Simple and easily accessible chiral lithium amide salts are reported as efficient (pre)catalysts for the diastereo‐ [up to (E:Z)=92:8] and enantioselective [up to 72% ee (E)] hydroamination/cyclisation of conjugated primary aminodienes. These chiral lithium salts are straightforwardly prepared by in situ combination of an N‐substituted (R)‐(+)‐1,1′‐binaphthyl‐2,2′‐diamine ligand and a commercial methyllithium
Synthesis, structure, and catalytic activity of chiral silver(I) and copper(II) complexes with biaryl-based nitrogen-containing ligands
作者:Haiyan Zhang、Liang Chen、Haibin Song、Guofu Zi
DOI:10.1016/j.ica.2010.11.023
日期:2011.1
two-coordinated Ag(I) complexes. Reaction of AgX with 1 equiv of chiral N4-ligands 5, 7, 8 and 10 gives the chiral, binuclear double helicate Ag(I) complexes, while chiral mono-nuclear single helicate Ag(I) complexes are obtained with N4-ligands 6 and 9. Treatment of either N3-ligand 1 or N4-ligand 9 or 10 with 1 equiv of CuX2 (X = Cl, ClO4) gives the mono-ligated Cu(II) complexes. All the complexes have been
Bistable compounds that exist in two interchangeable phases under identical conditions can act as switches under external stimuli. Among such switchable materials, coordination complexes have energy levels (or phases) that are determined by the electronic states of their constituent metal ions and ligands. They can exhibit multiple bistabilities and hold promise in the search for multifaceted materials that display different properties in different phases, accessible through the application of contrasting external stimuli. Molecular systems that exhibit both thermo- and photoinduced magnetic bistabilities are excellent candidates for such systems. Here we describe a cyanide-bridged [CoFe] one-dimensional chiral coordination polymer that displays both magnetic and electric bistabilities in the same temperature range. Both the electric and magnetic switching probably arise from the same electron-transfer coupled spin-transition phenomenon, which enables the reversible conversion between an insulating diamagnetic phase and either a semiconducting paramagnetic (thermoinduced) or a type of ferromagnetic single-chain magnet (photoinduced) state. Bistable materials, which exist in either one of two phases under identical conditions, are intriguing both from a fundamental perspective and for their practical applications. A cyanide-bridged [CoFe] coordination chain has now been prepared that shows both magnetic and electric bistabilities in the same temperature range, undergoing thermo- and photo-induced conversions between insulating, semiconducting and single-chain magnet-type phases.
An achiral molecular square and a chiral chain composed of cyanide bridged Fe(III) and Ni(II) ions were prepared, and they act as a singlemoleculemagnet and a chiralsingle chain magnet, respectively.
Syntheses, structures and magnetic properties of two-dimensional chiral coordination polymers based on a tetradentate chiral ligand
作者:Takuya Shiga、Mayumi Takeo、Fumichika Iijima、Graham N. Newton、Hiroki Oshio
DOI:10.1039/c3nj01128c
日期:——
Two chiral coordination polymers, Δ-[MII(S-pabn)]2[MoIV(CN)8]·3H2O (M = Cu and Co, S-pabn = (S)-N2,N2′-bis(pyridin-2-ylmethyl-1,1′-binaphthyl-2,2′-diamine)), with two-dimensional network structures, were synthesized by the reaction of MCl2·6H2O, S-pabn and K4[Mo(CN)8]. The compounds show paramagnetic behavior originating from the unpaired electrons of the Cu(II) or Co(II) centers.