Control of Biohazards: A High Performance Energetic Polycyclized Iodine-Containing Biocide

The article of record as published may be found at http://dx.doi.org/10.1021/acs.inorgchem.8b01600Biohazards and chemical hazards as well as radioactive hazards have always been a threat to human health. The search for solutions to these problems is an ongoing worldwide effort. In order to control biohazards by chemical methods, a synthetically useful fused tricyclic iodine-rich compound, 2,6-diiodo-3,5-dinitro-4,9-dihydrodipyrazolo [1,5a:5',1'-d][1,3,5]triazine (5), with good detonation performance was synthesized, characterized, and its properties determined. This compound which acts as an agent defeat weapon has been shown to destroy certain microorganisms effectively by releasing iodine after undergoing decomposition or combustion. The small iodine residues remaining will not be deleterious to human life after 1 month.Financial support of the Office of Naval Research (N00014-16- 1-2089), and the Defense Threat Reduction Agency (HDTRA 1-15-1-0028) is gratefully acknowledged. The M. J. Murdock Charitable Trust (No. 2014120) is thanked for funds supporting the purchase of a 500 MHz NMR.Financial support of the Office of Naval Research (N00014-16- 1-2089), and the Defense Threat Reduction Agency (HDTRA 1-15-1-0028) is gratefully acknowledged. The M. J. Murdock Charitable Trust (No. 2014120) is thanked for funds supporting the purchase of a 500 MHz NMR

Hydrochloride Salt of the GABAkine KRM-II-81

Imidazodiazepine (5-(8-ethynyl-6-(pyridin-2-yl)-4H-benzo[f]imidazole[1,5-α][1,4]diazepin-3-yl) oxazole or KRM-II-81) is a potentiator of GABAA receptors (a GABAkine) undergoing preparation for clinical development. KRM-II-81 is active against many seizure and pain models in rodents, where it exhibits improved pharmacological properties over standard-of-care agents. Since salts can be utilized to create opportunities for increased solubility, enhanced absorption, and distribution, as well as for efficient methods of bulk synthesis, a hydrochloride salt of KRM-II-81 was prepared. KRM-II-81·HCl was produced from the free base with anhydrous hydrochloric acid. The formation of the monohydrochloride salt was confirmed by X-ray crystallography, as well as 1H NMR and 13C NMR analyses. High water solubility and a lower partition coefficient (octanol/water) were exhibited by KRM-II-81·HCl as compared to the free base. Oral administration of either KRM-II-81·HCl or the free base resulted in high concentrations in the brain and plasma of rats. Oral dosing in mice significantly increased the latency to both clonic and tonic convulsions and decreased pentylenetetrazol-induced lethality. The increased water solubility of the HCl salt enables intravenous dosing and the potential for higher concentration formulations compared with the free base without impacting anticonvulsant potency. Thus, KRM-II-81·HCl adds an important new compound to facilitate the development of these imidazodiazepines for clinical evaluation

Immune pathways and defence mechanisms in honey bees Apis mellifera

Social insects are able to mount both group-level and individual defences against pathogens. Here we focus on individual defences, by presenting a genome-wide analysis of immunity in a social insect, the honey bee Apis mellifera. We present honey bee models for each of four signalling pathways associated with immunity, identifying plausible orthologues for nearly all predicted pathway members. When compared to the sequenced Drosophila and Anopheles genomes, honey bees possess roughly one-third as many genes in 17 gene families implicated in insect immunity. We suggest that an implied reduction in immune flexibility in bees reflects either the strength of social barriers to disease, or a tendency for bees to be attacked by a limited set of highly coevolved pathogens

Iridium Porphyrins in CD₃OD: Reduction of Ir(III), CD₃–OD Bond Cleavage, Ir–D Acid Dissociation and Alkene Reactions

Methanol solutions of iridium­(III) tetra­(<i>p</i>-sulfonatophenyl)­porphyrin [(TSPP)­Ir^III] form an equilibrium distribution of methanol and methoxide complexes ([(TSPP)­Ir^III(CD₃OD)_{(2–<i>n</i>)}(OCD₃)_n]^{(3+<i>n</i>)–}). Reaction of [(TSPP)­Ir^III with dihydrogen (D₂) in methanol produces an iridium hydride [(TSPP)­Ir^III–D­(CD₃OD)]^4– in equilibrium with an iridium­(I) complex ([(TSPP)­Ir^I(CD₃OD)]^5–). The acid dissociation constant of the iridium hydride (Ir–D) in methanol at 298 K is 3.5 × 10^–12. The iridium­(I) complex ([(TSPP)­Ir^I(CD₃OD)]^5–) catalyzes reaction of [(TSPP)­Ir^III–D­(CD₃OD)]^4– with CD₃–OD to produce an iridium methyl complex [(TSPP)­Ir^III–CD₃(CD₃OD)]^4– and D₂O. Reactions of the iridium hydride with ethene and propene produce iridium alkyl complexes, but the Ir–D complex fails to give observable addition with acetaldehyde and carbon monoxide in methanol. Reaction of the iridium hydride with propene forms both the isopropyl and propyl complexes with free energy changes (Δ<i>G</i>° 298 K) of −1.3 and −0.4 kcal mol^–1 respectively. Equilibrium thermodynamics and reactivity studies are used in discussing relative Ir–D, Ir–OCD₃ and Ir–CD₂- bond energetics in methanol

Equilibrium Thermodynamics To Form a Rhodium Formyl Complex from Reactions of CO and H₂: Metal σ Donor Activation of CO

A rhodium­(II) dibenzo­tetra­methyl­aza­[14]­annulene dimer ([(tmtaa)­Rh]₂) (<b>1</b>) reacts with CO and H₂ in toluene and pyridine to form equilibrium distributions with hydride and formyl complexes ((tmtaa)­Rh–H (<b>2</b>); (tmtaa)­Rh–C­(O)H (<b>3</b>)). The rhodium formyl complex ((tmtaa)­Rh–C­(O)­H) was isolated under a CO/H₂ atmosphere, and the molecular structure was determined by X-ray diffraction. Equilibrium constants were evaluated for reactions of (tmtaa)­Rh–H with CO to produce formyl complexes in toluene (<i>K</i>_{2(298 K)(tol)} = 10.8 (1.0) × 10³) and pyridine (<i>K</i>_{2(298 K)(py)} = 2.2 (0.2) × 10³). Reactions of <b>1</b> and <b>2</b> in toluene and pyridine are discussed in the context of alternative radical and ionic pathways. The five-coordinate 18-electron Rh­(I) complex ([(py)­(tmtaa)­Rh^I]⁻) is proposed to function as a nucleophile toward CO to give a two-electron activated bent Rh–CO unit. Results from DFT calculations on the (tmtaa)­Rh system correlate well with experimental observations. Reactions of <b>1</b> with CO and H₂ suggest metal catalyst design features to reduce the activation barriers for homogeneous CO hydrogenation

Evaluation of the Rh^(II)–Rh^(II) Bond Dissociation Enthalpy for [(TMTAA)Rh]₂ by ¹H NMR T₂ Measurements: Application in Determining the Rh–C(O)– BDE in [(TMTAA)Rh]₂CO

Toluene solutions of the rhodium­(II) dimer of dibenzotetramethylaza[14]­annulene ([(TMTAA)­Rh]₂; (<b>1</b>)) manifest an increase in the line widths for the singlet methine and methyl ¹H NMR resonances with increasing temperature that result from the rate of dissociation of the diamagnetic Rh^II–Rh^II bonded dimer (<b>1</b>) dissociating into paramagnetic Rh^II monomers (TMTAA) Rh (<b>2</b>). Temperature dependence of the rates of Rh^II–Rh^II dissociation give the activation parameters for bond homolysis Δ<i>H</i>^⧧_app = 24(1) kcal mol^–1 and Δ<i>S</i>^⧧_app = 10 (1) cal K^–1 mol^–1 and an estimate for the Rh^II–Rh^II bond dissociation enthalpy (BDE) of 22 kcal mol^–1. Thermodynamic values for reaction of <b>1</b> with CO to form (TMTAA)­Rh–C­(O)–Rh­(TMTAA) (<b>3</b>) Δ<i>H</i>₁° = −14 (1) kcal mol^–1, Δ<i>S</i>₁°= −30(3) cal K^–1 mol^–1) were used in deriving a (TMTAA)­Rh–C­(O)– BDE of 53 kcal mol^–1

Reduction of Carbon Monoxide by [(TMTAA)Rh]₂ To Form a Dimetal Ketone Complex

Benzene solutions of [(TMTAA)­Rh]₂ (<b>1</b>) react with CO (<i>P</i>_CO = 0.8–20 atm; <i>T</i> = 298 K) by cleaving the Rh^II–Rh^II bond to form dirhodium­(III) ketone (TMTAA)­Rh–C­(O)–Rh­(TMTAA) [<b>2</b>; ν_CO = 1726 cm^–1; ¹<i>J</i>¹⁰³Rh¹³C­(O)¹⁰³Rh = 45 Hz]. Thermodynamic values for the reaction of <b>1</b> with CO to form <b>2</b> were evaluated from equilibrium constant measurements [<i>K</i>₁(298 K) = 5.0(0.6) × 10³, Δ<i>G</i>₁°(298 K) = −5.0(0.1) kcal mol^–1, Δ<i>H</i>₁° = −14(1) kcal mol^–1, and Δ<i>S</i>₁° = −30(3) cal K^–1 mol^–1]

Heterobimetallic Complexes of Rhodium Dibenzotetramethylaza[14]annulene [(tmtaa)Rh-M]: Formation, Structures, and Bond Dissociation Energetics

A rhodium­(II) dibenzotetramethylaza[14]­annulene dimer ([(tmtaa)­Rh]₂) undergoes metathesis reactions with [CpCr­(CO)₃]₂, [CpMo­(CO)₃]₂, [CpFe­(CO)₂]₂, [Co­(CO)₄]₂, and [Mn­(CO)₅]₂ to form (tmtaa)­Rh-M complexes (M = CrCp­(CO)₃, MoCp­(CO)₃, FeCp­(CO)₂, Co­(CO)₄, or Mn­(CO)₅). Molecular structures were determined for (tmtaa)­Rh-FeCp­(CO)₂, (tmtaa)­Rh-Co­(μ-CO)­(CO)₃, and (tmtaa)­Rh-Mn­(CO)₅ by X-ray diffraction. Equilibrium constants measured for the metathesis reactions permit the estimation of several (tmtaa)­Rh-M bond dissociation enthalpies (RhCr = 19 kcal mol^–1, RhMo = 25 kcal mol^–1, and RhFe = 27 kcal mol^–1). Reactivities of the bimetallic complexes with synthesis gas to form (tmtaa)­Rh-C­(O)H and M-H are surveyed

Crystal structures of the three closely related compounds: bis[(1H-tetrazol-5-yl)methyl]nitramide, triaminoguanidinium 5-({[(1H-tetrazol-5-yl)methyl](nitro)amino}methyl)tetrazol-1-ide, and diammonium bis[(tetrazol-1-id-5-yl)methyl]nitramide monohydrate

In the molecule of neutral bis[(1H-tetrazol-5-yl)methyl]nitramide, (I), C4H6N10O2, there are two intramolecular N—H...O hydrogen bonds. In the crystal, N—H...N hydrogen bonds link molecules, forming a two-dimensional network parallel to (-201) and weak C—H...O, C—H...N hydrogen bonds, and intermolecular π–π stacking completes the three-dimensional network. The anion in the molecular salt, triaminoguanidinium 5-({[(1H-tetrazol-5-yl)methyl](nitro)amino}methyl)tetrazol-1-ide, (II), CH9N6+·C4H5N10O2−, displays intramolecular π–π stacking and in the crystal, N—H...N and N—H...O hydrogen bonds link the components of the structure, forming a three-dimensional network. In the crystal of diammonium bis[(tetrazol-1-id-5-yl)methyl]nitramide monohydrate, (III), 2NH4+·C4H4N10O22−·H2O, O—H...N, N—H...N, and N—H...O hydrogen bonds link the components of the structure into a three-dimensional network. In addition, there is intermolecular π–π stacking. In all three structures, the central N atom of the nitramide is mainly sp2-hybridized. Bond lengths indicate delocalization of charges on the tetrazole rings for all three compounds. Compound (II) was found to be a non-merohedral twin and was solved and refined in the major component