desilylation

Condensation of 1,3-diaminopropane-2-ol with diacetylmonoxime, acetylacetone, salicylaldehyde and orthohydroxyacetophenone yielded the tetradentate Schiff bases N,N′-(2-hydroxy)propylenebis{(2-imino-3-oximino)butane} (H₂dampnol), N,N′-(2-hydroxy)propylenebis(acetylacetoneimine) (H₂acacpnol), N,N′-(2-hydroxy)propylenebis-(salicyalaldimine) (H₂salpnol) and N,N′-(2-hydroxy)propylenebis(7-methylsalicylaldimine) (H₂ohacpnol), respectively. The ligands form complexes with oxovanadium(IV), vanadium(IV) and oxovanadium(V) salts. Some mixed ligand complexes involving σ-bonded phenyl and benzyl radical along with tetradentate ligand, H₂L (where, H₂L stands for H₂dampnol, H₂acacpnol, H₂salpnol or H₂ohacpnol) of the types [(L)V(C₆H₅)₂]CH₃OH and [(L)V(CH₂Ph)₂]CH₃OH have been synthesized, characterized and also provide the syntheses of some new organovanadium(IV) complexes. Silylation coupled with desilylation have been employed as a route to new organovanadium(IV) complexes. All the complexes have been characterized with the help of elemental analyses, molar conductance values, molecular weights, magnetic moments and spectroscopic (IR, UV-Vis, ESR) data.