and Ondřej Vodochodský [a] 1I ntroduction Erythritol tetranitrate (ETN) is as imple nitrate ester structurally similar to nitroglycerine (see Scheme 1). This ester of nitric acid was first synthesized in 1849 by Stenhouse [1]. Although it is as tructurally simple and easily synthesized powerful explosive, only af ew authors have paid attention to it as an explosive in the past. The main reason was the high cost caused by limited availability of erythritol (ETN precursor), which was obtained by costly extraction from seaweed, algae, or lichen [2].L ater,p roduction of erythritol via acetylene chemistry did not significantly change anything;t he price of ETN was still too high for industrial use [3].H owever new technology for erythritol production using microbial methods from osmophilic yeasts has been developed recently [4].T he price of erythritol has been significantly reduced and its technological accessibility is no longer al imitation.Unfortunately,t he properties of ETN are described only briefly in scientific literature [3,[5][6][7].R esearch into the fundamental parameters of this explosive is therefore important. There have been plenty of articles concerning the medical effects and uses of erythritol tetranitrate (it is used as an effective cardiovascular medicine [5]), but only af ew remarks have appeared in tertiary literature about its explosive properties. The subject was addressed three years ago by Oxley et al. [8],w ho published some analytical data for ETN, along with certain physical and explosive properties. The thermal behavior and decomposition kinetics of pure ETN and its mixtures with pentaerythritol tetranitrate (PETN) and hexogen (1,3,5-trinitro-1,3,5-triazinane, RDX) have also been published recently [9].W ed ecided to study fundamental physical characteristics of this nitrate ester that, according to our best information, have not been published to date. The results of our research are summarized in this article. 2E xperimental SectionCaution: Erythritol tetranitratei sapowerful explosive, sensitive to external stimuli. Itss ensitivity to friction andimpactis on thel evel of PETN.T he standard safety procedures for preparationand handling of explosives must be used.Abstract:T he article describes the molecular structure and fundamental physical properties of erythritol tetranitrate (ETN). Although ETN is simple nitrate ester this explosive is described in the literature relatively briefly.T he molecular structure of ETN was characterized by single-crystal X-ray diffraction. The structure of the ETN molecule is composed of the central carbohydrate chain and two pairs of facing coplanar ONO 2 groups. The crystal density of ETN is 1.827 gcm À3 .I ti sanon-hygroscopic compound. Solubility in water was determined in at emperature range from 5 8C to 80 8C. ETN is slightly soluble in water;s olubility at 20 8C is on the same level as that of PETN.

Tetraamminecopper perchlorate (TACP) is one of the most interesting explosive copper perchlorate‐ammonia complexes. Despite the fact that this complex has been known for more than 100 years there is very little information in the literature about its detonation parameters. Impact sensitivity of TACP is slightly higher than that for PETN while friction sensitivity is between those for PETN and RDX. Detonation velocity for infinite diameter is 3230 m s−1 (density 0.9 g cm−3). Critical diameter of TACP is low – less than 2 mm. Based on the heat of combustion measurement the previously published erroneous enthalpy of formation was corrected to −496 kJ mol−1. Detonation heat of TACP is 4322 kJ kg−1 and Gurney velocity is 1536 m s−1. Experimentally measured detonation parameters of TACP were also compared with theoretically calculated values by the EXPLO5 code.

Erythritol tetranitrate (ETN) is a low melting, solid, nitrate ester with significant explosive properties. The increased availability of its precursor (erythritol), which is now used as a sweetener, has attracted attention to the possible misuse of ETN as an improvised explosive. However, ETN also has some potential to be used as a component of military explosives or propellants. This article focuses on the properties of melt-cast ETN. The sensitivity of the compound towards impact and friction was tested. The explosive performance was evaluated, based on cylinder expansion tests and detonation velocity measurements. The impact energy and friction force required for 50% probability of initiation was 3.79 J and 47.7 N, respectively. A Gurney velocity value of G = 2771 m·s −1 and a detonation velocity of 8027 m·s −1 at a charge density of 1.700 g·cm −3, were found for the melt-cast material. The sensitivity characteristics of melt-cast ETN does not differ significantly from either literature values or the authors' data measured using the crystalline material. The explosive performance properties were found to be close to those of PETN.

Tetraamminecopper(II) nitrate(V) (TACN) is a complex copper salt which is easily formed when ammonium nitrate (AN) comes into contact with copper. It is considered to be an unwanted contaminant of AN because of its sensitivity to mechanical stimuli and significant explosive properties. The formation of TACN by the reaction of copper with molten ammonium nitrate(V) was demonstrated by powder diffraction. Friction and impact sensitivity testing was performed and field experiments were then conducted to reveal the detonation parameters of TACN and its initiation capability towards ammonium nitrate. The dependence of the detonation velocity on charge diameter was revealed and the ideal detonation velocity of 3500 m·s −1 at 0.87 g·cm −3 was measured. AN with the addition of 16 wt.% of TACN was found to detonate when initiated with a small booster charge. Moreover, TACN was able to initiate detonation in fertilizer grade ammonium nitrate(V) under massive steel confinement. TACN should be therefore considered as a possible contributory initiation source in some large scale accidents. In this article, some properties of TACN are revealed which could be useful for the investigation of accidents.

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