51437-25-3Relevant articles and documents
Windmill-type mixed-metal clusters containing Schiff-base ligands as an efficient catalyst for cyclohexene oxidation
Li, Xiaoqin,Ma, Dan,Cao, Bingran,Lu, Ying
, p. 11619 - 11625 (2017)
Two new mixed-metal clusters {CuM2(H2O)2[Cu(C14H16N2O3)Cl]6}·H2O (M = Mn 1, Zn 2) based on Schiff-base ligands were designed and synthesized by the reaction of 1,2-cyclohexanediamine-N,N′-bis-(3-carboxylsalicylide), copper chloride and zinc chloride or manganese chloride under solvothermal conditions. They were characterized by various techniques including single-crystal X-ray diffraction, powder X-ray diffraction (XPRD), elemental analysis, TG analysis, IR and UV-visible spectroscopy. Compounds 1 and 2 are isostructural, and display an interesting windmill-type structure built from a trinuclear mixed-metal center [CuM2(CO2)6(H2O)2] (M = Mn 1, Zn 2) linked with six [CuLCl] (L = C14H16N2O3) units. The oxidation of cyclohexene catalysed by 1 and 2 as heterogeneous catalysts was investigated and showed high activity. In addition, a magnetic study indicates that antiferromagnetic interactions exist in compound 1.
Lanthanide metal-organic frameworks for catalytic oxidation of olefins
Tran,Nguyen, Phuong T. K.
, p. 2090 - 2102 (2021/02/06)
Two isostructural lanthanide metal-organic frameworks (Ln-MOF-589, Ln = La3+, Ce3+), constructed from a tetratopic linker, benzoimidephenanthroline tetracarboxylic acid (H4BIPA-TC), have been solvothermally synthesized and characterized. These Ln-MOF-589 materials consist of Lewis acid [Ln2(-COO)6(-COOH)2(H2O)6] units and a naphthalene diimide core, which exhibited promising catalytic activity for the oxidation of olefins. Among them, Ce-MOF-589 exhibited outstanding performance with high conversions of styrene and cyclohexene (94 and 90%, respectively), and good selectivities towards styrene oxide and 2-cyclohexen-1-one (85, and 95%, respectively). Notably, the catalytic activity of Ce-MOF-589 outperformed that of homogeneous and heterogeneous catalysts, and representative MOFs. Also, Ce-MOF-589 can be recycled for at least up to six cycles with no significant loss of catalytic performance.
A highly efficient heterogeneous catalyst of cobalt-based coordination polymers for aerobic epoxidation of cyclohexene
Yu, Fan
, p. 5074 - 5078 (2018/09/09)
A novel heterogeneous catalyst of cobalt-based coordination polymers has been successfully fabricated using a tyrosine-based derivative. Heterogeneous catalytic experiments on allylic oxidation of cyclohexene indicate that the titled complexes present high catalytic activities using tert-butyl hydroperoxide (t-BuOOH) as an oxidant. The activation energy for the whole process of oxidation of cyclohexene has been calculated to be 25.5 kJ mol-1, which indicates the important role of the selected ancillary ligands in the synthesis of the heterogeneous catalyst.
Cobalt(II) complexes with N,N,N-scorpionates and bidentate ligands: Comparison of hydrotris(3,5-dimethylpyrazol-1-yl)borate Tp? vs. Phenyltris(4,4-dimethyloxazolin-2-yl)borate ToM to control the structural properties and reactivities of cobalt centers
Nishiura, Toshiki,Uramoto, Takahiro,Takiyama, Yuichiro,Nakazawa, Jun,Hikichi, Shiro
, (2018/06/29)
Scorpionate ligands Tp? (hydrotris(3,5-dimethylpyrazol-1-yl)borate) and ToM (tris(4,4- dimethyloxazolin-2-yl)phenylborate) complexes of cobalt(II) with bidentate ligands were synthesized. Both Tp? and ToM coordinate to cobalt(II) in a tridentate fashion when the bidentate ligand is the less hindered acetylacetonate. In crystal structures, the geometry of cobalt(II) supported by the N3O2 donor set in the Tp? complex is a square-pyramid, whereas that in the ToM complex is close to a trigonal-bipyramid. Both Tp?- and ToM-acac complexes exhibit solvatochromic behavior, although the changing structural equilibria of these complexes in MeCN are quite different. In the bis(1-methylimidazol-2-yl)methylphenylborate (LPh) complexes, Tp? retains the tridentate (k3) mode, whereas ToM functions as the bidentate (k2) ligand, giving the tetrahedral cobalt(II) complex. The bowl-shaped cavity derived from the six methyl groups on ToM lead to susceptibility to the bulkiness of the opposite bidentate ligand. The entitled scorpionate compounds mediate hydrocarbon oxidation with organic peroxides. Allylic oxidation of cyclohexene occurs mainly on the reaction with tert-butyl hydroperoxide (TBHP), although the catalytic efficiency of the scorpionate ligand complexes is lower than that of Co(OAc)2 and Co(acac)2. On cyclohexane oxidation with meta-chloroperbenzoic acid (mCPBA), both ToM and Tp? complexes function as catalysts for hydroxylation. The higher electron-donating ToM complexes show faster initial reaction rates compared to the corresponding Tp? complexes.