Modeling of the interaction of porphyrin molecules in a nonpolar solvent

The article presents the data of a theoretical molecular dynamics study of the interaction between a pair of porphyrin molecules, i.e. symmetrically substituted 5,10,15,20-tetra (4-n-methyloxyphenyl) porphyrin (P) and asymmetrically substituted 5-(4 hydroxyphenyl)-10,15,20-tris (4-n-methyloxyphenyl) porphyrin (P-OH). We studied three systems, each of which consisted of a pair of porphyrin molecules (P || P, P-OH ↑↑ P-OH and P-OH ↑↓ P-OH) and chloroform molecules as a non-polar solvent. The effect of substitution, different orientations of asymmetrically substituted molecules and temperature on the geometry and energy of the system was investigated. It was shown that all three systems show signs of a true solution with chloroform as a solvent; the distance between asymmetrically substituted P-OH molecules was less than in the case of two P molecules. This may serve as an indirect evidence that the molecules are not prone to aggregation in the presence of chloroform.

Pressurized Steam Conversion of Biomass Residues for Liquid Hydrocarbons Generation

Biomass residues are often considered as a resource if conveniently converted in fuel and alternative feedstock for chemical processes, and their conversion into valuable products may occur by different pathways. This work is focused on the thermochemical conversion at moderate temperature and in steam atmosphere, a mild process in comparison to hydrothermal liquefaction, followed by extraction of soluble products in a solvent. Such process has been already applied to various residues and here extended to the case of marc, the residual pomace from wine making, largely produced worldwide. A pressurized batch reactor was used for the quantitative determination of produced solid and liquid fractions, and their qualitative characterization was performed by instrumental analyses. The pressurized steam conversion of marc was effective, providing a yield in liquid fraction, upon extraction in solvent, up to 30% of the raw dried biomass. The use of polar and nonpolar solvent for the extraction of the liquid fraction was inspected. Applied operating conditions, namely residence time in the batch reactor and extraction modality, showed a significant influence on the process performance. In particular, long residence and extraction times and use of nonpolar solvent substantially improved the yield in liquid fraction.

Isolation and Elucidation Structure of 28-Hydroxy-3-Friedelanone of Nyamplung (Callophyllum inophyllum, Linn.) Leaves

The isolation triterpenoid from Nyamplung (Callophyllum inophyllum, Linn.) leaves has been conducted. The isolation was employed by maceration using ethanol as solvent and liquids extraction using ethyl acetate. Ethyl acetate extract was partitioned successively using nonpolar solvent with hexane, dichloromethane, and diethyl ether, respectively. The diethyl ether extract was purified by column chromatography. The isolated compound of fraction D1 was obtained as white solids crystal with yield of 0.0035%. The isolated compound was determined based on the FTIR, 1HNMR, 13CNMR, HSQC, and HMBC spectra. The isolated compound was identified as 28-hydroxy-3-friedelanone.

An Approach to Nonsymmetric Bis(tertiary phosphine oxides) Comprising Heterocyclic Fragments via the Pd-Catalyzed Phosphorylation

Nonsymmetric tertiary phosphine oxides with different five- and six-membered heterocyclic fragments such as pyridine, 2,2′-bipyridine, 1,10-phenantroline, quinoline, imidazole, and thiazole were synthesized in good yields via the successive introduction of phosphine oxide groups into the initial dihalogenated heterocycles by means of Pd-catalyzed phosphorylation reaction. The synthesis of pyridine-type compounds is hindered by competing double coupling, while for five-membered heterocycles the principal difficulty is the dehalogenation. Both side processes were successfully suppressed by the use of an excess of a dihalide (which can be easily recovered during the product purification step), proper phosphine ligand for palladium, and nonpolar solvent such as toluene.