100165-82-0

Upstream product

• 7646-79-9 cobalt(II) chloride 
• 56396-12-4 5,10,15,20-tetramesitylporphyrin 
• 71-48-7 cobalt(II) acetate 

Downstream Products

• 188894-00-0 tetramesitylporphyrinato bis(1,2-dimethylimidazole)cobalt(III) tetrafluoroborate 
• 197790-31-1 [(tetramesitylporphinate)Co(4-dimethylaminopyridine)2]BF₄ 
• 205173-11-1 (tetramesitylporphyrinato)Co-C(CH₃)2CN 

Relevant academic research and scientific papers

Resonance Raman characterization of five-coordinate dioxygen adducts of porphyrinatocobalt(II) complexes formed in low temperature O2 matrices

Resonance Raman (RR) spectra of five-coordinate dioxygen adducts of cobalt(tetramesitylporphine) and cobalt(tetramesopropylporphine) formed in low temperature O2 matrices are reported. For the first time, all three vibrations expected for the C

Reaction, structure and spectroscopic properties of bis(cyano) cobalt(III) porphyrin complexes

Cyanocobalamin and analogues have drawn much attention for the promising applications in photovoltaic and photocatalytic systems. In this study, two low spin bis(cyano) cobalt(III) porphyrin complexes [K(222)][CoIII(TPP)(CN)2] and [K(222)][CoIII(TMP)(CN)2] (222 = 4,7,13,16,21,24-hexaoxo-1,10-diazabicyclo[8.8.8]hexacosane, TPP = meso-tetraphenylporphyrin dianion, TMP = meso-tetramesitylporphyrin dianion), which were isolated from the reactions between [CoII(Porph)] (Porph = Porphyrin) and [K(222)(CN)], are characterized by a single crystal X-ray diffraction, FT-IR and UV-vis spectroscopies. Combined UV-vis and electron paramagnetic resonance (EPR) investigations have been conducted to understand the reaction mechanisms. The work gives new insights into the reactivities and spectroscopic properties of cyano cobalt macrocyclic complexes.

Cobalt-Porphyrin-Catalysed Intramolecular Ring-Closing C?H Amination of Aliphatic Azides: A Nitrene-Radical Approach to Saturated Heterocycles

Cobalt-porphyrin-catalysed intramolecular ring-closing C?H bond amination enables direct synthesis of various N-heterocycles from aliphatic azides. Pyrrolidines, oxazolidines, imidazolidines, isoindolines and tetrahydroisoquinoline can be obtained in good to excellent yields in a single reaction step with an air- and moisture-stable catalyst. Kinetic studies of the reaction in combination with DFT calculations reveal a metallo-radical-type mechanism involving rate-limiting azide activation to form the key cobalt(III)-nitrene radical intermediate. A subsequent low barrier intramolecular hydrogen-atom transfer from a benzylic C?H bond to the nitrene-radical intermediate followed by a radical rebound step leads to formation of the desired N-heterocyclic ring products. Kinetic isotope competition experiments are in agreement with a radical-type C?H bond-activation step (intramolecular KIE=7), which occurs after the rate-limiting azide activation step. The use of di-tert-butyldicarbonate (Boc2O) significantly enhances the reaction rate by preventing competitive binding of the formed amine product. Under these conditions, the reaction shows clean first-order kinetics in both the [catalyst] and the [azide substrate], and is zero-order in [Boc2O]. Modest enantioselectivities (29–46 % ee in the temperature range of 100–80 °C) could be achieved in the ring closure of (4-azidobutyl)benzene using a new chiral cobalt-porphyrin catalyst equipped with four (1S)-(?)-camphanic-ester groups.

Rates of axial ligand rotation in diamagnetic d6 Co(III) and Fe(II) porphyrinates

In order to investigate the rates of rotation of pyridine and imidazole ligands in diamagnetic low-spin d6 Co(III) and Fe(II) porphyrinate systems, we have synthesized tetramesitylporphyrinate (TMP) complexes of each of these metals with pyridine and imidazole ligands and investigated them as a function of temperature by 1H NMR spectroscopy. We have already reported that for TMPFe(III) and -Co(III) complexes with hindered imidazoles the TMP o-CH3 resonances can be used to measure the rates of rotation (N.V Shokhirev, T.Kh. Shokhireva, J.R. Polam, C.T. Watson, K. Raffii, U. Simonis and F.A. Walker, J. Phys. Chem. A, 101 (1997) 2778). For the bis-1,2-dimethylimidazole complex, [TMPCo(1,2-Me2Im)2]BF4, at ambient temperatures ligand rotation is slow but measureable on the NMR time scale, and four o-CH3 resonances are observed, as we have already reported. In contrast, as shown in the present work, for the bis-4-dimethylaminopyridine complex, [TMPCo(4-NMe2Py)2] BF4, ligand rotation is extremely rapid at ambient temperatures. At temperatures below - 50°C at 300 MHz the o-CH3 resonance broadens and the rates of rotation can be estimated using the modified Bloch equations simplified for the fast exchange regime. The activation parameters ΔH≠ and ΔS≠ have been determined, and the extrapolated rate constant at 25°C, kex ≥ 1.1 × 106 s-1. These results contradict previous reports (J. Huet and A. Gaudemer, Org. Magn. Reson., 15 (1981) 347; I. Cassidei, H. Bang, J.O. Edwards and R. G. Lawler, J. Phys. Chem., 95 (1991) 7186) that pyridine ligands bound to Co(III) porphyrinates do not rotate at room temperature in homogeneous solution. For unhindered imidazole complexes, such as [TMPCo(NMeIm)2]+BF4-, no broadening of the o-CH3 resonance is observed, even at -90°C, and thus the rate of axial ligand rotation is too fast to measure, even at that low temperature (or the difference in chemical shift of the two resonances expected if ligand rotation is slow is very small). For the corresponding Fe(II) porphyrinate complexes, the rates of pyridine and unhindered imidazole rotation are too fast to measure, even at -90°C. The 2-methylimidazole complex undergoes chemical reactions that prevent detailed study of this system by NMR spectroscopy, but the 1,2-dimethylimidazole complex is stable and of similar structure (ruffled porphyrinate ring, axial ligands in perpendicular planes) to the Co(III) and Fe(III) analogs, with the rate constant for ligand rotation, kex ～ 1 s-1, at -90°C. Assuming a similar activation enthalpy to those of the Co(III) and Fe(III) systems, the rate of rotation of axial ligands in [TMPFe(1,2-Me2Im)2] at 25°C is estimated to be about 2 × 104 s-1.