Chromium(IV)–Peroxo Complex Formation and Its Nitric Oxide Dioxygenase Reactivity
摘要:
The O-2 and NO reactivity of a Cr(II) complex bearing a 12-membered tetraazamacrocyclic N-tetramethylated cyclam (TMC) ligand, [Cr-II(12-TMC)-(Cl)](+) (1), and the NO reactivity of its peroxo derivative, [Cr-IV(12-TMC)(O-2)(Cl)](+) (2), are described. By contrast to the previously reported Cr(III)-superoxo complex, [Cr-III(14-TMC)(O-2)(Cl)](+), the Cr(IV)-peroxo complex 2 is formed in the reaction of 1 and O-2. Full spectroscopic and X-ray analysis revealed that 2 possesses side-on eta(2)-peroxo ligation. The quantitative reaction of 2 with NO affords a reduction in Cr oxidation state, producing a Cr(III)-nitrato complex, [Cr-III(12-TMC)(NO3)(Cl)](+) (3). The latter is suggested to form via a Cr(III)- peroxynitrite intermediate. [Cr-II(12-TMC)(NO)(Cl)](+) (4), a Cr(II)-nitrosyl complex derived from 1 and NO, could also be synthesized; however, it does not react with O-2.
Deaggregation of Zinc Dihydride by Lewis Acids Including Carbon Dioxide in the Presence of Nitrogen Donors
作者:Florian Ritter、Louis J. Morris、Karl N. McCabe、Thomas P. Spaniol、Laurent Maron、Jun Okuda
DOI:10.1021/acs.inorgchem.1c02207
日期:2021.10.18
complexes show an exchange with free BPh3 as well as [HBPh3]−. DFT calculations suggest the presence of [HBPh3]− anion with a highly polarized B–H bond that interacts with the Lewis acidic zinc hydride cation [(L2)Zn(H)]+. The hydridotriphenylborates [(Ln)Zn(H)(HBPh3)] underwent CO2 insertion to give (formato)zinc (formoxy)triphenylborate complexes [(Ln)Zn(OCHO)][(OCHO)BPh3] (Ln = TMPDA, PMDTA, Me4TACD)
热敏聚合二氢化锌[ZnH 2 ] n可以方便地通过ZnEt 2与[AlH 3 (NEt 3 )]反应制备。当在螯合 N-供体配体 L n = N , N , N ', N '-四甲基乙二胺(TMEDA), N , N , N ', N '-四甲基-1存在下与 CO 2 (1 bar)反应时, 3-丙二胺 (TMPDA)、N,N,N',N",N'' -五甲基二亚乙基三胺 (PMDTA) 和 1,4,7,10-四甲基-1,4,7,10-四氮杂环十二烷 (Me 4TACD),很容易插入到 Zn-H 键中。根据齿数n,甲酸盐 [(L n )Zn(OCHO) 2 ] 被分离并在结构上进行表征,无论是作为分子 (L n = TMEDA、TMPDA、PMDTA) 还是电荷分离的离子对 [(L n ) Zn(OCHO)][OCHO] (L n = Me 4 TACD)。[ZnH 2 ] n与温和的路易斯酸
Ligand Influence on Carbonyl Hydroboration Catalysis by Alkali Metal Hydridotriphenylborates [(L)M][HBPh<sub>3</sub>
] (M=Li, Na, K)
作者:Hassan Osseili、Debabrata Mukherjee、Thomas P. Spaniol、Jun Okuda
DOI:10.1002/chem.201702818
日期:2017.10.12
Alkali metal hydridotriphenylborates [(L1)M][HBPh3] (L1=Me6TREN; M=Li, Na, K) chemoselectively catalyze the hydroboration of carbonyls and CO2, with lithium being the most active system. A new series of complexes [(L2)M][HBPh3] [M=Li (1), Na (2), K (3)] featuring the cyclen‐derived macrocyclic polyamine Me4TACD (L2) were synthesized in a “one‐pot” fashion and fully characterized including X‐ray crystallography
Regioselective Hydrosilylation of Olefins Catalyzed by a Molecular Calcium Hydride Cation
作者:Danny Schuhknecht、Thomas P. Spaniol、Laurent Maron、Jun Okuda
DOI:10.1002/anie.201909585
日期:2020.1.2
Chemo- and regioselectivity are often difficult to control during olefin hydrosilylation catalyzed by d- and f-block metal complexes. The cationichydride of calcium [CaH]+ stabilized by an NNNNmacrocycle was found to catalyze the regioselective hydrosilylation of aliphatic olefins to give anti-Markovnikov products, while aryl-substituted olefins were hydrosilyated with Markovnikov regioselectivity
Zinc hydridotriphenylborates supported by a neutral macrocyclic polyamine
作者:Debabrata Mukherjee、Ann-Kristin Wiegand、Thomas P. Spaniol、Jun Okuda
DOI:10.1039/c7dt01094j
日期:——
A neutral macrocyclic polyamine 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane (Me4TACD) stabilizes cationic zinc hydridotriphenylborates that react with CO2(1 atm) under insertion into the B–H bonds.
Calcium Hydride Cation [CaH]<sup>+</sup>Stabilized by an NNNN-type Macrocyclic Ligand: A Selective Catalyst for Olefin Hydrogenation
作者:Danny Schuhknecht、Carolin Lhotzky、Thomas P. Spaniol、Laurent Maron、Jun Okuda
DOI:10.1002/anie.201706848
日期:2017.9.25
Reaction of dibenzyl calcium complex [Ca(Me4TACD)(CH2Ph)2], containing the neutral NNNN‐type macrocyclic ligand Me4TACD (Me4TACD=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane), with triphenylsilane gave the cationic dinuclear calcium hydride [Ca2H2(Me4TACD)2](PhCHSiPh3)2 which was characterized by NMR spectroscopy and single‐crystal X‐ray diffraction. The cation can be regarded as the ligand‐stabilized