Triisopropoxyniobium(V) and tantalum(V)bis-O,O′-dialkyl dithiophosphates

Summary Triisopropoxy bis(O,O-dialkyl dithiophosphates), (i-PrO)₃M[S₂P(OR)₂]₂ (M = Nb^v, Ta^v; R = n-Pr, i-Pr, i-Bu and Ph) have been prepared by reacting the appropriate triisopropoxymetal(V)dichloride, (i-PrO)₃MCl₂ (1 mol) with sodium/ammonium dialkyl dithiophosphates (2 mols)in THF. The monomeric products which are viscous liquids, soluble in common organic solvents and highly susceptible to hydrolysis, were characterized by i.r. and n.m.r. spectra which indicate a bidentate mode of attachment of dithiophosphato groups to the metal.     

Synthesis,spectral characterization,and evaluation of antimicrobial activity of O,O′-alkanediyl S-(N-phthalimidomethyl) dithiophosphates and zinc bis(O,O′-alkanediyl) dithiophosphates

The synthesis of novel dithiophosphate derivatives has been achieved. Two O,O′-alkanediyl S-(N-phthalimidomethyl) dithiophosphates and two Zinc bis(O,O′-alkanediyl) dithiophosphates are synthesized by an easy and facile chemical synthetic route. Zinc bis[O,O′-(2-methylpentane-2,4-diyl) dithiophosphate] L¹, Zinc bis[O,O′-(2-ethylhexane-1,3-diyl) dithiophosphate] L², O,O′-(2-methylpentane-2,4-diyl) S-(N-phthalimidomethyl) dithiophosphate L³ and O,O′-(2-ethylhexane-1,3-diyl) S-(N-phthalimidomethyl) dithiophosphate L⁴ are synthesized from the respective ammonium salts. Compounds L¹, L², L³, and L⁴ are characterized by (CHN) elemental analysis, ESI mass, FT-IR, ¹H, ¹³C, and ³¹P NMR techniques. The crystal structure of ammonium O,O′-(2-methylpentane-2,4-diyl) dithiophosphate is discussed. L¹, L², L³, and L⁴ were evaluated for antimicrobial activity. It was found that the phthalimide derivatives L³ and L⁴ showed much better antifungal potential against some species of fungus. The Zinc dithiophosphates L¹ and L² showed good antibacterial activity against Bacillus cereus and Escherichia coli.     

Synthesis and characterization of nitrogen-containing Lewis base adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes

The adducts of bis(O,O′-dialkylmonoselenophosphato)cobalt(II) complexes, Co{O(Se)P(OR)₂}₂(L)₄ (where R?=?n-Pr, i-Pr; L?=?C₅H₅N, NC₅H₄Me-2, NC₅H₄Me-3), were synthesized by in situ reactions of CoCl₂?·?6H₂O, Lewis base, and NaO(Se)P(OR)₂. The single crystal structure of Co{O(Se)P(OⁱPr)₂}₂(C₅H₅N)₄ shows distorted octahedral geometry around cobalt(II) and monoselenophosphates are trans. The CoN₄ forms a square plane. These bis(O,O′-dialkylmonoselenophosphato)cobalt(II) adducts were characterized by elemental analyses, spectroscopic techniques (UV-Vis, infrared, ¹H and ³¹P), and magnetic moment measurements.     

Synthesis,characterization and properties of 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea)

In this paper, 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea) (DEOECTU), was synthesized by phase transfer catalysis and then characterized by UV, elemental analysis, infrared spectra, mass spectrum, ¹H NMR and TGA. DEOECTU properties, such as response to metal ions, adsorption on sulfide mineral surfaces, and hydrometallurgical performance as flotation collectors, were also investigated. The results indicated that DEOECTU reacted chemically with Cu²⁺ ions through its S and N atoms in the C(=S)–NH–C(=O) group to form a new chelate compound, but no reaction of DEOECTU with Zn²⁺, Pb²⁺, Fe³⁺ or Fe²⁺ ions was observed. The results of adsorption and flotation experiments demonstrated, that compared to pyrite, sphalerite and galena, DEOECTU exhibited a superior collecting power for chalcopyrite and might attach on chalcopyrite surface by chemisorption. The further theoretical analysis from Pearson’s HSAB view point briefly explained the experimental results of the selective response of DEOECTU to Cu²⁺ ions and chalcopyrite.     

Trichloro-mono- β -diketonato oxorhenium(V) complexes: synthesis,characterization and crystal structure

Oxorhenium(V) complexes of β-diketonate systems have been synthesized and isolated in pure form. The red complexes n-Bu₄N[ReO(R₁COCHCOR₂)Cl₃] (acac, R₁=R₂=CH₃; bzac, R₁=CH₃ and R₂=C₆H₅; bzbz, R₁=R₂=C₆H₅) have been characterized by elemental analyses, spectroscopic and other physico-chemical tools. One complex, n-Bu₄N[ReO(bzbz)Cl₃] (1c) has been subjected to single-crystal X-ray analysis. In the structure of the anion, the metal has a six-coordinate octahedral environment in which the bidentate β-diketone ligand is cis and trans to the terminal oxygen.     

Ruthenium(II) complexes of 2-(2′-pyridyl)naphthoimidazole: synthesis,characterization and DNA-binding studies

The perchlorate salts of two new ruthenium(II) complexes incorporating 2-(2′-pyridyl)naphthoimidazole are synthesized in good yield. Complexes [Ru(phen)₂(PYNI)]²⁺ (phen = 1,10-phenanthroline) 1 and [Ru(dmp)₂(PYNI)]²⁺ (dmp = 2,9-dimethyl-1,10-phenanthroline, PYNI = 2-(2′-pyridyl)naphthoimidazole) 2 are fully characterized by elemental analysis, FAB-MS, ES-MS, ¹H NMR and cyclic voltammetric methods. The DNA-binding behavior of the complexes have been studied by spectroscopic titration, viscosity measurements and thermal denaturation. Absorption titration and thermal denaturation studies reveal that these complexes are moderately strong binders of calf-thymus DNA (CT-DNA), with their binding constants spanning the range (2.73–5.35) × 10⁴ M^?1. The experimental results show that 1 interacts with calf thymus DNA (CT-DNA) by intercalative mode, while 2 binds to CT-DNA by partial intercalation.     

Synthesis,characterization and nucleolytic property of bis(N,N′-dimethylglycinato)copper(II)

Aquabis(N,N-dimethylglycinato)copper(II) dihydrate, [Cu(dmg)₂(H₂O)]·2H₂O, has been synthesized and characterized by elemental analysis, FT-IR, magnetic data, thermal analysis, solution UV-visible spectroscopy, X-ray crystal structure analysis and electrospray ionization mass spectroscopy. The square pyramidal copper(II) complex crystallizes in the orthorhombic space group P2₁2₁2₁. The complex cleaves circular plasmid DNA (pBR322) in the presence of H₂O₂. The extent of cleavage varies with the concentration range of the complex, the type of buffer used, pH of buffer and the concentration of H₂O₂. Hydroxyl radical scavenger can inhibit the nucleolytic ability of this complex.     

Cadmium(II) complexes containing 2,2′-dimethyl-4,4′-bithiazole ligand: synthesis,characterization, and crystal structure

Mononuclear and coordination polymer compounds of 2,2′-dimethyl-4,4′-bithiazole (dm4bt) ligand have been prepared by metallation of dm4bt with Cd(NO₃)₂ · 4H₂O and CdCl₂ · H₂O. The compounds were characterized by IR, ¹H NMR, UV–Vis spectroscopy, and X-ray crystallography. The structural study of [Cd(dm4bt)₂(NO₃)₂] · H₂O (1) shows that the complex is a monomeric seven-coordinate (CdN₄O₃) cadmium(II)-bithiazole system with two bidentate dm4bt and mono and bidentate nitrates. The structure of [Cd(dm4bt)Cl₂] _n (2) is a distorted octahedral environment around the cadmium(II) (CdN₂Cl₄) forming a 1-D coordination polymer as a result of bridging by two chlorides and 2-D structure from π–π stacking interactions.     

N′-(3-Bromo-2-hydroxybenzylidene)isonicotinohydrazide and its oxovanadium(V) complex: synthesis,structures, and catalytic properties

A new hydrazone N′-(3-bromo-2-hydroxybenzylidene)isonicotinohydrazide (H₂L) and its oxovanadium(V) complex, [VOLL′]·2H₂O (L′ = 2-hydroxybenzohydroxamate), were prepared and structurally characterized by physico-chemical, spectroscopic methods, and single-crystal X-ray determination. The hydrazone coordinates to V through the phenolate oxygen, imino nitrogen, and enolate oxygen. The hydroxamate coordinates to V through the carbonyl oxygen and deprotonated hydroxyl oxygen. Vanadium in the complex is octahedral. The oxidation of olefins with the complex as catalyst was evaluated, which indicated that the complex showed catalytic efficiency in oxidation of several aliphatic and aromatic substrates under mild conditions, using tert-butyl hydrogen peroxide as oxidant.     

Nitrogen-donor base adducts of bis(O,O′-di-isoamyldithiophosphato)nickel(II)

A series of Ni^II complexes with the O,O-di-isoamylester of dithiophosphoric acid and nitrogen-donor ligands of composition [Ni(i-Am₂dtp)₂(L)]; [dtp = O₂PS₂ ^–; L = 2,2-bipyridine (bpy); 1,10-phenanthroline (phen); 5-nitro-1,10-phenanthroline (nphen); 4,7-diphenyl-1,10-phenanthroline (baphen); 2,9-dimethyl-1,10-phenanthroline (neo), 2-aminomethylpyridine (amp), 2-(2-aminoethyl)pyridine (aep), 2,2-dipiridylamine (dpa), 1,2-diaminopropane (1,2-dap) or trans 1,2-diaminocyclohexane (dch)] have been prepared. The compounds have been characterized by elemental analyses (C,H,N,S), electronic and i.r. spectroscopy, magnetic and conductivity measurements and by cyclic voltammetry. The results show that all complexes behave as non-electrolytes in acetone. Electronic spectra and magnetic moments suggest a distorted cis-octahedral geometry around the Ni^II atom [_eff/_B <3.10, 3.40 >], except for [Ni(i-Am₂dtp)₂(aep)], where the measured temperature dependence of the magnetic susceptibility proved the tetrahedrally coordinated nickel [4.06 _eff/_B (298 K) – 3.20 _eff/_B (80 K)]. In the [Ni(i-Am₂dtp)₂(neo)] complex, the nickel atom is penta-coordinated. The X-ray crystal and molecular structure of [Ni(i-Am₂dtp)₂(1,2-dap)] has been determined.     

Preparation and characterization of organogermanium O,O′-dimethyl and diethyl-dithiophosphates

Organogermanium derivatives of dithiophosphoric acid of general formula R₄−_nGe[SP(S)(OR′)₂]_n, where n = 1–3, R, = Me, Ph and R′ = Me, Et, have been prepared and characterized by means of ¹H, ¹³C NMR and vibrational spectroscopy and mass spectrometry. The spectroscopic results indicate that the dithiophosphate groups are monodenate and that an approximate tetrahedral geometry about the germanium atom is maintained. This is in part confirmed by a preliminary X-ray crystallographic determination of PhGe[SP(S)(OMe)₂]₃, whose crystals are orthorhombic, space group Pn2₂₁a, a 13.674(4), b 14.566(3), c 13.154(3) Å, V 26201(1) ų and Z = 4 from 1225 observed reflections [1 > 2σI].     

Mononuclear copper(I) complexes with triphenylphosphine and N,N′-disubstituted thioureas: synthesis,characterization, and biological evaluation

Abstract

Twelve new complexes, of the general formula CuCl(TPP)₂Tu^1–12 (Tu?=?thiourea), were synthesized by the reaction of CuCl(TPP)₃ (TPP?=?triphenylphosphine) and various N,N′-disubstituted thioureas. The structures of the synthesized complexes were characterized by different techniques such as Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy (¹H, ¹³C, ³¹P, and ¹⁹F), and the representative complexes (1, 2 and 12) were analyzed via single crystal X-ray diffraction. The single crystal X-ray analysis revealed that copper(I) is coordinated with chlorine, two TPP, and the thiourea ligands through the sulfur atom in a mononuclear distorted tetrahedral mode. The compounds were tested for antibacterial, antifungal, cytotoxicity, antileishmanial, and antioxidant activities. The results showed that the synthesized complexes are significantly more active than the free ligands and the commercial reference compounds. The high biological activities of the complexes versus free ligands can be attributed to the copper(I) chloride complexation with thiourea ligands. The synthesized complexes were also evaluated, both experimentally and theoretically, for DNA binding studies. The UV-visible spectroscopic and molecular docking studies demonstrated that the complexes are conjugating with DNA through a groove binding mode.     

Intercalation of tris-(2,2′-bipyridyl) ruthenium (II) in α- and γ-zirconium phosphate: synthesis, thermal behaviour and X-ray characterization

Intercalation compounds such as the ruthenium trisbipyridyl complex in inorganic layered ion-exchangers (α- and γ-zirconium phosphate) have been synthesized using the batch method. There is no loss of bipyridyl ligand from the metal ion during the exchange of the ruthenium trisbipyridyl complex in these host matrices. The materials obtained are thermally stable up to ~330 °C (γ-phase) or ~380 °C (α-phase). The complex decomposition occurs in one or more steps and at ~600 °C the complex decomposition is complete. The X-ray patterns of ruthenium materials show a new phase with an increase in the interlayer distance with respect to the initial phase. Microanalysis measurements confirm the fact that the ruthenium complex is not modified when exchanged and the complex decomposition depends on its position in the host matrices.     

Synthesis,characterization and in vitro antitumor behavior of a vanadium(V) complex with 4′-(3-methoxyphenyl)-2,2′:6′2″-terpyridine

A dioxovanadium(V) complex, [VO₂(moptpy)](ClO₄) (1, moptpy = 4′-(3-methoxyphenyl)2,2′:6′2″-terpyridine), was synthesized and characterized by elemental analysis, ESI-MS, UV–vis, IR, and ¹H, ¹³C, and ⁵¹V NMR. The cytotoxicity in vitro of 1 was evaluated against cancer cell lines HepG-2 (hepatocellular carcinoma), SGC-7901 (gastric carcinoma), SiHa (cervical cancer), BEL-7402 (hepatocellular), and rat PC-12 (pheochromocytoma) by the MTT method. The results demonstrated that 1 exhibits superior anticancer activity in vitro with much lower values of 50% inhibitive concentration (IC₅₀) against the selected cell lines than cisplatin, and 1 shows the highest cytotoxic activity toward SGC-7901 cells (IC₅₀ = 1.3 ± 0.1 μM) among the selected cell lines. A series of cellular morphological and staining experiments were carried out, and the results indicated that 1 can effectively induce apoptosis of SGC-7901 cells through a ROS-mediated mitochondrial dysfunction pathway. In addition, cellular incorporation and cell cycle analysis were also performed, and it was concluded from the experimental observations that 1 can efficiently enter into the cell nuclei, and the complex inhibits cell growth in SGC-7901 cell at G0/G1 phase.     

Mn(II) complexes of N′-(2-methoxybenzoyl)hydrazine carbodithioic acid ethyl ester: synthesis, spectral and structural characterization

Two new Mn(II) complexes [Mn(Hmbhce)₂(o-phen)] (1) and [Mn(Hmbhce)₂(bpy)] (2) based on N??-(2-methoxybenzoyl)hydrazine carbodithioic acid ethyl ester (H₂mbhce) have been synthesized by reacting Mn(OAc)₂·4H₂O with H₂mbhce in the presence of o-phen/bpy. The complexes have been characterized by elemental analyses, magnetic susceptibility measurement, IR, UV?CVis and single crystal X-ray data. Both complexes [Mn(Hmbhce)₂(o-phen)] and [Mn(Hmbhce)₂(bpy)] crystallize in monoclinic system with space group P 21/c and P 21/n, respectively. The single crystal X-ray structures of 1 and 2 show that the Mn(II) center is bonded with two (Hmbhce)^? through carbonyl oxygen and deprotonated hydrazinic nitrogen, plus two nitrogen atoms from one o-phen/bpy co-ligand. The crystal structures of complexes 1 and 2 are stabilized by weak intramolecular N?CH···O hydrogen bonding and C?CH···?? interactions giving supramolecular architectures.     

Chloro(η-dihydropentalenyl)bis(triphenylphosphine)ruthenium(II): synthesis, structural characterization and catalytic activity in the dimerization of phenylacetylene

Reactions between HRuCl(PPh₃)₃ and 1,3- or 1,5-cyclooctadiene yield the 1,2-dihydropentalenyl complex (η⁵-C₈H₉)Ru(PPh₃)₂Cl through a series of steps including olefin insertion and electrocyclization. The reaction is accompanied by the loss of two equivalents of hydrogen. The product crystallizes in the monoclinic space group (No. 2). (η⁵-C₈H₉)Ru(PPh₃)₂Cl catalyzes the dimerization of phenylacetylene to a ≈2:1 mixture of Z:E 1,4-diphenyl-1-buten-3-yne. Comparison of the catalytic activity of (η⁵-C₈H₉)Ru(PPh₃)₂Cl with (η⁵-C₅H₅)Ru(PPh₃)₂Cl, (η⁵-C₅Me₅)Ru(PPh₃)H₃ and {η⁵-HB(pz)₃}Ru(PPh₃)₂Cl suggests that the more electron-rich η⁵ ligands favor formation of the Z isomer.     

Preparation and characterization of octacyanomolybdates(IV and V) and octacyanotungstates(IV and V) with 2,2′-bipyridylium cation

Reaction of protonated 2,2′-bipyridine (bpy) with octacyanometalates(IV and V), [M(CN)₈]ⁿ⁻ (M = Mo or W, n = 3 or 4), gave the following complexes: {(bpyH)₃[M(CN)₈]·4H₂O}, {(bpyH)₃(H₃O)[M(CN)₈]·H₂O}, {(bpyH₂)₂[W(CN)₈]·3H₂O} and {(bpyH₂)K₂[W(CN)₈]·2H₂SO₄·7H₂O}. These salts were characterized by electron absorption and reflectance spectrometry, IR, Raman and ESR spectrometry, thermo gravimetry and differential thermal analysis, cyclic voltammetry and potentiometry. The solubility of the salts in water and some polar organic solvents has been measured. The intensively coloured salts of molybdenum(IV) and tungsten(IV) have been discussed in terms of the bpyH⁺-[M(CN)₈]⁴⁻ ion pairs, which exhibit an outer-sphere electron transfer between adjacent redox sites.     

Synthesis and crystal structure of bis[(μ-κO:κO′-acetato)(μ-κO:κ2O′-acetato)][(η5-Cp)tris(dimethylphosphito-P)cobalt-O,O′,O″]yttrium(III)

The [η⁵-CpCo{P(O)(OMe)₂}₃Y(O₂CCH₃)₂]₂, yttrium(III) complex has been synthesized by the stoichiometric mixture of YCl₃, NaL_OMe and NaAc in a 1:1:2 molecular ratio in dry THF solvent and we have determined the structure by X-ray diffraction. The molecule is a dimeric compound, which consists of one tripodal ligand (L_OMe=CpCo[P(O)(OMe)₂]₃) and two bridging acetato (Ac) ligands on each yttrium atom. The acetate ligands of this complex have two different coordination modes, which are μ-κO:κO′-acetato and μ-κO:κ²O′-acetato bound to each yttrium atom.