Ester Elimination Research Articles

An Improved Synthesis of Glucuronide Metabolites of Hindered Phenolic Xenoestrogens.

The syntheses of glucuronide metabolites of phenolic xenoestrogens triclosan and 2-phenylphenol, namely triclosan-O-glucuronide (TCS-G; 1), and 2-phenylphenol-Oglucuronide (OPP-G; 2), were achieved for use as analytical standards. Under classical conditions previously reported for glucuronide synthesis, the final basic hydrolysis of the peracylated ester intermediate leading to the free glucuronides is often a limiting step. Indeed, the presence of contaminating by-products resulting from ester elimination has often been observed during this step. This is particularly relevant when the sugar unit is close to a crowded environment as for triclosan and 2-phenylphenol. To circumvent these problems, we proposed mild conditions for the deprotection of peracetylated glucuronate intermediates. A new methodology using a key imidate following a two-step protocol for acetates and methyl ester hydrolysis was successfully applied to the preparation of TCS-d3 (1) and OPP-G (2) as well as deuterated isotopomers TCS-d3-G (1-d3) and OPP-d5-G (2-d5).

Degradation of dibutyl phthalate by Paenarthrobacter sp. Shss isolated from Saravan landfill, Hyrcanian Forests, Iran

Phthalic acid esters are predominantly used as plasticizers and are industrially produced on the million ton scale per year. They exhibit endocrine-disrupting, carcinogenic, teratogenic, and mutagenic effects on wildlife and humans. For this reason, biodegradation, the major process of phthalic acid ester elimination from the environment, is of global importance. Here, we studied bacterial phthalic acid ester degradation at Saravan landfill in Hyrcanian Forests, Iran, an active disposal site with 800 tons of solid waste input per day. A di-n-butyl phthalate degrading enrichment culture was established from which Paenarthrobacter sp. strain Shss was isolated. This strain efficiently degraded 1 g L–1 di-n-butyl phthalate within 15 h with a doubling time of 5 h. In addition, dimethyl phthalate, diethyl phthalate, mono butyl phthalate, and phthalic acid where degraded to CO2, whereas diethyl hexyl phthalate did not serve as a substrate. During the biodegradation of di-n-butyl phthalate, mono-n-butyl phthalate was identified in culture supernatants by ultra-performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry. In vitro assays identified two cellular esterase activities that converted di-n-butyl phthalate to mono-n-butyl phthalate, and the latter to phthalic acid, respectively. Our findings identified Paenarthrobacter sp. Shss amongst the most efficient phthalic acid esters degrading bacteria known, that possibly plays an important role in di-n-butyl phthalate elimination at a highly phthalic acid esters contaminated landfill.

A coumarin-boronic ester derivative as fluorescent chemosensor for detecting H2O2 in living cells

A coumarin derivative CBE fluorescent chemosensor based on boronic ester elimination by introducing boronic ester moiety as sensing site for efficient detecting H2O2 in living cells was developed. The probe can specifically recognize H2O2 in PBS buffer solution (containing 1% DMSO, pH = 7.4) with fluorescence enhancement response at 454 nm without interference from other substances. After H2O2 addition, the absorption band is red-shifted from 360 nm to 415 nm, and fluorescence is enhanced with fluorescence quantum yield increasing from 5.1% to 58.7%. The response is sensitive with detection limit being 0.17 nM within 16 min. The mechanism is that H2O2 triggers oxidative hydrolysis of the boronic ester and subsequent 1,6-elimination, causing C-O bond to break, thereby forming 7-hydroxycoumarin-3-acetyl and 5-cyclohexadien-1-one, 4-methylene-. The probe also has high photostability and excellent potential application in monitoring H2O2 in living cells.

Acetic Anhydride as an Oxygen Donor in the Non-Hydrolytic Sol-Gel Synthesis of Mesoporous TiO2 with High Electrochemical Lithium Storage Performances.

An original, halide-free non-hydrolytic sol-gel route to mesoporous anatase TiO2 with hierarchical porosity and high specific surface area is reported. This route is based on the reaction at 200 °C of titanium(IV) isopropoxide with acetic anhydride, in the absence of a catalyst or solvent. NMR spectroscopic studies indicate that this method provides an efficient, truly non-hydrolytic and aprotic route to TiO2 . Formation of the oxide involves successive acetoxylation and condensation reactions, both with ester elimination. The resulting TiO2 materials were nanocrystalline, even before calcination. Small (about 10 nm) anatase nanocrystals spontaneously aggregated to form mesoporous micron-sized particles with high specific surface area (240 m2 g-1 before calcination). Evaluation of the lithium storage performances shows a high reversible specific capacity, particularly for the non-calcined sample with the highest specific surface area favouring pseudo-capacitive storage: 253 mAh g-1 at 0.1 C and 218 mAh g-1 at 1 C (C=336 mA g-1 ). This sample also shows good cyclability (92 % retention after 200 cycles at 336 mA g-1 ) with a high coulombic efficiency (99.8 %). Synthesis in the presence of a solvent (toluene or squalane) offers the possibility to tune the morphology and texture of the TiO2 nanomaterials.

Photo-electron chemistry of photoresist outgassing upon DUV, VUV, EUV, and BEUV irradiation

Abstract This study qualitatively and quantitatively characterized photoresist outgassing upon irradiation with 193 nm (DUV), 103.3 nm (VUV), 13.5 nm (EUV), and 6.7 nm (BEUV) synchrotron light. The photoresist samples used were polymethylmethacrylate (PMMA), poly(4-hydroxystyrene-co-tertbutylacrylate) (HS-TBA) and an EUV model resist denoted as HS-TBA-H (HS-TBA with TPS-Nf, a photoacid generator (PAG), added). The distribution of outgassed species from the resist samples was characterized and found to exhibit a negligible dependence on the film thickness in the 50–125 nm range. Outgassed species from the main-chain scission of PMMA comprised 62% of the overall amount of outgassing upon DUV/VUV irradiation, while outgassing from the methoxycarbonyl side chain were summed up to 83% of outgassing upon EUV/BEUV irradiation. On the other hand, about 68% of outgassing resulting from the ester elimination reaction, and 15–20% of that from the Norrish type I reaction, from the TBA unit of HS-TBA had no observable energy dependence; nevertheless, the distribution gravity shifted toward dehydrogenated species, from DUV/VUV to EUV/BEUV. Benzene outgassing was significant from TPS-Nf in HS-TBA-H at all wavelengths, with 0.13 “PAG reactions” per EUV photon absorbed per 1 wt% TPS-Nf added. A quantitative assessment of the absolute outgassing rates from these photoresist films upon EUV irradiation suggests an escape length of neutral outgassing detected herein on the order of 60–80 nm, and PMMA, HS-TBA-H, and the TBA-H moieties would require ∼11 eV/outgassing, 22.4 eV/outgassing, and 9.4 eV/outgassing following EUV and BEUV photoabsorption, respectively.

Microstructural and electrical properties of CuAlO2 ceramic prepared by a novel solvent-free ester elimination process

A novel solvent–free ester elimination technique was designed for the preparation of CuAlO2 ceramic. It involved a direct reaction between aluminum sec-butoxide and copper (II) acetate in the absence of a solvent. Elimination of ester was confirmed from the sharp and intense peak at 1738 cm−1 on the FT-IR spectrum and the characteristic sweet smell obtained from the volatile by-product. The formation of Cu–O–Al mixed metal oxide bridge was demonstrated by a comparative XPS study of the as-prepared material and two separately prepared materials, one having pure Al–O bonds and the other having pure Cu–O bonds. The observed chemical shifts in of O 1s, Al 2p, Cu 2p3/2 and Cu 2p1/2 core levels and the disappearance of the Cu–O satellite peak support this formation. TG-DTA-EGA and XRD analysis revealed the mechanism that lead to the formation of a pure phase of CuAlO2 delafossite under ambient annealing at temperature of 900 °C. The BEI-EDXS and XRD information obtained for ceramic pellets made at different pressures (i.e. 10 MPa, 15 MPa and 20 MPa) also support this pure delafossite phase formation. The semiconductor behavior of the ceramics was confirmed from the temperature dependent resistivity curve and their p-type conductivity from Hall effect measurement.

Synthesis of homogeneous silicophosphate xerogels by non-hydrolytic condensation reactions

A novel non-hydrolytic synthesis of silicophosphate xerogels and optimization of reaction conditions to obtain products with a high degree of condensation and a large specific surface area are presented. Homogeneous products with a high content of Si–O–P bonds and SiO6 moieties were synthesized by an ester elimination route at low temperature from silicon acetate, Si(OAc)4, and tris(trimethylsilyl)phosphate, OP(OSiMe3)3 (TTP). Depending on the reaction conditions (temperature, solvent, time) it was possible to control the degree of condensation (up to 85.7%) and porosity of amorphous xerogels (apparent surface areas from 230 to 568m2g−1). The composition and morphology of the xerogels, volatile reaction byproducts, thermal transformations and surface modification with methanol were followed by elemental analysis, IR spectroscopy, thermal analysis TG-DSC, nitrogen adsorption, 13C, 29Si, and 31P solid-state NMR spectroscopy, and powder XRD.

Facile synthesis of novel hierarchical hollow ZnO microspheres

Novel hierarchical hollow ZnO microspheres, composed of large ZnO crystals on the outer surfaces and small ZnO crystals on the inner surfaces, were synthesized by a chemically induced self-transformation process, employing the ester elimination between zinc formate dihydrate and ethanol.

Template-free synthesis of TiO2 microspheres with tunable particle size via a non-aqueous sol–gel process

TiO2 microspheres with tunable particle size were prepared in alcohols without a template via a facile non-aqueous sol–gel process, on the basis of an ester elimination mechanism.

Non-hydrolytic ester-elimination reaction and its application in solution-processed zinc tin oxide thin film transistors

Solution-processed oxide thin films have many attractive features for various electronic applications as like a next generation display and flexible electronics. But a high temperature annealing is often required to obtain high quality oxide thin film and the applications of solution-processed thin films are limited. To overcome this limit, we adopted a strategy that utilizes chemical driving force in addition to thermal energy. We chose precursors that can react each other and condensate via non-hydrolytic ester elimination reaction. To prove our concept a zinc tin oxide thin film transistor was fabricated with thermal annealing at low-temperature down to 300 °C. Although the oxide film was processed with low-temperature annealing, fabricated thin film transistors were functional and mobility of those of devices exceeded 1.0 cm2 V−1 s−1.

Non-hydrolytic synthesis of titanosilicate xerogels by acetamide elimination and their use as epoxidation catalysts

Novel non-hydrolytic syntheses of titanosilicate xerogels by polycondensation of silicon acetate, Si(OAc)4, with titanium (IV) dimethylamide or diethylamide, Ti(NR2)4 (R = Me, Et), are presented. The reactions are based on acetamide elimination and yield gels with a high content of Si–O−Ti bonds in comparison with the ester elimination route. Although a ligand exchange was observed, it was interestingly not followed by homo-condensation and during the synthesis the phase separation to SiO2 and TiO2 was avoided. The degree of condensation reached up to 68 %. The xerogels prepared for a comparison by ester elimination from Si(OAc)4 and titanium (IV) isopropoxide featured a significantly lower content of the Si–O–Ti bonds. The initial tests in the epoxidation of cyclohexene by cumyl hydroperoxide (CHP) indicated a high selectivity and moderate activity of the xerogels. The catalytic properties were significantly improved by combining non-hydrolytic and hydrolytic methods yielding mesoporous and homogeneous Si/Ti mixed oxides. The catalysts prepared by these methods provided a complete epoxidation of cyclohexene in 2 h at 65 °C.

Polyvinyl alcohol–In2O3 nanocomposite films: synthesis, characterization and gas sensing properties

Poly(vinyl alcohol) (PVA)–In2O3 (with 1 and 5 wt% In2O3 loading) nanocomposite films have been prepared by a solvent-casting technique. The In2O3 nanoparticles used in this work were prepared by nonhydrolytic alcoholysis ester elimination reaction of indium acetate in the presence of oleic acid and oleyl alcohol at 220 °C. X-Ray diffraction (XRD) patterns and transmission electron microscopy (TEM) studies indicate that the In2O3 nanocrystals obtained in this work are nearly monodisperse, highly crystalline with cubic bixbyite structure without the presence of any other impurity phase. The PVA–In2O3 nanocomposite films have been structurally characterized by XRD, Fourier transform infrared (FTIR) and Raman spectroscopy. The results confirm the incorporation of In2O3 nanocrystals in the PVA matrix and interactions between In2O3 nanocrystals and PVA molecules. The thermal properties of nanocomposite films have been investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The thermo-oxidative degradation temperature of PVA increases with the addition of In2O3 nanocrystals and the degree of crystallinity of the PVA matrix decreases in the presence of In2O3 nanocrystals in the nanocomposite films. The room temperature sensing characteristics of the naocomposite films have been studied for various gases, namely, H2S, NH3, CH3, CO, and NO. The PVA–In2O3 nanocomposite films show maximum sensitivity for H2S gas with fast response and reversibility. The response mechanism of the nanocomposite films to various gases is also proposed.

One-Step Synthesis of Monodisperse In-Doped ZnO Nanocrystals.

A method for the synthesis of high quality indium-doped zinc oxide (In-doped ZnO) nanocrystals was developed using a one-step ester elimination reaction based on alcoholysis of metal carboxylate salts. The resulting nearly monodisperse nanocrystals are well-crystallized with typically crystal structure identical to that of wurtzite type of ZnO. Structural, optical, and elemental analyses on the products indicate the incorporation of indium into the host ZnO lattices. The individual nanocrystals with cubic structures were observed in the 5% In–ZnO reaction, due to the relatively high reactivity of indium precursors. Our study would provide further insights for the growth of doped oxide nanocrystals, and deepen the understanding of doping process in colloidal nanocrystal syntheses.

Hybrid Sol−Gel Combustion Synthesis of Nanoporous Anatase

Nanoporous anatase with a thin interconnected filmlike morphology has been synthesized in a single step by coupling a nonhydrolytic condensation reaction of a Ti precursor with a hybrid sol-gel combustion reaction. The method combines the advantages of a conventional sol-gel method for the formation of porous structures with the high crystallinity of the products obtained by combustion methods to yield highly crystalline, phase-pure nanoporous anatase. The generation of pores is initiated by the formation of reverse micelles in a polymeric polycondensation product, which expand during heating, leading to larger pores. A reaction scheme involving a complex formation and nonhydrolytic polycondensation reaction with ester elimination leads to the formation of ail extended Ti-O-Ti network. The effect of process parameters, such as temperature and relative ratio of cosurfactants, on phase formation has been studied. The possibility of band gap engineering by controlled doping during synthesis and the possibility of attachment of molecular/nanoparticle sensitizers provide opportunities for easy preparation of photoanodes for solar cell applications.

Colloidal Chemical Synthesis and Formation Kinetics of Uniformly Sized Nanocrystals of Metals, Oxides, and Chalcogenides

Nanocrystals exhibit interesting electrical, optical, magnetic, and chemical properties not achieved by their bulk counterparts. Consequently, to fully exploit the potential of nanocrystals, the synthesis of nanocrystals must focus on producing materials with uniform size and shape. Top-down physical processes can produce large quantities of nanocrystals, but controlling the size is difficult with these methods. On the other hand, colloidal chemical synthetic methods can produce uniform nanocrystals with a controlled particle size. In this Account, we present our synthesis of uniform nanocrystals of various shapes and materials, and we discuss the kinetics of nanocrystal formation. We employed four different synthetic approaches including thermal decomposition, nonhydrolytic sol-gel reactions, thermal reduction, and use of reactive chalcogen reagents. We synthesized uniform oxide nanocrystals via heat-up methods. This method involved slowly heat-up reaction mixtures composed of metal precursors, surfactants, and solvents from room temperature to high temperature. We then held reaction mixtures at an aging temperature for a few minutes to a few hours. Kinetics studies revealed a three-step mechanism for the synthesis of nanocrystals through the heat-up method with size distribution control. First, as metal precursors thermally decompose, monomers accumulate. At the aging temperature, burst nucleation occurs rapidly; at the end of this second phase, nucleation stops, but continued diffusion-controlled growth leads to size focusing to produce uniform nanocrystals. We used nonhydrolytic sol-gel reactions to synthesize various transition metal oxide nanocrystals. We employed ester elimination reactions for the synthesis of ZnO and TiO(2) nanocrystals. Uniform Pd nanoparticles were synthesized via a thermal reduction reaction induced by heating up a mixture of Pd(acac)(2), tri-n-octylphosphine, and oleylamine to the aging temperature. Similarly, we synthesized nanoparticles of copper and nickel using metal(II) acetylacetonates. Ni/Pd core/shell nanoparticles were synthesized by simply heating the reaction mixture composed of acetylacetonates of nickel and palladium. Using alternative chalcogen reagents, we synthesized uniform nanocrystals of various metal chalcogenides. Uniform nanocrystals of PbS, ZnS, CdS, and MnS were obtained by heating reaction mixtures composed of metal chlorides and sulfur dissolved in oleylamine. In the future, a detailed understanding of nanocrystal formation kinetics and synthetic chemistry will lead to the synthesis of uniform nanocrystals with controlled size, shape, and composition. In particular, the synthesis of uniform nanocrystals of doped materials, core/shell materials, and multicomponent materials is still a challenge. We expect that these uniformly sized nanocrystals will find important applications in areas including information technology, biomedicine, and energy/environmental technology.

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

Nonaqueous-solution routes to metal oxide nanoparticles are a valuable alternative to the known aqueous sol-gel processes, offering advantages such as high crystallinity at low temperatures, robust synthesis parameters and ability to control the crystal growth without the use of surfactants. In the first part of the review we give a detailed overview of the various solution routes to metal oxides in organic solvents, with a strong focus on surfactant-free processes. In most of these synthesis approaches, the organic solvent plays the role of the reactant that provides the oxygen for the metal oxide, controls the crystal growth, influences particle shape, and, in some cases, also determines the assembly behavior. We have a closer look at the following reaction systems in this order: 1) metal halides in alcohols, 2) metal alkoxides, acetates, and acetylacetonates in alcohols, 3) metal alkoxides in ketones, and 4) metal acetylacetonates in benzylamine. All these systems offer some peculiarities with respect to each other, providing many possibilities to control and tailor the particle size and shape, as well as the surface and assembly properties. In the second part we present general mechanistic principles for aqueous and nonaqueous sol-gel processes, followed by the discussion of reaction pathways relevant for nanoparticle formation in organic solvents. Depending on the system several mechanisms have been postulated: 1) alkyl halide elimination, 2) elimination of organic ethers, 3) ester elimination, 4) C--C bond formation between benzylic alcohols and alkoxides, 5) ketimine and aldol-like condensation reactions, 6) oxidation of metal nanoparticles, and 7) thermal decomposition methods.

Synthesis of ZnO Nanocrystals with Cone, Hexagonal Cone, and Rod Shapes via Non‐Hydrolytic Ester Elimination Sol–Gel Reactions

ZnO nanocrystals with various shapes (see Figure) have been synthesized via non-hydrolytic ester elimination sol–gel reactions between zinc acetate and 1,12-dodecanediol. Uniform anisotropic cone-shaped, hexagonal cone-shaped, and rod-shaped ZnO nanocrystals have been synthesized using various surfactants.

Alcoholysis of acylpalladium(II) complexes relevant to the alternating copolymerization of ethene and carbon monoxide and the alkoxycarbonylation of alkenes: the importance of Cis-coordinating phosphines.

The mechanism and kinetics of the solvolysis of complexes of the type [(L-L)Pd(C(O)CH(3))(S)](+)[CF(3)SO(3)](-) (L-L = diphosphine ligand, S = solvent, CO, or donor atom in the ligand backbone) was studied by NMR and UV-vis spectroscopy with the use of the ligands a-j: SPANphos (a), dtbpf (b), Xantphos (c), dippf (d), DPEphos (e), dtbpx (f), dppf (g), dppp (h), calix-6-diphosphite (j). Acetyl palladium complexes containing trans-coordinating ligands that resist cis coordination (SPANphos, dtbpf) showed no methanolysis. Trans complexes that can undergo isomerization to the cis analogue (Xantphos, dippf, DPEphos) showed methanolyis of the acyl group at a moderate rate. The reaction of [trans-(DPEphos)Pd(C(O)CH(3))](+)[CF(3)SO(3)](-) (2e) with methanol shows a large negative entropy of activation. Cis complexes underwent competing decarbonylation and methanolysis with the exception of 2j, [cis-(calix-diphosphite)Pd(C(O)CH(3))(CD(3)OD)](+)[CF(3)SO(3)](-). The calix-6-diphosphite complex showed a large positive entropy of activation. It is concluded that ester elimination from acylpalladium complexes with alcohols requires cis geometry of the acyl group and coordinating alcohol. The reductive elimination of methyl acetate is described as a migratory elimination or a 1,2-shift of the alkoxy group from palladium to the acyl carbon atom. Cis complexes with bulky ligands such as dtbpx undergo an extremely fast methanolysis. An increasing steric bulk of the ligand favors the formation of methyl propanoate relative to the insertion of ethene leading to formation of oligomers or polymers in the catalytic reaction of ethene, carbon monoxide, and methanol.

Polymer photochemistry at advanced optical wavelengths

As lithography is extended to 157 nm, the molecular absorptivity becomes high for most organic polymers. Polymer photochemistry depends on photon absorption, and the higher energy associated with 157 nm light should lead to higher quantum yields of photoproducts. Polymers representative of those commonly employed in 193 or 248 nm resists were selected for this study. A gel permeation chromatography based method was developed to determine quantum yields for chain scission and crosslinking on thin polymers films coated on silicon wafers. This method was applied to determine the ΦS and ΦX of a number of lithographically significant homopolymers and copolymers at both the 157 and 248 nm wavelengths. It was found that polymers containing hydroxystyrene only undergo crosslinking while acrylate and methacrylate polymer only undergo chain scission. The film loss of 157 nm exposed poly-t-butyl acrylate and polymethyl methacrylate was found to be very high and attributed primarily to side chain cleavage of the esters, while no film loss of polyhydroxystyrene was detected. The analysis of outgassing materials showed that ester elimination in poly-t-butyl acrylate was responsible for all outgassed products and that the sum of the quantum yields of all outgassed products exceeded one, implying a reaction mechanism that recycled the initially produced radical. Direct polymer photolysis is significant at 157 nm and must be considered in resist design given the relatively high absorbance of most organic molecules at 157 nm.

Synthesis, characterization and reactivity of crown ether adducts of barium carboxylates: Ba(O 2CCH 3) 2(18-crown-6)·4H 2O and Ba(O 2C(CH 2) 4CO 2)(18-crown-6)·8H 2O

The compounds Ba(O 2CCH 3) 2(18-crown-6)·nH 2O and Ba(O 2C(CH 2) 4CO 2)(18-crown-6)·nH 2O were prepared by the reaction between barium carbonate and the appropriate organic acid in the presence of 18-crown-6. These compounds were characterized by a variety of spectroscopic and analytical methods which showed that various hydrates could be formed. The species Ba(O 2CCH 3) 2(18-crown-6)·4H 2O( 1) and Ba(O 2C(CH 2) 4CO 2) (18-crown-6)·8H 2O ( 2) were structurally characterized by single-crystal X-ray diffraction. In the solid state compound 1 was comprised of a Ba atom in the center of the 18-crown-6 ring with chelating acetate ligands being in the axial positions of the equitorial coordination plane. Water molecules were hydrogen bonded to the oxygen atoms of the acetate ligands. Compound 2 is an infinite polymer in the solid state with the Ba atom also in the center of the 18-crown-6 ring with each carboxylate group chelating to one Ba and each adipate bridging through the second carboxylate group of the dicarboxylate to another Ba atom. Compound 1 crystallizes in the monoclinic space group P2 1/ c with cell dimensions of a = 9.512(1) A ̊ , b = 7.811(1) A ̊ , c = 16.906(1) A ̊ , ß = 99.049(8)°, V = 1240.5(3) A ̊ 3 and Z = 2 . Compound 2 crystallizes in the triclinic space group P 1 with cell dimensions of a = 8.525(1) A ̊ , b = 9.769(1) A ̊ , c = 10.200(1) A ̊ , α = 106.59(1)°, ß = 90.37(1)°, γ = 110.34(1)°, V = 757.4(1) A ̊ 3 and Z = 1 . Compounds 1 and 2 thermally decompose to evolve the 18-crown-6 ligand intact at approximately 200°C, prior to the thermal decomposition of the carboxylate ligand to form BaCO 3. Compounds 1 or 2 were mixed with Ti(O- i-Pr) 4 in ethanol, spin coated onto Pt substrates and heated to 400°C followed by annealing at 700°C for 1 h in air. Coumpound 1 resulted in formation of a mixture of BaTiO 3, BaCO 3 and TiO 2, while 2 produced only BaCO 3 films. The difference in reactivity of 1 and 2 may be connected to the availability of a thermal window for ester elimination as indicated by the TGA results.