Polymeric [dihydrobis(pyrazol-1-yl)borato]potassium(I) and three dihydrobis(pyrazol-1-yl)borate–magnesium(I) compounds obtained by disproportionation of the Grignard reagent

Abstract

Reaction of the Grignard reagent with polydentate nitrogen-donor ligands yields new species with rare magnesium coordination and possible catalytic activity. In the first of the title compounds, poly[[mu4-dihydrobis(pyrazol-1-yl)borato-kappa2N,N']potassium(I)], [K(C6H8BN4)]n, (I), polymeric chains form a two-dimensional network in the [100] plane. Each potassium ion is coordinated by four N atoms of pyrazolyl ligands, while weak (mu-BH)...K+ interactions additionally stabilize the structure. The K and B atoms both lie on a mirror plane. In three new structures obtained by disproportionation of the Grignard reagent, each Mg atom is bound to a kappa2N,N'-type ligand, forming the basal plane, and tetrahydrofuran molecules occupy the axial positions. Di-mu-chlorido-bis[dihydridobis(pyrazol-1-yl)borato]tris(tetrahydrofuran)dimagnesium(II), [Mg2(C6H8BN4)2Cl2(C4H8O)3], (II), adopts a dimeric structure with mu-Cl-Mg interactions. One of the Mg atoms has an octahedral coordination, while the other has a distorted square-pyramidal environment. However, in the bis-chelate compounds bis[dihydridobis(pyrazol-1-yl)borato-kappa2N,N'](tetrahydrofuran-kappaO)magnesium(II), [Mg(C6H8BN4)2(C4H8O)], (III), and bis[dihydridobis(pyrazol-1-yl)borato-kappa2N,N']bis(tetrahydrofuran-kappaO)magnesium(II), [Mg(C6H8BN4)2(C4H8O)2], (IV), the Mg atoms have square-pyramidal and octahedral environments, respectively. The Mg atom in (IV) lies on an inversion centre.

Energetic High-Nitrogen Compounds: 5-(Trinitromethyl)-2H-tetrazole and -tetrazolates, Preparation, Characterization, and Conversion into 5-(Dinitromethyl)tetrazoles

“…The frames were then integrated with the SAINT algorithm to give the hkl files corrected for Lp/decay. Absorption correction was performed with the SADABS program . The structures were solved by the direct method and refined on F 2 by use of the Bruker SHELXTL software package. − All non-hydrogen atoms were refined anisotropically.…”

“…Absorption correction was performed with the SADABS program. 27 The structures were solved by the direct method and refined on F 2 by use of the Bruker SHELXTL software package. 28−31 All non-hydrogen atoms were refined anisotropically.…”

Energetic Bis(3,5-dinitro-1H-1,2,4-triazolyl)dihydro- and dichloroborates and Bis(5-nitro-2H-tetrazolyl)-, Bis(5-(trinitromethyl)-2H-tetrazolyl)-, and Bis(5-(fluorodinitromethyl)-2H-tetrazolyl)dihydroborate

“…1,2,4-Triazoles and tetrazoles are readily accessible nitrogen-rich, energetic compounds whose usefulness as energetic materials can be further increased by the introduction of nitro functionalities. While poly(azolyl)borates derived from pyrazoles − and triazoles , are commonly used ligands in coordination and organometallic and bioinorganic chemistry, the chemistry of tetrazolylborates is much less developed. Although a series of tetrazolyldihydroborates such as bis(5- H -tetrazolyl)dihydroborate, − bis(5-aminotetrazolyl)dihydroborate, bis(1-methyl-5-thiotetrazolyl)dihydroborate, and tris(tetrazolyl)hydroborate have been reported, these compounds did not contain the necessary oxidizing substituents for rendering them highly energetic materials.…”

Comparison of Functionalized Lithium Dihydrobis(azolyl)borates with Their Corresponding Azolates as Environmentally Friendly Red Pyrotechnic Coloring Agents

“…Both compounds crystallize in the monoclinic space group P2 1 /n . The more carbon atoms in the unsubstituted heterocycle are replaced by smaller and heavier nitrogen, the higher the density seems to be (potassium dihydrobis(pyrazol‐1‐yl)borate: ρ=1.41 g cm −3 at 150 K; potassium dihydrobis(tetrazol‐1‐yl)borate: ρ=1.47 g cm −3 at 283–303 K). Nitro and amino substituents contribute approximately equally to a closer packing, since the oxygen atoms of nitro functionalities offer additional coordination sites for metal cations and amino groups push electron density into the ring and thus enhance its σ‐donation toward metal centers ( 2 : ρ=1.69 g cm −3 at 100 K, potassium dihydrobis(5‐aminotetrazol‐1‐yl)borate: ρ=1.70 g cm −3 at 296 K).…”