Synthesis, characterisation and in vitro evaluation of palladium(II) iminophosphine complexes for anticancer activity

Palladium(II) complexes have been obtained from the reactions of the iminophosphine ligands, (L1–L7), respectively, with [PdCl₂(COD)] and [PdMeCl(COD)] in CH₂Cl₂ at room temperature. The palladium(II) complexes were characterised using elemental analysis, electro spray ionisation–mass spectrometry (ESI–MS), NMR (¹H and ³¹P), IR spectroscopy and X-ray diffraction studies. Single-crystal X-ray diffraction analysis for complexes 2, 7 and 8 revealed that the complexes exhibited a slightly distorted square planar geometry. In vitro cytotoxic study results show that the palladium complexes exhibit moderate activity and block the proliferation of WHCO1 cells with an IC₅₀ range of 19.02–45.27 μM, and IC₅₀ range of 10.03–68.54 μM for the KYSE450 cell lines.     

Synthesis and structure of new compounds with Pt-Ga bonds: Insertion of the bulky gallium (I) bisimidinate Ga(DDP) into Pt-Cl bond

Reactions of the sterically bulky mono-valent group 13 bisimidinate gallium(I), Ga(DDP) (1) (DDP = 2-{(2, 6-diisopropylphenyl)amino}-4-{(2, 6-diisopropylphenyl)imino}-2-pentene, HC(CMeNC₆H₃-2,6-ⁱPr₂)₂) with olefin supported group 10 complexes, [(diene)PtCl₂] [diene = 1,5-cyclooctadiene (COD), endo-dicyclopentadiene (dcy)] and [(COD)Pd(Me)(OTf)] (OTf = O₃SCF₃) are reported. These reactions afforded [(COD)Pt(Cl){ClGa(DDP)}] (2), [(dcy)Pt(Cl){ClGa(DDP)}] (3) and [(DDP)Ga(Me)(OTf)] (4) in moderate yields. Compounds 2-4 were characterized by elemental analysis, NMR (¹H, ¹³C) spectroscopy and also by single crystal X-ray structural analysis. The solid state structures of complexes 2 and 3 reveal the oxidative insertion of Ga(DDP) into the Pt-Cl bond without altering the π-coordinated double bonds in the olefin.     

Complexes in polymers III: Addition reactions of trans-Ir(PPh3)2(CO)Cl embedded in polystyrene with hydrogen,oxygen, sulfur dioxide,carbon monoxide and gaseous iodine and of (η-C5H5)Ru(η4-1,5-cyclooctadiene)Cl in polystyrene with carbon monoxide

The addition rections of trans-Ir(PPh₃)₂(CO)Cl embedded in films of polystyrene (PS) with hydrogen, oxygen, sulfur dioxide, carbon monoxide and gaseous iodine were monitored by infrared spectroscopy and found to be similar to those occurring in toluene. While the reaction with iodine was rapid at the surface of the film as determined by attenuated-total-reflectance infrared spectroscopy, the reaction was much slower in the body of the film, as shown by transmission infrared spectroscopy. No such difference was observed for oxygen. The complex CpRu(COD)Cl (Cp = η-C₅H₅, COD = 1,5-cyclooctadiene) in PS readily undergoes ligand substitution by carbon monoxide (CO and ¹³CO) to give CpRu(CO)₂Cl and CpRu(¹³CO)₂Cl embedded in PS, respectively.     

Conformational behaviour of dinuclear Rh(I) complexes of the open-chain tetrapyrrolic ligand 2,2′-bidipyrrin (H2BDP)

The reaction of 2,2′-bidipyrrins H₂BDP with the Rh^I complexes [Rh(COD)(μ-OMe)]₂ and [Rh(CO)₂(μ-Cl)]₂ yields the neutral species [{Rh(COD)}₂BDP] (7, 8) and [{Rh(CO)₂}₂BDP] (2, 9), respectively. Treatment of the COD complexes with carbon monoxide results in the exchange of all COD ligands against CO. Ligand exchange studies on the carbonyl complexes 2 and 9 with different phosphane donors reveal the regioselective exchange of one CO per metal ion. In most cases, the reaction is accompanied by a large conformational change of the tetrapyrrole from a syn to an anti conformation. This conformational change was resolved by a combination of NMR spectroscopy and X-ray diffraction studies.     

Reactions of chiral phosphoramidites with complexes Pd(COD)Cl2 and Pt(COD)Cl2

Reactions of phosphoramidites based on (−)-ephedrine and [(1S)-endo]-(−)-borneol with the complexes M(COD)Cl₂ (M is Pd or Pt, and COD is cycloocta-1,5-diene) were studied. The formation ofcis andtrans complexes of the general formulas MCl₂L₂ and M₂Cl₂(μ-Cl)₂L₂ was observed. The structures of the resulting compounds were established by³¹P,¹³C, and¹⁹⁵Pt NMR and IR spectroscopy and by plasma desorption mass spectrometry. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1627–1630, August, 1998.     

Transition metal (Group 6, Ru and Group 10) derivatives of aminophosphines, Ph2PN(H)R (R=Ph, C6H11)

The reactions of aminophosphines with Group 6 metal carbonyls afford both mono-substituted and disubstituted complexes. The reaction of Ph₂PN(H)C₆H₁₁ with molybdenum tetracarbonyl derivative gives a mixture of cis and trans-isomers. The reaction of Ph₂PN(H)Ph with Pd(COD)Cl₂ leads to the PN bond cleavage to give chloro bridged dimer, [Pd(PPh₂O)(PPh₂OH)(μ-Cl)]₂, whereas with Pt(COD)Cl₂, disubstituted cis-[PtCl₂{PPh₂N(H)R}₂]₂ was obtained. The reaction of Ph₂PN(H)C₆H₁₁ with RuCl₂(DMSO)₄ or RuCl₂(PPh₃)₃ leads to the formation of ionic complex, [RuCl{Ph₂PN(H)C₆H₁₁}₃]Cl.     

π-Olefin—iridium -komplexe : III. Über (η4-cyclodien)(η5-cyclodienyl)iridium-verbindungen,einen neuartigen hydridoiridium-komplex und das (η4-cyclooctadien)(η6-cyclooctatrien)iridium-kation

The complexes [Ir(COD)(η⁵-C₇H₉)] and [Ir(COD)(η⁵-C₈H₁₁)] are obtained by the isoprophyl Grignard synthesis of [Ir(COD)Cl]₂ (COD = η⁴-1,5-cyclooctadiene) in the presence of cycloheptatriene, and cyclooctatriene, respectively. The later reaction yields [IrH(COD)(δ⁴-1,3,6-C₈H₁₀)] as a by-product which, in contrast to other [IrH(η⁴-cyclodiene)₂] complexes, does not show H-addition-elimination equilibria. Reduction of [Ir(1,3-C₇H₁₀)₂Cl] with C₂H₅OH/Na₂CO₃ yields [Ir(η⁴-1,3-C₇H₁₀)](η⁵-C₇H₉)] which was characterized by X-ray analysis. [Ir(COD)Cl]₂ reacts with Na₂C₈H₈, and after hydrolysis unstable [Ir(COD)(η⁵-C₈H₉)] is formed which by protonation with HPF₆ is converted into the [Ir(COD)(η⁶-1,3,5-C₈H₁₀)]⁺ cation. All these compounds are fluxional in solution.     

Stannylierungsexperimente mit NH-funktionellen Aminoiminophosphoranen. Synthese und Struktur der tricyclischen Stannaphosphazene [Me2Sn(tBu2PN)NH]2 und [nBu2Sn(Ph2PN)2NH]2

Stannylation Experiments with NH-functional Aminoiminophosphoranes. Synthesis and Structure of the Tricyclic Stannaphosphazenes [Me₂Sn(^tBu₂PN)NH]₂ and [ⁿBu₂Sn(Ph₂PN)₂NH]₂ Aminoiminophosphoranes ^tBu₂P(NH)NH₂ ( 1 ) and (H₂NPPh₂)N(Ph₂PNH) ( 2 ) react with diaminostannanes R₂Sn(NEt₂)₂ by cyclocondensation to give cyclostannaphosphazenes [Me₂Sn(^tBu₂PN)NH]₂ ( 3 ) and [R₂Sn(Ph₂PN)₂NH]₂ ( 4 a , b ) ( a : R = Me, b : R = ⁿBu). With 2 and Me₃SnNEt₂ the ring compound Me₂Sn(Ph₂PN)₂NSnMe₃ ( 5 ) besides Me₄Sn is formed by per-N-stannylation and Sn-methyl group transfer. The crystal structures of 3 and 4 b were determined by X-ray structure analysis. 3 forms a planar heterotricyclus containing three four-membered rings with two pentacoordinated tin atoms (space group P 1 (No. 2); Z = 1). 4 b consists of a tricyclic molecule with two puckered six-membered rings and one planar four membered tin-nitrogen ring with two pentacoordinated tin atoms (space group P 1 (No. 2); Z = 1).     

The Synthesis and Structure of Hexakis(dimethylphenylphosphonite)ruthenium(II) bis[tetraphenylborate(–1)]

Abstract . Treatment of the hydrazine salt [Ru(COD)(H₂NNH₂)₄][BPh₄]₂ with excess of P(OMe)₂Ph in acetone gave a homoleptic complex trans‐[Ru{P(OMe)₂Ph}₆][BPh₄]₂, which was characterized by IR, ³¹P{¹H}, ¹³C{¹H}, and ¹H NMR spectroscopy, elemental analysis, and X‐ray crystallography. The ruthenium in the complex has distorted octahedral coordination arrangement and bonded to all the six P(OMe)₂Ph molecules through the phosphorus atoms.     

Pentacoordinated iridium(I) complexes incorporating azopyridine chelation. Synthesis,structure and bonding

The reaction of [Ir(COD)Cl]₂ with 2-(arylazo)pyridine (L) in dichloromethane solution has afforded the nonelectrolytic pentacoordinated species of type Ir(L)(COD)(Cl) from which the corresponding bromides and iodides have been synthesised by metathesis (COD=1,5-cyclooctadiene). L ligands used are: 2-(phenylazo)pyridine (L¹); 2-(m-tolylazo)pyridine (L²) and 2-(p-chlorophenylazo)pyridine (L³). The X-ray structures of Ir(L²)(COD)(Cl)·0.5 CH₂Cl₂ and Ir(L³)(COD)(I) have been determined revealing square-pyramidal geometry. The relatively short IrN(azo) lengths (∼2.00 Å) and the relatively long NN bond distance (∼1.30 Å) are consistent with significant dππ* (azo) back-bonding. The HOMO (50% Ir and 15% azo character) and LUMO (50% azo and 30% Ir character) are primarily localised in the IrL fragment and the absorption bands near 600 nm is assigned tentatively to the HOMO→LUMO transition. The stability of the pentacoordinated structures and the inertness to oxidative addition of the present complexes in contrast to the behaviour of corresponding 2,2′-bipyridine species (tetracoordinated, reactive) is rationalised in terms of π-acidity order L≫bpy.     

Synthesis and Reactivity of Hydrolysis Products of Cyclic Phosphites with Amino Substituents

Abstract

Hydrolysis of several cyclic aminophosphites are discussed and compared with that of cyclic chloro/ phenoxy phosphites. An X-ray structure of a hydrolysis product, (C₆H₁₁NH₃)⁺O^?P(O)(H)(2,2′-OC₆H₄-C₆H₄OH) has been determined.     

Synthesis and Characterization of New Schiff Bases 2-(2-(2-(Aryl)Methyleneamino)Phenylthio) Ethylthio)-N-((aryl)Methylene)Benzeneamine

A series of Schiff bases containing four to six coordination sites N₂S₂ X₂(X = O,N) 2-(2-(2-(aryl)methyleneamino)phenylthio)ethylthio)-N-((aryl)methylene)benzeneamine (2c–f) were prepared from the reaction of 1,2-di(2-aminophenylthio)ethane (1) with aromatic aldehydes. All compounds were characterized by means IR, mass, ¹H and ¹³C NMR spectroscopy, and elemental analysis, and in the case of 2b with a single crystal X-ray diffraction. The X-ray crystal structure of 2b showed that the resonance occurs between aromatic rings, through the C=N bonds of the molecule.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Two tetrakis(benzoylacetonato)lanthanide species: synthesis,characterization and structures of tetrakis(benzoylacetonato)cerium(IV) and triethylammonium tetrakis(benzoylacetonato)lanthanate(III) tetrahydrate

Tetrakis(benzoylacetonato)cerium(IV), [Ce(bzac)₄] and triethylammonium tetrakis(benzoylacetonato)lanthanate(III) tetrahydrate, [Et₃NH][La(bzac)₄] · 4H₂O were prepared and characterized by TG and DCS measurements, IR spectroscopy, and X-ray structure analysis. The coordination polyhedron of cerium is a trigonal dodecahedron, while that of lanthanum is a distorted square antiprism. Thermal and spectroscopic measurements indicate that bonding of the ligand to metal is stronger in [Ce(bzac)₄] than in [La(bzac)₄]^?.     

Complexes of Co(II) and Zn(II) with N-(Thio)phosphorylthioureas AdNHC(S)NHP(O)(OiPr)2 and MeNHC(S)NHP(S)(OiPr)2

The reaction of the potassium salt of the N-(thio)phosphorylated thioureas AdNHC(S)NHP(O)(OiPr)₂ (HL^I , Ad = Adamantyl) and MeNHC(S)NHP(S)(OiPr)₂ (HL^II ) with Co(II) and Zn(II) in aqueous EtOH leads to [ML^I,II ₂] chelate complexes. They were investigated by UV-vis, ¹H and ³¹P NMR spectroscopy, and microanalysis. The molecular structures of [ML^I ₂] were elucidated by single crystal X-ray diffraction analysis. The metal centers in both complexes are found to be in a distorted-tetrahedral O₂S₂ environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated L^I ligands. The photoluminescence properties of [ZnL^II ₂] are also reported.     

Thermal Decompositions of the Molybdotellurates of Nickel(II) and Cobalt(II)

Molybdotellurates [M(H₂O)₆]₃·[TeMo₆O₂₄], with M=Ni(II) and Co(II), were synthesized and characterized by single-crystal X-ray diffraction for compound 1 and X-ray powder diffraction for compound 2, EDAX, IR, electronic spectra in the solid phase and in solution, and magnetic properties. Thermogravimetry and differential scanning calorimetry of both compounds revealed a loss of 11 water molecules through an endothermal process with ΔH=800 kJ mol⁻¹ for the nickel compound and ΔH=833 kJ mol⁻¹ for the cobalt compound. The residual compounds were characterized by chemical analysis, IR and XPS spectroscopy This revised version was published online in July 2006 with corrections to the Cover Date.     

Structural and theoretical studies of (E,E)-benzaldehyde azine and its rhenium(IV) complex

The azine bridged dicatechol ligand (E,E)-benzaldehyde azine (H₄L) was fully characterized by X-ray analysis. The reaction of [ReCl₆]²⁻ with this compound was studied and the novel Re(IV) complex (HNEt₃)(NBu₄)[ReCl₄(H₂L)] was prepared and characterized. The structure and spectroscopy of the compound H₄L and its Re(IV) complex were studied experimentally and by means of density functional calculations.     

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN-2H)] · CH3OH, [SnEt2(PN-2H)(DMSO)] and [SnBu2(PN-2H)]

The reactions of dimethyl-, diethyl- and dibutyltin(IV) oxides with pyridoxine (PN) in toluene/ethanol led to the formation of compounds [SnR₂(PN-2H)] which were characterized by EI and FAB mass spectrometry and by IR, Raman, Mössbauer and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy. The structures of [SnEt₂(PN-2H)] · CH₃OH, [SnBu₂(PN-2H)] and [SnEt₂(PN-2H)(DMSO)] were determined by X-ray diffractometry. The first two contain dimeric [SnR₂(PN-2H)]₂ units in which two bridging-chelating pyridoxinate anions link the Sn atoms, while in [SnEt₂(PN-2H)(DMSO)] the DMSO coordinates to the tin atom via its O atom in a similar dimeric unit.     

New biimidazole and bibenzimidazole derivatives: mono and binuclear palladium(II) or platinum(II) complexes and heterobinuclear palladium(II)-rhodium(I) or platinum(II)-rhodium(I) complexes

Novel neutral biimidazolate or bibenzimidazolate palladium(II) and platinum(II) complexes of the type M(NN)₂(dpe) [M = Pd, Pt; (NN)₂^2? = BiIm^2?, BiBzIm^2?. dpe = 1,2-bis(diphenylphosphino) ethane] have been obtained by reacting MCl₂(dpe) with TI₂(NN)₂. Complexes M(NN)₂(dpe) which are Lewis bases react with HClO₄ or [M(dpe)(Me₂CO)₂](ClO₄)₂ to yield, respectively, mononuclear cationic complexes of general formula [M{H₂(NN)₂](dpe) (M = Pd, Pt; H₂(NN)₂ = H₂BiIm, H₂BiBzIm) and homobinuclear palladium(II) or platinum(II) cationic complexes of the type [M₂{μ - (NN)₂}(dpe)₂](ClO₄)₂. Reactions of M(BiBzIm)(dpe) with [Rh(COD) (Me₂CO)_X](ClO₄) render similar heterobinuclear palladium(II)-rhodium(I) and platinum(II)-rhodium(I) cationic complexes, of general formula [(dpe)M(μ-BiBzIm)Rh(COD)](ClO₄) (M = Pd, Pt; COD = 1,5-cyclooctadiene). Di- and mono-carbonyl derivatives [(dpe)M(μ-BiBzIm)Rh(CO)L](ClO₄) (M = Pd, Pt; L = CO, PPh₃) have also been prepared. The structures of the resulting complexes have been elucidated by conductance studies and IR spectroscopy.     

Synthesis and characterization of platinum(II) complexes with 2-imidazolidinethione. X-ray crystal structure of tetra(2-imidazolidinethione- S )platinum(II) iodide dimethylsulfoxide solvate monohydrate

Preparations of trans-[PtX₂(Imt)₂] (Imt =?2-imidazolidinethione, X=Cl^? or I^?) and [Pt(Imt)₄]I₂ are described. These complexes were characterized by elemental analysis, thermal analysis, mid- and far-IR spectroscopy, and NMR (¹H and ¹³C) spectroscopy. The crystal and molecular structure of [Pt(Imt)₄]I₂ ·?DMSO ·?H₂O was determined by X-ray diffraction methods. The structural data reveal the following features: (a) the platinum atom in [Pt(Imt)₄]²⁺ is essentially in a square-planar environment, (b) the entire dication possesses approximately C _2h symmetry, (c) no appreciable hydrogen bonding exists between the iodide ions and the Imt ligands in the dication, (d) two pairs of two mutually cis Imt ligands are arranged above and below the PtS₄ plane, respectively, and (e) two planes defined by two trans Imt rings are perpendicular to each other.     

Ti/TiO2 Electrode Preparation Using Laser Anneal and Its Application to Determination of Chemical Oxygen Demand

A method for Ti/TiO₂ photoelectrode preparation using laser calcination instead of oven calcination process was introduced. The prepared TiO₂ film was investigated by X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS) and amperometry, and it was found that the prepared electrode mainly consisted of anatase TiO₂ nanoparticles on its surface and exhibited a superior photocatalytic activity. The electrode was employed as a sensor to measure chemical oxygen demand (COD) of the wastewater. The measuring principle was based on the photocurrent responses of the electrode which were proportional to the COD values. Under the optimized experimental conditions, the linear range was 50–2000 mg L⁻¹, and the detection limit was 16 mg L⁻¹ (S/N=3). This method was characterized by short analysis time, simplicity, low environmental impact and long lifetime of the sensor. Additionally, the COD values obtained from the proposed and conventional methods agreed well as demonstrated by the high significant correlation between the two sets of COD values (R=0.9895, n=25).