Two polymorph modifications of BF2 complex of 1-phenyl-3-(3,5-dimethoxyphenyl)-propane-1,3 dione were prepared. In this molecule the two methoxy groups in one of the phenyl rings are at meta positions. In A polymorph they are away from each other (anti) while in polymorph B towards the other. In the crystal structure of both polymorphs molecules which are antiparallel form a stack through π-π interactions. Polymorph A in further stabilized with hydrogen bonds. Solid A exhibits mechano and thermochromic effect. Crystalline B polymorph undergoes phase transition into polymorph A. The prepared compound shows also solvatochromic effect.
COBISS.SI-ID: 1718063
A simple procedure was used to prepare stable SERS-active substrate. It is based on photoreduction of AgNO3 by ultraviolet light utilising hydroxypropyl cellulose as stabilising agent. Using a new substrate, it was possible to detect organic dye alizarin red S and two organic pigments, as well as organic colourants in paint layers, where different organic binders are also present. The investigated substrate shows promising characteristics for the analysis of cross sections of the samples. Better application control on the layer of interest is possible because of its viscosity.
COBISS.SI-ID: 513147947
The new method for aerobic oxidative iodination of organic compounds using reaction system air / ammonium nitrate (cat) /molecular iodine / H2SO4 (cat) was developed and used for selective and efficient iodination of activated aromatics and ketones at alpha to carbonyl position.
COBISS.SI-ID: 27879975
Cyclic and acyclic ketones were selectively converted to gem-dihydroperoxides in 72-99% yield with 30% aq. hydrogen peroxide by azeotropic distillation of water from the reaction mixture without any catalyst. The reactions were more selective as with 100% H2O2 and due to neutral conditions also less stable products could be obtained.
COBISS.SI-ID: 28856871
Thiols were functionalized with PhNHSCF3 in the presence of acidic promoter. Aril-, benzyl- and alkyl-substituted thiols were converted into trifluoromethyl disulfides in good yields. The heterocyclic thiols were converted into trifluoromethyl disulfides as well; however, the yields were somewhat lower. Some of the sterically hindered- and biologically important thiols were successfully functionalized. Benzeneselenol was transformed into phenylselenyl trifluoromethyl sulfide. PhNHSCF3 was demonstrated to be a suitable reagent for conversion of sodium sulfinates into trifluoromethyl thiosulfonates. A relative reactivity of the aryl-substituted thiols was determined, and the Hammett reaction constant ρ = –1.65 was obtained with a good correlation (r2 ) 0.95), thus suggesting formation of a positive charge in the transition state, which was confirmed with the quantum chemical calculations, too.
COBISS.SI-ID: 1536347331