Volume 30, Issue 7-8

After a brief discussion on the output capacity of the methods used for the study of the isopolymetalates, a classification and characterization of the solid isopolymolybdates obtainable from aqueous solution is given, and the relation of the solid isopolymolybdates to the isopolymolybdate ions in solution is studied. A correlation between the occurrence or non-occurrence of a species in a solid and in its solution detectable by Raman spectroscopy, the solubility of the solid, and the time necessary for the formation of the solid was found. This gives important informations on the mechanisms of formation of the isopolymetalate ions. The most remarkable result of this investigation is that contrary to the view of the majority of the papers on this subject the octamolybdate ion Mo 8 O 26 4- having the structure found by LINDQVIST does not occur in important quantities in solution at room temperature. For setting up a reaction scheme on the isopolymolybdates only very few of the confusing multiplicity of the papers give evidentiary informations. Most of the papers are overinterpreted.

Conductometric titrations of some of the lanthanon nitrates with monofunctional bidentate Schiff bases in the ethanolic medium reveal the formation of Ln(NO 3 ) 3 · 3 SBH and Ln′(NO 3 ) 3 · 2 SBH (where, Ln = La(III), Pr(III) or Sm(III); Ln’ = Yb(III) and SBH = 2,4-pentanedionebenzylimine or o-hydroxyacetophenoneanil) type of derivatives. Preparative studies also support these results.

The dimerisation equilibrium of o-phenylenedioxydimethylsilane (2,2-dimethyl-1,3,2-benzodioxasilole) has been established and studied by 1 H NMR spectroscopy. Equilibrium constants between 36 and 130°C have been determined. The enthalpy of dimerisation (about 5 kcal/mole) was obtained from these data and was attributed mainly to ring strain in the five membered dioxasilole ring. A mechanism for the reaction has been proposed.

Colourless needles of the compound CsGaS 2 were obtained by the reaction of cesium carbonate with gallium oxide at 850°C under a stream of H 2 S. Structural investigations of (100) twinned crystals revealed an atomic arrangement isotypical with RbFeS 2 . Space group C2/c; a = 7.425(6) Å, b = 12.21(1) Å, c = 5.907(6) Å, β = 113.1(1)°; z = 4. The structural similarities between alkalithiogallates and -ferrates can be utilized in studying the magnetic interactions between the iron atoms within the sequence of mixed crystals of AFe 1-x Ga x S 2 (A ≙ alkali metal).

The crystal structure of Na 3.7 Sn, earlier reported as Na 4 Sn and Na 15 Sn 4 , has been determined. Na 3.7 Sn crystallizes orthorhombic, space group Pnma - D 2h’ 16 = 9.82 ± 0.02 Å, b = 5.57 ± 0.01 Å, c = 22.79 ± 0.04 Å. The Sn-atoms are isolated with respect to each other. The packing of atoms is less dense as in Na 15 Pb 4 .

Isotope effects were investigated at the surface of aqueous lithium and calcium salt solutions. The dependence on the temperature in the gas phase was determined. The surfaces of the solutions were isolated by spray experiments. In the case of calcium salt solutions an enrichment of the lighter isotope 40 Ca in relation to the heavier isotopes 44 Ca and 48 Ca was found at the solution surface. The experiments with lithium fluoride and lithium iodide gave inverse isotope effects. The calcium isotope effect could be qualitatively explained by the Gibbs theorem. The isotope separation of lithium possibly can be referred to the more covalent bonding character than the ionic one of lithium compounds at the solution surface.

Azidoformamidinium chloride reacts with triphenylphosphine to yield the triphenylphosphine imino azo formamidinium chloride (1). 1 eliminate nitrogen to give triphenylphosphine imino formamidinium chloride (2). The vibrational spectra of 2 is discussed in view of the structure.

The molecular structures of the two trifluoromethyl phosphoranes (CF 3 ) 2 PCl 3 and (CF 3 ) 3 PCl 2 have been determined by electron diffraction of gases. The structure of (CF 3 ) 2 PCl 3 was found to be a regular trigonal bipyramid with both CF 3 groups in axial positions (D 3h symmetry) and the fluorine atoms staggered to the equatorial chlorine atoms. The following geometric parameters (r a -values) were obtained: r(C-F) = 1.331(2) Å, r(P-C) = 1.950(II) Å, r(P-Cl) = 2.036(2) Å and ⦓ FCF = 108.3°(0.4). (CF 3 ) 3 PCl 2 possesses the structure of a distorted trigonal bipyramid with two CF 3 groups in axial and one in equatorial position. Again the fluorine atoms of the axial CF 3 groups are staggered to the equatorial atoms. The r a -values for the geometric parameters are: r(C-F)= 1.329(2) Å, r(P-C) eq = 1.938(31) Å, r(P-C) ax = 1.946(14) Å, r(P-Cl) = 2.053(6) Å, ⦓ FCF = 108.5°(0.3), ⦓ ClPCl = 133.0°(1.7) and ⦓ C ax PC eq = 95.5°(1.9). The average P-C bond length was found to be r(P-C) av = 1.943(5) A. The results for the mean square amplitudes are given in the article. It was shown that in both molecules the torsional amplitudes of the CF 3 groups around the P-C bond directions are small, indicating high potential barriers to internal rotation.

Diphenylmethylenetriphenylphosphorane, a stable phosphonium ylide, has been prepared and reacted with a range of substituted aromatic aldehyde to afford 1,1,2-triaryl-substituted ethylenes in fair to good yields. The structure of the products are based on IR and NMR spectral evidence.

We have investigated the kinetics of methane-ammonia mixture decomposition in a cold plasma. Among the products of methane decomposition H 2 , C 2 H 6 , C 2 H 4 and C 2 H 2 were identified. Their ratio was dependent on time and discharge of the used power in the experiments. When the ammonia was used as medium, there were identified only H 2 and hydrazine as reaction products. For the CH 4 -NH 3 mixture among the decomposition gases we could find hydrogen cyanide, ethylamine, methylamine and other aliphatic amines.

Transphosphination reactions of (Me 3 M) 3 P and Me 3 MPH 2 compounds (M = Si, Ge, Sn; Me = CH 3 ) using HE(CF 3 ) 2 or H 2 ECF 3 (E = P, As) yield derivatives of the types Me 3 ME(CF 3 ) 2 , Me 3 ME(H)CF 3 , and (Me 3 M) 2 ECF 3 , respectively. The reactivity of the different systems depends on M (Si < Ge < Sn), E (P < As), and the phosphine [Me 3 MPH 2 < (Me 3 M) 2 PH < (Me 3 M) 3 P]. Me 3 ME(H)CF 3 compounds undergo dismutation forming (Me 3 M) 2 ECF 3 and H 2 ECF 3 . Reactions of the new derivatives with polar compounds (HBr, H 2 E′CF 3 , Me 3 M′Br) result in cleavage of the M-E bond. Decomposition of the CF 3 E derivatives occurs by β-elimination of fluorine yielding Me 3 MF besides polymers of unknown structure.

The organotin compounds Me 3 SnE(CF 3 ) 2 , Me 3 SnE(H)CF 3 and (Me 3 Sn) 2 ECF 3 (Me = CH 3 , E = P, As) are obtained in good yield by the reaction of E 2 (CF 3 ) 4 and (CF 3 E) n (n = 4,5), respectively, with trimethylstannane.

Metal complexes obtained by reacting various 1,2-benzoquinonedioximes with metal salts of Ni(II), Pd(II), Pt(II) and Cu(II) show evidence of considerable metal-metal interactions. In the diamagnetic Pd(II) and Pt(II) derivatives the intermolecular interactions are accomplished by direct metal-metal contacts, which are heavily influenced by different substituents on the 1,2-benzoquinonedioxime (BCDH) moiety as evidenced by their optical behaviour. The unpaired electrons of the paramagnetic copper(II) species interact via ligand atoms in dinuclear clusters or linear chain polymers. The former solids crystallize with stoichiometry [Cu(BCD) 2 ], while the latter compounds have the composition CuCl · BCDH.

The gas phase IR and liquid phase IR and Raman spectra of (CF 3 ) 2 PMn(CO) 5 and (CF 3 ) 2 AsMn(CO) 6 have been recorded. The spectra are assigned on the basis of a normal coordinate analysis using a transferred force field.

The preparation and properties of cis-diazido platinum complexes (R 3 P) 2 Pt(N 3 ) 2 are described. The dipole moments, the IR, 31 P- and 14 N NMR spectra and the data of analogous cis and trans pseudohalogeno-bis(phosphine) compounds (R 2 P) 2 Pt(X)Y (X = N 3 , NCO, NCS; Y = N 3 , NCO, NCS, H, CN) are reported.

By means of Slater orbital exponents it is possible to differentiate between the positive and the negative end of the permanent electric dipole of diatomic heteronuclear molecules. Thus Slater orbital exponents hold a clue to the direction of the electric dipole moment vector μ⃗ of the molecular ground state. A comparison with electron population analysis is made.

The mean square thermal displacements of the carbon and deuterium atoms in crystalline orthorhombic acetylene-d 2 , C 2 D 2 , derived from earlier thermal neutron powder diffraction studies were interpreted as rigid-body translational and librational motions of the C 2 D 2 molecule. An attempt to assign the derived amplitudes of the angular vibrations to the Raman-active rotational lattice modes was not unambiguous. Finally, a calculation was made to correct the apparent shortening in the bond lengths and the molecular dimension.

The rates of formation of three mono- and three dicarbenium ions of the triphenylmethyl type from the corresponding carbinols in trifluoro acetic acid - toluene mixtures were investigated using stopped flow techniques. The reaction mechanisms are discussed in view of the obtained dependencies of the rate constants on acid concentration and temperature.

Octacarbonyldicobalt reacts with the ditertiary phosphine and arsine (C 6 H 5 ) 2 -ECH 2 CH 2 E(C 6 H 5 ) 2 (E = P, As) in a direct route to give primarily the non CO-bridged, but ligand-bridged complexes Co 2 (CO) 6 (C 6 H 5 ) 2 ECH 2 CH 2 E(C 6 H 5 ) 2 . From Co 2 (CO) 6 -(C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H 5 ) 2 secondarily a CO-bridged isomer has been also isolated. The non-CO-bridged form of Co 2 (CO) 6 (C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H 5 ) 2 gives insertion reactions with Hg, SnCl 2 and CsGeCl 3 yielding the probably oligo- or polymeric compounds Hg[Co(CO) 3 ] 2 (C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H 5 ) 2 and Cl 2 M[Co(CO) 3 ] 2 (C 6 H 5 ) 2 PCH 2 CH 2 P(C 6 H 5 ) 2 (M = Sn, Ge). The characteristic IR absorptions of all compounds and some Raman spectra are reported.

Mixtures of citric acid (H 3 Ci) and Fe(NO 3 ) 3 with variable molar ratios (H 3 Ci/Fe(NO 3 ) 3 from 0 to 2.55) were titrated with NaOH. The change in pH and the occurring inflection points were registered with a potentiograph (Fig. 1). For each inflection point (I.P.) the existing H 3 Ci/Fe(NO 3 ) 3 molar ratio was plotted against the NaOH/Fe(NO 3 ) 3 molar ratio which existed at the corresponding inflection point (at most three I.P. for each titration curve). The coefficients e j , f j and g j for each dehydrated Fe-Ci-complex [Fe fj (OH) gj-3ej Ci cj ] (gj-3fj)⁻ with j = 1, 2, . . . , could be calculated from the points of intersection (P j ) in the x-y-diagram (Fig. 2). Thus, the following three Fe-Ci-complexes were calculated: From the 1st I.P. [Fe 10 (OH) 18 Ci 5 ] 3- with its maximum at pH ≃ 4.3. From the 2nd I.P. [Fe 5 (OH) 9 Ci 4 ] 6- with its maximum at pH ≃ 8.0. From the 3rd I.P. [Fe 4 (OH) 11 Ci] 2- with its maximum at pH ≃ 10.1. The range of their existence as functions of H 3 Ci/Fe(NO 3 ) 3 ratios (Fig. 3 and 4) and pH (Fig. 4) is discussed.

Arylidenbarbituric acids (4) and arylidendimethylbarbituric acids (5) are compounds with a polarized C = C-double bond, and hence are electrically neutral lewis acids. Therefore they are able to add bases. The measured UV spectra show a characteristic dependence on the pH value. pK values are reported.

This paper deals with the study of dielectric polarisation of pyridine at 35°C in four non polar solvents namely benzene, carbon tetrachloride, dioxan and cyclohexane. The results have been discussed to understand the merits of PALIT equation. It is observed that the moment value μ s obtained by this is fairly comparable with that calculated by the method of HALVERSTADT and KUMLER 2 . The order of apparent dipole moment has been discussed in terms of influence of solvent and solute-solvent interaction as well.

The stable conformation of 1-azabicyclo[3,3,0]octane-2,8-dione (1), 2,8-biscyanomethylen-l-azabicyclo[3,3,0]octane (2) and 2-oxo-8-ethoxycarbonylmethylen-1-azabicyclo[3,3,0]octane (3) was obtained by analysis of the 270 MHz PMR spectra. The results are correlated with force field calculations.

N-(2-Thiophenoyl)urea, its 5-chloro and 5-methyl derivatives, N-ethyl-N′-(2-thiophenoyl)urea, N-phenyl-N′-(5-methyl-2-thiophenoyl)urea, N-(2-furanoyl)urea, N-(1-methyl-2-pyrroyl)urea and 5-methyl-2-thiophene-carboxamide have been prepared. The 1 H NMR spectra of the ureides have been analysed. These ureides show antiviral activity.

The 5-arylazo-1-methyl-2-benzyl-2-imidazolin-4-ones (1 a-c) undergo ring cleavage with 1% aqueous sodium hydroxide solution affording α-arylhydrazono-phenacetyl-sarcosine amide (2). Prolonged heating of 1 and 2 with the same reagent yields the cyanamide (3). On the other hand, when 1 a-c were refluxed with acetic acid the triazinones (4) were obtained. The latter adds one mole of Grignards reagent to yield the 5-hydroxy-1,2,4-triazine derivatives (5).

The flavanone glycosides naringin, neohesperidin and hesperidin were converted chemically to the corresponding chalcones and dihydrochalcones; the one-step synthesis, performed at room temperature, required the presence of 25% KOH in the reaction mixture for the former and 10% KOH, a catalyst and molecular hydrogen at atmospheric pressure for the latter.

The reaction of hydroxyl radicals with ribose-5-phosphate in oxygenated aqueous solution leads to the following phosphate free products (G-values): Erythrodialdose (0.4), formic acid (0.4) and ribodialdose (0.1). In addition, inorganic phosphate (0.6) and some minor phosphate free products (total G≈ 0.08) are formed. Within the limits of experimental error material balance between dephosphorylation products and inorganic phosphate is obtained. A mechanism is proposed which can account for the main products. The primary steps of the dephosphorylation are H atom abstraction from C-5 of ribose-5-phosphate by OH radicals and subsequent addition of O 2 . The peroxy radicals formed decompose to ~80% by C-C bond cleavage followed by elimination of inorganic phosphate and only to ~20% by direct dephosphorylation. The relevance of these results with respect to the radiolysis of DNA is discussed.

Quaternary salts of nicotinamide react in presence of bases with chlorofrom to substituted 2- (or 3-)azabicyclo[4,1,0]hepten-3 (or -4). An intermediate is isolated.

The synthesis of 3-diethylamino-1,4-bis(1,1,1,3,3,3-hexafluoroisopropyl)-pyrazole from hexafluoroacetone azine and 1-diethylamino-propine via an azomethinimine intermediate is described.

From the culture filtrates of Streptomyces tendae (Tü 901) a ninhydrin positive substance was isolated, which was identified as 3-cyclohexenylglycine by gas chromatography-mass spectrometry of some volatile derivatives.

Photoelectron spectra of nitroso compounds X-NO (X = CH 3 , OCH 3 ) are assigned using chemical relationship and CNDO calculations. Comparison of ionization energies and of calculated charge distributions includes as well derivatives X = N(CH 3 ) 2 , Cl, F.

Bis(mercaptomethyl)sulfide is synthesized from 1,3,5-trithiohexane and dichlorodisulfane via Bis(chloromethyl)sulfide and polymeric bisthiomethylsulfide by cleavage of the latter in liquid ammonia by sodium.

The title compound, C 6 H 5 O-(S)P[NH-NH-Si(CH 3 ) 3 ] 2 (1), m. p. 37-39°C, is prepared by silylation of the parent dihydrazide with (CH 3 ) 3 SiCl in the presence of an excess of base. 1 is purified by vacuum destillation and characterized by 1 H NMR, IR, Ra, mass spectra and analysis. Phosphorus hydrazine heterocycles, such as cis- and trans-C 6 H 5 O-(S)P(NH-NH) 2 P(X)-OC 6 H 5 (X = S, O) and others can be prepared from 1 and C 6 H 5 O-(X)PCl 2 or other element dihalogene compounds.

The results of an X-ray structure analysis of the title compound prove the molecular structure proposed earlier to be correct. Mean values of bond lengths are Fe-C(π): 2.06, Ti-C(σ): 2.15, and Ti-N: 1.89 A.

The corundum-type structure of Lu 2 S 3 was confirmed and refined from single-crystal data.

The results of a bond order/bond distance relationship have been applied upon the known structure of Mo-O and Mo-S double bridge compounds. Mo-O t bonds neighboring to Mo-S bridges are always about 0.03 Å longer than expected, indicating a π-bonding contribution in these bridges in contrary to the Mo-O double bridges.

Radical initiated hydrophosphination of diethylaminodipropinylborane with phenylphosphine leads to the new heterocyclic system 1-bora-4-phospha-cyclohexadiene. Some properties and NMR data of the 3,5-dimethyl-1-diethylamino-4-phenyl derivative are reported.

The reaction of in situ generated LiAlX 4 , (X = SCH 3' SeCH 3' , N(CH 3 ) 2 ) with (C 2 H 5 ) 2 O BF 3 leads to BX 3 in good yields.

With a catalyst, prepared by reaction of NiCl 2 with NaBH 4 in dimethylformamide, 1,3-cyclohexadiene is selectively hydrogenated to cyclohexene without formation of cyclohexane.

Dimethyl indium chloride alkylates SbCl 5 , (CH 3 ) 3 SbCl 2 and (CH 3 ) 3 AsCl 2 forming ionic tetramethylstibonium and tetramethylarsonium derivatives such as [(CH 3 ) 4 Sb] + [SbCl 6 ] - , [(CH 3 ) 4 Sb] + [CH 3 InCl 3 ] - and [(CH 3 ) 4 As] + [CH 3 InCl 3 ] - . The vibrational spectra are discussed.

The reaction of 3.4-xylenyl-1-diiodoborane with polymeric iodoboron selenide at 180°C yields golden-yellow xyleno-1,2,5-selenathiadiborolene (2).

1 H CW NMR spectra of paramagnetic compounds are frequently disturbed by sidebands. This problem is circumvented by variation of the nuclear single sideband technique or by application of a variable sideband oscillator. Both methods are demonstrated by the 1 H spectrum of Bis-(h 5 -ethylcyclopentadienyl)cobalt.

Trifluormethyl phosphines and arsines (CF 3 ) 2 EH and CF 3 EH 2 , respectively, (E = P, As) are obtained in almost quantitative yield by the reaction of (CF 3 ) 2 EI and CF 3 EI 2 , respectively, with trimethylstannane. The intermediate formation of CF 3 E(H)I was shown for E = P by NMR spectroscopic investigation of a 1:1 mixture of CF 3 PI 2 and HSnMe 3 .

Reaction of harmaline with formyl cyclohexanone has afforded methoxyisosempervirine.

The 13 C chemical shifts of several alkylsubstituted pyrylium salts are presented. Charge densities in the isoelectronic series benzene, pyridine, pyridinium cation and pyrylium cation, calculated from INDO M. O. theory, are shown to correlate well with the ring carbon 13 C chemical shifts. The effect of alkyl substitution on ring carbon 13 C chemical shifts in the pyrylium salts are shown to correlate with those of the alkyl benzenes.

Different mechanisms are considered to explain the formation of 5-deoxy-D-erythropentos-4-ulose in the γ-radiolysis of ribose-5-phosphate in aqueous solution. On the basis of deuterium labelling experiments one mechanism involving an enol as an intermediate could be excluded. The identification of twelve further radiolysis products from ribose-5-phosphate is reported.