Synthesis, structure and magnetism of a new ionic pentanuclear iron cluster

A new ionic pentanuclear FeIII cluster, namely, triethylazanium tetrakis(μ2-5-amino-1,2,3,4-tetrazolido)tetrakis(μ3-4-chloro-2-{[(1H-tetrazol-1-id-5-yl)imino]methyl}phenolato)di-μ3-oxido-pentairon(III) acetonitrile monosolvate monohydrate, (C6H16N)[Fe5(C8H4ClN5O)4(CH2N5)4O2]·CH3CN·H2O, was synthesized using microvial synthesis methods and characterized by elemental analysis, FT–IR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. Magnetic studies reveal that the complex displays dominant antiferromagnetic intracluster interactions between the FeIII ions through the μ3-oxide bridges.

Two new 3-D cadmium bromoplumbates: the only example of heterometallic bromoplumbate based on crown [Cd(Pb4O4)Br2] clusters

This work provides the only example of 3-D heterometallic bromoplumbate based on the combination of heterometallic crown [Cd(Pb₄O₄)Br₂] clusters and dimeric [Pb₂Br₄] units.

PbII-catalyzed transformation of aromatic nitriles to heptanitrogen anions via sodium azide: a combined experimental and theoretical study

Under hydrothermal conditions, an open-chain N₇³⁻ anion stabilized in a metal–organic framework (MOF) was achieved for the first time via the in situ reaction of 4-fluorobenzonitrile and sodium azide with Pb²⁺ ion as catalyst. The anion with C_2h symmetry in the MOF was studied by FT-IR, single-crystal XRD and theoretical calculations. Thermal analysis results demonstrated the stability of the anion in the MOF below 430 °C and a high energy content of 8.61 kJ g⁻¹. The anion is also a good reducing agent. It can easily react with basic KMnO₄ solution. Moreover, the present study indicates that the Pb²⁺ ion activates the azide rather than nitrile in the in situ reaction of nitriles with azides to form polynitrogen and this mechanism is a distinct contradiction with the previous results in which the nitrile reacts with azide in the presence of transition metal ions. Our findings may open a new avenue towards the synthesis and capture of polynitrogen compounds.

Heptanitrogen anion: a chain of seven nitrogen atoms stabilized in a MOF has been isolated for the first time.

A highly stable and tightly packed 3D energetic coordination polymer assembled from nitrogen-rich tetrazole derivatives

A tightly packed 3D energetic cadmium(ii) coordination polymer was synthesized with high stability and remarkable energetic performance.

Nitrogen-Rich Tetranuclear Metal Complex as a New Structural Motif for Energetic Materials

For designing energetic materials (EMs), the most challenging issue is to achieve a balance between energetic performance and reliable stability. In this work, we employed an efficient and convenient method to synthesize a new class of EMs: nitrogen-rich tetranuclear metal complexes [M(Hdtim)(H₂O)₂]₄ (M = Zn 1, Mn 2; H₃dtim = 1H-imidazol-4,5-tetrazole) with the N content of >46%. The structural analyses illustrate that isomorphous compounds 1 and 2 feature isolated hollow ellipsoid tetranuclear units, which are linked by both π-π interactions and hydrogen-bonding interactions to give a 3D supramolecular architecture. Compounds 1 and 2 exhibit prominent energetic characteristics: excellent detonation performances and reliable thermal, impact, and friction stabilities. Being nitrogen-rich tetrazolate compounds, the enthalpies of combustion of 1 (-11.570 kJ g^-1) and 2 (-12.186 kJ g^-1) are higher than those of classical EMs, RDX and HMX, and they possess high positive heats of formation. Sensitivity tests demonstrate that 1 and 2 are insensitive to external mechanical action. Excellent energetic performances and low sensitivities promote 1 and 2 to serve as a new class of promising EMs with a desirable level of safety.

Microporous rod metal–organic frameworks with diverse Zn/Cd–triazolate ribbons as secondary building units for CO2 uptake and selective adsorption of hydrocarbons

Three rod MOFs exhibiting remarkable CO₂ uptake and high CO₂ and C₂-hydrocarbons over CH₄ selectivity, as well as high isosteric heat of adsorption for C₂H₂.

High performance 5-aminotetrazole-based energetic MOF and its catalytic effect on decomposition of RDX

The energetic compound [Ag₂(5-ATZ)(N₃)] (1) features a compacted 3D framework structure, remarkable thermostability above 300 °C and perfect detonation performance. Remarkably, 1 can accelerate effectively the thermal decomposition of RDX.

Rendering non-energetic microporous coordination polymers explosive

A stable microporous coordination polymer is transformed into a sensitive primary explosive by simple infiltration with an organic oxidizer.

An Ag(i) energetic metal–organic framework assembled with the energetic combination of furazan and tetrazole: synthesis, structure and energetic performance

A novel 3D Ag(i) energetic MOF assembled with a furazan derivative (4,4′-oxybis[3,3′-(1H-5-tetrazol)]furazan) shows low sensitivity, good thermostability and ultrahigh detonation pressure and detonation velocity.

New organically templated thiocyanatocadmates and chlorocuprate(II): synthesis and structural characterization

With various organic base molecules as the countercations, five new thiocyanatocadmates [H2(tmen)][Cd(SCN)4] (tmen = N,N,N',N'-tetramethylethylenediamine) 1, [H2(tmba)][Cd2(SCN)6] (tmba = N,N,N',N'-tetramethyl-1,4-butanediamine) 2, [H2(teen)][Cd2(SCN)6] (teen = N,N,N',N'-tetra-ethylethylenediamine) 3, [H(amp)][Cd(SCN)2(CH3COO)] (amp = 2-amino-6-methylpyridine) 4 and [H(abp)]4[Cd(SCN)4]SO4·H2O (abp = 2-amino-6-bromopyridine) 5, and one new chlorocuprate(II) [H2(cha)][CuCl4] (cha = 1,4-cyclohexanediamine) 6 were obtained from a series of simple room-temperature self-assemblies at pH = 2 or 6.5. X-ray single-crystal diffraction analysis reveals that (i) templated by [(CH3)2NH(CH2)2NH(CH3)2](2+) (H2(tmen)(2+)), the anion [Cd(SCN)4](2-) in 1 shows a 1-D linear single-chain structure, whereas templated by [(CH3)2NH(CH2)4NH(CH3)2](2+) (H2(tmba)(2+)), the anion [Cd2(SCN)6](2-) in 2 shows a 1-D linear double-chain structure. The number of C atoms between the two N atoms in the templating agent controls the width of the anionic chain through the N(amino)-H···N(SCN) interactions; (ii) templated by [(C2H5)2NH(CH2)2NH(C2H5)2](2+) (H2(teen)(2+)), the anion [Cd2(SCN)6](2-) in 3 exhibits a 3-D open-framework structure, which is based on zigzag anionic chains. A direct change of the substituent group from -CH3 to -C2H5 alters indirectly the shape of the anionic chain from a linear shape to a zigzag shape; (iii) 4 shows a 3-D supramolecular network structure, which is built up from the 1-D zigzag anionic structures by the H(amp)(+) molecules via N-H···O interactions. The formation of the zigzag chain derives from the chelation of the CH3COO(-) groups to the Cd(2+) centers; (iv) 5 is indeed a double salt of [H(abp)]2[Cd(SCN)4] and [H(abp)]2SO4. SO4(2-) and H(abp)(+) form a supramolecular aggregation. Surrounded by the aggregations, the anion [Cd(SCN)4](2-) only shows a dinuclear structure; and (v) templated by H2(cha)(2+), the anion [CuCl4](2-) in 6 displays a 2-D perovskite layer structure. The photoluminescence analysis indicates that upon excitation (λ(ex) = 335 nm for 4, λ(ex) = 395 nm for 5), and emit light (λ(em) = 365 nm for 4, λ(em) = 470 nm for 5), which can be seen clearly under the UV lamp.

New 1-D and 3-D thiocyanatocadmates modified by various amine molecules and Cl−/CH3COO− ions: synthesis, structural characterization, thermal behavior and photoluminescence properties

Reactions of CdCl₂/Cd(CH₃COO)₂, SCN⁻ and various organic amines yielded five new thiocyanatocadmates; structural, thermal and photoluminescence properties are reported.