Zr<Subscript>5</Subscript>Ir<Subscript>2</Subscript>In<Subscript>4</Subscript> – A Superstructure of the Lu<Subscript>5</Subscript>Ni<Subscript>2</Subscript>In<Subscript>4</Subscript> Type

Summary. Zr₅Ir₂In₄ was synthesized by reaction of the elements in a glassy carbon crucible in a water-cooled sample chamber of an induction furnace. The sample was characterized by X-ray diffraction on both powder and single crystals. Zr₅Ir₂In₄ crystallizes with a pronounced Lu₅Ni₂In₄ type subcell, space group Pbam, a=1739.5(6), b=766.3(2), c=338.9(2) pm. Weak additional reflections force a doubling of the subcell c axis. The superstructure of Zr₅Ir₂In₄ is of a new type: Pnma, a=1739.5(6), b=677.8(2), c=766.3(2) pm, wR2=0.0529, 1592 F² values, and 60 variable parameters. The group-subgroup scheme for the klassengleiche symmetry reduction is presented. The formation of the superstructure is most likely due to a puckering effect (size of the iridium atoms). The crystal chemistry of Zr₅Ir₂In₄ is briefly discussed.     

Critical discussion of simple adsorption methods used to evaluate the micropore size distribution

The well-known simple adsorption methods used to evaluate the micropore size distribution from low pressure adsorption isotherms were examined by employing model isotherms for slit-like graphite micropores obtained from nonlocal density functional theory. It was shown that in the range of pore sizes from about 0.4 to 0.9 nm, the Horvath Kawazoe (HK) method satisfactorily reproduces the shape of the micropore size distribution, but the pore sizes are underestimated. In the case of micropores wider than 0.9 nm, the method fails as the formation of the monolayer on the pore walls produces a peak corresponding to 0.6 nm micropores on the HK pore size distribution. Therefore, the HK method indicates the presence of microporosity even for nonporous samples. The Dubinin-Astakhov adsorption isotherms were also examined and it was shown that their application to represent local adsorption isotherms for homogeneous pores is questionable. However, the adsorption potential distributions seem to be promising for micropore analysis.Nomenclature A Adsorption potential kJ/mol - C ₁ Constant in Eq. 3 and 4 kJ * nm/mol - C ₂ Constant in Eq. 3 and 4 nm³ - C ₃ Constant in Eq. 3 and 4 nm⁹ - C ₄ Constant in Eq. 3 and 4 - d Adsorbate molecule diameter nm - d _A Adsorbent atom diameter nm - G Change in the Gibbs free energy kJ/mol - J Pore size distribution cm³/(g*nm) - R The universal gas constant = 8.31431 J/(mol * K) - T Absolute temperature K - V Amount adsorbed expressed in cm³ of liquid adsorbate per 1 g of the adsorbent = 0.0015468 * amount adsorbed expressed in cm³ STP/g cm³/g - x Pore width nm - X Differential adsorption potential distribution cm³ * mol/(g*kJ) - Constant defined as nm - p Pressure Pa - p ₀ Saturated pressure = 760 torr = 101325 Pa Pa - P _c Condensation pressure Pa - Degree of pore filling - S _BET BET specific surface area m²/g - S _ex External surface area obtained fromt-plot method m²/g - V _mi Micropore volume obtained fromt-plot method cm³/g - V ₁ Total pore volume cm³/g - E Characteristic energy in the Dubinin-Astakhov equation kJ/mol - n Exponent in the Dubinin-Astakhov equation      

Electric moments and polarizabilities for LiH (X1Σ+)

Near Hartree-Fock values have been obtained for all independent components of electric multipole moment and polarizability tensors up to the fourth rank for the ground state of LiH. The dependence of the electric properties on internuclear separation is inferred from calculations at three different bond lengths. The calculation of the interaction potential LiH. e^– leads to deductions about the relative importance of the polarizability tensors in intermolecular interaction studies. The independent components of the tensors at r _e =3.034286 a₀ are, in atomic units, _zz =22.0884, _xx =25.2846, _zzz =224.3, _zxx =203.1, _zzzz =76848, _xxxx =21472, and _xxzz =19485.Member of the Ottawa-Carleton Chemistry Institute     

Photoadsorption, photooxidation and photodecomposition of simple molecules on alkali halide surfaces

Data have been obtained on the activities of 19 alkali halides in photoadsorption of O₂ and CO₂, photooxidation of H₂ and CO and photodecomposition of H₂O and CO₂.

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19 O₂ CO₂, H₂ CO H₂O CO₂.

     

Thermochemical studies on the systems ACl/CeCl3 (A=Na-Cs)

The pseudobinary systems ACl/CeCl₃ (A=Na-Cs) were reinvestigated by means of DTA. The following compounds were found and identified through their X-ray patterns (primarily detected compounds in italics):NaCe _1.67 Cl ₆; K₃CeCl₆, K₂CeCl₅,KCe _1.67 Cl ₆;Rb ₃ CeCl ₆, Rb₂CeCl₅,RbCe ₂ Cl ₇; Cs₃CeCl₆, Cs₂CeCl₅,CsCe ₂ Cl ₇. The compounds A₂CeCl₅ crystallize with the K₂PrCl₅ structure. The high-temperature modifications of the compounds A₃CeCl₆ have the cubic elpasolite structure. The hexagonal unit cell of KCe_1.67Cl₆ is related to the CeCl₃ structure: 0.33 Ce³⁺ are substituted by one K^s+. The structure of CsCe₂Cl₇ can be described with a hexagonal subcellZ=4,a=9.72 andc=14.94 Å; however, small superstructure reflexions reduce the symmetry.The thermodynamic functions for the reactionsnACl+CeCl₃=A _n CeCl _n+3(A=K, Rb) were determined by means of e.m.f. measurements.Measurements of the e.m.f.E vs. T yielded the Gibbs enthalpiesG ^r . The temperature-dependence was found to be linear.The most important result is the formation of the elpasolites (A₃CeCl₆) and ACe₂Cl₇.

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Zusammenfassung Die pseudobinären Systeme ACl/CeCl₃ (A=Na-Cs) wurden mittels Differenzthermoanalyse (DTA) neu untersucht. Folgende Verbindungen wurden gefunden und durch ihre Röntgenbeugungsmuster charakterisiert (erstmalig nachgewiesene Verbindungen sind kursiv):NaCe _1.67 Cl ₆; K₃CeCl₆, K₂CeCl₅,KCe _1.67 Cl ₆;Rb ₃ CeCl ₆, Rb₂CeCl₅,RbCe ₂ Cl ₇; Cs₃CeCl₆, Cs₂CeCl₅,CsCe ₂ Cl ₇. Die Verbindungen A₂CeCl₅ kristallisieren im K₂PrCl₅-Typ. Die Hochtemperaturmodifikationen der Verbindungen A₃CeCl₆ liegen in der kubischen Elpasolith-Struktur vor. Die hexagonale Elementarzelle des KCe_1.67Cl₆ ist mit der CeCl₃-Struktur verwandt: 0,33 Ce³⁺ sind durch ein K⁺ ersetzt. Die Struktur des CsCe₂Cl₇ kann mit einer hexagonalen Pseudozelle beschrieben werden:a=9,72;c=14,94Å;Z=4; schwache Überstrukturreflexe reduzieren jedoch die Symmetrie. Die thermodynamischen Funktionen für die Reaktionen:n ACl + CeCl₃=A _n CeCl _n+3 (A=K, Rb) wurden durch EMK-Messungen bestimmt. Messungen der Abhängigkeit von e. m. f.E gegenT ergaben die Gibbs-EnthalpienG ^r . Es wurde eine lineare Temperaturabhängigkeit gefunden. Als wichtigstes Resultat ist die Bildung von Elpasoliten (A₃CeCl₆) und von Verbindungen (ACe₂Cl₇) anzusehen.

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ACl/CeCl₃, A . - ( ):NaCe _1.67 Cl ₆; K₃CeCl₆, K₂CeCl₅,KCe _1.67 Cl ₆;Rb ₃ CeCl ₆, Rb₂CeCl₅,RbCe ₂ Cl ₇; Cs₃CeCl₆, Cs₂CeCl₅ CsCe ₂Cl₇. A₂CeCl₅ K₂PrCl₅. A₃CeCl₆ . KCe_1.67Cl₆ CeCl₃, 0,33 Ce³⁺ . CsCe₂Cl₇ a=9,72 Å,c=14,94 Å Z=4. , . n ACl + CeCl₃=A _n CeCl _n+3(A=K, Rb) . . . . . .E , G ^r . ACe₂Cl₇.

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Presented as a poster at the 8th ICTA, Bratislava, 1985.

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This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie.     

Application of the Bjerrum Association Model to Electrolyte Solutions. II. Enthalpies of Dilution in Water and Nonaqueous Solvents

The association theory based on the Bjerrum model, which had been developed for the treatment of apparent and partial molar volumes of electrolyte solutions, is extended to apparent molar relative enthalpies L _2,. Experimental enthalpies of dilution for tetrabutylammonium bromide in acetonitrile, propylene carbonate, and -butyrolactone and for lithium perchlorate and sodium thiocyanate in acetonitrile were obtained and analyzed with this model. Literature data for various electrolytes in water, acetonitrile, and n-propanol were also reanalyzed. Through the Bjerrum equations, enthalpies of dilution can be extrapolated to infinite dilution and reliable L _2, obtained for associated electrolytes. The model can be used to estimate the association constant K _A of the electrolyte and these K _A are compared with literature values (generally obtained from conductivity). Considering the difference in the concentration ranges investigated in L _2, and measurements, K _A extracted from L _2, generally fall within an expected range of deviation from the ones obtained by conductivity, provided that no specific interactions are present in solution.     

Amphoteric character of polyelectrolyte complex particles as revealed by isotachophoresis and viscometry

Isotachophoresis and viscometric measurements were performed on aqueous dispersions of non-stoichiometric polyelectrolyte complexes in order to elucidate the surface charge situation of the complex particles in dependence on component charge density, ratio of cationic to anionic groups in the complex, and pH and ionic strengths of the ambient medium. Components for complex formation were acryl-based anionic and cationic polyelectrolytes of the pendent type. From our results, an amphoteric character of the polyelectrolyte complex particles can be concluded, with an isoelectric point characterized by zero mobility and a minimum in reduced viscosity _spec/c of the particle dispersion, and with the sign of net surface charge depending on ambient pH and component charge density. The influence of ionic strength on the _spec/c vs pH plots can be interpreted by assuming a competition between salting-out and electrostatic shielding effects. No correlation could be established between the overall molar ratio of cationic to anionic groups and the isoelectric point of the complex particles, which obviously indicates a different composition of surface and bulk of the polyelectrolyte complex particles.     

Radical scavenging properties of a flavouring agent–Vanillin

Using pulse radiolysis technique, the one-electron oxidation of vanillin (V-OH) with azide radicals, at pH 6 and 9 resulted in the formation of vanillin phenoxyl radical with k = 6.7 × 10⁷ and 2.5 × 10⁹ dm³ mol^-1 s^-1, respectively. The transient absorption spectra of the vanillin phenoxyl radical (V-O) formed either at pH 6 or 9, showed a _max at 410 nm. At pH 5, the OH radicals seem to form an adduct with vanillin, _max at 430 nm and k(OH + V-OH) = 3.3 × 10⁹ dm³ mol^-1 s^-1, while at pH 9, the OH radical reaction resulted in the formation of vanillin phenoxyl radical with _max at 410 nm and k(OH + V-O-) = 6.6 × 10⁹ dm³ mol^-1 s^-1. The reactivity of NO₂radicals with vanillin is lower by orders of magnitude signifying an incomplete reaction. In general, the rate constants for the reaction of OH, N, NO radicals with vanillin were higher at pH 9 than at the lower pH. Its reactivity with other one-electron oxidants like CCl₃OO, CHCl₂OO and CH radicals and the ability to chemically repair tryptophanyl and guanosyl radicals with k = 1.5 - 4 × 10⁷ dm³ mol^-1 s^-1 indicate its antioxidative behaviour.     

Efficiency calibration and summation effects in gamma-ray spectrometry

Precise, absolute -ray efficiences ( ) and total efficiences ( _T), have been measured at various distances from the detector, using a set of standards. The observed linear variation of and _T as well as / _T with E and provides a simple means of interpolation and extrapolation. Experimental coincidence summation effects were determined for various nuclides and compared with calculated values. The results are found to be in good agreement with each other.     

Thermal behaviour of the monoclinic allotropesγ-sulfur andα-selenium and some structurally related sulfur-selenium compounds

The thermal behaviour of-sulfur, monoclinic-Se, S₆Se₂, S₅Se₃, S₄Se₄ and S₃Se₅, has been studied by hot-stage microscopy and differential scanning calorimetry. X-ray diffraction results show that S₆Se₂ and S₅Se₃ are isostructural with S, but S₄Se₄ and S₃Se₅ are isostructural with monoclinic-Se. The melting of S, is accompanied by rapid crystallization of S, which often occurs almost simultaneously with melting. The melting of S₆Se₂, S₅Se₃, S₄S₄ and S₃Se₅ is irreversible as the compounds decompose on melting. For monoclinic-Se no phase transformation to monoclinic Se was observed at 110–120°, but it changes to hexagonal-Se when the temperature is over 120°.

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Zusammenfassung Das thermische Verhalten von -Schwefel, monoklinem-Se, S₆Se₂, S₅Se₃, S₄Se₄ und S₃Se₅ wurde mittels Heißphasenmikroskopie und Differential Scanning-Kalorimetrie untersucht. Röntgendiffraktionsergebnisse zeigen, daß S₆Se₂ und S₅Se₃ mit S isostrukturell sind, doch sind S₄Se₄ und S₃Se₅ mit monoklinem-Se isostrukturell. Das Schmelzen von S wird von der schnellen Kristallisation von S begleitet, welche oft beinahe simultan mit dem Schmelzen verläuft. Das Schmelzen von S₆Se₂, S₅Se₃, S₄Se₄ und S₃Se₅ ist irreversibel, da die Verbindungen während des Schmelzens zersetzt werden. Bei monoklinem-Se wurde zwischen 110 und 120° keine Phasentransformation zu monoklinem -Se beobachtet, doch wird ersteres bei Temperaturen über 120° in hexagonales-Se umgewandelt.

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Résumé On a étudié le comportement thermique du soufre, du sélénium monoclinique, de S₆Se₂, S₅Se₃, S₄Se₄ et de S₃Se₅ par microscopie avec platine chauffante et par analyse calorimétrique différentielle (DSC). Les résultats de la diffraction des rayons X montrent que S₆Se₂ et S₅Se₃ sont isostructuraux avec S, tandis que S₄Se₄ et S₃Se₅sont isostructuraux avec Se monoclinique. La fusion de S s'accompagne d'une cristallisation rapide de S qui a souvent lieu presque simultanément avec la fusion. La fusion de S₆Se₂, S₅Se₃, S₄Se₄ et S₃Se₅ est irréversible car ces composés se décomposent lors de la fusion. On n'a pas observé la transformation de phase Se Se entre 100 et 120° mais la transformation en Se hexagonal au-dessus de 120°.

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-, -Se, S₆Se₂, S₅Se₃, S₄Se₄, S₃Se₅ . , S₆Se₂ S₅Se₃ Sy, S4Se4 S3Se6 -Se. S S, . S₆Se₂, S₅Se₃ S₄Se₄ S₃Se₅ , . 110–120; a-Se -Se, 120° -Se.

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Financial aid from the Neste Oy Foundation (to R. L.) is gratefully acknowledged.     

Molecular Encapsulation of Half-Sandwich Complexes of Iron with Cyclodextrins: New Laminar Materials

The treatment of - and -cyclodextrins with the half-sandwich complexes of iron afford the inclusion compounds CpFe(L₂)XCD ( and ) (X = Cl, I; L = CO; L₂ = dppe, dppe = (Ph)₂P(CH₂)₂P(Ph)₂), [CpFe(L₂)L-]PF₆CD ( and ) L- neutral donor ligands and[(Cp(dppe)Fe)₂-µ-CN]PF₆2CD ( and ). The inclusion compounds [Cp(dppe)Fe-NCCH₃]PF₆-CD and [Cp(dppe)Fe-(¹-dppm)]PF₆-CD have a laminar structure. The - and -cyclodextrin encapsulation effect on the electro-oxidation of the binuclear complex was studied using cyclic voltammetry.The electron-transfer reactions associated with the oxidation of the two different N-bonded and C-bonded organometallic fragments are substantially affected by and encapsulation.     

Photochemistry of acetylenic derivatives of aromatic amines. Communication 1. Photolysis products of P-ethynyl-N,N-dimethylaniline in carbon tetrachloride

Conclusions During photolysis of p-ethynyl-N,N-dimethylaniline in CCl₄, products are formed that are exclusively due to a reaction at the triple bond and amino group, without affecting the aromatic ring: p-dimethylaminoacetophenone, N-methyl-N-(p-ethynylphenyl)-carbamoyl chloride, N-methyl-N-[p-(-chlorovinylphenyl)]-carbamoyl chloride, p-dimethylamino--chlorostyrene, and p-dimethylamino-,-dichlorostyrene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1163–1166, May, 1986.     

Isothermal DSC method for evaluation of the kinetics of crystallization in the Ge-Sb-S glassy system

The isothermal DSC method was used to study the crystallization kinetics of Sb₂S₃ in glassy (GeS₂)_0.3(Sb₂S₃)_0.7. The effective activation energy of crystallization (E _a /n) was evaluated from the DSC curves using the Johnson-Mehl-Avrami transition equation.The value of the effective activation energy (E _a /n)=178.4 kJ/mol) found from the isothermal DSC curves was only slightly higher than that obtained previously with the non-isothermal DTA method (E _a /n=166.4 kJ/mol). It turns out that both methods can be used in this case.

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Zusammenfassung Die isotherme DSC wurde zur Untersuchung der Kristallisationskinetik von Sb₂S₃ in glasigem (GeS₂)_0.3(Sb₂S₃)_0.7 herangezogen. Die effective Aktivierungsenergie der Kristallisation (E _a /n) wurde aus den DSC-Kurven nach der Johnson-Mehl-Avrami-Gleichung ermittelt. Der Wert der aus isothermen DSC-Kurven bestimmten effektiven Aktivierungsenergie (178.4 kJ/mol) liegt nur wenig über den früher durch nicht-isotherme DTA erhaltenen Wert (166.4 kJ/mol). Es stellt sich heraus, daß in diesem Fall beide Methoden angewandt werden können.

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Sb₂S₃ (GeS₂)_0.3(Sb₂S₃)_0.7. -- (E _a /n) , 178,4 /. , (166,4 /). , .

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The authors are grateful to Professor S. Budurov and Dr. C. Barta for providing research facilities and for useful suggestions.     

Synthesis of pyrimidyl-N1-α-amino acids

-(5-Fluoro-N₁-uracilyl)--alanine, -(5-bromo-N₁-uracilyl)--alanine, -(5-chloro-N₁-uracilyl)--alanine, -(N₁-thyminyl)--alanine, -(N₁-cytosinyl)--alanine, -(2-oxo-4-carboxymethylamino-1, 2-dihydro-N₁-pyrimidyl)--alanine, -(N₁-uracilyl)--aminobutyric acid, -(N₁-thyminyl)--aminobutyric acid, and -(N₁-cytosinyl)--aminobutyric acid were synthesized by the reactions involving the cyanohydrin synthesis and other transformations. In addition, a number of substituted N₁-pyrimidylacetaldehydes and N₁pyrimidylpropionaldehydes and their diethylacetals were synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 530–534, April, 1971.     

Investigation of the redox properties of polynuclear “ladder” complexes containing Cr,Mn, and Fe

The redox potentials of new Cr, Mn, and Fe polynuclear ladder complexes, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Fe(CO)₂(¹,⁵-C₅H₄)Mn(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Mn(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁶-Ph)Cr(CO)₃, (⁵-Cp)Fe(CO)₂(¹,⁵-C₅H₄)Fe(CO)₂CH₂Ph, (⁵-Cp)Fe(CO)₂(¹,⁶-CH₂Ph)Cr(CO)₃, were measured and the mechanism of their electrochemical oxidation and reduction was suggested. It was shown that the - or -bonds of the bridging ligand can be cleaved selectively by applying cathodic or anodic potentials, respectively. On the basis of the obtained electrochemical data, a mechanism is suggested for the rearrangement observed when the complexes are metallated by butyllithium.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 362–366, February, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No 94-03-08628a).     

Structure and hyperfine coupling constants of radicals in muon-irradiated single-crystal naphthalene

We have observed muonated cyclohexadienyl-type radicals in a naphthalene single crystal, using the standard transverse-fieldSR technique. Two types of radicals were found, corresponding to muonium addition at the and positions. Owing to the crystal field, the isotropic hyperfine coupling constants show large shifts from the solution values, and there is significant anisotropy in the hyperfine tensors. The results for the radicals are similar to those observed for protonated-hydronaphthyl radicals, but isotope effects are evident. The radicals, whose protonated analogues have not been fully studied, show a more pronounced localized character. Based on the hyperfine tensor directions and geometrical considerations, we have assigned each radical to a specific muon site within the crystal.     

Spectra and structure of small ring compounds. Part L VIII: Structural parameters for chlorocyclobutane from combined microwave data and ab initio calculations

The structural parameters of chlorocyclobutane,c-C₄H₇Cl, have been obtained fromab initio Hartree-Fock calculations employing the 6–31G^* basis set for both the more stable equatorial and the high energy axial conformers. The determined carbonhydrogen distances were adjusted by 0.010 Å and held fixed while a weighted least-squares adjust was used to obtain all of the heavy atom parameters for the equatorial conformer by fitting the rotational constants of nine isotopic species. The determinedr ₀ parameters are:r(C - C) = 1.535(8) År(C - C) = 1.548(3) År(C - Cl) = 1.788(9) Å CCC, - CL = 132.0(2)°; CCC, = 89.7(6)°; CCC, = 87.1(2)°, and CCC, = 88.7(2)°. These results are compared to the calculated values as well as those obtained earlier from electron diffraction and microwave studies.For Part LVII, seeJ. Raman Spectrosc.,1990,21, 591.Taken in part from the thesis of M. J. Lee which will be submitted to the Department of Chemistry in partial fulfillment of the Ph.D. degree.     

The structure of the products of the interaction of benzoxazolone derivatives with α, β-dichloropropionyl chloride in the presence of triethylamine

It has been shown that the products of the reaction of benzoxazolone (I) and 6-chlorobenzoxazolone (II) with , -dichloropropionyl chloride in the presence of triethylamine are, respectively, 3-[-(N-benzoxazolonyl)--chloropropionyl] benzoxazolone and 3-[-(N-6-chlorobenzoxazolonyl)--chloropropionyl]-6-chlorobenzoxazolone. A possible explanation of the fact that in the reaction of I and II in the presence of triethylamine only the chlorine atom in the -position of derivatives of , -dichloropropionic acid takes part, is that the chlorine in the -position is deactivated through enolization.     

Synthesen von Heterocyclen, 68. Mitt.: ÜberMannich-Basen heterocyclischer β-Dicarbonylverbindungen

Zusammenfassung Durch Variation der Versuchsbedingungen konntenMannich-Basen vom 6-Methyl-2,4-pyronon, 2-Äthoxy-4-hydroxy-[1,3-thiazinon-(6)] und von verschiedenen 2-Phenyl-4-hydroxy-[1,3-thiazinonen-(6)] sowie vom 4-Hydroxy-5,6,7,8-tetrahydrocumarin, Malonyl--aminopyridin und -Oxo--hydroxy-julolin hergestellt werden. Auch Barbitursäure und Thiobarbitursäure lassen sich unter gewissen Bedingungen aminoalkylieren.

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Mannich bases have been obtained from 6-methyl-2,4-pyronon, 2-ethoxy-4-hydroxy-1,3-thiazinon-(6), 2-phenyl-4-hydroxy-1,3-thiazinones-(6), 4-hydroxy-5,6,7,8-tetrahydrocoumarin, malonyl--aminopyridin and -oxo--hydroxy-julolin by appropriate variation of the reaction conditions. Also barbituric acid and thiobarbituric acid have been aminoalkylated under certain conditions.

     

Thermolysis of complex cyanides,XV

The thermal decompositions of K₂[Fe(CN)₄ L]·4 H₂O, H₂[Fe(CN)₄ L] and H[Fe(CN)L](L=1,1-bipyridine, of 1,10-phenanthroline) were studied. The experimental results showed that the protonated ferrous complexes decompose with formation of HCN at lower temperature than the corresponding potassium salts. The decomposition of K₂[Fe(CN)₄ L] starts by removal of the ligand L. HCN elimination is followed by a redox reaction with formation of cyanogen in the case of H[Fe^III(CN)₄ L].

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Zusammenfassung Die thermische Zersetzung von K₂ [Fe(CN)₄ Z]·4H₂O, H₂[Fe(CN)₄ L] und H[Fe(CN)₄ L] (L=1,1'-Dipyridin, 1,10-Phenantrolin) wurde untersucht. Die Versuchsergebnisse zeigten, dass die protonierten Ferrokomplexe unter Bildung von HCN bei niedrigeren Temperaturen zersetzt werden, als die entsprechenden Kaliumsalze. Die Zersetzung von K₂ [Fe(CN)₄ L] beginnt durch die Abspaltung des LigandenL. Nach Eliminierung des HCN folgt eine Redox-Reaktion unter Bildung von Dizyan im Falle von H[Fe^III(CN)₄ Z].

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K₂[Fe(CN)₄ L]·4₂, H₂[Fe(CN)₄ L] H[Fe(CN)₄ L] L=1,1- 1.10-. , , . K₂[Fe(CN)₄ L] L. H[Fe¹¹¹(CN)₄ L] HCN - .

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XIV. A. Hantshmann, J. Salvetter, H. Hennig and B. Mohai, Thermochim. Acta. 25 (1978) 341

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The authors thank I. Ötvös for mass-spectroscopic investigations, and Mrs. Csukás, Mrs. Csiszár and Mrs. Haeffner for experimental assistance.