New complex of lead(II) with beta-diketonate ligand PbL2 is described, where L=CH3COCHCOC(OCH3)(CH3)2, 5-methoxy-5-methylhexan-2,4-dionate). Crystal structure of the compound has been determined and its thermal properties have been studied. Chains of 1D coordination polymers form crystals of the complex, where the molecules are connected through the chelate-bridging oxygen atoms, methoxy groups remain free and form hydrogen bonds between the chains. PbL2 sublimates at 120 degrees C under reduced pressure (P=10- 2 Torr) with partial decomposition. When heated in the condensed phase the complex decomposes with the formation of lead (II) oxide and evolution of a pyran derivative into gas phase. The mechanism of lead(II) complex thermolysis in support of the condensation of two ligands is discussed. A new organic product was identified by 13C and 1H NMR, IR and PL spectroscopy and mass spectrometry; the crystal structure of the product was determined.

An approach is proposed to design new lithium MOCVD precursors by minor ligand modification. It has been shown that β-ketoiminate ligand can significantly improve the properties of volatile lithium complexes compared to β-diketonate analogues. For this purpose, the structure and properties of two volatile lithium complexes with similar bulky ligands are compared: for β-diketonate Li(tmhd) (1) (tmhd=2,2,6,6-tetramethyl-heptane-3,5-dionate or dipivaloylmethanate, tBu-CO-CH-CO-tBu, where tBu=C(CH3)3) and β-ketoiminate Li(tmha) (2) (tmha= 2,2,6,6-tetramethyl-heptane-3-imino-5-onate, tBu-CO-CH-C(NH)-tBu). Compound 2 is new, and is formally derived from 1 by substitution of oxygen donor atom by NH-group. The compounds were prepared by the same technique and were studied by X-ray diffraction and IR and Raman spectroscopy. Molecular structure of these complexes is similar, built of tetrameric aggregates [LiL]4 with cubane-like Li4O4 core. Both 1 and 2 crystallize in C2/c space group with Z = 4 and Z’ = 0.5 but with different packing motif. According to DSC data, only 2 experiences a crystal-to-crystal phase transition at 384K, which manifests itself as a shift of molecular rows along the a axis, while geometry of [Li(tmha)]4and crystal space group remain unchanged. Analysis of intermolecular contacts using Hirshfeld surface analysis showed that [Li(tmha)]4 molecules are less densely packed compared to [Li(tmhd)]4. This explains the greater volatility of 2 compared to 1, due to the lower value of the lattice energy.

A series of volatile Li-Ni heteroleptic complexes [Ni(SB)Li(dkt)] were prepared as single-source precursors (SSP) for thin-film lithium ion microbatteries, Ni(SB) = Ni(acacen) (1) or Ni(CH3acacen) (2), dkt = beta-diketonate ligand. Crystal structures of heterometallic complexes [Ni(acacen)Li(ptac)] (3), [Ni(CH3acacen)Li(ptac)] (4), [Ni (acacen)Li(LF)] (5), [Ni(acacen)Li(tmhd)] (6), [Ni(CH3acacen)Li(tmhd)] (7), [Ni(acacen)Li(tmha)] (8) (where acacen = N,N'-ethylenebis (acetylacetoniminate), CH3acacen = N,N'-propylenebis(acetylacetoniminate), tmhd = 2,2,6,6-tetramethyl-heptane-3-imino-5-onate, ptac = 1,1,1-trifluoro-5,5-dimethyl-hexane-2,4-dionate, LF = 1,1,1-trifluoro-5-methoxy-5-methyl-hexane-2,4-dionate, tmha = 2,2,6,6-tetramethyl-heptane-3-imino-5-onate) were studied by X-ray diffraction. Structures of 3-8 are molecular, the packing motif of binuclear complexes is largely determined by the stacking of Ni(SB) fragments. Li atoms always have a tetrahedral coordination involving donor oxygen atoms of the ligands, while oxygen atoms of SB are bridging. Crystals of 3,5,6 are formed by infinite stacking of binuclear molecules, while centrosymmetric pairs of heterocomplexes are formed in crystals of 4,7,8. The thermal properties of the compounds were studied by vacuum sublimation and TGA. It was established that Ni(CH3acacen)-derivatives 2,4,7 are more volatile and have lower melting point compared to Ni (acacen)-ones 1,3,5,6. Li(dkt) moiety in the heterocomplex affects thermal properties as following: fluorinecontaining complexes 3,4,5 are less volatile than non-fluorinated ones, and ketoiminate complex 8 is the least thermally stable. Following the obtained results, complexes 6,7 can be recommended as SSP for chemical vapor deposition of mixed oxides films.

Two volatile lithium complexes with bulky tert-butyl terminal substituents: β-diketonate Li(tmhd) (1) (tmhd=2,2,6,6-tetramethyl-heptane-3,5-dionate or dipivaloylmethanate, tBu-CO-CH-CO-tBu, where tBu=C(CH3)3) and β-ketoiminate Li(tmha) (2) (tmha= 2,2,6,6-tetramethyl-heptane-3-imino-5-onate, tBu-CO-CH-C(NH)-tBu) were studied by X-ray diffraction analysis and IR and Raman spectroscopy. Compound 2 is new, and is formally derived from 1 by substitution of oxygen donor atom by NH-group. Molecular structure of these complexes is similar, built from tetrameric aggregates with cubane-like Li4O4 core. Both 1 and 2 crystallize in C2/c space group with Z = 4 and Z’ = 0.5. According to DSC data, only 2 experiences a crystal-to-crystal phase transition at 384K, which manifests itself as a shift of molecular rows along the a axis, while geometry of [Li(tmha)]4 remains unchanged. The high-temperature structure also has C2/c space group.Analysis of intermolecular contacts using Hirshfeld surface analysis showed that [Li(tmha)]4 molecules are less densely packed compared to [Li(tmhd)]4. This explains the greater volatility of 2 compared to 1, due to the lower value of the lattice energy.

Министерство науки и высшего образования Российской Федерации Российское химическое общество им.Д.И.Менделеева Секция по химической термодинамике и термохимии Научного совета РАН по физической химии Сибирское Отделение Российской Академии Наук Институт неорганической химии им.А.В.Николаева СО РАН

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Five volatile lithium beta-diketonates: Li(tmhd) (1), Li(pta) (2), LiL (3), LiLF (4), Li(tmha) (5) (tmhd = 2,2,6,6tetramethyl-heptane-3,5-dionate, pta = 1,1,1-trifluoro-5,5-dimethyl-hexane-2,4-dionate, L = 2-methoxy-2,6,6trimethyl-heptane-3,5-dionate, LF = 1,1,1-trifluoro-5-methoxy-5-methyl-hexane-2,4-dionate, tmha = 2,2,6,6tetramethyl-heptane-3-imino-5-onate) and lithium alkoxide Li(OtBu) (6) were examined by combination of several complementary methods to study their thermal behavior in solid and gas phase and to check their suitability as precursors for chemical vapor deposition of Li-containing films. The best storage stability was observed for 3 and 4. Thermal gravimetric analysis and vacuum sublimation test were used to compare stability of the complexes under vaporization. In situ mass spectrometry was used to study the gas phase composition and the surface decomposition chemistry. Diketonate complexes 1, 3-5 passed into the gas phase as tetranuclear particles. Upon further heating, they split into binuclear species. The binuclear species thermolysis is responsible for the film deposition. The vapor thermal stability in oxygen increases in the row 3 > 1>5 > 2>4 > 6. CVD films obtained at 500 degrees C in the presence of oxygen using 1, 3 and 5 consisted of Li2CO3. LiF films can be obtained using 2, while 4 allow one to obtain the Li metal films in the oxygen presence on both Si and Pt/Si substrates.

New lithium complexes with fluorinated and non-fluorinated methoxy-substituted, beta-diketonates L-F = 1,1,1-trifluoro-5-methoxy-5-methyl-hexane-2,4-dionato, L = 2-methoxy-2,6,6-trimethyl-heptane-3,5dionato were prepared. X-ray analysis indicates the crystal structure of these complexes is molecular built of cyclic tetramers [LiL](4) and [LiLF](4). Li atoms are bonded to four oxygens in a tetrahedral environment. Methoxy groups of the ligands are involved in the coordination. The crystallographic data for [LiL]4: C44H76Li4O12, P21/n, a = 14.2759(9) A, b = 11.9116(7) A, c = 17.5870(11) A, ,B = 90.948(2) & DEG;, Z = 4, d = 1.101 g/cm(3); for [LiLF]4: C(32)H(40)F(12L)i4O(12), P2/n, a = 9.5710(5) A, b = 10.9946(17) A, c = 18.8476(10) A, ,B = 103.2212(10) & DEG;, Z = 2, d = 1.385 g/cm3. Thermal properties were investigated with TG-DTA, sublimation test. It was established that the complexes are volatile and sublime upon heating in a vacuum (170 ?, similar to 10(-2) Torr). As it was established by mass spectrometric technique, the tetrameric structure is retained in the gas phase under vaporization of the complexes.(c) 2022 Elsevier B.V. All rights reserved.

Thermophysical and thermochemical data including condensed and vapor phase transformations and temperature stability ranges, melting, sublimation and vaporization processes for a volatile metal-organic precursor are of current importance to optimize the preparation of functional nano-materials through chemical vapor deposition, atomic layer deposition and their modifications. Here, we present the results of a comprehensive thermal characterization of indium tris-dipivaloylmethanate, In(thd)3 or In(dpm)3, which is a convenient air-stable precursor for widely demanded indium oxide ceramics. Thermogravimetry was applied to evaluate the condensed phase stability both in inert and oxidizing atmosphere. The melting temperature and enthalpy were measured by differential scanning calorimetry. The pressure of saturated and unsaturated In(thd)3 vapors was measured using a static method with glass membrane-gauge manometer. The p(T) equations of saturated vapors over the solid and liquid complex were obtained and the thermodynamic characteristics of the processes under study were calculated. The thermal decomposition of In(thd)3 vapors on a heated surface in vacuum and in oxygen presence was investigated by in situ mass spectrometry. The temperature range of this process and its intramolecular character were revealed. A critical review of the literature data on the thermal properties of In(thd)3 was also performed.

Using a flow technique, the temperature dependences of saturated vapor pressure of two crystalline modifications of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(III) - Co(thd)(3): stable (P over line 3c1) and metastable (Pnma) have been firstly determined. The temperature dependences of saturated vapor pressure of two crystalline modifications of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)cobalt(III) - Co(thd)(3): stable (P over line 3c1) and metastable (Pnma) have been firstly determined using a flow technique. The onset temperatures of thermolysis and decomposition ways of Co(thd)(3) vapors in vacuum and in the oxygen and hydrogen presence were established by a means of in situ mass spectrometry. The Co-oxide based materials were obtained via deposition of metastable phase of Co(thd)(3) by Pulse-CVD on Si(100) substrates. The composition and microstructure of Co-oxide based materials depending on deposition temperature and career gas was studied by using X-ray diffraction, X-ray photoelectron, Raman spectroscopy and SEM. The (111)-oriented Co3O4 film demonstrates electrochemical stability in 1 M NaOH solution and it has 0.63 V potential which is reached at 10 mA/cm(2).

The direct liquid injection chemical vapor deposition (DLI-CVD) of uniform and dense zirconium oxide (ZrO2) thin films applicable as corrosion protection coatings (CPCs) is reported. We present the entire development chain from the rational choice and thermal evaluation of the suitable heteroleptic precursor [Zr(OiPr)2(tbaoac)2] over the detailed DLI-CVD process design and finally benchmarking the CPC behavior using electrochemical impedance spectroscopy (EIS). For a thorough development of the growth process, the deposition temperature (Tdep) is varied in the range of 400 – 700 °C on Si(100) and stainless steel (AISI 304) substrates. Resulting thin films are thoroughly analyzed in terms of structure, composition, and morphology. Grazing incidence X-ray diffractometry (GIXRD) reveals an onset of crystallization at Tdep ≥ 500 °C yielding monoclinic and even cubic phase at low temperatures. At Tdep = 400 °C, isotropic growth of XRD amorphous material is shown to feature cubic crystalline domains at the interfacial region as revealed by electron diffraction. Corrosion results obtained through EIS measurements and further immersion tests revealed improved CPC characteristic for the 400 °C processed ZrO2 coatings compared to the ones deposited at Tdep ≥ 500 °C, yielding valuable insights into the correlation between growth parameter and CPC performance which are of high relevance for future exploration of CPCs.

Integral regularities in the growth of 7YSZ thermal barrier coatings during MO CVD (Metal–Organic Chemical Vapor Deposition) are proposed. Within the framework of the model of the reacting boundary layer, the coating deposition process is considered as a process of independent global reactions of diffusion combustion of Zr(dpm)4 and Y(dpm)3 under convection conditions on a permeable surface. The rate of coating growth and the efficiency of using a precursor are analytically evaluated. The correctness of the proposed approach is confirmed by comparison with known experimental data. The considered model can be used to analyze the deposition of coatings from various mixtures of precursors, such as Nd(dpm)3, Hf(dpm)4, and Sm(dpm)3.

The functional properties of photocatalytic CVD processed TiO2 films can be monitored by appropriately selecting the precursors chemistry.

The thermal properties of individual precursors, zirconium(IV) and yttrium(III) dipivaloylmethanates, and of their mixtures [Zr(thd)4–Y(thd)3, Hthd = 2,2,6,6-tetramethylheptane-3,5-dione] used for preparing mixed oxide films by chemical vapor deposition were studied in the condensed and gas phases. In the condensed phase, the vaporization rate of both individual compounds and their mixtures considerably exceeds the decomposition rate. The vaporization, thermal stability of the vapors, and thermal decomposition of the compounds in a vacuum and in the presence of oxygen were studied using mass-spectrometric monitoring of the gas phase composition. Comparison of the thermal behavior of individual Zr(thd)4 and Y(thd)3, heated in separate vaporizers of the mass spectrometer inlet system, and of their mixtures with different Zr(thd)4 to Y(thd)3 ratios reveals no chemical interaction between the precursors in the examined temperature interval.

The rough, even discontinuous morphology of vapor-deposited copper films inhibits their attractive electrical properties. In the present study, we investigate the influence of deposition time, deposition temperature, and the flow rate of the precursors on the morphology of Cu films deposited from metalorganic chemical vapor deposition. We show that it is necessary to purify the copper(I) cyclopentadienyl triethylphophine (CpCuPEt3) precursor in order to improve its stability and volatility. We also determined its saturated vapor pressure law, logP(sat) (Pa) = 8.614 - 2272/T (K). The Arrhenius plot of the global deposition reaction of Cu films in the presence of hydrogen between 431 and 523 K shows a low apparent activation energy of 10 kJ/mol. Electron probe microanalysis, grazing incidence X-Ray diffraction, and image analysis of the micrographs obtained by top-down surface scanning electron microscopy reveal metallic films composed of Cu islands. Their size and packed density increase and, ultimately, the islands coalesce with increasing precursor flow rate and, to a lesser extent, with increasing deposition temperature.

Three volatile mixed-metal precursors [ZrL4Pb(hfa)2] (1), [ZrL4PbL2] (2), and [ZrL4La(dpm)3] (3) (L = 2-methoxy-2,6,6-trimethyl-3,5-heptanedionate; dpm = 2,2,6,6-tetramethyl-3,5-heptanedionate; hfa = 1,1,1,5,5,5-hexafluore-2,4-pentanedionate) are used to prepare ZrO2-based multicomponent films by metalorganic chemical vapor deposition (MOCVD). The deposition experiments are carried out in a hot-wall reactor at 600-750 °C on silicon substrates under 20 Torr in the presence of oxygen. According to X-ray powder diffraction, the main crystal phases in the films prepared from precursors 1 and 2 are solid solutions based on tetragonal and cubic ZrO2. Lead does not form separate crystal phases but is dissolved in the oxide form within the ZrO2 matrix, as is indicated by X-ray photoelectron spectroscopy data. La2Zr2O7 films are prepared from 3 using two ways of precursor supply: evaporation in argon and by direct liquid injection (DLI). It is shown that the composition and structure of obtained films are determined by the precursor composition. The results obtained for thermal behavior of precursors in condensed and gas phases are discussed.

A series of new trinuclear molecular complexes [PbL21{Co(hfa)(2)}(2)] (1), [PbL21{Ni(hfa)(2)}(2)] (2), [PbL22{Co(hfa)(2)}(2)] (3), [PbL22{Ni(hfa)(2)}(2)] (4), [PbL23{Co(hfa)(2)}(2)] (5), [PbL23{Ni(hfa)(2)}(2)] (6), where L = methoxy-substituted beta-diketonate RCOCHCOC(CH3)(2)OCH3, L-1: R = CH3, L-2: R = CF3, L-3: R = C(CH3)(3); hfa = hexafluoroacetylacetonate, were synthesized. Crystal structures were determined by single crystal X-ray analysis. Volatility and thermal stability of the obtained compounds were studied by thermal gravimetric analysis, vacuum sublimation and by mass transfer in helium flow. It was established that all the obtained heterometallic complexes are volatile and can be sublimed in vacuum without dissociation into monometallic complexes. Compounds 3-6 were examined as SSP (single source precursors) in conventional low pressure MOCVD (Metalorganic Chemical Vapor Deposition) of inorganic films on Si(100) substrates. Influence of precursor composition on their structure and thermal properties as well as on the composition of the deposited inorganic films are discussed. (C) 2020 Elsevier Ltd. All rights reserved.

Методом РСА изучено строение двух β-дикетонатов Al(III) и Fe(III) с γ-замещенным лигандом при 150(2) K. Кристаллографические данные для Al(γ-Me-hd)3 (I): пространственная группа P–1, a = 10.855(1) Å, b = 11.129(1) Å, с = 11.894(1) Å, α = 85.634(3)°, β = 73.118(3)°, γ = 66.771(3)°, V = 1262.2(2) Å3, Z = 2, R1 = 0.0438; для Fe(γ-Me-hd)3 (II): пространственная группа P21/с, a = 10.0374(5) Å, b = 17.0798(7) Å, с = 15.7213(6) Å, β = 107.459(1)°, V = 2571.1(2) Å3, Z = 4, R = 0.0364. Соединения I и II изотипны, так как имеют одинаковые по строению молекулы, но кристаллизуются в разных сингониях. Кристаллические структуры I и II молекулярные и состоят из дискретных молекул M(γ-Me-hd)3 (M = Al, Fe). Термогравиметрические исследования показали, что комплексы I и II обладают близкой летучестью. Для комплекса Cu(γ-Me-hd)2 (III) проведено измерение давления насыщенного пара методом Кнудсена в интервале температур 100—150 °C, установлены термодинамические параметры сублимации и исследован термолиз паров.

The structures of two Al(III) and Fe(III) β-diketonates with a γ-substituted ligand are studied by single crystal X-ray diffraction at 150(2) K. Crystallographic data for Al(γ-Me-hd)3 (I) are: space group $$P\bar{1}$$ , a = 10.855(1) Å, b = 11.129(1) Å, с = 11.894(1) Å, α = 85.634(3)°, F0200062 = 73.118(3)°, γ = 66.771(3)°, V = 1262.2(2) Å3, Z = 2, R1 = 0.0438. For Fe(γ-Me-hd)3 (II): space group P21/с, a = 10.0374(5) Å, b = 17.0798(7) Å, с = 15.7213(6) Å, F0200062 = 107.459(1)°, V = 2571.1(2) Å3, Z = 4, R1 = 0.0364. Compounds I and II are isotypical because their molecules have the same structure but crystallize in different crystal systems. The crystal structures of I and II are molecular and consist of discrete M(γ-Me-hd)3 (M = Al, Fe) molecules. Thermogravimetric studies show that complexes I and II are similarly volatile. For Cu(γ-Me-hd)2 complex (III) the saturated vapor pressure is measured by the Knudsen method in the temperature range 100-150 °C. Sublimation thermodynamic parameters are found and vapor thermolysis is investigated.

Три летучих смешанно-металльных прекурсора [ZrL4Pb(hfa)2] (1), [ZrL4PbL2] (2) и [ZrL4La(dpm)3] (3) (L = 2-метокси-2,6,6-триметил-3,5-гептандионат; dpm = 2,2,6,6-тетраметил-3,5-гептандионат; hfa = 1,1,1,5,5,5-гексафтор-2,4-пентандионат) использованы для химического осаждения из газовой фазы (MOCVD) многокомпонентных пленок на основе оксида циркония. Эксперименты по осаждению проводились в реакторе с горячими стенками в диапазоне 600—750 °C на кремниевых подложках при 20 Торр, в присутствии кислорода. Рентгенофазовый анализ показал, что прекурсоры 1 и 2 дают пленки, где основные кристаллические фазы — это твердые растворы на основе тетрагональной и кубической ZrO2. Свинец не образует отдельные кристаллические фазы, однако по данным рентгенофотоэлектронной спектроскопии он растворен в матрице ZrO2 в виде оксида. Из 3 получены пленки La2Zr2O7 с использованием двух способов подачи прекурсора: испарение в потоке аргона и в системе прямого впрыска раствора (DLI). показано, что состав и структура полученных пленок определяются составом используемого предшественника. Обсуждаются результаты исследования термического поведения прекурсоров в конденсированной и газовой фазе.