Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, India.
Inorg Chem. 2023 Apr 3;62(13):5292-5301. doi: 10.1021/acs.inorgchem.3c00504. Epub 2023 Mar 23.
Two new -substituted oxido-molybdenum corroles were synthesized and characterized by various spectroscopic techniques. In the thermogram, MoO[TTC] () exhibited excellent thermal stability up to 491 °C while MoO[TNPC] () exhibited good stability up to 318 °C. The oxidation states of the molybdenum(V) were verified by electron paramagnetic resonance (EPR) spectroscopy and exhibited an axial compression with configuration. Oxido-molybdenum(V) complexes were utilized for the selective epoxidation of various olefins with high TOF values (2066-3287 h) in good yields in a CHCN/HO (3:2, v/v) mixture in the presence of hydrogen peroxide as a green oxidant and NaHCO as a promoter. The oxidative bromination catalytic activity of oxido-molybdenum(V) complexes in an aqueous medium has been reported for the first time. Surprisingly, MoO[TNPC] () biomimics of the vanadium bromoperoxidase (VBPO) enzyme activity exhibited remarkably high TOF values (36 988-61 646 h) for the selective oxidative bromination of -cresol and other phenol derivatives. Catalyst MoO[TNPC] () exhibited higher TOF values and better catalytic activity than catalyst MoO[TTC] () due to the presence of electron-withdrawing nitro groups evident from cyclic voltammetric studies.
两种新型取代的氧化钼卟啉被合成并通过各种光谱技术进行了表征。在热谱中,MoO[TTC]()表现出极好的热稳定性,高达 491°C,而 MoO[TNPC]()在高达 318°C 时表现出良好的稳定性。钼(V)的氧化态通过电子顺磁共振(EPR)光谱得到证实,并表现出轴向压缩的[MoO]构型。氧化钼(V)配合物在 CHCN/HO(3:2,v/v)混合物中,以过氧化氢为绿色氧化剂,以 NaHCO为促进剂,用于各种烯烃的选择性环氧化,具有高 TOF 值(2066-3287 h)和良好的收率。氧化钼(V)配合物在水介质中的溴化催化活性是首次报道的。令人惊讶的是,MoO[TNPC]()模拟了钒溴过氧化物酶(VBPO)酶活性,对 -甲酚和其他苯酚衍生物的选择性氧化溴化表现出极高的 TOF 值(36988-61646 h)。由于存在吸电子的硝基基团,催化剂 MoO[TNPC]()的 TOF 值和催化活性均高于催化剂 MoO[TTC](),这从循环伏安研究中可以明显看出。