Niobium isocyanide complexes, Nb(CNAr)6, with Ar = 2,6-dimethylphenyl (Xyl), a diamagnetic dimer containing four reductively coupled isocyanides, and Ar = 2,6-diisopropylphenyl (Dipp), a paramagnetic monomer analogous to the highly unstable hexacarbonylniobium(0)

Crystal structures of two novel iron isocyanides from the reaction of 2,6-di-methyl-phenyl isocyanide, CNXyl, with bis-(anthracene)ferrate(-1)

Three crystal structures from the reaction of 2,6-di­methyl­phenyl isocyanide with bis­(anthracene)ferrate(−1) are presented.

The reaction of the [K(18-crown-6)(thf)₂]¹⁺ (thf is tetra­hydro­furan) salt of bis­(anthracene)ferrate(−1), or [Fe(C₁₄H₁₀)₂]⁻, with 2,6-di­methyl­phenyl isocyan­ide (CNX­yl) in thf resulted in the formation of two new iron isocyanide complexes, namely, [(1,2,3,4-η)-anthracene]tris­(2,6-di­methyl­phenyl isocyanide)iron, [Fe(C₁₄H₁₀)(C₉H₉N)₃] or [Fe(1,2,3,4-η-C₁₄H₁₀)(CNX­yl)₃], and {5,6-bis­(2,6-di­methyl­anilino)-3-(2,6-di­methyl­phen­yl)-1,2,7-tris­[(2,6-di­methyl­phen­yl)imino]-3-azoniahept-3-ene-1,4,7-triido}tris­(2,6-di­methyl­phenyl isocyanide)iron tetra­hydro­furan disolvate, [Fe(C₅₄H₅₆N₆)(C₉H₉N)₃]·2C₄H₈O or [Fe(C₅₄H₅₆N₆)(CNX­yl)₃]·2C₄H₈O, which were characterized by single-crystal X-ray diffraction. The former is likely an inter­mediate along the path to the known homoleptic [Fe(CNX­yl)₅], while the latter contains a tridentate ligand that is formed from the ‘coupling’ of six CNXyl ligands. A third crystal structure from this reaction, (7-methyl­indol-1-ido-κN)(1,4,7,10,13,16-hexa­oxa­cyclo­octa­decane-κ⁶O)potassium, [K(C₉H₈N)(C₁₂H₂₄O₆)] or [K(C₉H₈N)(18-crown-6)], contains a 7-methyl­indol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.

Effect of Spin-Orbit Coupling on Phonon-Mediated Magnetic Relaxation in a Series of Zero-Valent Vanadium, Niobium, and Tantalum Isocyanide Complexes

Spin-vibronic coupling leads to spin relaxation in paramagnetic molecules, and an understanding of factors that contribute to this phenomenon is essential for designing next-generation spintronics technology, including single-molecule magnets and spin-based qubits, wherein long-lifetime magnetic ground states are desired. We report spectroscopic and magnetic characterization of the isoelectronic and isostructural series of homoleptic zerovalent transition metal triad M(CNDipp)₆ (M = V, Nb, Ta; CNDipp = 2,6-diisopropylphenyl isocyanide) and show experimentally the significant increase in spin relaxation rate upon going from V to Nb to Ta. Correlated electronic calculations and first principle spin-phonon computations support the role of spin-orbit coupling in modulating spin-phonon relaxation. Our results provide experimental evidence that increasing magnetic anisotropy through spin-orbit coupling interactions leads to increased spin-vibronic relaxation, which is detrimental to long spin lifetime in paramagnetic molecules.

Systematic reductive oligomerization of isocyanides with a vanadium(ii) complex

Using a V(ii) complex as a reducing reagent, we demonstrate controlled reduction of isocyanides, resulting in decyanation of alkyl isocyanides to form a V(iii) cyanide complex or oligomerization of aryl isocyanides to form trimers and a tetramer. The pathways leading to the trimers involve a divanadium ynediamido intermediate, which further reacts with the third isocyanide molecule to selectively produce a tri(imino)deltate or an indolenine complex, by altering the temperature and stoichiometry.