The solubility of hydrogen in the Venezuela Orinoco, China Liaohe, and Fengcheng atmospheric residues under reaction conditions 400 °C, 4 MPa for 20 min was analyzed by determining composition structure changes products. Activation during upgrading process also determined discussed probe method. results show that lighter components produced can increase as proceeds, present at liquid level have...

We present a theoretical investigation of electronic and optical properties of free-base porphyrins based on density functional theory and many-body perturbation theory. The electronic levels of free-base porphine (H(2)P) and its phenyl derivative, free-base tetraphenylporphyrin (H(2)TPP) are calculated using the ab initio GW approximation for the self-energy. The approach is found to yield res...

The catalytic effect of tetraphenylporphyrin on the oxygen reduction with ferrocene in 1,2-dichloroethane can be finely tuned by varying the molar ratio of the acid to the catalyst present in the solution. The mechanism involves binding of molecular oxygen to the protonated free porphyrin base, in competition with ion pairing between the protonated base and the acid anion present.

ABSTRACT A series of mono-alkylcarboxylic acid derivatives of tetraphenylporphyrin have been prepared. All the porphyrins were completely characterized by use of mass, 1H NMR, UV-visible, and fluorescence spectroscopy. Experimental log P were determined by use of reversed-phase thin-layer chromatography with use of log PRekker. These porphyrins are potential photosensitizers in photodynamic the...

An approach for colorimetric and fluorescent sensing of thiocyanate (SCN ) has been proposed based on the competitive-displacement strategy between meso-tetraphenylporphyrin (TPP) and meso-tetraphenylporphyrin cobalt(II) (CoTPP). In THF-water solution, TPP emits strong fluorescence at 651 nm; however, the fluorescence was quenched stepwise by CoTPP, and then restored by SCN , the detection limi...

The performance of time-dependent density functional theory (TDDFT) for calculations of long-range exciton circular dichroism (CD) is investigated. Tetraphenylporphyrin (TPP) is used as a representative of a class of strongly absorbing chromophores for which exciton CD with chromophore separations of 50 Å and even beyond has been observed experimentally. A dimer model for TPP is set up to repro...

The presence of an oxygen reconstruction on the Cu(001) surface results in the self-metalation of 5,10,15,20-tetraphenylporphyrin (2HTPP) below room temperature (at ~285 K), in contrast to 2HTPP on the bare Cu(001) substrate, where a temperature of ~450 K is required. This study demonstrates the decisive impact of a surface reconstruction on the redox reaction in the solvent-free ultra-high vac...

formation of the molecular complexes between meso-tetraphenylporphyrin (tpp) and the p-acceptors 2,3-dichloro-5,6-dicyanobenzoquinone (ddq) and tetracyanothylene (tcne) in chloroform solution was investigated spectrophotometrically. the formation constants of the resulting 1:1 molecular complexes were determined using the benesi-hildebrand and nash methods. the tpp-ddq proved to be more stable ...

The water oxidation (WO) activity of a chlorinated cobalt tetraphenylporphyrin (CoClPS), possessing Cl atoms on the 2,6-positions of the aryl groups, shows higher resistance to attack by singlet oxygen, in situ generated during photochemical WO using Ru(bpy)3(2+) and S2O8(2-) with the turnover frequency (TOF) and turnover number (TON) reaching 1.7 s(-1) and 836, respectively.