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[en] The presently known approaches to the synthesis of non-symmetrically substituted phthalocyanines of the A3B and A2B2 types are surveyed. The prospects for the use of these compounds for the synthesis of binuclear and heteronuclear complexes and phthalocyanine oligomers and polymers are demonstrated.
[en] KinBot is a Python code that automatically characterizes kinetically important stationary points on reactive potential energy surfaces and arranges the results into a form that lends itself easily to master equation calculations. This version of KinBot tackles C, H, O and S atom containing species and unimolecular (isomerization or dissociation) reactions. KinBot iteratively changes the geometry of the reactant to obtain initial guesses for reactive saddle points defined by KinBot’s reaction types, which are then optimized by a third-party quantum chemistry package. KinBot verifies the connectivity of the saddle points with the reactant and identifies the products through intrinsic reaction coordinate calculations. Here, new calculations can be automatically spawned from the products to obtain complete potential energy surfaces. The utilities of KinBot include conformer searches, projected frequency and hindered rotor calculations, and the automatic determination of the rotational symmetry numbers. Input files for popular RRKM master equation codes are automatically built, enabling an automated workflow all the way to the calculation of pressure and temperature dependent rate coefficients. Four examples are as follows: (i) [1,3]-sigmatropic H-migration reactions of unsaturated hydrocarbons and oxygenates are calculated to assess the relative importance of suprafacial and antrafacial reactions. (ii) Saddle points on three products of gamma-valerolactone thermal decomposition are studied and compared to literature potential energy surfaces. (iii) The previously published propene+OH reaction is reproduced to show the capability of building an entire potential energy surface. (iv) All species up to C4 in the Aramco Mech 2.0 are subjected to a KinBot search.
[en] To gain insight into how the electronic properties of discotic organic materials may be modified through substitution, the reorganization energy and the charge mobility of metal free phthalocyanine, and of several mono-substituted derivatives, are studied by electronic structure methods. It is found that the reorganization energy of phthalocyanine is not significantly changed by substitution on an outer phenyl ring, but is more strongly influenced when the inner crown amine ring is substituted. The relationship between reorganization energy and substituent is studied through the use of; substituent constant, HOMO energy, and geometry relaxation. The computed charge mobility shows stronger relationship to coupling matrix element than reorganization energy. A hybrid computational screening method in which the reorganization energy is calculated at the DFT level and the coupling matrix element is calculated at the AM1 level shows good predicting power for trends in charge mobility at reduced computational expense.
[en] Highlights: • Amine and carboxyl plasma modification of PCL nanofibers is compared. • The cell adhesion and proliferation on modified PCL nanofibers are studied. • The influence of surface chemistry and wettability of plasma coated PCL nanofibers is described. The plasma modification of biodegradable nanofibers is of great interest for improvement of their biocompatibility. However, there are no systematic studies regarding the influence of plasma polymer deposition onto the surface of nanofibers to improve cell adhesion. In the present study, homogenous and reproducible modification of polycaprolactone (PCL) nanofibers by amine and carboxyl/anhydride groups was achieved. The concentration of amines NH2/C and C(O)O contribution were up to 2.9 and 14.1%, respectively. Regardless the plasma conditions, the deposition of amine and carboxyl-anhydride plasma coatings onto the PCL nanofibers sufficiently improved the cell adhesion and viability, as was evidenced by microscopy observations and ATP assay results. It should be emphasized that the deposition of negatively charged carboxyl-anhydride coatings resulted in slightly better cell adhesion compared to the positively charged amine plasma coatings, unlike the widespread opinion that COOH modification has less effect on myoblasts adhesion.
[en] The nuclear spin-lattice relaxation of methyl-protons in (TMTSF)2ClO4 is measured versus temperature between 330 and 40 K. The relaxation from the hyperfine coupling to the itinerant electrons is found to be dominant above 200 K. Similar conclusions apply to (TMTSF)2PF6. At 300 K two regimes of relaxation are identified versus magnetic field: (i) a low-field regime (2-25) kOe where l/T1 is field independent and (ii) a field regime above 25 kOe where fitting the data with a l-D diffusion law leads to consistent values of hopping rates along a and b directions. By comparison with earlier measurements on TTF-TCNQ and HMTSF-TCNQ it is concluded that the transverse coupling of (TMTSF)2X is intermediate between that of the two-chain conductors
[en] In this review we discus literature data and results of our researches on the isolation of dianon guianolides from plant material. We determined their structures and chemical modifications and characterized their biological activities. The structure of the new biological active compounds has been determined by methods of IR, UV-, 13C, 1H NMR and mass spectroscopy