Volume 34, Issue 4

By new preparative methods [(CH 3 ) 2 AlN 3 ] 3 , [(CH 3 ) 2 GaN 3 ] 3 , and (CH 3 ) 2 AsN 3 were 15 N-labelled. The compounds show a temperature-dependent exchange of the azido groups on the NMR time scale. For the last two compounds the vibrational spectra were recorded and discussed.

(CH 3 ) 3 SnN 3 (1) and (CH 3 ) 3 SnN 3 · (CH 3 ) 3 SnOH (2) were characterized by physical and spectroscopic properties. In solution the azido groups show a temperature dependent site exchange.

K 2 CdPb crystallizes orthorhombically, with space group Ama2 = Cmc2, a = 645.8 pm, b = 860.2 pm, c - 1095.5 pm. The structure is built of a potassium-3D-net forming eight-edged channels parallel to the a-axis; these channels are penetrated by infinite Cd-Pb-zigzag-chains. The powder-diagram shows the homologous phase K 2 CdSn (a = 643.2 pm, b = 854.3 pm, c = 1087.7 pm) to be isotypic to K 2 CdPb.

Ag 2 BaGeS 4 was prepared for the first time and the crystal structure determined using X-ray methods, a - b = 682,g; c = 801, 7 pm, Space group I4̅2 m (No. 121) tetragonal. The atomic parameters and interatomic distances are reported and the structure is discussed.

The tert-butyl cation is formed in the reaction of tert-BuCl with AlCl 3 or GaCl 3 in anhydrous liquid HCl as a solvent, or of tert-BuBr with AlBr 3 in HBr. At - 30 °C solutions of [C(CH 3 ) 3 + ] are stable. At room temperature very slow decomposition occurs over months. In the systems BCI 3 /HCl, InCl 3 /HCl and BBr 3 /HBr no formation of [C(CH 3 ) 3+ ] from the corresponding tert-butyl halide was observed. The tert-amyl cation can be stabilized only in AlBr 3 /HBr. The iso-propyl cation is not stable in any of the systems investigated. The ability of the Lewis acids employed to form carbenium ions corresponds with their catalytic activity in Friedel-Crafts alkylations.

Compounds of the systems Fe 2 O 3 -Nb 2 O 5 (O/Me < 2.5) and Nb 2 O 5 -WO 3 (O/Me > 2.5) were prepared by chemical transport. The block structures of the obtained phases were investigated by high resolution transmission electron microscopy. The unusual defects observed were nearly identical in both systems. A recently developed method to calculate the O/Me value of block structures [1] was extended and used for these defects.

Tetrachloroantimony(V) carboxilates and tetrachloroantimony(V) alkoxides, resp., react with carboxilic acids and alkohols or water, resp., to yield d,h-μ-carboxilato-e-μ-hydroxo-f-μ-oxo-bis[trichloroantimony(V)] (1, R = H, CH 3 ), a new type of cyclic antimony(V) compounds. The crystal and molecular structure of 1 (R = CH 3 ) is determined by X-ray analysis. Units of 1 (R - CH 3 ) are associated by strong hydrogen bonds. The vibrational spectra of 1 (R = H, CH 3 ) are discussed.

Reaction of the ring systems NPCl 2 (NSOX) 2 and (NPCl 2 ) 2 NSOX (X = F, Cl, Ph) with HNPPh 3 in molar ratio 1:2 gives their mono(tripbenylphosphazenyl) derivatives. The compound NPCl(NPPh 3 )(NSOPh) 2 forms a stable 1:1 adduct with acetonitrile. All compounds are characterized by NMR ( 31 P, 19 F), IR and mass spectra.

The mutual interconversions of the species Cp(CO) 3 M - (2), Cp(CO) 3 M-M′(CO) 3 Cp (1), and Cp(CO) 3 M (3), (M,M′ = Cr, Mo, W) were investigated. Of the mixed dinuclear complexes 1, the Cr-Mo and Cr-W compounds were prepared for the first time, and the Mo-W compound was shown not to exist in a pure state. The Mo and W radicals 3, in contrast to the corresponding Cr radical, are not stable in measurable quantities in solution. Electrochemical measurements as well as simple redox and redistribution reactions, however, prove their ready formation and existence under normal conditions. There is a good correlation between the energies of the σ-σ* transitions of the metal-metal bonded dimers (1) and the electrochemical potentials for their reductive cleavage.

The mechanism of formation of the exocyclic dimeric π-enyl complex (C 8 H 13 PdCl) 2 by reaction of 1,3-dimethylenecyclohexane, C 8 H 12 with trans-PdCl 2 (C 6 H 5 CN) 2 is discussed. Through UV, 1 H NMR (90 MHz, 360 MHz) and 13 C spectroscopic studies it was possible to show that the dimer is formed by the disproportionate of C 8 H 12 to C 8 H 14 and m-xylene, and further that it consists of diastereomeric products. The reaction of (-) R-3-methyl-1-methylencyclohexane, C 8 H 14 , with the Pd-salt confirms that during the reaction between C 8 H 12 and trans-PdCl 2 (C 6 H 5 CN) 2 no free C 8 H 14 is formed in solution. Studies on cleavage reactions of the dimer are also described in this paper.

Raman spectra of solid H 3 BO 3 , Na 2 [B 4 O 5 (OH) 4 ] · 8 H 2 O, K[B 5 O 6 (OH) 4 ] · 2H 2 O and Na[B(OH) 4 ] were recorded between 300 and 1500 cm -1 as well as of borax in aqueous solutions as a function of concentration and pH. Because of better solubility in water, the Raman spectrum of ammonium tetraborate in aqueous solution was also recorded as a function of pH. For comparisons the Raman spectra of solid (NH 4 ) 2 [B 4 O 5 (OH) 4 ] · 2 H 2 O, β-NH 4 [B 5 O 6 (OH) 4 ] · 2 H 2 O, NH 4 [B 5 O 6 (OH) 4 ] · 0,67 H 2 O and NH 4 [B 5 O 6 (OH) 4 ] were considered. In solution, all lines in the Raman spectra could be assigned and the degree of depolarization measured. The assigned Raman frequencies can be used for the identification of unknown B-O-lines and therefore of unknown borate or polyborate structures.

The complexes UX 4 · 2 POX 3 (X = Cl, Br) are prepared by the reaction of excess POX 3 with the corresponding uranium pentahalides. The dichlorophosphate, CLUO 2 (O 2 PCl 2 ) · POCl 3 , is prepared by treating UCl 2 · 2 POCl 3 with dichloromonoxide. According to the IR spectra the POX 3 solvate molecules are cis coordinated via oxygen. An improved method to prepare uranium pentaehloride is described in detail.

Cis-and trans-[OsX 2 (acac) 2 ], X = Cl, Br, I, are prepared by heating of K 2 [OsX 6 ] in a 1:1 mixture of acetylacetone: water. The pure stereoisomeres are separated by chromato-graphy on silica gel. The new complexes are characterized by UV-Vis, IR and Raman spectra.

The transition metal arsines C 5 H 5 (CO) 2 LM-As(CH 3 ) 2 (M = Mo, W; L = CO, P(CH 3 ) 3 ) react with elementary sulfur (selenium) in CS 2 to give the transition metal substituted arsine chalcogenides C 5 H 5 (CO) 2 LM-As(CH 3 ) 2 S(Se). Due to the pronounced basicity of the chalcogen centre they are easily converted into cationic mononuclear complexes [trans-C 5 H 5 (CO) 2 P(CH 3 ) 3 Mo-As(CH 3 ) 2 SR] ⊕ X ⊖ by alkylhalides, and into bridged dinuclear complexes tans-C 5 H 5 (CO) 2 P(CH 3 ) 3 Mo-As(CH 3 ) 2 S-ML n on treatment with THF · Cr(CO) 5 or AgI. The structures of the new compounds are established by spectroscopic investigations.

Reactions of several semi-stabilized phosphonium ylides with 2,7-dibromofluorenethione and thiobenzophenone, have been reported to give substituted 9-benzylidene-2,7-dibromo-fluorenes and 1-(substituted phenyl)-2,2-diphenyl ethylenes respectively in fair to good yields. The structural identities were based on spectral data.

Novel cluster compounds of the composition [(η 3 -C 3 H 5 ) 2 M 2 S] x , wherein M represents nickel, palladium or platinum are obtained by reaction of 2,5-disubstituted-1,6,6a-trithiopentalenes or H 2 S with (η 3 -C 3 H 5 ) 2 M in THF solution. The molecular structure of one of these new cluster types [(η 3 -C 3 H 5 Ni) 2 S] 3 has been established by X-ray methods. It is best described as being a fraction of a NiS-framework in which peripheral coordination sites are occupied by partial disordered η 3 -allyl groups. Molecular data (cell data: a = 19.868(4), b = 8.988(2), c = 14.501(3) Å, β = 115.30(2)°, space group C2/c, Z = 4, R = 0.106) are compared with the parent Bs-NiS lattice. Spectroscopic evidence for the structural similarity of the related Pd- and Pt-compounds is given.

It is shown in this paper that a consistent set of values of pK BH ⁺ for 24 ethers, in good agreement with the few which have been obtained by other methods, can be calculated from a correlation of the HCl solubility in the ethers with ∑σ I of the R groups, and also with the gas phase I.P.'s of the ethers. We find that in solution the order of basicity is ROH>R 2 O>H 2 O whereas in the gas phase it is R 2 O>ROH>H 2 O. Evidence for complete H + transfer to R 2 O is deduced for most cases, but a H-bonding "basicity" occurs for the less basic ethers. A brief review of previously obtained pK BH ⁺'s for some ethers, MeOH, and H 2 O is also presented.

Cyclocondensation reaction of 3-isatylideneoxime (1a), -hydrazone (1b), -phenyl-hydrazone (1c), semicarbazone (1d) and -thiosemicarbazone (1e) with chloroacetyl chloride (and thioglycolic acid) gave the corresponding spiro azetidinones (2) and spiro thiazolidinones (3). 3-Isatylidenehydrazone (1b) was condensed easily with aromatic aldehydes afforded a new 3-isatylidene azomethines (4) which submitted for cyclocondensation reaction with chloroacetyl chloride (and thioglycolic acid) giving bis-azetidinones (5) and bis-thiazolidinones (6), respectively.

The preparation of 5,6-dimethyl- (1g), 5-methoxy-6-methyl-1,3-benzodioxole-4,7- quinone(1k), 6,7-dimethyl-1,4-benzodioxan-5,8-quinone (3e), 7,8-dimethyl-3,4-dihydro- 2H-1,5-benzodioxepin-6,9-quinone (4e), 8,9-dimethyl-2,3,4,5-tetrahydro-1,6-benzodioxo- cin-7,10-quinone (5f) and of 9,10-dimethyl-3,4,5,6-tetrahydro-2H-1,7-benzodioxonin-8,11-quinone (6e) by potassiumnitrosodisulfonate-oxidation of the phenols 1f, 1j, 3d, 4d, 5e, and 6d is described. To obtain the phenols by Baeyer-Villigeroxidation of the aldehydes 1e, 1i, 3c, 4c, 5d, 6c, the cyclic ethers are subjected to bromination, bromine-lithium-exchange, and formylation of the lithium-compounds.

The preparative column chromatographic separation on small grained silica gel of the bacteriophaeophorbide-c- and -d-methyl esters into their homologous and isomeric components is described. The influence of particular regions of the molecule, which carry different alkyl-substituents, on the chromatographic separability is selectively enhanced through the variation of the eluent. Mass and 1 H NMR spectra of the pure components are discussed.

Bis(1,5-cyclooctadiene)platinum has been pre­pared in 74-82% yield by reduction of dichloro-(1,5-cyclooctadiene)platinum with bis(cyclopentadienyl)cobalt in the presence of excess 1,5-cyclooctadiene.

The preparation and characterization of Cs 3 [V(NO)(H 2 NO)(CN) 4 ] · 2 H 2 0 a nitrosyl-oxamido(O,N) complex of vanadium is reported.

The desulfuration of Me 2 P(S)P(S)Me 2 by tri-n-butyl phosphine in the presence of protic substances (water, alcohols, carbonic acids and others) is accompanied by hydrolytic cleavage of the P-P bond with formation of dimethyl phosphine.

NiC 6 H 14 N 8 O 6 is obtained in a dimeric form, bridged by oxime O atoms, as a by-product during the preparation of bis(malonenamide-oximato)nickel(II). It crystallizes in the mono-clinic space group P2 1 /c with a = 10.053(3), b = 9.338(3), c = 13.392(3) Å, β = 92.09°. The structure was solved by direct and Fourier methods and refined by least squares to R = 0.071 for 2462 intensities.

Ternary high temperature carbides were found in the system Cr-Ru-C, Cr-Rh-C, Cr-Ir-C, Cr-Pt-C, Mo-Ru-C, Mo-Rh-C, Mo-Os-C, Mo-Ir-C, Mo-Pt-C, W-Ru-C, W-Rh-C, W-Os-S and W-Pt-C. The com-pounds crystallize in the face centered cubic structure. The carbon content changes systematically with the content and the valence electron concentration of the respective platinum metal.

Silica-X described in 1964 as a new SiO 2 modification is the dehydrated form of the crystalline silicic acid H 2 Si 8 O 17 · xH 2 O which is obtained by cation exchange from the potassium silicate K 2 Si 8 O 17 · xH 2 O.

The fully interpreted 13 C NMR spectra of mupamine, carbazole, and of some carbazole derivatives are reported.