Organic heterobimetallic complexes of the alkaline earth metals (Ae = Ca, Sr, Ba) with tetrahedral metallate anions of three-valent metals (M = B, Al, Ga, and V)

The Allylcalcium Monocation: A Bridging Allyl Ligand with a Non‐Bent Coordination Geometry

“…15 They are slightly longer than the CaO bonds found in calcium complexes with non‐macrocyclic ether ligands, which is due to the geometry dictated by the macrocycle 5b. 16…”

Das Calciumallyl‐Monokation: ein verbrückender Allylligand in nicht‐gewinkelter Koordinationsgeometrie

“…15 Die Bindungen sind wenig länger als Ca‐O‐Bindungen in Calciumverbindungen mit nicht‐makrocyclischen Etherliganden, was mit der durch den Kronenether vorgegebenen Geometrie zu begründen ist 5b. 16 Das Zinkatom im anionischen Teil von 1 weist eine trigonal planare Koordinationsgeometrie auf. Die drei Allylliganden koordinieren in einem η 1 ‐Modus an das Metallzentrum.…”

Heavy Grignard Reagents: Synthesis, Physical and Structural Properties, Chemical Behavior, and Reactivity

“…Transmetalation of trimesitylvanadium(III) with activated calcium in tetrahydrofuran yields the solvent‐separated pair [(thf) 6 Ca] 2+ [V(Mes) 4 ] 2 2− with a tetrakis(mesityl)vanadate(III) anion as mentioned above . Phenylcopper(I) also reacts with activated calcium in THF according to Equation .…”

“…Two heterobimetallic complexes might exemplify the structural diversity that can be accomplished. In an addition reaction of mesitylcalcium iodide with trimesitylvanadium(III) in tetrahydrofuran, the calcium‐bound aryl substituent is transferred to the Lewis acidic vanadium derivative and the solvent‐separated ion pair [(thf) 5 CaI] + [V(Mes) 4 ] − forms . Weaker basic solvents such as diethyl ether allow the isolation of contact ion pairs as observed for a cuprate.…”

“…Furthermore, slight changes might give different products; whereas the transmetalation of Sn[N(SiMe 3 ) 2 ] 2 with calcium quantitatively yields Ca[N(SiMe 3 ) 2 ] 2 , the transmetalation of isoelectronic Sn[CH(SiMe 3 ) 2 ] 2 with calcium in 1,2‐dimethoxyethane under similar reaction conditions leads to the formation of [(dme) 2 Ca{Sn[CH(SiMe 3 ) 2 ] 3 } 2 ] . With other organometallics also an incomplete metal–metal exchange is often observed and the formation of “ate” complexes, such as vanadates, manganates, zincates, and cuprates, has been observed. A complete metal–metal exchange is hindered, because metalates are sterically shielded and, hence, kinetically stabilized and also because this exchange requires the disadvantageous reduction of (and electron transfer to) a metallate anion.…”