Synthesis and Crystal Structure of Copper(II) Trifluoroacetates,Cu2(CF3COO)4 · 2 CH3CN and Cu(CF3COO)2(H2O)4

Cu₂(CF₃COO)₄ · 2 CH₃CN ( I ) and Cu(CF₃COO)₂(H₂O)₄ ( II ) have been prepared by concentrating of acetonitrile and aqueous solutions respectively. According to X-ray data, the complex I consists of binuclear molecules with Cu–O 1.969 Å, Cu–N 2.114 Å. The Cu…Cu distance was found to be 2.766 Å, one of the longest for dimeric structures, apparently, due to the high acidity of trifluoroacetic acid. The coordination environment of Cu atom in II can be described as 4 + 2: 2 Cu–O (H₂O) 1.937 Å, 2 Cu–O (CF₃COO) 1.985 Å, 2 Cu–O (H₂O) 2.447 Å. The mononuclear structure is stabilized by formation of two intra- and six intermolecular hydrogen bonds.     

Synthesis,Crystal Structure and Magnetic Behaviour of the new Tetrameric Gadolinium Carboxylate [Gd4(OH)4(CF3COO)8(H2O)4] · 2.5 H2O

The novel tetrameric gadolinium(III) compound [Gd₄(OH)₄(CF₃COO)₈(H₂O)₄] · 2.5 H₂O was synthesized and structurally characterized by X‐ray crystallography. The Gd³⁺ ions are bridged by hydroxide ions and carboxylate groups to tetramers with Gd³⁺‐Gd³⁺ distances between 384.2(2) and 388.1(2) pm. The compound crystallizes in the monoclinic space group C2/c (Z = 4). The magnetic behaviour of [Gd₄(OH)₄(CF₃COO)₈(H₂O)₄] · 2.5 H₂O was investigated in the temperature range of 2 to 300 K. The magnetic data of this compound indicate antiferromagnetic interactions (J_ex = ?0.0197 cm^?1).     

Synthesis, Crystal Structure and Optical Properties of Europium Trifluoroacetate Complexes with 1,10-Phenanthroline and 2,2-Bipyridine

Two europium trifluoroacetate complexes, Eu(CF₃COO)₃·phen ( 1 ) and Eu(CF₃COO)₃·bpy ( 2 ) (where phen=1,10‐phenanthroline, bpy=2,2′‐bipyridine), were synthesized and characterized by elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), photoluminescence (PL) spectroscopy and thermogravimetric analysis (TA). Single‐crystal X‐ray structure has been determined for the complex [Eu₂(CF₃COO)₆·(phen)₃·(H₂O)₂]·EtOH. The crystal structure of [Eu₂(CF₃COO)₆·(phen)₃·(H₂O)₂]·EtOH shows that two different coordination styles with europium ions coexist in the same crystal and have entirely different coordination geometries and numbers. This crystal can be considered as an 1:1 adduct of [Eu(CF₃COO)₃·(Phen)₂·H₂O]·EtOH (9‐coordination part) and Eu(CF₃COO)₃·phen·H₂O (8‐coordination part). The excitation spectra of the two complexes demonstrate that the energy collected by "antenna ligands" is transferred to Eu³⁺ ions efficiently. The room‐temperature PL spectra of the complexes are composed of the typical Eu³⁺ ions red emission, due to transitions between ⁵D₀→⁷F_J(J=0→4). The lifetimes of ⁵D₀ of Eu³⁺ in the complexes were examined using time‐resolved spectroscopic analysis, and the lifetime values of Eu(CF₃COO)₃·phen and Eu(CF₃COO)₃·bpy were fitting with bi‐exponential (2987 and 353 µs) and monoexponential (3191 µs) curves, respectively. In order to elucidate the energy transfer process of the europium complexes, the energy levels of the relevant electronic states had been estimated. The thermal analyses indicate that they are all quite stable to heat.     

Synthesis,crystal structure and thermal stability of new copper(II) trichloroacetate complexes

We have synthesized two novel complexes of copper(II) trichloro acetate, Cu₂(CCl₃COO)₃(OH)(H₂O)₄·H₂O and Cu(CCl₃COO)₂(MeCN), and determined their crystal structures and thermal stability. While the complex with acetonitrile has a discrete binuclear paddle-wheel structure, typical of copper carboxylates, the aqua-hydroxo complex belongs to a novel unique chain–molecular type of basic copper complexes.     

A Room‐Temperature Luminescent AgCF3COO Complex Consisting of Cationic Complex Chains and Anionic Guests

Reaction of p‐phenylenediacetonitrile (p‐phda) with AgCF₃COO afforded the coordination polymer, {[Ag₂(p‐phda)₂] [Ag₄(CF₃COO)₆]}_n ( 1 ), where the 1D cationic [Ag₂(p‐phda)₂]²⁺ chain acts as host and the anionic [Ag₄(CF₃COO)₆]^2– as guest molecules occupy the channel between neighboring host chains. This is a rare crystal example of AgCF₃COO complex consisting of cationic complex chains and anionic guests. In addition, complex 1 exhibits luminescence at room temperature in solid state.     

Isomerism in the Terbium(III) Trifluoroacetate Trihydrate Dimer

Precision Xray diffraction analysis of a perfect single crystal showed that the molecule of terbium(III) trifluoroacetate trihydrate is a combination of two isomers (monomeric form), Tb(CF₃COO)₃(H₂O)₃ and Tb(CF₃COO)₂(CF₃COOH)(H₂O)₂(OH) with a statistical weight of 0.5. Based on precision Xray diffraction analysis, the statistical composition of the compound resulting from neutralization of terbium(III) hydroxide with trifluoroacetic acid is Tb(CF₃COO)_2.5(CF₃COOH)_0.5(H₂O)_2.5(OH)_0.5. The presence of the CF₃COOH molecule and the OH^- group is also confirmed by IR and ¹H NMR spectra, respectively. The presence of 18 rather than the anticipated nine Stark components of the ⁵D₄⁷F₀ transition of the Tb³⁺ ion can be explained in terms of both a static and a dynamic model. In the static case, the compound can be represented as a combination of equal fractions of two isomers; hence the doubled number of Stark components. In this case, the molecule of the dimer remains statistically centrosymmetric. In the dynamic version, migration of a proton across the dimer from one of the water molecules to the nearest monodentate anion CF₃COO^- and back leads to an electron density redistribution in the vicinity of each Tb³⁺ ion within the dimer, the crystallographic equivalence of their positions being preserved. However, Xray structure analysis cannot distinguish between these two cases. In any case, the observed isomerism in terbium(III) trifluoroacetate trihydrate removes discrepancies between the data of Xray structural and luminescent analyses.     

Electrospray mass spectrometric study of homogeneous catalytic system Pd(CF3COO)2-Ph2P(CH2)3PPh2-MeOH/Me2CO-H2O for copolymerization of ethylene and carbon monoxide

The catalytic system Pd(CF₃COO)₂-Ph₂P(CH₂)₃PPh₂-MeOH/Me₂CO was studied by electrospray mass spectrometry. The {[Pd(dPPP)₂]²⁺ [(dppp)₂Pd(CF₃COO)]⁺, [(dppp)Pd(CF₃COO)]⁺, and [(dppp)Pd(CF₃COO)₂Pd(dppp)]²⁺} cations were found in the system. The addition of H₂O to the system resulted in the formation of binuclear bicharged ions [(dppp)Pd(OH)]₂ ²⁺ and their associates with water.Translated from Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 494–496, February, 1996     

Synthese,Kristallstruktur und magnetisches Verhalten von Gd(CF3CF2COO)3(H2O)3

Synthesis, Crystal Structure and Magnetic Behaviour of Gd(CF₃CF₂COO)₃(H₂O)₃ Single crystals of Gd(CF₃CF₂COO)₃(H₂O)₃ have been obtained by reaction of Gd₂O₃ with an aqueous solution of CF₃CF₂COOH. The compound crystallizes triclinically in the space group (No. 2; Z = 2; a = 928.5(1) pm, b = 1037.1(1) pm, c = 1147.3(2) pm, α = 90.44(2)°, β = 108.56(1)°, γ = 106.49(1)°). In the crystal structure the gadolinium ions are bridged by carboxylate groups to dimers and are coordinated eightfold by oxygen atoms. The magnetic behaviour was investigated in the temperature range of 1.77 to 300 K. The magnetic data indicate weak antiferromagnetic interactions within the dimeric unit (J_ex = ?0.0057 cm^?1).     

Structural aspects of a trimetallic CuII derivative: cytotoxicity and anti-proliferative activity on human cancer cell lines

A trimetallic Cu^II derivative, [Cu₃(L)₂(CF₃COO)₂] (1) (where H₂L = N,N′-bis(salicylidene)-1,3-propanediamine), was prepared and characterized. In 1, the two terminal Cu^II ions are linked to the central Cu^II by trifluoroacetato and doubly bridging phenoxido. Both the square-pyramidal and octahedral geometries are observed among two different Cu^II centers in the linear arrangement of the trimetallic unit. Compound 1 is characterized by IR and UV-Vis spectra. Compound 1 has high cytotoxic activity in breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT116) and particularly, in ovarian carcinoma (A2780) cell line compared to a lung adenocarcinoma cell line. The IC₅₀ in A2780 cells is 25 times lower than the respective value for normal human primary fibroblasts demonstrating 1 has higher cytotoxicity towards cancer cells. Additionally, combination of DOX with 1 induces a higher loss of HCT116 cell viability compared with each drug alone.     

Acetate-Functionalized Zirconium-Substituted Tungstogermanate, [Zr4O2(OH)2(CH3COO)2(α-GeW10O37)2]12−

The two acetate-functionalized zirconium(IV)-substituted tungstogermanates, Na₈K₄[Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂] · 33H₂O and Na₈Cs₄[Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂] · 32H₂O, were synthesized by the reaction of ZrOCl₂ with [A-α-GeW₉O₃₄]¹⁰⁻ in pH = 4.8 buffer and their structures were determined by single-crystal X-ray analysis. Both of them contain a centrosymmetric polyanion [Zr₄O₂(OH)₂(CH₃COO)₂(α-GeW₁₀O₃₇)₂]¹²⁻ consisting of two {α-GeW₁₀O₃₇} units sandwiching an inorganic–organic hybrid {Zr₄O₂(OH)₂(CH₃COO)₂} cluster. The polyanion contains a mixing of seven- and eight-coordinate Zr centres. The two compounds were also characterized by elemental analysis, IR spectroscopy, UV–vis and TG–DSC analysis.     

Mixed-ligand complexes of alkaline-earth metal trifluoroacetates with monoethanolamine

The mixed-ligand complexes of the formula [M(CF₃COO)₂(MEA) _n ] (MEA is monoethanolamine; M = Ca (I) and Sr (II), n = 1.5; M = Ba (III), (n = 1) were obtained from appropriate salts M(CF₃COO)₂ · nH₂O and MEA in ethanol. Complexes I–III were characterized by elemental analysis data and IR spectra. Slow crystallization of a solution of complex III in air gave a single crystal of the formula [Ba(CF₃COO)₂(MEA)(H₂O)], which is a coordination polymer with C.N.(Ba) 9 (X-ray diffraction data). Thermal analysis showed that complexes I–III decompose under argon and in air to the corresponding fluorides at T < 400°C.     

X-ray structure of Fe{C(CF3)2(OH)}(CO)2(η-C5H5), a complex containing a substituted hydroxymethyl ligand

An X-ray structure determination on Fe{C(CF₃)₂(OH)}(CO)₂(η-C₅H₅), obtained by protonating the product from Na[Fe(CO)₂(η-C₅H₅)] and (CF₃)₂CO, showed the crystal to contain discrete molecules. There are substantial intramolecular OH…FCF₂ bonds but only weak intermolecular OH…O interactions. Important distances are: FeC 2.060(6), CCF₃ 1.505(9), COH 1.435(7), CF…HO 2.131(6), 2.485(6) Å.     

Synthesis,crystal structure and thermal properties of Na2Ti(CF3COO)6(CF3COOH)2

The compound Na₂Ti(CF₃COO)₆(CF₃COOH)₂ was synthesized as colorless crystals, extremely unstable in air, by the reaction of TiCl₄ with trifluoroacetic acid and sodium trifluoroacetate. Crystallographic studies have shown that this sodium trifluoroacetatotitanate is the first example of a tetravalent titanium carboxylate [Ti(RCOO)₆]²– containing titanium in an octahedral environment of oxygen atoms of carboxylate groups. Thermal decomposition of Na₂Ti(CF₃COO)₆(CF₃COOH)₂ in an argon atmosphere results in the complex fluoride Na₂TiF₆.     

Photoinduced Oxidation Reaction of Benzotrifluoride with OH Radical by the Laser Flash Method

The optical transient and kinetics characterizations of the transients formed in the reaction of OH with benzotrifluoride (BTF) were performed by a laser flash photolysis technique. The results indicated that the formation of π‐type adduct of C₆H₅(OH)CF₃ was the major reaction channel, and the δ‐type adduct of C₆H₅CF₃OH formation was an additional minor process in the oxidation reaction of BTF attacked by OH radicals yielded from the photolysis of H₂O₂. Addition of OH to the CF₃ group led to the fluoride ion elimination to yield α,α‐difluorophenylcarbinol (C₆H₅CF₂OH). Trifluoromethylphenol (HOC₆H₄CF₃) of meta‐, para‐ and ortho‐substituted isomers resulted from the addition of OH to the BTF aromatic ring.     

A novel metallo‐organically templated pentaborate: acetato[N,N′‐bis(2‐aminoethyl)ethane‐1,2‐diamine]zinc(II) 4,4′,6,6′‐tetrahydroxy‐2,2′‐spirobi[cyclotriboroxane](1−)

The title compound, [Zn(C₂H₃O₂)(C₆H₁₈N₄)][B₅O₆(OH)₄], contains mixed‐ligand [Zn(CH₃COO)(teta)]⁺ complex cations (teta is triethylenetetramine) and pentaborate [B₅O₆(OH)₄]⁻ anions. The [B₅O₆(OH)₄]⁻ anions are connected to one another through hydrogen bonds, forming a three‐dimensional supramolecular network, in which the [Zn(CH₃COO)(teta)]⁺ cations are located.     

Study on the equilibrium in the M(CH3COO)2 ? CH3OH ? H2O system (M  Mg2+, Ca2+, Ba2+) at 25°C

The complex formation and dehydration processes in the system M(CH₃COO)₂? CH₃OH? H₂O have been studied by the methods of the physico-chemical analysis at 25°C; (M = Mg²⁺, Ca²⁺ and Ba²⁺). In the Mg(CH₃COO)₂? CH₃OH? H₂O system. methanol was found to behave as a solvent in which complex formation reactions take place, including also methanolation of Mg²⁺. The fields of equilibrium existence of two new compounds have been found: Mg(CH₃COO)₂ · 3H₂O · CH₃OH and Mg(CH₃COO)₂ · 1,5 CH₃OH. In the systems M(CH₃COO)₂? CH₃OH? H₂O (M = Ca²⁺, Ba²⁺), methanol was found to react as a dehydrating reagent.     

Synthesis and characterization of new copper(II) complex compounds with chlorhexidine. Part I

Three new copper(II) complex compounds with chlorhexidine diacetate as a ligand have been prepared and characterized by elemental and thermogravimetrical analyses, molar conductances, magnetic susceptibility measurements, infrared, electronic and EPR spectra. The complexes correspond to the formulas: [Cu₂(CHX)Cl₄]·2C₂H₅OH, [Cu₂(CHX)Br₄]·2C₂H₅OH and [Cu₂(CHX)(CH₃COO)₂] (CH₃COO)₂·2C₂H₅OH, where CHX = chlorhexidine, their composition and stereochemistry depending on the reaction conditions and the metal salt used. Chlorhexidine acts as neutral tetradentate NNNN donor, coordinating through the four imine nitrogen atoms. Investigations on antimicrobial activity in vitro show that all the complexes are active against the tested microorganisms, the complex with chloride being more active against Gram negative bacteria than chlorhexidine diacetate..      

CF3CH(ONO)CF3: Synthesis,IR spectrum,and use as OH radical source for kinetic and mechanistic studies

The synthesis, IR spectrum, and first‐principles characterization of CF₃CH(ONO)CF₃ as well as its use as an OH radical source in kinetic and mechanistic studies are reported. CF₃CH(ONO)CF₃ exists in two conformers corresponding to rotation about the RCO? NO bond. The more prevalent trans conformer accounts for the prominent IR absorption features at frequencies (cm^?1) of 1766 (N?O stretch), 1302, 1210, and 1119 (C? F stretches), and 761 (O? N? O bend); the cis conformer contributes a number of distinct weaker features. CF₃CH(ONO)CF₃ was readily photolyzed using fluorescent blacklamps to generate CF₃C(O)CF₃ and, by implication, OH radicals in 100% yield. CF₃CH(ONO)CF₃ photolysis is a convenient source of OH radicals in the studies of the yields of CO, CO₂, HCHO, and HC(O)OH products which can be difficult to measure using more conventional OH radical sources (e.g., CH₃ONO photolysis). CF₃CH(ONO)CF₃ photolysis was used to measure k(OH + C₂H₄)/k(OH + C₃H₆) = 0.29 ± 0.01 and to establish upper limits of 16 and 6% for the molar yields of CO and HC(O)OH from the reaction of OH radicals with benzene in 700 Torr of air at 296 K. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 159–165, 2003     

The addition of small molecules to (η-C5H5)2Rh2(CO)(CF3C2CF3) : I. The coordinative-addition of CO,CNR, and some group V donor ligands

Treatment of the μ(η¹)-alkyne complex (η-C₅H₅)₂Rh₂(CO)₂(CF₃C₂CF₃) with trimethylamine-N-oxide results in mono-decarbonylation to give the μ(η²)- alkyne complex (η-C₅H₅)₂Rh₂(μ-CO)(CF₃C₂CF₃). Coordinative addition of a variety of ligands L to the monocarbonyl complex has been achieved at room temperature, and stable adducts (η-C₅H₅)₂Rh₂(CO)L(CF₃C₂CF₃) (L  CO, CNBu^t, PPh₃, PMePh₂, P(OMe)₃, AsPh₃, PF₃ and PF₂(NEt₂)) have been fully characterized by infrared and NMR spectroscopy. In each complex, there is a μ(η¹)-attachment of the hexafluorobut-2-yne and a trans-arrangement of CO and L. The spectroscopic data establish that there is rapid scrambling of CO and L when L  CNBu^t. An unstable adduct is formed when (η-C₅H₅)₂Rh₂(μ-CO)(CF₃C₂CF₃) is dissolved in pyridine.     

Novel Oxidovanadium Complexes with Redox-Active R-Mian and R-Bian Ligands: Synthesis,Structure, Redox and Catalytic Properties

A new monoiminoacenaphthenone 3,5-(CF₃)₂C₆H₃-mian (complex 2) was synthesized and further exploited, along with the already known monoiminoacenaphthenone dpp-mian, to obtain oxidovanadium(IV) complexes [VOCl₂(dpp-mian)(CH₃CN)] (3) and [VOCl(3,5-(CF₃)₂C₆H₃-bian)(H₂O)][VOCl₃(3,5-(CF₃)₂C₆H₃-bian)]·2.85DME (4) from [VOCl₂(CH₃CN)₂(H₂O)] (1) or [VCl₃(THF)₃]. The structure of all compounds was determined using X-ray structural analysis. The vanadium atom in these structures has an octahedral coordination environment. Complex 4 has an unexpected structure. Firstly, it contains 3,5-(CF₃)₂C₆H₃-bian instead of 3,5-(CF₃)₂C₆H₃-mian. Secondly, it has a binuclear structure, in contrast to 3, in which two oxovanadium parts are linked to each other through V=O···V interaction. This interaction is non-covalent in origin, according to DFT calculations. In structures 2 and 3, non-covalent π-π staking interactions between acenaphthene moieties of the neighboring molecules (distances are 3.36–3.40 Å) with an estimated energy of 3 kcal/mol were also found. The redox properties of the obtained compounds were studied using cyclic voltammetry in solution. In all cases, the reduction processes initiated by the redox-active nature of the mian or bian ligand were identified. The paramagnetic nature of complexes 3 and 4 has been proven by EPR spectroscopy. Complexes 3 and 4 exhibited high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The yields of products of cyclohexane oxidation were 43% (complex 3) and 27% (complex 4). Based on the data regarding the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play the most crucial role in the reaction. The initial products in the reactions with alkanes are alkyl hydroperoxides, which are easily reduced to their corresponding alcohols by the action of triphenylphosphine (PPh₃). According to the DFT calculations, the difference in the catalytic activity of 3 and 4 is most likely associated with a different mechanism for the generation of ^●OH radicals. For complex 4 with electron-withdrawing CF₃ substituents at the diimine ligand, an alternative mechanism, different from Fenton’s and involving a redox-active ligand, is assumed.