Synthesis and Structure of a Trigonal Monopyramidal Vanadium(III) Complex, [(C₆F₅NCH₂CH₂)₃N]V, and the Vanadium(IV) Product of Its Oxidation, {[(C₆F₅NCH₂CH₂)₂N(CH₂CH₂NHC₆F₅)]V(O)}₂

Abstract

Reduction of [N3NF]VCl ([N3NF]3- = [(C6F5NCH2CH2)3N]3-) with sodium amalgam in toluene yields dark green, trigonal monpyramidal, paramagnetic [N3NF]V (1). During attempts to recrystallize 1 from toluene at room temperature, bright green crystals of {[(C6F5NCH2CH2)2N(CH2CH2NHC6F5)]V(O)}2 (2) formed over a period of 2 weeks, possibly from traces of water. A key feature of 2 is that one arm of the triamidoamine ligand has been protonated and is now “dangling” away from the metal.

Synthesis and structure of mono-, bi- and trimetallic amine-bis(phenolate) cobalt(ii) complexes

“…Data were collected and processed using CrystalClear (Rigaku). 67 For 1(CH 3 COCH 3 ), 1(CH 3 OH) [excluding alcoholic protons, H (109,113,117,121,125,129,133), that were introduced in difference map positions], and 1(C 3 H 6 O) hydrogen atoms were introduced in calculated positions with isotropic thermal parameters set twenty percent greater than those of their bonding partners. For 5, H(61) and H (65) were introduced in their difference map positions and allowed to refine positionally, with fixed isotropic thermal parameters (1.2 times greater than their bonding partners at the time they were introduced) and all other hydrogen atoms were introduced in calculated positions with isotropic thermal parameters set twenty percent greater than those of their bonding partners.…”

Mapping the Stereochemistry and Symmetry of Tetracoordinate Transition‐Metal Complexes

“…[71] Also a point can be identified along the umbrella distortion path (highest line), which corresponds to a V III complex with a tetradentate tripod ligand. [72] All these compounds seem to have a triplet ground state. [73] ions, but these clearly suggest that both the tetrahedron and the square are likely, whereas intermediate geometries seem to be forbidden.…”

Titanium(IV) Cations with Trigonal Monopyramidal Geometry: Unusual Lewis Acids Supported by a Triaryl Triamidoamine Ligand

“…Unlike the commonly observed bowl‐shaped apical cavity in pentacoordinate triamidoamine complexes, with the aryl groups directed away from the titanium center, the xylyl rings in 1[B(Ar X ) 4 ] are inclined towards titanium and form a propeller‐shaped apical cavity (Figure , right). A comparable arrangement was also observed for the aryl groups in the tetracoordinate vanadium complex [{(C 6 F 5 NCH 2 CH 2 ) 3 N}V], in which the ortho ‐F atoms were proposed to interact with the coordinatively unsaturated vanadium center . The inclination of the xylyl groups toward the titanium center is clearly evident from the very short Ti1−C ipso distances ( 1[B(Ar Cl ) 4 ] : d (Ti1−C ipso ) avg =2.521 Å; 1[B(Ar F ) 4 ] : d (Ti1−C ipso ) avg =2.541 Å), which are significantly shorter than the observed values in pentacoordinate titanium(IV) cations (see below).…”

“…The 1 H NMR signals of the ortho ‐CH of the xylyl groups at δ =5.29 and 5.30 ppm for 1[B(Ar X ) 4 ] appear remarkably shifted upfield relative to the para ‐CH proton signal. This may be due to interactions with the coordinatively unsaturated titanium center, as observed between the fluoro substituents and the vanadium center in [V{(C 6 F 5 NCH 2 CH 2 ) 3 N}] …”