A density functional theoretical (DFT) method was applied to understand the effects of the substituent on dioxygen activation by a series of substituted iron tetraphenylporphyrins [FeT(o/p-R)PP (o = ortho-substituted, p = para-substituted; R = −H, −Cl, −NO2, −CH3, −OCH3)]. The ground states (GS) of the dioxygen adducts of the substituted iron tetraphenylporphyrins [FeT(o/p-R)PPO2] were determined at the B3LYP/6-31G(d) level without any symmetry constraints. Binding energy calculations indicated that the presence of electron-withdrawing substituents at the para position favors O2 binding. Calculations of the O–O bond length of the adsorbed dioxygen revealed that the influence of the p-substituent on the activation of dioxygen decreases in the order p-CH3 > p-Cl > p-OCH3 > −H > p-NO2, while the influence of the o-substituent decreases in the order o-NO2 > o-CH3 > o-Cl > o-OCH3 > −H. The low-lying excited states (LLES) of the FeT(o/p-R)PPO2 adducts suggest that the ability to activate dioxygen decreases in the order o-CH3 > o-OCH3 = −H > o-NO2 > o-Cl for o-substituents and p-CH3 > p-Cl > −H > p-NO2 > p-OCH3 for p-substituents. NBO charge population analysis and spin density analysis showed that substitution caused more β-electrons to be transferred from the iron tetraphenylporphyrin to the dioxygen, which enhanced dioxygen activation. Spin density analysis confirmed that the β-electron population at the adsorbed dioxygen is an accurate indicator of the degree of dioxygen activation. The trend observed in porphyrin catalytic activity as the substituent on the dioxygen adduct was varied is consistent with the trend in the binding energy. It is clear that substituents at the ortho and para positions in these dioxygen adducts play different roles in dioxygen activation.

Rapid and sensitive recognition of herbal pieces according to different concocted processing is crucial to quality control and pharmaceutical effect. Near-infrared (NIR) and mid-infrared (MIR) technology combined with supervised pattern recognition based on partial least-squares discriminant analysis (PLSDA) was attempted to classify and recognize six different concocted processing pieces of 600 Areca catechu L. samples and the influence of fingerprint information preprocessing methods on recognition performance was also investigated in this work. Recognition rates of 99.24%, 100% and 99.49% for original fingerprint, multiple scatter correct (MSC) fingerprint and second derivative (2nd derivative) fingerprint of NIR spectra were achieved by PLSDA models, respectively. Meanwhile, a perfect recognition rate of 100% was obtained for the above three fingerprint models of MIR spectra. In conclusion, PLSDA can rapidly and effectively extract otherness of fingerprint information from NIR and MIR spectra to identify different concocted herbal pieces of A. catechu.Near-infrared (NIR) and mid-infrared (MIR) technology combined with supervised pattern recognition based on partial least-squares discriminant analysis (PLSDA) was attempted to classify and verify six different concocted pieces of 600 Areca catechu L. samples and the influence of fingerprint information preprocessing methods on recognition performance was also investigated in this work. In conclusion, PLSDA can rapidly and effectively extract otherness of fingerprint information from NIR and MIR spectra to identify different concocted herbal pieces of A. catechu.

The latest progress and developments in catalysts for the oxidation of cyclohexane are reviewed. Catalytic systems for the oxidation of cyclohexane including metal supported, metal oxides, molecular sieves, metal substituted polyoxometalates, photocatalysts, organocatalysts, Gif systems, metal-organic catalysts and metalloporphyrins are discussed with a particular emphasis on metalloporphyrin catalytic systems. The advantages and disadvantages of these methods are summarized and analyzed. Finally, the development trends in the oxidation technology of cyclohexane are examined.

Basic properties of cuboctahedral Pd–Pb clusters ranging from 13 to 116 atoms were studied by computational analysis, and the effects of doped Pb atoms on Pd clusters were investigated. The average bond length of Pd–Pb clusters was found to be ∼0.1 Å longer than pure ones, but doped Pb atoms did not constantly expand the Pd–Pd bond lengths in Pd–Pb clusters owing to size effect. In addition, doped Pb atom changed the thickness of surface phase and surface morphology of Pd cluster. The chemical activity of Pd clusters could be enhanced by the doped Pd atoms, although an enough size was required. Lead atoms essentially changed the surface charge population of Pd clusters. The Pd atoms in Pd–Pb clusters were seen to become more electrophilic than in pure Pd clusters, and the probability of being attacked by nucleophilic reagent could be comparable with that of being attacked by electrophilic reagent. Total electron density and deformation electron density revealed that the nature of interaction between metal atoms was metal bond. Weak covalent bond might exist when clusters were in small size.

A green synthetic method using mixted solvents of di-methyl formamide (DMF) and acids instead of single DMF to synthesize metalloporphyrins (TRPPMCl) from TRPPH2 and MCl2 metallization was proposed in this paper. A series of TRPPMCl (M = Fe, Mn, Co) were synthesized through this innovative synthetic method, and these complexes were characterized with various spectroscopic techniques, including IR and UV-Vis spectroscopy. The results showed that the metallization time was markedly reduced from about 10 h to 0.5 h in contrast with the conventional synthetic methods.

A novel method for the synthesis of μ-oxo-bis [tetraarylporphyrinatoiron] ([TRPPFe]2O) based on the reaction between tetraarylporphyrinironchloride (TRPPFeCl) and H2O in toluene was investigated in this paper. Three kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, IR spectra and UV-Vis spectroscopy.

The epoxidation of linear terminal olefins with metalloporphyrins in the presence of dioxygen and isobutyraldehyde under ambient temperature and atmospheric pressure was investigated. The results show that all olefins could be smoothly converted to epoxides with high selectivities (70%–90%). For the metalloporphyrins with different catalytic activities within 1-hexene epoxidation in the order of Fe > Mn > Co, T(o-Cl)PPFe(III)Cl was most effective, with a 41.7% yield and 80.2% selectivity of 1,2-epoxyhexane. Various amounts of catalyst were investigated, and it was found that with only 10 ppm catalyst the yield of 1,2-epoxyhexane and turnover number (TON) could reach up to 41.9% and 41859, respectively.

By using mixed-solvents method, five kinds of p-substituted tetraphenylporphyrin compounds [T(p-R)PPH2, R=NO2, Cl, CH3, OCH3, OH] were synthesized by the condensation of p-substituted benzaldehyde with pyrrole in mixed solvents (propionic acid, acetic acid and nitrobenzene), and corresponding ferric complexes [T(p-R)PPFeIIICl] were synthesized in dimethylformamide. The above free base porphyrins were obtained in 30%–50% yields, metalation yields were up to 90% and total yields of ferric complexes were 27%–50%. Effects of reactive conditions, solvents and oxidants on yields of free base porphyrins were investigated and the relevant mechanism was discussed. Structures of the above porphyrin complexes were characterized by ultravioletvisible (UV-Vis), infrared (IR) and far infrared (FIR) spectroscopy.

Selective oxidation of o-nitrotoluene to o-nitrobenzaldehyde with metalloporphyrins as biomimetic catalysts was studied. The peripheral substituent around porphyrin rings and various process parameters of NaOH concentration, reaction temperature, reaction time and oxygen pressure all affect the selectivity of o-nitrobenzaldehyde. Further, 82.0% selectivity of o-nitrobenzaldehyde was achieved under the optimum conditions: 1.0×10t-5 mol · L−1 of T(p-NO2)PPFeCl catalyst, 2.5 mol · L−1 of NaOH, 0.2 mol · Lt-1 of o-nitrotoluene, 45°C and 2.0 MPa for 6 h.

The catalysis of chloridized metalloporphyrins in the oxidation of cyclohexane to adipic acid was systematically investigated. The turnover numbers (TON) data of 19 catalysts were obtained experimentally under optimal reaction conditions, and 2.4×106 TON for T(o-Cl)PP-MnIIICl catalyst at 2.0×10−6 mol/L of dosage was reached under the conditions of dioxygen pressure of 2.5 MPa at 150°C for 4 h. This was the best result reported for this reaction up to now. The QSAR models for each concerned metalloporphyrin were established, where the catalytic activity was significantly correlated with the ELUMO (the energy level of the lowest unoccupied molecule orbit) and LM-N (the bond length between metal-nitrogen atoms). Using the QSAR models, four new metalloporphyrins with substituted nitro group were designed, and their catalytic activities were predicted. The experimental TON data of newly designed porphyrins were in good agreement with the predicted ones, and the square of their correlation coefficient was more than 0.958. The above results demonstrated that the proposed structure-activity relationship model could be applied to design some new metalloporphyrin catalysts, and to predict their catalytic activity in cyclohexane oxidation.

Highly efficient solvent-free coupling reaction of carbon dioxide (CO2) and epichlorohydrin catalyzed by meso-tetraphenyl porphyrin magnesium (MgTPP) in the presence of triethylamine as co-catalysts is reported. As a chlorophyll-like catalyst, MgTPP showed excellent activity for the coupling reaction of CO2 and epichlorohydrin to chloropropene carbonate, in which the turnover number could reach up to 9200. Moreover, different factors including the amount of catalyst, reaction temperature, pressure and time were systematically investigated and the optimal reaction conditions were obtained (epichlorohydrin 50 mmol, MgTPP 5.0×10−3 mmol, triethylamine 6.25(10−3 mmol, 140 °C, 1.5 MPa, 8 h). A plausible two-pathway mechanism for the coupling reaction of CO2 and epichlorohydrin is proposed to propound the catalysis of MgTPP.

The two novel green oxidation processes of p/o-cresols to p/o-hydroxybenzaldehydes catalyzed by metalloporphyrins in the presence of molecular oxygen were developed in this work. Among the metalloporphyrins with different central ions and substituents studied, T(p-NO2)PPCoCl and T(p-OCH3)PPFeCl presented the highest activities for p-cresol and o-cresol oxidation reactions respectively. The molar ratio of sodium hydroxide to cresols and different reaction parameters including reaction temperature, reaction time and reaction pressure have been investigated, and 69.8%/50.4% conversions of p/o-cresol and 86.6%/26.6% selectivities for p/o-hydroxybenzaldehydes were reached under optimized conditions.