A variety of gold（Ⅲ） adducts having a-ligated oxygen-donor ligands have been prepared from [Au（ppy）Cl2]（ppy.phenylpyridine）（1） either by partial or total replacement of the chloride ions. The new species comp...A variety of gold（Ⅲ） adducts having a-ligated oxygen-donor ligands have been prepared from [Au（ppy）Cl2]（ppy.phenylpyridine）（1） either by partial or total replacement of the chloride ions. The new species comprise hydroxo-[Au（ppy）（OH）Cl]（2）, and [Au（ppy）（OH）2]（3）, oxo-[Au2（ppy）2（μ-O）2]（4）, acetate-[Au（ppy）（O2CMe2）] （5）, and alkoxo complexes-[Au（ppy）（OR）Cl]（6, 7） and [Au（ppy）（OR）2]（8--10）（R=Me, 6 and 8; Et, 7 and 9; Pr, 10）. The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution（R=Me, Et or Pr） to give the corresponding alkoxides.展开更多
The tide compound is formed by controlled hydrolytic polymerization in nonaqueous solution of simple oxo-bridged binuclear ferric salts under the presence of carboxylate ligands. The rhombohedral crystalline form of t...The tide compound is formed by controlled hydrolytic polymerization in nonaqueous solution of simple oxo-bridged binuclear ferric salts under the presence of carboxylate ligands. The rhombohedral crystalline form of the cluster with six imidazole molecules, which has crystallographically required C3v symmetry, will be reported. The largest Fe-Fe distance in the undecairon oxo-hydroxo cluster is about 0.68 nm and the cluster has a diameter near 2 nm, which implies that this cluster reaches a nanometer-sized dimension.展开更多
A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing t...A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing the triflate anion with Cl^(-)or Br^(-),we were able to halogenate toluene with high selectivity for C(sp^(2))-H bonds over C(sp^(3))-H bonds,such as chlorination with Cl^(-)or bromination with Br^(-)in the aromatic ring.We have also examined the halogenation of naphthalene and benzene derivatives with[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)(X=Cl^(-)and Br^(-)).In all of these reactions,halogenated products were formed dominantly,and the source of the halogens in the products was found to be halides present in the[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)complexes.In the absence of halides,naphthalene was found to undergo dimerization.Kinetic isotope effect(KIE)experiments on this reaction showed no isotopic effect in the halogenation reactions.DFT calculations on models with the naphthalene substrate supported a mechanism involving an initial(rate-limiting)electron transfer from the substrate to[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+),coupled by the attachment of Cl^(-)to the C1 position of the naphthalene radical cation.This mechanism was also supported by the Marcus theory of outer-sphere electron transfer.The so-formed[Mn^(IV)(OH)(Por)(OTf)](a manganese compound II analogue)underwent a hydrogen atom transfer from the C1 position of the substrate to form chlorinated naphthalene and[Mn^(III)(H_(2)O)(Por)(OTf)].DFT calculations showed that[Mn^(IV)(OH)(Por)(OTf)]can also undergo direct OH-transfer to the substrate competitively,leaving open possibilities for side reactions or alternative reactions in a different environment.This study provides a deeper understanding of chloroperoxidase-like reactions.展开更多
基金Supported by the Ministerio De Ciencia Y Technologia(NoSB2004-oobo)
文摘A variety of gold（Ⅲ） adducts having a-ligated oxygen-donor ligands have been prepared from [Au（ppy）Cl2]（ppy.phenylpyridine）（1） either by partial or total replacement of the chloride ions. The new species comprise hydroxo-[Au（ppy）（OH）Cl]（2）, and [Au（ppy）（OH）2]（3）, oxo-[Au2（ppy）2（μ-O）2]（4）, acetate-[Au（ppy）（O2CMe2）] （5）, and alkoxo complexes-[Au（ppy）（OR）Cl]（6, 7） and [Au（ppy）（OR）2]（8--10）（R=Me, 6 and 8; Et, 7 and 9; Pr, 10）. The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution（R=Me, Et or Pr） to give the corresponding alkoxides.
基金Project (No. 29871003) Supported by the National Natural Science Foundation of China.
文摘The tide compound is formed by controlled hydrolytic polymerization in nonaqueous solution of simple oxo-bridged binuclear ferric salts under the presence of carboxylate ligands. The rhombohedral crystalline form of the cluster with six imidazole molecules, which has crystallographically required C3v symmetry, will be reported. The largest Fe-Fe distance in the undecairon oxo-hydroxo cluster is about 0.68 nm and the cluster has a diameter near 2 nm, which implies that this cluster reaches a nanometer-sized dimension.
基金supported by the NRF of Korea(NRF-2021R1A3B1076539 and NRF-2023K2A9A2A11098996 to W.N.,NRF-2023R1A2C1007668 to Y.-M.L.and RS-2021-NR058689 to K.-B.C.)the MoE G-LAMP Program(No.RS-2024-00443714 to K.-B.C)the Henan Center for Outstanding Overseas Scientists,China(GZS2024020 to W.N.).
文摘A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing the triflate anion with Cl^(-)or Br^(-),we were able to halogenate toluene with high selectivity for C(sp^(2))-H bonds over C(sp^(3))-H bonds,such as chlorination with Cl^(-)or bromination with Br^(-)in the aromatic ring.We have also examined the halogenation of naphthalene and benzene derivatives with[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)(X=Cl^(-)and Br^(-)).In all of these reactions,halogenated products were formed dominantly,and the source of the halogens in the products was found to be halides present in the[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)complexes.In the absence of halides,naphthalene was found to undergo dimerization.Kinetic isotope effect(KIE)experiments on this reaction showed no isotopic effect in the halogenation reactions.DFT calculations on models with the naphthalene substrate supported a mechanism involving an initial(rate-limiting)electron transfer from the substrate to[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+),coupled by the attachment of Cl^(-)to the C1 position of the naphthalene radical cation.This mechanism was also supported by the Marcus theory of outer-sphere electron transfer.The so-formed[Mn^(IV)(OH)(Por)(OTf)](a manganese compound II analogue)underwent a hydrogen atom transfer from the C1 position of the substrate to form chlorinated naphthalene and[Mn^(III)(H_(2)O)(Por)(OTf)].DFT calculations showed that[Mn^(IV)(OH)(Por)(OTf)]can also undergo direct OH-transfer to the substrate competitively,leaving open possibilities for side reactions or alternative reactions in a different environment.This study provides a deeper understanding of chloroperoxidase-like reactions.
