Synthesis and Molecular Structures of Monosubstituted Pentamethylcobaltocenium Cations

Metastable Charged Dimers in Organometallic Species: A Look into Hydrogen Bonding between Metallocene Derivatives

Multiply charged complexes bound by noncovalent interactions have been previously described in the literature, although they were mostly focused on organic and main group inorganic systems. In this work, we show that similar complexes can also be found for organometallic systems containing transition metals and deepen in the reasons behind the existence of these species. We have studied the structures, binding energies, and dissociation profiles in the gas phase of a series of charged hydrogen-bonded dimers of metallocene (Ru, Co, Rh, and Mn) derivatives isoelectronic with the ferrocene dimer. Our results indicate that the carboxylic acid-containing dimers are more strongly bonded and present larger barriers to dissociation than the amide ones and that the cationic complexes tend to be more stable than the anionic ones. Additionally, we describe for the first time the symmetric proton transfer that can occur while in the metastable phase. Finally, we use a density-based energy decomposition analysis to shine light on the nature of the interaction between the dimers.

Direct Amination of Cobaltocenium Hexafluoridophosphate via Vicarious Nucleophilic Substitution

In this communication we report a convenient, as short as possible synthesis of aminocobaltocenium hexafluoridophosphate, a very useful compound for further functionalization in cobaltocenium chemistry. Via vicarious nucleophilic substitution of hydrogen of cobaltocenium hexafluoridophosphate with 1,1,1-trimethylhydrazinium iodide as nucleophile bearing its own leaving group, a one-step amination of cobaltocenium in 50% isolated yield is possible, a major improvement over the standard multistep procedure involving common Curtius rearrangement chemistry.

Crystal structures of 1'-amino-cobaltocenium-1-carb-oxy-lic acid chloride monohydrate and of its azo dye 1'-[2-(1-amino-2,6-dimethylphenyl)diazen-1-yl]cobaltocenium-1-carb-oxy-lic acid hexa-fluorido-phosphate monohydrate

1'-Amino-cobaltocenium-1-carb-oxy-lic acid chloride, [Co(C5H6N)(C6H5O2)]Cl·H2O, (3), and its azo derivative 1'-[2-(1-amino-2,6-dimethylphenyl)diazen-1-yl]cobaltocenium-1-carb-oxy-lic acid hexa-fluorido-phosphate, [Co(C13H14N3)(C6H5O2)]PF6·H2O (5) were obtained from cobaltocenium-1,1'-di-carb-oxy-lic acid hexa-fluorido-phosphate by converting one carboxyl group to its chloro-carboxyl derivative followed by chloride/azide exchange, Curtius rearrangement, diazo-tiation and azo coupling with 2,6-di-methyl-aniline. Both title compounds crystallize as their monohydrates. In the crystal structure of 3, both functional groups lie in the same direction, with the Cp rings being nearly eclipsed, and participate in an extended hydrogen-bonded supra-molecular network including the counter-ion and the water mol-ecule of crystallization. Although the functional groups in 5 are somewhat further apart, bearing a greater torsion angle with the Cp rings now staggered, a similar supra-molecular network is observed with not only the carb-oxy-lic acid and azo groups, but also with the more remote amino group participating in a hydrogen-bonded network, again including the counter-ion and the water mol-ecule. The hexa-fluorido-phosphate ion shows positional disorder. Compound 3 was refined as an inversion twin. In 5, each of the six F atoms is disordered over two sets of sites in a 1:1 ratio.

N-Nitrosarcosine: An Economic Precursor for the Synthesis of New Energetic Materials

New energetic compounds have been synthesized starting from the readily available N-(cyanomethyl)-N-methylamine. From this, N-nitrosarcosine was prepared in few steps, which serves as a starting material for the synthesis of oxygen-rich compounds. The compounds were thoroughly characterized including multinuclear NMR and vibrational spectroscopy and also molecular structures by single X-ray diffraction were obtained. Their energetic properties were determined including the sensitivities towards impact and friction, their heat of formations were calculated and the detonation and combustion parameters were predicted using EXPLO5 V6.02.

Convenient synthesis of energetic polynitro materials including (NO2)3CCH2CH2NH3-saltsviaMichael addition of trinitromethane

Acrylamide and nitroform are precursors for the formation of the 3,3,3-trinitropropylammonium cation, which was combined with several oxygen-containing anions in order to serve as potential HEDO salts.