A Highly Stable Copper‐Based Catalyst for Clarifying the Catalytic Roles of Cu0 and Cu+ Species in Methanol Dehydrogenation

Identification of the active copper species, and further illustration of the catalytic mechanism of Cu‐based catalysts is still a challenge because of the mobility and evolution of Cu⁰ and Cu⁺ species in the reaction process. Thus, an unprecedentedly stable Cu‐based catalyst was prepared by uniformly embedding Cu nanoparticles in a mesoporous silica shell allowing clarification of the catalytic roles of Cu⁰ and Cu⁺ in the dehydrogenation of methanol to methyl formate by combining isotope‐labeling experiment, in situ spectroscopy, and DFT calculations. It is shown that Cu⁰ sites promote the cleavage of the O?H bond in methanol and of the C?H bond in the reaction intermediates CH₃O and H₂COOCH₃ which is formed from CH₃O and HCHO, whereas Cu⁺ sites cause rapid decomposition of formaldehyde generated on the Cu⁰ sites into CO and H₂.     

Thermal analysis of catalyst precursors: Part 2. Influence of support and metal precursor on the reducibility of copper catalysts

The reductions of supported CuO and CuCI₂ have been studied by thermal analytical methods. Upon calcination of Cu(NO₃)₂ impregnated onto SiO₂ or Al₂O₃, there are formed both particles of non-interacting CuO, which are reduced over a narrow temperature range with T_max ≊ 490 K, and dispersed Cu^II species, which are less easily reduced (T_max ≊ 560–610 K on SiO₂ and 515–545 K on Al₂O₃). On TiO₂, particulate CuO is reduced at a somewhat lower temperature (T_max ≊ 465 K) and there is evidence of a more easily reducible dispersed Cu^II phase on anatase samples. However, the presence of residual additives on the surface of pigmentary anatase raises T_max, for CuO particles to ~525 K. Deposition-precipitation and ion exchange methods both lead to Cu(OH)₂; this on calcination affords CuO, which is generally reduced in a single step, at a temperature characteristic of particulate CuO.On the other hand, reduction of supported CuCl₂ proceeds in two clearly defined steps, the ratio of the peak areas being close to 1:1 ; an intermediate Cu¹ state is clearly implicated. Evolution of HCl does not however occur simultaneously with the H₂ uptake; little if any appears during the reduction of Cu^II to Cu^I, but (except on Al₂O₃) the evolution is almost complete before the final reduction step starts. This is thought to be due to dissociation of Cu-Cl bonds and formation of Cl⁻ on the support, this being the major intermediate in the formation of gaseous HCl.     

Cu/活性炭催化剂：水合肼还原制备及催化甲醇氧化羰基化

以活性炭为载体,水合肼为还原剂制备了负载型Cu/活性炭催化剂,考察了水合肼/硝酸铜物质的量的比对催化甲醇气相氧化羰基化性能的影响,并采用XRD、XPS、H2-TPR和SEM等手段对催化剂进行了表征。结果表明,不加入还原剂水合肼时,催化剂中仅有CuO;随着水合肼/硝酸铜物质的量的比的增加,二价铜逐步被还原为Cu2O和/或单质Cu0,未被还原的Cu(OH)2在催化剂干燥过程中分解形成分散态CuO存在于催化剂表面。当水合肼/硝酸铜物质的量的比为0.75时,催化剂的催化性能最好,碳酸二甲酯的时空收率为120.62 mg.(g.h)-1,选择性为74.51%,甲醇转化率达到3.88%。在93 h反应时间内,催化剂都保持了较高的反应活性和选择性。此时铜物种以Cu2O和分散态CuO为主,Cu2O是主要的活性物种。     

Synthesis,structures, and magnetic properties of two pyrazolato-bridged trinuclear copper(II) complexes

One nonlinear and one linear trinuclear copper(II) complex [Cu₃(dien)₂(pdc)₂CH₃OH]₂?·?6CH₃OH (1) and [Cu₃(pdc)₂(CH₃OH)₆(H₂O)₄] (2) were prepared and characterized structurally, where dien is diethylenetriamine and pdc^3? the trianion of 3,5-pyrazoledicarboxylic acid. Both complexes consist of 3,5-pyrazoledicarboxylato-bridged trinuclear copper(II) centers. In 1, copper(II) ions are five-coordinate in distorted square pyramids with bond angles 164.78° for Cu(1)–Cu(2)–Cu(3) and 164.51° for Cu(4)–Cu(5)–Cu(6). In 2, the three copper(II) ions are six-coordinate with elongated octahedral geometry. The trinuclear units of 1 and 2 interact through hydrogen bonds to form 3-D and 2-D supramolecular networks, respectively. Variable temperature magnetic susceptibility measurements show that 1 and 2 are antiferromagnetically coupled with J values of ?11.2 and ?13.3?cm^?1.     

Fabrication and characterization of composition-gradient CuO/SiO2 composite aerogel

With tetramethoxysilane as the silica precursor, CuCl₂·2H₂O as the copper–oxide precursor, acetonitrile as the solvent and gelled by PO via a sol–gel process, the CuO/SiO₂ composite aerogel was fabricated. By adjusting the amount of CuCl₂·2H₂O, CuO/SiO₂ composite aerogels with different molar ratio of Cu/Si such as 1, 5, 10, 20, 30 and 35 % was prepared. Finally, via a self-built device and sol-co-gelation technic, a continuous formation process was developed to fabricate the composition-gradient CuO/SiO₂ composite aerogel. Density of these aerogels was about 200 mg/cm³, the composition-gradient CuO/SiO₂ composite aerogel was cylindrical and about 2.5 cm in height. Scanning electron microscope was used to characterize its microstructure at different position. X-ray diffraction, energy dispersive spectrometer and Fourier transform infrared spectrometer were used to characterize its composition and composition distribution, the results showed that the cylindrical CuO/SiO₂ composite aerogel’s molar ratio of Cu/Si changed from 31.06 to 4.43 % as the measure point from the bottom up, the whole sample displayed obvious composition-gradient.     

柠檬酸辅助固相研磨法制备铜基催化剂及在CO_2加氢合成甲醇反应中的性能研究

通过柠檬酸辅助固相研磨法制备铜基催化剂,采用XRD、TPR、TG-DSC、SEM、BET、TEM、XPS、CO_2-TPD等手段对催化剂性能进行表征.结果表明室温固相研磨的前驱体在惰性气体N_2中焙烧使体系中的CuO绝大部分被原位还原成Cu~0,不需外加H_2还原,直接制得了C/I-Cu/ZnO催化剂,催化剂具有中孔.利用高压固定床连续反应装置对催化剂活性进行了评价,结果表明,柠檬酸用量、前驱体焙烧温度、焙烧升温速率等条件对催化剂活性产生影响,当C_6H_8O_7/(Cu+Zn)摩尔比为1.2/1并Cu/Zn摩尔比1/1,前驱体在N_2中以3 K·min~(-1)升温速率于623 K焙烧3 h,制得的C/I-Cu/ZnO催化剂比表面积最大,Cu~0粒径最小,在CO_2加氢合成甲醇反应中表现出最佳的活性,CO_2转化率、甲醇选择性和产率分别达到了28.28%、74.29%和21.01%.与外加H_2还原的C/H-Cu/ZnO催化剂相比,原位还原C/I-Cu/ZnO催化剂比表面积较大,Cu~0的粒径较小,活性较高.     

Characterization of Cu species on SiO2 and ZSM-5 by temperature-programmed reduction by ammonia

We studied the temperature-programmed reduction by NH₃ (NH₃-TPR) as a supplement to the temperature-programmed reduction by H₂ (H₂-TPR) for the characterization of supported Cu species. The NH₃-TPR profile of Cu/SiO₂, which contained only bulk CuO, exhibited two peaks for N₂ formation in equal amounts, suggesting stepwise reduction of the bulk CuO. In contrast, the H₂-TPR profile exhibited only one H₂ consumption peak. We also studied Cu-NaZSM-5 samples with various Cu and Na loadings. The Cu ions on ZSM-5 were reduced to Cu⁺ but no further. Kinetic analysis revealed that the NH₃-TPR profile exhibited peaks for separate reductions of isolated and binuclear Cu²⁺ ions. Thus, we found NH₃-TPR to be useful for detailed analysis of the reducibility of Cu²⁺ to Cu⁺ in zeolite pores.     

A Novel Heterometallic Cluster-Based Coordinational Polymer with 2-[Bis-(2-hydroxy-ethyl)-Amino]-Ethanesulfonic Acid: Synthesis and Crystal Structure

A rare heterometallic cluster-based polymer [Cu₄(Hbhea)₄(μ ₂-OCH₃) K(CH₃OH))] _n ·(H₂O) _n (1) (H₃bhea = 2-[bis-(2-hydroxy-ethyl)-amino]-ethanesulfonic acid), has been synthesized and structurally determined by single crystal X-ray diffraction, elemental analysis. Crystallographic unit of 1 consists of four Cu(II), four Hbhea ligands, one methanol molecule, one methanol anion, one K ion and one crystal lattice water and formed anion cluster [Cu₄(Hbhea)₄(CH₃O)]^? which further constructed a 3-D polymer by linking the six-coordination K ions.     

Photocatalytic reduction of CO2 with H2O on TiO2 and Cu/TiO2 catalysts

Photoinduced reduction of CO₂ by H₂O to produce CH₄ and CH₃OH has been investigated on wellcharacterized standard TiO₂ catalysts and on a Cu²⁺ loaded TiO₂ catalyst. The efficiency of this photoreaction depends strongly on the kind of catalyst and the ratio of H₂O to CO₂. Anatase TiO₂, which has a large band gap and numerous surface OH groups, shows high efficiency for photocatalytic CH₄ formation. Photogenerated Ti³⁺ ions, H and CH₃ radicals are observed as reactive intermediates, by ESR at 77 K. Cu-loading of the small, powdered TiO₂ catalyst (Cu/TiO₂) brings about additional formation of CH₃OH. XPS studies suggest that Cu⁺ plays a significant role in CH₃OH formation.     

The composite catalysts of Cu/CuxO nanoparticles supported on the carbon fibers were prepared for styrene oxidation reaction

In this paper a novel simple method for preparing two different catalysts with various‐valences copper was reported. Carbon nanofibers supported copper‐cuprous oxide nanoparticles (Cu‐Cu₂O NPs/CNFs) and copper oxide nanoparticles (CuO NPs/CNFs) through electrospinning, adsorption and reduction in the high‐pressure hydrogenation and the high‐temperature calcination methods. These catalysts were investigated by a series of characterizations and were applied in reaction in nitrogen atmosphere, which had a good catalytic activity and selectivity of benzaldehyde for the reaction. Above all, the new study has been certified clearly, in which Cu‐Cu₂O NPs/CNFs and CuO NPs/CNFs composite catalysts enhanced the generation of benzaldehydeand the excellent catalytic properties were exhibited.     

Solution/Ammonolysis Syntheses of Unsupported and Silica-Supported Copper(I) Nitride Nanostructures from Oxidic Precursors

Herein we describe an alternative strategy to achieve the preparation of nanoscale Cu₃N. Copper(II) oxide/hydroxide nanopowder precursors were successfully fabricated by solution methods. Ammonolysis of the oxidic precursors can be achieved essentially pseudomorphically to produce either unsupported or supported nanoparticles of the nitride. Hence, Cu₃N particles with diverse morphologies were synthesized from oxygen-containing precursors in two-step processes combining solvothermal and solid−gas ammonolysis stages. The single-phase hydroxochloride precursor, Cu₂(OH)₃Cl was prepared by solution-state synthesis from CuCl₂·2H₂O and urea, crystallising with the atacamite structure. Alternative precursors, CuO and Cu(OH)₂, were obtained after subsequent treatment of Cu₂(OH)₃Cl with NaOH solution. Cu₃N, in the form of micro- and nanorods, was the sole product formed from ammonolysis using either CuO or Cu(OH)₂. Conversely, the ammonolysis of dicopper trihydroxide chloride resulted in two-phase mixtures of Cu₃N and the monoamine, Cu(NH₃)Cl under similar experimental conditions. Importantly, this pathway is applicable to afford composite materials by incorporating substrates or matrices that are resistant to ammoniation at relatively low temperatures (ca. 300 °C). We present preliminary evidence that Cu₃N/SiO₂ nanocomposites (up to ca. 5 wt.% Cu₃N supported on SiO₂) could be prepared from CuCl₂·2H₂O and urea starting materials following similar reaction steps. Evidence suggests that in this case Cu₃N nanoparticles are confined within the porous SiO₂ matrix.     

Structural Observations of Heterometallic Uranyl Copper(II) Carboxylates and Their Solid‐State Topotactic Transformation upon Dehydration

The hydrothermal reactions of uranyl nitrate and metallic copper with aromatic polycarboxylic acids gave rise to the formation of five heterometallic UO₂²⁺? Cu²⁺ coordination polymers: (UO₂)Cu(H₂O)₂(1,2‐bdc)₂ ( 1 ; 1,2‐bdc=phthalate), (UO₂)Cu(H₂O)₂(btec) ? 4 H₂O ( 2 ) and (UO₂)Cu(btec) ( 2′ ; btec=pyromellitate), (UO₂)₂Cu(H₂O)₄(mel) ( 3 ; mel=mellitate), and (UO₂)₂O(OH)₂Cu(H₂O)₂(1,3‐bdc) ? H₂O ( 4 ; 1,3‐bdc=isophthlalate). Single‐crystal X‐ray diffraction (XRD) analysis of compound 1 revealed 2D layers of chains of UO₈ and CuO₄(H₂O)₂ units that were connected through the phthalate ligands. In compound 2 , these sheets were connected to each other through the two additional carboxylate arms of the pyromellitate, thus resulting in a 3D open‐framework with 1D channels that trapped water molecules. Upon heating, free and bonded water species (from Cu? OH₂) were evacuated from the structure. This thermal transition was followed by in situ XRD and IR spectroscopy. Heating induced a solid‐state topotactic transformation with the formation of a new set of Cu? O interactions in the crystalline anhydrous structure ( 2′ ), in order to keep the square‐planar environment around the copper centers. The structure of compound 3 was built up from trinuclear motifs, in which one copper center, CuO₄(OH₂)₂, was linked to two uranium units, UO₅(H₂O)₂. The assembly of this trimer, “U₂Cu”, with the mellitate generated a 3D network. Complex 4 contained a tetranuclear uranyl core of UO₅(OH)₂ and UO₆(OH) units that were linked to two copper centers, CuO(OH)₂(H₂O)₂, which were then connected to each other through isophthalate ligands and U?O? Cu interactions to create a 3D structure. The common structural feature of these different compounds is a bridging oxo group of U?O? Cu type, which is reflected by apical Cu? O distances in the range 2.350(3)–2.745(5) Å. In the case of a shorter Cu? O distance, a slight lengthening of the uranyl bond (U?O) is observed (e.g., 1.805(3) Å in complex 4 ).     

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,magnetochemical studies and X-ray molecular structures of some mononuclear copper(II)–1H-pyrazole adducts and mono(μ-pyrazolate) bridged dicopper(II) complexes derived from N-salicylidenearoylhydrazines

1H-Pyrazole complexes, [Cu(HL)HPz Cl] nH₂O and [Cu(L)HPz] nH₂O were prepared and characterized, where HL and L, respectively, refer to the mononegative and dinegative N-salicylidenearoylhydrazine anions. The X-ray crystal and molecular structure of [monochloro(N-salicylidenebenzoylhydrazinato)ONO(−1)monopyrazole] copper(II) monohydrate, [Cu(HSBzh)HPz Cl] H₂O, and [(N-salicylidenebenzoylhydrazinato)ONO(−2)monopyrazole] copper(II) hemihydrate, [Cu(SBzh)HPz] 1/2H₂O, were determined. The Cu(II) in [Cu(HSBzh)HPz Cl] H₂O is in a distorted square pyramidal environment and is bound in the equatorial plane with the mononegative tridentate aroylhydrazone anion and pyrazole nitrogen, the axial fifth coordination site is occupied by a chloride ion. On the other hand, the complex [Cu(SBzh)HPz] 1/2H₂O consists of two monomeric crystallographically independent but chemically similar molecules. In each molecule, the Cu(II) is in a distorted square planar geometry and is coordinated to the dinegative tridentate aroylhydrazone via the phenoxy oxygen, azomethine nitrogen and enolimide oxygen, and the fourth coordination site is occupied by the pyrazole nitrogen. The mono(μ-pyrazolate) dicopper(II) complexes, K[Cu₂(L)₂Pz] nH₂O, were also prepared and the X-ray molecular structure of K₂[Cu₄(SBzh)₄(Pz)₂] 2H₂O 1/2CH₃OH was determined. In this complex, two copper(II) atoms are bridged by only one pyrazolate anion forming a dicopper mono(μ-pyrazolate) unit. Each two units are connected together by a five coordinate K⁺ cation forming a tetranuclear assembly. These tetranuclear assemblies are connected together by another K⁺ cation forming a supramolecular structure. Variable temperature magnetic studies on these pyrazolate complexes indicated antiferromagnetic behaviour with −2J values varying from 25 to 36 cm⁻¹.     

溶剂极性对微波辐射老化制备前驱体及CuO/ZnO/Al2O3催化剂结构的影响

在制备CuO/ZnO/Al2O3催化剂的老化过程中,采用微波辐射老化技术,着重研究了溶剂极性对前躯体物相组成,烧后CuO/ZnO/Al2O3催化剂结构及其在浆态床合成甲醇工艺中催化性能的影响。通过XRD、DTG、H2-TPR,FTIR、HR-TEM和XPS对前驱体及催化剂表征表明,沉淀母液在微波辐射条件下进行老化,溶剂的极性对前躯体物相组成及催化剂结构影响显著。随着溶剂极性的增大,Zn2+/Cu2+取代Cu2(CO3)(OH)2/Zn5(CO3)2(OH)6中Cu2+/Zn2+的取代反应增强,使得前躯体中(Cu,Zn)5(CO3)2(OH)6和(Cu,Zn)2(CO3)(OH)2物相的含量增多,结晶度提高,导致烧后CuO/ZnO/Al2O3催化剂中CuO-ZnO协同作用增强,且CuO晶粒减小,表面Cu含量增加,催化剂活性和稳定性提高。水溶剂的极性最大,制备的催化剂活性和稳定性最好,甲醇的时空收率(STY)和平均失活率分别为320 mg.g-1.h-1和0.11%.d-1。     

Methanol[1‐(methoxymethanimidoyl)‐2‐(pyridin‐2‐ylmethyl)guanidine]bis(perchlorato)copper(II)

The title complex, [Cu(ClO₄)₂(C₉H₁₃N₅O)(CH₃OH)], was synthesized from a methanolysis reaction of N‐(methylpyridin‐2‐yl)cyanoguanidine (L³) and copper(II) perchlorate hexahydrate in a 1:1 molar ratio. The Cu^II ion is six‐coordinated by an N₃O₃ donor set which confers a highly distorted and asymmetric octahedral geometry. Three N‐donor atoms from the chelating 1‐(methoxymethanimidoyl)‐2‐(pyridin‐2‐ylmethyl)guanidine (L^3m) ligand and one O atom from the methanol molecule define the equatorial plane, with two perchlorate O atoms in the apical sites, one of which has a long Cu—O bond of 2.9074 (19) Å. The dihedral angle between the five‐ and six‐membered chelate rings is 8.21 (8)°. Two molecules are associated into a dimeric unit by intermolecular N—H...O(perchlorate) hydrogen bonds. Additionally, the weakly coordinated perchlorate anions also link adjacent [Cu(ClO₄)₂(L^3m)(CH₃OH)] dimers by hydrogen‐bonding interactions, resulting in a two‐dimensional layer in the (100) plane. Further C—H...O hydrogen bonds link the two‐dimensional layers along [100] to generate a three‐dimensional network.     

Phase equilibria and thermodynamics of the double oxide phase Cu3TiO4

Phase equilibria in the system CuCu₂OTiO₂ were investigated in the temperature range of 1160–1270 K by means of thermogravimetry and measurements of the oxygen partial pressure. The tie lines on the isothermal phase diagram run from the phase Cu₃TiO₄ to CuO, Cu₂O, and TiO₂. The existence of Cu₃TiO₅ and Cu₂TiO₃ could not be confirmed in this temperature range. The phase “Cu₃TiO₄” is only stable above about 1140 K and its composition fluctuates between about Cu₃TiO_4.3 and Cu₃TiO_3.9. The formation of Cu₃TiO_4.3 according to the reaction 1.6 CuO + 0.7 Cu₂O + TiO₂ = Cu₃TiO_4.3 is endothermic: (1160 < T < 1270 K) ΔH° = (7600 ± 450 J-mole^?1; ΔS° = (6.7 ± 0.4) J·K^?1·mole^?1. The standard Gibbs free energy, enthalpy, and entropy of formation of Cu₃TiO_4.3 at 1200 K are ΔG°_f = ?101.39 kJ, ΔH°_f = ?1115.84 kJ, and S°_f = 466.76 J·K^?1. Rather similar values were found for Cu₃TiO_3.9.     

Tracking the dissolution–recrystallization structural transformation (DRST) of copper(II) complexes: a combined crystallographic,mass spectrometric and DFT study

Methanol‐ and temperature‐induced dissolution–recrystallization structural transformation (DRST) was observed among two novel Cu^II complexes. This is first time that the combination of X‐ray crystallography, mass spectrometry and density functional theory (DFT) theoretical calculations has been used to describe the fragmentation and recombination of a mononuclear Cu^II complex at 60 °C in methanol to obtain a binuclear copper(II) complex. Combining time‐dependent high‐resolution electrospray mass spectrometry, we propose a possible mechanism for the conversion of bis(8‐methoxyquinoline‐κ²N,O)bis(thiocyanato‐κN)copper(II), [Cu(NCS)₂(C₁₀H₉NO)₂], Cu1 , to di‐μ‐methanolato‐κ⁴O:O‐bis[(8‐methoxyquinoline‐κ²N,O)(thiocyanato‐κN)copper(II)], [Cu₂(CH₃O)₂(NCS)₂(C₁₀H₉NO)₂], Cu2 , viz. [Cu(SCN)₂( L )₂] ( Cu1 ) → [Cu( L )₂] → [Cu( L )]/ L → [Cu₂(CH₃O)₂(NCS)₂( L )₂] ( Cu2 ). We screened the antitumour activities of L (8‐methoxyquinoline), Cu1 and Cu2 and found that the antiproliferative effect of Cu2 on some tumour cells was much greater than that of L and Cu1 .     

Bis[bis­(methoxy­carbimido)amine‐κ2N,N′]bis­(perchlorato‐κO)copper(II) bis­[bis­(methoxy­carbimido)amine‐κ2N,N′]bis­(methanol‐κO)copper(II) bis­(perchlorate) methanol disolvate

The title compound, [Cu(ClO₄)₂(C₄H₉N₃O₂)₂][Cu(C₄H₉N₃O₂)₂(CH₄O)₂](ClO₄)₂·2CH₃OH, comprises two independent Cu^II species lying on different inversion sites. In the Cu complexes, a distorted octa­hedral geometry arises (from basic square‐planar N₄ coordination) from the weak coordination of two perchlorate ions (as Cu—O) in one species and two methanol mol­ecules in the other (also as Cu—O). Inter­actions between the O atoms of the perchlorate anions or methanol groups and the imide or amine NH groups afford an extensive inter­molecular hydrogen‐bonding network.     

Oxidative dehydrogenation of N-(2-hydroxy-3,5-R<Superscript>1</Superscript>,R<Superscript>2</Superscript>-benzyl)-4-aminoantipyrines in the complexation reaction

Reactions of N-(2-hydroxy-3,5-R¹,R²-benzyl)-4-aminoantipyrines with copper acetate in ethanol gave complexes with Schiff bases (SBs) rather than the expected complexes with reduced SBs; i.e., the starting ligands undergo oxidative dehydrogenation during the complexation reaction. The corresponding complexes with reduced SBs were obtained from sodium salts of the ligands and cupric sulfate in aqueous solutions. Kinetic measurements showed that oxidative dehydrogenation occurs in the heteroleptic complexes Cu(L ⁱ )(CH₃COO)(X) (L ⁱ H are derivatives of N-(2-hydroxy-3,5-R¹,R²-benzyl)-4-aminoantipyrines; i = 6–10; X = H₂O, CH₃OH, CH₃CH₂OH) but does not occur in the complexes CH₃OH, CH₃CH₂OH. The absence of oxidative dehydrogenation of the ligands in Cu(L ⁱ )₂ · H₂O can be explained by the octahedral environment of the Cu²⁺ ion and, accordingly, the absence of the coordination site for molecular oxygen. The molecular structures of two Cu(II) complexes with SBs were determined by X-ray diffraction.