Solid-state and Solution Studies on a β-Diketiminate Zinc Hydride Complex

Abstract

[MesnacnacZn(µ-H)] 2 (1) was synthesized by reaction of MesnacnacZnI with either an equimolar amount of KNH(iPr)BH 3 or an excess of NaH and characterized by multinuclear NMR and IR spectroscopy as well as X-ray diffraction. Two polymorphs of 1 were found and their structures determined on single crystals.

An Air‐ and Water‐Tolerant Zinc Hydride Cluster That Reacts Selectively With CO2

“…11 Bond metrics observed in 2 are comparable to those in dimeric and monomeric nacnac and NHC zinc hydride complexes 12. The hydride resonance in 2 is shifted downfield by about 2 ppm relative to those reported for mono‐ and dinuclear zinc hydride complexes,12c,d, 13 probably as a result of the ring currents of the cyclophane aromatic rings 14…”

“…21 Our results and these prior reports suggest that CO 2 selectivity can be controlled by limiting access to the metal coordination sphere prior to hydride transfer. However for (nacnac)metal hydrides, the mononuclear species are speculated to be reactive, whereas the hydride‐bridged dimers are not 12d. 22 Alternatively then, the Zn 3 H 3 cluster could undergo a structural distortion to generate either an asymmetric bridging hydride or a terminal hydride that reacts readily with CO 2 .…”

Well‐Defined Molecular Magnesium Hydride Clusters: Relationship between Size and Hydrogen‐Elimination Temperature

“…The hydrodynamic radii for [(DIPP‐nacnacMgH ⋅ THF) 2 ] and [(DIPP‐nacnacCaH ⋅ THF) 2 ] are both 6.8(1) Å. This result is significantly larger than the hydrodynamic radii for [DIPP‐nacnacZnH] (5.2(1) Å)16 and [Mes‐nacnacZnH] (Mes=mesityl, 5.0(2) Å),17 both of which are monomeric in solution. The ratio of the hydrodynamic radii between the magnesium and zinc hydride complexes or the calcium and zinc hydride complexes, 1.3:1, corresponds to a volume ratio of about 2.2:1, thus indicating that the THF adducts of the magnesium and calcium hydride complexes are dimeric in aromatic solvents (at least at room temperature).…”

Aminotroponiminatozinc(I) Complexes: Syntheses and Spectroscopic Analyses

“…Reaction of the aminotroponimines N-isopropyl-2-(isopropylamino)troponimine [{(iPr) 2 ATI}H] [17] and 4-bromo N-isopropyl-2-(isopropylamino)troponimine [{4-BrA C H T U N G T R E N N U N G (iPr) 2 ATI}H] [18] with [(h 5 -Cp*) 2 Zn 2 ] in toluene at room temperature resulted in the formation of [{(iPr) 2 [20] in the 1 H NMR spectra of the complexes, and the IR spectrum had no absorption peak, which is in the typical range for Zn 2 H 2 four-membered-ring systems. [19] Crystals of 1 and 2 suitable for single-crystal X-ray diffraction analysis were obtained from a solution of 1 and 2 in toluene at À30 8C. The data confirm the dimeric nature of 1 and 2 with the central ZnÀZn bond.…”