Jiří Příhoda

ON THE REACTION OF CHLORODITHIOPHOSPHORIC ACID PYRIDINIUMBETAINE WITH DIPHENYLTHIOUREA

Chlorodithiophosphoric acid pyridiniumbetaine, PyPS 2 Cl ( I ), reacts with diphenylthiourea (PhNH) 2 CS in acetonitrile and in the presence of triethylamine to the pyridinium salt of 1,3-diphenyl-4-mercapto-2,4-dithioxo-1,3-diaza-4λ 5 -phosphetidine ( II ). The pyridinium salt of 1,3-diphenyl-2,4-dimercapto-2,4-dithioxo-1,3-diaza-2λ 5 ,4λ 5 -diphosphetidine ( III ) is formed after longer reaction times. Compound II reacts easily with methyl iodide to corresponding methylderivative IV . All new prepared compounds were characterised by 31 P-NMR and FT-IR spectroscopies. The crystal structures of II , III and IV were determined by X-ray diffraction.

On the reaction of chlorodithiophosphoric acid pyridiniumbetaine with polyfunctional nucleophiles ☆: Part II. Reaction with thiosemicarbazide derivatives

Abstract Chlorodithiophosphoric acid pyridiniumbetaine, PyPS2Cl (I), reacts with thiosemicarbazide derivatives (RNH)(H2NNMe)CS, R= iso-propyl, tert-butyl, in acetonitrile in the absence of any HCl-acceptor to form new compounds with a five-membered heterocycle, i.e. 5-iso-propylamino-4-methyl-2-sulfido-2-thioxo-1,3,4,2λ5-thiadiazaphospholan-5-onium (II) or 5-tert-butylamino-4-methyl-2-sulfido-2-thioxo-1,3,4,2λ5-thiadiazaphospholan-5-onium (III). The triethylammonium salt of 1,3-bis-(N-methyl-N′-tert-butyl-thioureido)-2,4-disulfido-2,4-dithioxo-1,3-diaza-2λ5,4λ5-diphosphetidine (IV) is formed when the reaction is carried out in the presence of triethylamine. The prepared compounds were characterized by 31P NMR, FT-IR spectroscopies, mass spectrometry and the molecular structures of II, III and IV were determined by X-ray crystallography.

Pyridinium 2‐thio­xo‐2,3‐di­hydro‐1H‐naphtho­[2,3‐d]‐1,3,2λ5‐di­aza­phospho­le‐2‐thiol­ate

Pyridinium 2-thioxo-2,3-dihydro-1H-naphtho[2,3-d]-1,3,2 5-diazaphosphole-2-thiolate. The crystal structure of the titled compound.

Reaction of Trichlorophosphazo-N-sulfurylchloride and its Derivatives II. The Reaction of (Me3Si)RNPCl2NSO2Cl (R = H, Me) with BCl3, the Structures of Cyclic Cl2PNS(O)ClOBCl2NMe and Linear [ClSO2NPCl2NH]2BCl

The reaction of (Me3Si)MeNPCl2NSO2Cl with BCl3 gives rise to the cyclic 2,2,4,4,6-pentachlor-3-methyl-6-oxo-1,6,2,3,5,4-oxathiaboradiazafosfinine-6-onio-2-ide Cl2PNSO2ClBCl2NMe (IV) while the reaction of Me3SiNHPCl2NSO2Cl with BCl3 leads to the linear compound bis(N-chlorosulfuryl-dichlorophosphazoamino)chloroborane (ClSO2NPCl2NH)2BCl (VI). Both compounds were characterized by 31P- and 11B-NMR spectrometry and elemental analysis, and their crystal structures were determined.

The study on corrosion of Pb–Sn–Sb alloys in soil

Abstract The paper studies corrosion of selected Pb-Sn-Sb alloys in soil. Corrosion tests were proposed and performed based on the survey of the mechanism of corrosion of archaeological objects – letter types. The composition of tested lead alloys corresponds to the phases in structures of alloys the original types were made from. Three types of soil with different pH were selected as the corrosion environment and one of the set of specimens was exposed additionally to acetic acid vapours to monitor the impact of volatile organic compounds. The results were compared with similar corrosion tests performed at the University of Antwerp. The results implied that it was predominantly the character of the microstructure the lead alloys form that affects corrosion of Pb–Sn–Sb alloys. Intermetallic phases SnSb are formed within the lead matrix, the average composition of which corresponds to 55 % of Sn and 45 % of Sb. The SnSb phase is very hard and resistant; a corrosion microcell is formed when in contact with the matrix, with the lead matrix being preferentially susceptible to corrosion. The content of antimony and tin in the alloy affects formation and the quantity of the SnSb phase.

Průzkum vlastností Pragokor Sealu Fe při příležitosti restaurování panelu klimatizace z vily Tugendhat / Examination of Seal Fe properties on the occasion of restoration of an air-conditioning panel from the Tugendhat Villa

Příspěvek se zaměřuje na průzkum vlastností dvou různých nátěrových systémů v souvislosti s restaurováním ovládacího panelu klimatizace z vily Tugendhat, která je součástí kulturního dědictví. Předmětem zájmu je ochranné antikorozní působení nátěrů a jejich přilnavost k podkladu. Koroze byla sledována na modelových vzorcích v umělé atmosféře (norma ČSN ISO 7384 Korozní zkoušky v umělé atmosféře, všeobecné požadavky) a ve volné atmosféře (norma ČSN ISO 8565 Kovy a slitiny - Atmosférické korozní zkoušky, základní požadavky). Přilnavost byla sledována pomocí odtrhových zkoušek. V rámci studie byl především sledován vliv použití přípravku Pragokor Seal Fe jakožto součásti podkladové nátěrové vrstvy. Studie byly prováděny na dvou typech modelových plíšků (s otryskaným nebo neotryskaným povrchem), které se svým složením blížily složení kovového materiálu, ze kterého byl vyroben ovládací panel klimatizace. Z provedených experimentů vyplynulo, že vybraný nátěrový systém je přilnavější k otryskanému povrchu a přípravek Seal Fe zlepšuje přilnavost nátěrového systému k podkladu. Seal Fe má sám o sobě příznivé antikorozní vlastnosti. The paper focuses on the examination of properties of two different coating systems with respect to the restoration of an air-conditioning controlling panel from the Tugendhat Villa, which building has been recognised as a part of cultural heritage. The protective effect of coats against corrosion and their adhesion to the surface were the main points of interest. Corrosion was monitored on model specimens in an artifi`cial atmosphere (ČSN ISO 7384 standard Corrosion tests in an artificial atmosphere, General Requirements) and in an ambient atmosphere (ČSN ISO 8565 standard - Metals and alloys - Atmospheric corrosion tests, General Requirements). The adhesion was examined by tearing tests. They focused predominantly on the impact of using Seal Fe as a part of the base coat. Experiments were conducted with two types of model plates (with a blasted and non-blasted surface) the composition of which approximated the composition of the metallic material, which the air-conditioning controlling panel was made of. The experiments implied that the applied coating system was more adhesive to the blasted surface and that Seal Fe improved adhesion of the coating system to the base metal. Standing on its own, Seal Fe has positive anti-corrosion properties.

On the Reaction of Trichloromethylphosphonothioic Acid with Tertbutylamine and Hexamethyldisilazane

The reactions of trichloromethylphosphonothioic dichloride CCl3P(S)Cl2 with tertbutylamine (TBA) or hexamethyldisilazane (HMDSA) yield the corresponding amides. Both amides, i.e. CCl3P(S)(NH-But)2 (I) and CCl3P(S)(NH-SiMe3)2 (II), were isolated as crystalline compounds. I is orthorhombic, space group P212121, a = 623.00(10) pm, b = 1329.2(3) pm, c = 1967.6(4) pm; II crystallized as monoclinic, space group P21/n, a = 972.6(3) pm, b = 1144.4(3) pm, c = 1570.2(4) pm, β = 90.49(4)°.