Volume 29, Issue 1-2

The ternary oxide K 2 PdO 2 has been prepared by a reaction between K 2 O and PdO. X-ray investigations suggest a chain-structure-type which corresponds to that of K 2 PtS 2 . The planar oxygen coordinations of the palladium atoms are connected laterally in one dimension. The orthorhombic unit cell (a = 8.52 3 , b = 6.08 9 , c = 3.11 9 Å) contains two formula units.

Ca 2 Sb and Ca 2 Bi have been prepared and their structures determined. The two compounds are isotypic and crystallize tetragonal, space group I4/mmm. (Ca 2 Sb: α = 4.67 ± 0.02 Å, c = 16.28 ± 0.03 Å. Ca 2 Bi: α = 4.72 ± 0.02 Å, c = 16.54 ± 0.03 Å). There are very short Ca-Ca-distances in both compounds, the element(V)-atoms are coordinated only to Ca-atoms.

X-ray investigations are described using a single crystal of YbS 2 for the first time which formed during a ammono thermal synthesis. It crystallizes in the monoclinic space group C 2h 6 -C2/c with a = 9,32 6 , b = 4,75 4 , c = 9,02 5 and β = 118,3 9 °. The atomic parameters and a detailed description of the crystal structure are given. Especially the sulfur-sulfurbridges (d S-S = 2,11 A) represent a characteristic structural element in the a lattice of the genuine disulfide.

The compounds SrCuSn 2 and BaCuSn 2 have been prepared and their crystal structures have been determined. They crystallize in a lattice (space-group Cmcm-D 17 2h ) related to that of the BiOCl-type.

The IR absorption spectra of the ammonium salt of cupferrone and aluminium, scandium, yttrium and lanthanum trivalent cupferrate complexes are investigated. The IR absorption bands identified in the region 400-4000 cm -1 are given and assigned. It is shown that on complex formation NO stretching frequencies are lowered and new absorption bands are observed and assigned to the M-O band.

Single crystals of M 2 TeO 3 (M = Li, Na, K, Rb, Cs) have been investigated by X-ray diffraction. All compounds crystallize monoclinic. K 2 TeO 3 , Rb 2 TeO 3 and Cs 2 TeO 3 are isotypic

The crystal structures of (C 6 H 4 O 2 ) 2 PR with two chelating catechol residues and R = F (1) and CH 3 (2), respectively, at a phosphorus atom were determined. The observed geometry at this atom is between a trigonal bipyramid and a tetragonal pyramid in 1 and close to a tetragonal pyramid in 2. These results are discussed in the light of existing knowledge and theories on five-coordination of phosphorus.

Desilylation reactions of N-trimethylsilyl-triorganophosphine imines with diorganochlorophosphines do not afford phosphinimino-phosphines, because a second mole of diorganochlorophosphine is immediately added yielding phosphinimino-phosphonium chlorides containing a phosporus-phosphorus bond. These phosphonium chlorides can also be obtained from phosphinimino-phosphines and diorganochlorophosphines. The latter route has been extended to prepare analogous compounds with a phosphorusarsenic bond. All new compounds were characterized by elemental analysis, and by IR 1 H and 31 P NMR spectra.

A direct synthesis of the compounds F 3 SiAsH 2 and F 3 SiPH 2 (F 3 SiPD 2 ) by the reaction of F 3 SiBr with (CH 3 ) 3 Sn-AsH 2 and (CH 3 ) 3 Sn-PH 2 [(CH 3 ) 3 Sn-PD 2 ] respectively is reported (yield > 70%). F 3 SiBr itself was prepared by the cleavage of (C 2 H 5 ) 2 N-SiF 3 with HBr. NMR data of the compounds is shown.

The charge distribution in mica-type layer silicates, which are capable of intercrystalline swelling, is discussed on the basis of a statistical model. The model explains the distribution of exchangeable cations and water molecules onto the geometrically identical lattice sites and simplifies the calculation of the electrostatic interaction energy between adjacent layers.

Oxidfluorides A 2 WO 2 F 4 (A = Rb,Cs) and Cs 2 TaOF 5 were prepared and investigated by X-rays. All of the compounds crystallize hexogonally (K 2 GeF 6 -type).

Tetrachloroaminoborane (Cl 2 BNCl 2 ) has been prepared from nitrogen trichloride and boron trichloride. Its 11 B NMR shift with respect to boron trifluoride-diethylether is —34.7 ppm. The infrared frequency of the B-N stretching vibration appears to be 1312 cm -1 .

It is shown that reactions of tin(II) halides, SnX 2 (X = Cl, Br), with the [π-C 5 Η 5 Cr-(CO) 3 ] — anion in acetone yield (π-C 5 Η 5 Cr(CO) 3 ) 2 SnX 2 complexes. The compounds are characterised by their IR and mass spectra.

The infrared spectra of the compounds Cs 2 50 Cr 2 O 7 and Cs 2 53 Cr 2 O 7 have been measured. An approximate normal coordinate analysis has been performed on the basis of these frequencies. The result confirms the assignment of the band at 70-90 cm -1 to the CrOCr deformation mode.

The interaction of alkines with AlBr 3 was investigated by IR-spectroscopic methods. These investigations revealed that layers of pentin-1 and hexin-1 polimerized under the influence of AlBr 3 at about 170°K. Pentin-2, hexin-2 and hexin-3 however, showed new bands around 2200 cm -1 as the consequence of an interaction of these alines with AlBr 3 ; after annealing at 170°K these measurements were performed at 77°K, since these complexes are not stable at elevated temperatures (~220°K).

Poly-1-vinyl-2-pyrrolidinone of various molecular weight forms with transition metal chlorides in specific mixtures of solvents the following complexes: [Me(II)Cl 2 (C 6 H 9 NO) 2 ] 100 , [NiCl 2 (C 6 H 9 NO) 1 ] 100 , [Co(C 6 H 9 NO) 2 ] n , Me = Fe, Co, Ni, Cu, Zn, n = 220, 360, 6300. The IR spectra and electrical conductivity measurements are discussed.

Heteropolyacids, isomolybdates, dilatometric titrations By dilatometric titrations and a mathematical analysis of the titrations results the chemism of formation of the heteropolyanion [JMo 6 O 2 4] 5 - and its protonation was investigated.

The “Si-2s- and Si-2p-binding energies” of 5 o-arylenedioxy complexes containing penta- and hexacoordinate silicon have been obtained from their ESCA-spectra. The data have been compared to those of tetracovalent silicon compounds. A linear correlation between calculated Pauling charges and binding energies has been found for compounds where no (d ← n) -interaction should exist. Characteristic deviations from the linear relation were found both in tetravalent silicon compounds containing Si-O-bonds, the (d ← n)π-interaction of which is well established, and in the anionic tris(o-phenylenedioxy) siliconate and in the bis(o-phenylenedioxy) organosiliconates. No deviations were observed in case of the cationic 6-coordinate complexes of silicon with acetylacetone and 2-hydroxypyridine-N-oxide. We conclude that an additional back donation from the free electron pair (d Si ← n O o) only exists to a considerable extent in tetracovalent silicic ester derivatives, in the hexa- and pentacoordinate tris(o-phenylendioxy) siliconate and in the bis(o-phenylenedioxy) organosiliconates. A method is given to obtain crystalline tris(2-oxypyridine-N-oxy) siliconium chloride in good yield.

The preparation of the complexes (Ph 3 P) 2 (CO)IrNCNIr(CO)PPh 3 ) 2 , (Ph 3 P) 2 Ir(CO)-NCNH, [AsPh 4 ] 2 [Pd(NCNR) 4 ] (R = H,Ph), (Ph 3 P) 2 Pd(NCNH) 2 is described. The vibrational and 14 N NMR spectra are reported. In the complexes [Ni(H 2 NCN) e ]Br 2 , [Ni(H 2 NCN) 4 ]Cl 2 , [Co(H 2 NCN) 4 ]Cl 2 the cyanamide ligand presumably is coordinated through the amino nitrogen atom.

Graph-theoretical rules concerning the HOMO-LUMO separation in conjugated hydrocarbons are given. It has been found that a closure of odd-membered rings will not essentially change the HOMO-LUMO energy gap (ΔΕ). However, ΔΕ will be shifted down or up depending whether a (4m + 1)-or (4m + 3)-ring is closed. A closure of an even-membered ring increase the value of ΔΕ in the case of (4m + 2)- and decrease ΔΕ value in the case of (4m)-cycles if delocalized rings are formed. The effect is opposite if quinonoid rings are generated.

In the relation η r = 1 + Bm + Dm 2 the Β values of the complexes bis(glycinato)Cu(II) and (glycylglycinato)Cu(II) between 10 and 40°C indicate that these complexes are hydrated by two molecules of water at their carboxyl oxygens. Large values of D indicate solute-solute interactions via the axial positions of the cupric square microsymmetry, as the molecules are moving in the liquid streamlines. For both complexes dB/dT was found to be positive in the examined temperature range. This presumably indicates that the examined complexes have a structure breaking effect on the water structure.

To study the reaction of the solvated electron with 5-bromouracil an aqueous solution has been examined by conductometric pulse radiolysis at pH values between 4.68 and 8.74. Alcohol was added to scavenge the hydrogen atom and the hydroxyl radical. G(Br—) = (2.64 ± 0.08)/100 eV was found to be independent of the pH. The mobility of the bromouracil mono-anion was measured to be (2.7 ± 0.2) 10 -4 cm 2 V -1 s -1 at 20°C, and the rate constant of reaction (3b) was determined to be k(H + BrUr-) = (2.3 ± 0.2) 10 10 I mole -1 s -1 *.

2,2′-Bipyridyl dimethiodide in aqueous solution in the pH range 5.0-8.9 gives a symmetrical one-electron reduction wave independent of pH and concentration at a potential of —0.96 V against a standard calomel electrode due to the formation of the corresponding radical cation. At a much lower potential it also shows a second reduction wave which is pH dependent.

γ-Irradiation of aqueous acetaldehyde in the presence of N 2 O and O 2 at 0°C leads to the formation of 1.5 molecules of acetic acid per OH radical consumed. As intermediates peroxidic compounds are produced with a half life of about 50 min. H 2 O 2 is not formed. The primary step of the reaction is the interaction of the OH radical with acetyldehyde yielding water and acetyl radicals which add oxygen. The so formed acetylperoxy radicals form peroxidic intermediates which decompose to give oxygen, acetic acid, and peracetic acid. The peracetic acid interacts with additional acetaldehyde forming a peroxide that is converted into two molecules of acetic acid in a first order process. At temperatures above 10°C, a chain reaction takes place leading to acetic acid with a G-value of 40 at 40°C. The propagating species are the acetylperoxy and the acetyl radicals. The reaction steps are addition of oxygen to the acetyl radicals and transfer of hydrogen from acetaldehyde to the acetylperoxy radical leading to peracetic acid. In this reaction no hydrogen peroxide is formed.

The NMR spectra of pulvinic acids show large differences in the chemical shifts of the 2,6 and 2′, 6′ aromatic protons. This allows an unambiguous differentiation between the two possible isomers of unsymmetrically substituted pulvinic acids. Xerocomic acid, isoxerocomic acid and gomphidic acid have been shown to possess structures 1 a, 1 b and 2 a respectively.

4-Thiohydantoin and 1-phenyl-4-thiohydantoin reacted with aromatic aldehydes to give the corresponding 5-arylidene-4-thiohydantoin (1 a-h). la was obtained also from 5-benzylidene hydantoin and phosphorous pentasulphide. Grignard reagents added to the lateral double bond of (1 a-c) to give after hydrolysis the colorless products 3. Treatment of (1a, b) with alkylating agents gave the corresponding alkylmercapto derivatives (4 a-h). Also (4a, e) were obtained by the action of ethereal diazomethane on (1a, b). By further methylation of (4 e) with diazomethane, a cyclopropane derivative could be isolated.

The 1 H NMR spectrum of cyclopenta-1,3-diene partielly oriented in a nematic phase was recorded and analysed. A proton geometry characterised by the following H,H distance ratios was determined: r 12 /r 23 = 0.954 ± 0.007, r 13 /r 23 = 1.596 ± 0.004, r 25 /r 23 = 1.476 ± 0.009, r 14 /r 23 = 1.638 ± 0.005, r 15 /r 23 = 0.990 ± 0.001, and r 55 ,/r 23 = 0.653 ± 0.002. The molecule is found to be planar. CC bond lengths and bond angles were calculated on the basis of the proton geometry using molecular mechanics. Evidence for a possible influence of ring bending on the NMR results is discussed.

The 1 JPH and 1 Jpse absolute values showed a clear dependence on the orientation of the substituents at 2-P in several pairs of substituted diastereoisomeric 2-X-2-Y-1,3,2-dioxaphosphorinans (X = H, Se, SeR; Y=O, S, OR) and may therefore provide information about conformation and configuration at phosphorus atom.