Magnesium bromide radicals have to be prepared as high‐temperature molecules and trapped as a metastable solution because a seemingly simple reduction of donor‐free Grignardcompounds failed. However, the essential role of magnesium(I) species during the formation of Grignardcompounds could be demonstrated experimentally.
Heteroleptic β-Ketoiminate Magnesium Catalysts for the Ring-Opening Polymerization of Lactide
作者:Swarup Ghosh、Eduard Glöckler、Christoph Wölper、Alexander Tjaberings、André H. Gröschel、Stephan Schulz
DOI:10.1021/acs.organomet.0c00168
日期:2020.12.14
L22Mg2Cp2 (2), L12Mg2(OAr)2 (3 and 4), and L22Mg2(OAr)2 (5 and 6) (L1 = Me2NC2H4NC(Me)CHC(Me)O, L′1 = Me2NC2H4NC(CH2)CHC(Me)O, L2 = Me2NC3H6NC(Me)CHC(Me)O; Ar = Ph and 2,6-t-Bu2-C6H3) with different steric and electronic properties were synthesized. 1 and 3–6 adopt binuclear structures in the solidstate and in solution, whereas 2 forms a monomer/dimer equilibrium in solution. Complexes 1 and 2 showed
一系列杂合β-酮亚胺镁配合物L 1 L' 1 Mg 2 Cp *(1),L 2 2 Mg 2 Cp 2(2),L 1 2 Mg 2(OAr)2(3和4)和L 2 2 Mg 2(OAr)2(5和6)(L 1 = Me 2 NC 2 H 4 NC(Me)CHC(Me)O,L' 1 = Me 2 NC2 H 4 NC(CH 2)CHC(Me)O,L 2 = Me 2 NC 3 H 6 NC(Me)CHC(Me)O; 合成了具有不同空间和电子性质的Ar = Ph和2,6- t -Bu 2 -C 6 H 3)。1和3 – 6在固态和溶液中采用双核结构,而2在溶液中形成单体/二聚体平衡。配合物1和2在外消旋丙交酯的开环聚合(ROP)中显示非常差的活性(外消旋-LA),而杂酚盐配合物3 - 6是在不存在任何共引发剂的溶液变温活性聚合催化剂,得到全同立构富集的聚丙交酯(PLA)。催化活性和立体选择性受酚盐
Cooperative reduction by Ln<sup>2+</sup> and Cp*<sup>−</sup> ions: synthesis and properties of Sm, Eu, and Yb complexes with 3,6-di-tert-butyl-o-benzoquinone
作者:Nikolay A. Pushkarevsky、Mikhail A. Ogienko、Anton I. Smolentsev、Igor N. Novozhilov、Alexander Witt、Marat M. Khusniyarov、Vladimir K. Cherkasov、Sergey N. Konchenko
DOI:10.1039/c5dt03573b
日期:——
yield dimeric complexes [(LnCp*)2(dbcat)2], where each Ln ion loses one Cp* ligand. Eu forms a trimeric complex [(EuCp*)(Eu·thf)2(dbcat)3], in which one Eu ion is coordinated by one Cp* ligand, while two Eu ions have lost all Cp* ligands and are coordinated by THF molecules instead. Magneticproperties corroborate the assignment of oxidation states made on the basis of single-crystal X-ray diffraction:
Probing the Reactivity of Aluminum(I) Compounds: The Reaction of Pentamethylcyclopentadienyl-Aluminum, Al[C<sub>5</sub>(CH<sub>3</sub>)<sub>5</sub>], Monomers with Dihydrogen in a Solid Ar Matrix to Give the New Aluminum Hydride Molecule H<sub>2</sub>Al[C<sub>5</sub>(CH<sub>3</sub>)<sub>5</sub>]
作者:Hans-Jörg Himmel、Jean Vollet
DOI:10.1021/om020787x
日期:2002.12.1
photoinduced reaction of AlCp* [Cp* = C5(CH3)5] monomers with H2 in an Ar matrix at 12 K was followed with IR spectroscopy. The experimental results allied with detailed quantum chemical calculations show that the product of this reaction is the newaluminumhydride species H2AlCp*. The properties of this species are investigated and compared with those of related known monomeric hydrides such as AlH3
Organometallic coordination complexes of the bis(pentamethylcyclopentadienyl)-alkaline earth compounds, (Me5C5)2MLn, where M IS Mg, Ca, Sr, OR Ba and Me5C5BeCl