Mixed pseudohalide complexes of copper(II). Crystal and molecular structure of [Cu(N3)(NCS)(tmen)] n and of [Cu(N3)(NCO)(tmen)]2 (tmen = N,N,N′,N′-tetramethylethylenediamine)

The compounds [Cu(N₃)(NSC)(tmen)]_n (1), [Cu(N₃)(NCO)(tmen)]_n (2) and [Cu(N₃)(NCO)(tmen)]₂ (3) (tmen=N,N,N′,N′-tetramethylethylenediamine) were synthesized and studied by i.r. spectroscopy. Single crystals of compounds (1) and (3) were obtained and characterized by X-ray diffraction. The structure of compound (1) consists of neutral chains of copper(II) ions bridged by a single azido ligand showing the asymmetric end-to-end coordination fashion. Each copper ion is also surrounded by the other three nitrogen atoms; two from one N,N,N′,N′-tetramethylethylenediamine and one from a terminal bonded thiocyanate group. Compound (2) decomposes slowly in acetone and the product formed [Cu(N₃)(NCO)(tmen)]₂ (3) crystallizes in the monoclinic system (P2₁). The structure of (3) consists of dimeric units in which the Cu atoms are penta-coordinated and connected by μ(1,3) bridging azido and cyanate ligands. In both cases the five coordinated atoms give rise to a slightly distorted square-based pyramid coordination geometry at each copper ion. The thermal behavior of [Cu(N₃)(NSC)(tmen)]_n (1) and [Cu(N₃)(NCO)(tmen)]_n (2) were investigated and the final decomposition products were identified by X-ray powder diagrams.     

Synthesis and Characterization of Three Diverse Coordination Frameworks under Co-ligand Intervention

The chelating organic ligands of 2,2’-bipyridine (2,2’-bipy), di(pyrid-2-yl)amine (dpa) and 2,6-di(pyrid-2-ylamino)pyridine (dpap) were respectively applied to react with H2fum (fumaric acid) and copper salts, affording three different complexes [Cu2(fum)(2,2’-bipy)4]•2ClO4 (1), [Cu2(µ-OH)2(fum)(dpa)2]•2H2O (2) and [Cu(SO4)(H2O)(dpap)]•H2O (3). These complexes were determined by single-crystal X-ray diffraction. Each penta-coordinated Cu(II) ion exhibits a distorted trigonal bipyramidal geometry in 1. The fum ligand links copper ions to form a dinuclear copper unit. While in 2, the fum ligands connect [Cu2(µ-OH)2(dpa)2] unit to construct a 1D zigzag chain. Unexpectedly, when dpap instead of dpa was used under the same conditions, only one mononuclear complex 3 was formed. Crystal packings show that 1—3 form 3D supramolecular architectures through non-covalent interactions (multiple hydrogen bonds and C—H…π/π-π interactions). In addition, the study of the magnetic property reveals dominating ferromagnetic interactions between Cu(II) atoms in 1.     

Dicopper(II) trihydroxide cyanoureate dihydrate

The title compound, poly[[μ‐cyanoureato‐tri‐μ‐hydroxido‐dicopper(II)] dihydrate], {[Cu₂(C₂H₂N₃O)(OH)₃]·2H₂O}_n, is a new layered copper(II) hydroxide salt (LHS) with cyanoureate ions and water molecules in the interlayer space. The three distinct copper(II) ions have distorted octahedral geometry: one Cu (symmetry ) is coordinated to six hydroxide groups (4OH + 2OH), whilst the other two Cu atoms (symmetries and 1) are coordinated to four hydroxides and two N atoms from nitrile groups of the cyanoureate ions (4OH + 2N). The structure is held together by hydrogen‐bonding interactions between the terminal –NH₂ groups and the central cyanamide N atoms of organic anions associated with neighbouring layers.     

FeII2(PO4)(OH), a synthetic analogue of wolfeite

This paper reports the hydrothermal synthesis and crystal structure refinement of diiron(II) phosphate hydroxide, Fe^II₂(PO₄)(OH), obtained at 1063 K and 2.5 GPa. This phosphate is the synthetic analogue of the mineral wolfeite, and has a crystal structure topologically identical to those of minerals of the triplite–triploidite group. The complex framework contains edge‐ and corner‐sharing FeO₄(OH) and FeO₄(OH)₂ polyhedra, linked via corner‐sharing to the PO₄ tetrahedra (average P—O distances are between 1.537 and 1.544 Å). Four five‐coordinated Fe sites are at the centers of distorted trigonal bipyramids (average Fe—O distances are between 2.070 and 2.105 Å), whereas the coordination environments of the remaining Fe sites are distorted octahedra (average Fe—O distances are between 2.146 and 2.180 Å). The Fe—O distances are similar to those observed in natural Mg‐rich wolfeite, except for two Fe—O bond distances, which are significantly longer in synthetic Fe²⁺₂(PO₄)(OH).     

A Copper‐Based Metal–Organic Framework Acts as a Bifunctional Catalyst for the Homocoupling of Arylboronic Acids and Epoxidation of Olefins

A copper(I)‐based metal–organic framework ({[Cu₂Br₂(pypz)]_n?nH₂O} (Cu—Br–MOF) [pypz=bis[3,5‐dimethyl‐4‐(4’‐pyridyl)pyrazol‐1‐yl] methane] has been synthesized by using an elongated and flexible bridging ligand. The structure analysis reveals that each pypz ligand acts as a tritopic ligand connected to two Cu₂Br₂ dimeric units, forming a one‐dimensional zig–zag chain, and these chains further connected by a Cu₂Br₂ unit, give a two‐dimensional framework on the bc‐plane. In the Cu₂Br₂ dimeric unit, the copper ions are four coordinated, thereby possessing a tetrahedral geometry; this proves to be an excellent heterogeneous catalyst for the aerobic homocoupling of arylboronic acids under mild reaction conditions. This method requires only 3 mol % of catalyst and it does not require any base or oxidant—compared to other conventional (Cu, Pd, Fe, and Au) catalysts—for the transformation of arylboronic acids in very good yields (98 %). The shape and size selectivity of the catalyst in the homocoupling was investigated. The use of the catalyst was further extended to the epoxidation of olefins. Moreover, the catalyst can be easily separated by simple filtration and reused efficiently up to 5 cycles without major loss of reactivity.     

Synthesis,electrochemical and e.p.r. spectral studies of binuclear copper(II) complexes with new pentadentate L-proline-based binucleating ligands

The synthesis, reduction, optical and e.p.r. spectral properties of a series of new binuclear copper(II) complexes, containing bridging moieties (OH^–, MeCO₂ ^–, NO₂ ^–, and N₃ ^–), with new proline-based binuclear pentadentate Mannich base ligands is described. The ligands are: 2,6-bis[(prolin-1-yl)methyl]4-bromophenol [H₃L¹], 2,6-bis[(prolin-1-yl)methyl]4-t-butylphenol [H₃L²] and 2,6-bis[(prolin-1-yl)methyl]4-methoxyphenol [H₃L³]. The exogenous bridging complexes thus prepared were hydroxo: [Cu₂L¹(OH)(H₂O)₂] · H₂O (1a), [Cu₂L²(OH)(H₂O)₂] · H₂O (1b), [Cu₂L³(OH)(H₂O)₂] · H₂O (1c), acetato [Cu₂L¹(OAc)] · H₂O (2a), [Cu₂L²(OAc)] · H₂O (2b), [Cu₂L³(OAc)] · H₂O (2c), nitrito [Cu₂L¹(NO₂)(H₂O)₂] · H₂O (3a), [Cu₂L²(NO₂)(H₂O)₂] · H₂O (3b), [Cu₂L³(NO₂)(H₂O)₂] · H₂O (3c) and azido [Cu₂L¹(N₃)(H₂O)₂] · H₂O (4a), [Cu₂L²(N₃)(H₂O)₂] · H₂O (4b) and [Cu₂L³(N₃)(H₂O)₂] · H₂O (4c). The complexes were characterized by elemental analysis and by spectroscopy. They exhibit resolved copper hyperfine e.p.r. spectra at room temperature, indicating the presence of weak antiferromagnetic coupling between the copper atoms. The strength of the antiferromagnetic coupling lies in the order: NO₂ N₃ OH OAc. Cyclic voltammetry revealed the presence of two redox couples Cu^IICu^II Cu^IICu^I Cu^ICu^I. The conproportionality constant K _con for the mixed valent Cu^IICu^I species for all the complexes have been determined electrochemically.     

Synthesis,X-ray structure and properties of the trinuclear copper(I) complex [Cu3(dppm)3(NO3)(OH)](NO3)

The novel trinuclear Cu^I complex [Cu₃(dppm)₃(NO₃)(OH)](NO₃) obtained by reacting dppm with Cu(NO₃)₂ · 3H₂O in the presence of NaBPh₄ was characterized by a single-crystal X-ray analysis as well as by physico-chemical and spectroscopic methods. The [Cu₃(dppm)₃(NO₃)(OH)]⁺ cation consists of a triangular array of copper atoms, (with dppm ligands bridging each edge of the triangle), a triply bridging OH group and NO^– ₃ anion bound to two faces of the Cu₃ unit, respectively.     

Copper(II) Complexes with N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea (L) and a Derivative of L: Synthesis,Structure, and Fluorescent Properties

Three copper(II) complexes, [Cu₂(OAc)₄L₂] · 2CH₃OH ( 1 ), [CuBr₂L′₂(CH₃OH)] · CH₃OH ( 2a ), and [CuBr₂L′₂(DMSO)] · 0.5CH₃OH ( 2b ) {L = N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea and L′ = N‐[10‐(10‐methoxy‐anthronyl)]‐N′‐(3‐pyridyl)urea} have been synthesized by the reaction of L with the corresponding copper(II) salts. Complex 1 shows a dinuclear structure with a conventional “paddlewheel” motif, in which four acetate units bridge the two Cu^II ions. In complexes 2a and 2b , the anthracenyl ligand L has been converted to an anthronyl derivative L′, and the central metal ion exhibits a distorted square pyramidal arrangement, with two pyridyl nitrogen atoms and two bromide ions defining the basal plane and the apical position is occupied by a solvent molecule (CH₃OH in 2a and DMSO in 2b ).     

Metalloantitubercular compounds Part 3: Synthesis,crystal structure,spectroscopy, electrochemistry and antimycobacterial activity of the copper(II) ciproploxacin (cfH) complex and its phenanthroline adduct

The X-ray crystal structures of two ciprofloxacin compounds, viz. [Cu(cfH)₂(Cl)₂] · ₂MeOH · 6H₂O (2) and [Cu(cfH)(phen)Cl]BF₄ · 4H₂O (3) are reported. Complex (2) has a distorted octahedral geometry, whereas for the nitrogen adduct (3) a distorted square–pyramidal geometry is seen. Significant enhancement in the antimycobacterial activity of the copper conjugates correlates with their copper redox couples (Cu²⁺ /Cu⁺) probably due to its relevance to intracellular accumulations and subsequent role in generating oxidative stress.     

Two novel oxamido-bridge dinuclear copper(II) complexes containing four spin carriers involving the nitroxide radical ligand: synthesis,crystal structure and magnetic properties

The combined use of nitroxide free radicals as terminal ligands and precursor [Cu₂(oxpn)]²⁺ anions has led to the preparation of two novel oxamido-bridged dinuclear copper(II) complexes containing nitronyl nitroxide Cu₂(oxpn)(NIToBA)₂ (1) or imino nitroxide [Cu₂(oxpn)(IM_pPy)₂](ClO₄)₂ · 2H₂O (2). X-ray crystallography shows that both (1) and (2) have like as coordination modes where the oxamido group as a trans-form bridged ligand, combine two copper(II) atoms. Each copper (II) ion has a similar coordination environment, in which it adopts a distorted square planar geometry. The temperature dependence of the magnetic susceptibility measurements shows the weak antiferromagnetic co upling interaction between the copper(II) atoms and the nitronyl nitroxide radicals in both complexes.     

Structure and photophysical and electrochemical properties of a copper porphyrin complex with a three‐dimensional framework

Porphyrins and metalloporphyrins can generally show attractive structural motifs and interesting properties. A new copper porphyrin, namely poly[[μ‐chlorido‐[μ₅‐5,10,15,20‐tetrakis(pyridin‐4‐yl)‐21H,23H‐porphine]tricopper(I)] [aquadichloridocopper(II)]], {[Cu₃(C₄₀H₂₄N₈)Cl][CuCl₂(H₂O)]}_n ( 1 ), was synthesized by the self‐assembly of copper chloride with 5,10,15,20‐tetrakis(pyridin‐4‐yl)‐21H,23H‐porphine under solvothermal conditions. The structure of this copper porphyrin was characterized by single‐crystal X‐ray crystallography and elemental analysis. The porphyrin macrocycle shows a distorted saddle geometry, with the four pyrrole rings slightly distorted in an alternating mode either upwards or downwards. The copper ions show three‐coordinated triangular and four‐coordinated square‐planar geometries. Every copper–porphyrin unit connects to 12 others via four μ₄‐bridging Cu₂Cl moieties to complete the three‐dimensional framework of compound 1 , with isolated CuCl₂(H₂O) units located in the voids. This copper porphyrin displays a red photoluminescence. Electrochemical measurements showed that compound 1 has two redox waves (E_1/2 = ?160 and 91 mV).     

Poly[μ2‐4‐aminobenzoato‐aqua‐μ2‐nitrato‐zinc]

In the title compound, [Zn(C₇H₆NO₂)(NO₃)(H₂O)]_n, the Zn atom is coordinated by two nitrate ions, one aqua molecule and two 4‐aminobenzoate ions in a distorted octahedral geometry. The structure of the compound exhibits a two‐dimensional layer, which is formed by the interconnection of [Zn(C₇H₆NO₂)(H₂O)]_n chains viaμ₂‐nitrate bridges or by the interconnection of [Zn(NO₃)(H₂O)]_n chains viaμ₂‐4‐aminobenzoate bridges.     

Mixed‐ligand MnII and CuII complexes with alternating 2,2′‐bipyrimidine and terephthalate bridges

The novel polymeric complexes catena‐poly[[diaquamanganese(II)]‐μ‐2,2′‐bipyrimidine‐κ⁴N¹,N^1′:N³,N^3′‐[diaquamanganese(II)]‐bis(μ‐terephthalato‐κ²O¹:O⁴)], [Mn₂(C₈H₄O₄)₂(C₈H₆N₄)(H₂O)₄]_n, (I), and catena‐poly[[[aquacopper(II)]‐μ‐aqua‐μ‐hydroxido‐μ‐terephthalato‐κ²O¹:O^1′‐copper(II)‐μ‐aqua‐μ‐hydroxido‐μ‐terephthalato‐κ²O¹:O^1′‐[aquacopper(II)]‐μ‐2,2′‐bipyrimidine‐κ⁴N¹,N^1′:N³,N^3′] tetrahydrate], {[Cu₃(C₈H₄O₄)₂(OH)₂(C₈H₆N₄)(H₂O)₄]·4H₂O}_n, (II), containing bridging 2,2′‐bipyrimidine (bpym) ligands coordinated as bis‐chelates, have been prepared via a ligand‐exchange reaction. In both cases, quite unusual coordination modes of the terephthalate (tpht²⁻) anions were found. In (I), two tpht²⁻ anions acting as bis‐monodentate ligands bridge the Mn^II centres in a parallel fashion. In (II), the tpht²⁻ anions act as endo‐bridges and connect two Cu^II centres in combination with additional aqua and hydroxide bridges. In this way, the binuclear [Mn₂(tpht)₂(bpym)(H₂O)₄] entity in (I) and the trinuclear [Cu₃(tpht)₂(OH)₂(bpym)(H₂O)₄]·4H₂O coordination entity in (II) build up one‐dimensional polymeric chains along the b axis. In (I), the Mn^II cation lies on a twofold axis, whereas the four central C atoms of the bpym ligand are located on a mirror plane. In (II), the central Cu^II cation is also on a special position (site symmetry ). In the crystal structures, the packing of the chains is further strengthened by a system of hydrogen bonds [in both (I) and (II)] and weak face‐to‐face π–π interactions [in (I)], forming three‐dimensional metal–organic frameworks. The Mn^II cation in (I) has a trigonally deformed octahedral geometry, whereas the Cu^II cations in (II) are in distorted octahedral environments. The Cu^II polyhedra are inclined relative to each other and share common edges.     

A new type of mixed anionic framework in microporous rubidium copper vanadyl(V) phosphate,Rb2Cu(VO2)2(PO4)2

In dirubidium copper bis[vanadyl(V)] bis(phosphate), Rb₂Cu(VO₂)₂(PO₄)₂, three different oxo complexes form an anionic framework. VO₅ polyhedra in a trigonal bipyramidal configuration and PO₄ tetrahedra share vertices to form eight‐membered rings, which lie in layers perpendicular to the a axis of the monoclinic unit cell. Cu atoms at centres of symmetry have square‐planar coordination and link these layers along [100] to form a three‐dimensional anionic framework, viz. [Cu(VO₂)₂(PO₄)₂]_∞²⁻. Intersecting channels in the [100], [001] and [011] directions contain Rb⁺ cations. Topological relations between this new structure type and the crystal structures of A(VO₂)(PO₄) (A = Ba, Sr or Pb) and BaCrF₂LiF₄ are discussed.     

Altering the Activity of Catechol Oxidase Model Compounds by Electronic Influence on the Copper Core

The catecholase activity of the dicopper(II) complexes [Cu₂(L¹)(μ‐OCH₃)(NCCH₃)₂](PF₆)₂·H₂O·CH₃CN ( 1 ), [Cu₂(L²)(μ‐OH)(MeOH)(NCCH₃)](BF₄)₂ ( 2 ), [Cu₂(L³)(μ‐OMe)(NCCH₃)₂](BF₄)₂·2CH₃CN·H₂O ( 3 ), [Cu₂(L²)(μ‐OAc)₂]BF₄·H₂O ( 4 ), [Cu₂(L⁴)(μ‐OAc)₂]ClO₄ ( 5 ) and [Cu₂(L⁵)(μ‐OMe)(NCCH₃)₃(OH₂)](ClO₄)₂·2CH₃OH·CH₃CN ( 6 ) consisting of varying para‐substituted phenol ligands HL¹ = 4‐trifluoromethyl‐2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)phenol, HL² = 4‐bromo‐2,6‐bis((4‐methyl‐1,4‐diazepan‐1‐yl)methyl)phenol, HL³ = 4‐bromo‐2‐((4‐methyl‐1,4‐diazepan‐1‐yl)methyl)‐6‐((4‐methylpiperazin‐1‐yl)methyl)phenol, HL⁴ = 2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)‐4‐nitrophenol and HL⁵ = 4‐tert‐butyl‐2,6‐bis((4‐methylpiperazin‐1‐yl)methyl)phenol was studied. The main difference within the six complexes lies in the individual copper–copper separation that is enforced by the chelating side arms of the phenolate ligand entity and more importantly in the exogenous bridging solvent, hydroxide, methanolate or acetate ions. The distance between the copper cores varies from 2.94Å in 1 to 3.29Å in 5 . The catalytic activity of the complexes 1 – 6 towards the oxidation of 3,5‐di‐tert‐butylcatechol was determined spectrophotometrically by monitoring the increase of the 3,5–di‐tert‐butylquinone characteristic absorption band at about 400 nm over time saturated with O₂. The complexes are able to oxidize the substrate 3,5‐di‐tert‐butylcatechol to the corresponding o‐quinone with distinct catalytic activity (k_cat between 92 h^?1 and 189 h^?1), with an order of decreasing activity 6 > 5 > 1 , 2 , 4 ≥ 3 . A kinetic treatment of the data based on the Michaelis‐Menten approach was applied. A correlation of the catecholase activities with the variation of the para‐ substituents as well as other effects resulting from the copper core distances is discussed. [Cu₂(L⁵)(μ‐OMe)(NCCH₃)₃(OH)₂](ClO₄)₂·2CH₃OH·CH₃CN ( 6 ) exhibited the highest activity of the six complexes as a result of its high turnover rate.     

On Structural Features Necessary for Near‐IR‐Light Photocatalysts

In the search for photocatalysts that can directly utilize near‐IR (NIR) light, we investigated three oxides Cu₃(OH)₄SO₄ (antlerite), Cu₄(OH)₆SO₄, and Cu₂(OH)₃Cl by photodecomposing 2,4‐dichlorophenol over them under NIR irradiation and by comparing their electronic structures with that of the known NIR photocatalyst Cu₂(OH)PO₄. Both Cu₃(OH)₄SO₄ and Cu₄(OH)₆SO₄ are NIR photocatalysts, but Cu₂(OH)₃Cl is not. Thus, in addition to the presence of two different CuO_m and Cu′O_n polyhedra linked with Cu?O?Cu′ bridges, the presence of acceptor groups (e.g., SO₄, PO₄) linked to the metal oxygen polyhedra is necessary for NIR photocatalysts.     

Copper(II) manganese(II) orthophosphate,Cu0.5Mn2.5(PO4)2

The title compound, Cu_0.5Mn_2.5(PO₄)₂, is a copper–manganese phosphate solid solution with the graftonite‐type structure, viz. (Mn,Fe,Ca,Mg)₃(PO₄)₂. The structure has three distinct metal cation sites, two of which are occupied by Mn^II and one of which accommodates Cu^II. Incorporation of Cu^II into the structure distorts the coordination geometry of the metal cation site from five‐coordinate square‐pyramidal towards four‐coordinate flattened tetrahedral, and serves to contract the structure principally along the c axis.     

A cyanide‐bridged FeII–NdIII bimetallic assembly with a one‐dimensional ladder‐like chain structure

The title complex, catena‐poly[[[(2,2′‐bipyridine‐1κ²N,N′)tris(methanol‐2κO)(nitrato‐2κ²O,O′)‐μ‐cyanido‐1:2C:N‐cyanido‐1κC‐iron(II)neodymium(III)]‐di‐μ‐cyanido‐1:2′C:N;2:1′N:C] methanol solvate], {[Fe^IINd^III(CN)₄(NO₃)(C₁₀H₈N₂)(CH₃OH)₃]·CH₃OH}_n, is made up of ladder‐like one‐dimensional chains oriented along the c axis. Each ladder consists of two strands based on alternating Fe^II and Nd^III centers connected by cyanide bridges. Furthermore, two such parallel chains are connected by additional cyanide cross‐pieces (the `rungs' of the ladder), which likewise connect Fe^II and Nd^III centers, such that each [Fe(CN)₄(bipy)]²⁻ unit (bipy is 2,2′‐bipyridine) coordinates with three Nd^III centers and each Nd^III center connects with three different [Fe(CN)₄(bipy)]²⁻ units. In the complex, the iron(II) cation is six‐coordinated with a distorted octahedral geometry and the neodymium(III) cation is eight‐coordinated with a distorted dodecahedral environment.     

Synthesis,crystal structure,and magnetism of a binuclear Cu(II) complex with a single end-to-end bridged azido ligand

A binuclear copper(II) complex, [Cu₂(μ _1,3-N₃)(N₃)(pmp)₂(ClO₄)]ClO₄ (pmp = 2-((pyridin-2-yl) methoxy)-1,10-phenanthroline), was synthesized with a single azide as end-to-end bridge ligand, and pmp and perchlorate as ligands. In the crystal, Cu(II) is in a distorted square pyramidal geometry, and a single azide bridges equatorial-axial linking two Cu(II) ions with separation of 5.851 Å. There are π?π stacking interactions involving 1,10-phenanthroline rings. The variable-temperature (2–300 K) magnetic susceptibilities were analyzed using a binuclear Cu(II) magnetic formula and it indicates that there is a very weak ferromagnetic coupling with 2J = 2.82 cm^?1.     

Synergistic Catalytic Effect of a Series of Energetic Coordination Compounds based on Tetrazole‐1‐acetic Acid on Thermal Decomposition of HMX

A series of energetic coordination compounds [Co(tza)₂}_n ( 1 ), [Bi(tza)₃]_n ( 2 ), {[Cu₄(tza)₆(OH)₂] · 4H₂O}_n ( 3 ), [Mn(tza)₂]_n ( 4 ), {[Bi(tza)(C₂O₄)(H₂O)] · H₂O}_n ( 5 ) and [Fe₃O(tza)₆(H₂O)₃]NO₃ ( 6 ) based on tetrazole‐1‐acetic acid (Htza) were synthesized though environmentally friendly methods. The coordination compounds were characterized by elemental analyses, IR spectroscopy, single‐crystal and powder X‐ray diffraction (PXRD), thermogravimetric analyses (TG), and differential scanning calorimetry (DSC). Their catalytic performances and the synergetic catalytic effects between 1 and 2 , 3 and 4 , 5 and 6 on the thermal decomposition of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) were all investigated by DSC. The results revealed that compounds 1 – 6 are thermally stable energetic compounds and they all exhibit high catalytic action for HMX thermal decomposition. The catalytic effects of the compounds on HMX thermal decomposition are closely related to the oxides, which come from the decomposition of the compounds, but have no positive relationships with the heat releases of the compounds themselves. Moreover, the synergetic catalytic effects between 1 and 2 , 3 and 4 , 5 and 6 were observed. Their mixtures at different mass ratio have different synergetic catalytic effects, and the sequence of the biggest synergetic index (SI) in each system is copper‐manganese system (compounds 3 and 4 ) > iron‐bismuth system (compounds 5 and 6 ) > cobalt‐bismuth system (compounds 1 and 2 ), indicating that the synergistic catalytic effects are mainly related to the combination and the proportion of the compounds.