Band 34, Heft 8

K 2 Au 2 l 6 crystallizes in the monoclinic space group P2 1 /n. It is built up by linear anions AUI 2 -, square-planar anions AUI 4 -, and K + cations. The coordination of the gold(I) and gold(III) atoms is completed by additional iodine atoms at larger distances to form compressed and elongated octahedra, respectively. Like the other known alkali hexahalogeno aurates(I,III), K 2 AU 2 I 6 belongs to a family of topologically related structures in which the perovskite is the aristotype. The actual structures depend on the size of the alkali metals: more dense structures with smaller coordination numbers for the smaller alkali metals result from a rotation of the coordination octahedra of the gold atoms. Cs 2 AgAuBr 6 does not crystallize in the ideal cubic perovskite structure, as was described in 1942, but a disordered cubic phase (a = 550.1 pm, space group Pm3m), with the composition Cs 2 Ag x AuI 1-x AuIIIBr 6 (x ≈0.25), can be prepared from HBr solution. Its cubic symmetry is the result of a statistical superposition of the coordination polyhedra of Ag I , Au I and Au III

BaSb 2 Se 4 crystallizes in the monoclinic system, space group P2 1 /n, with a = 923.7 ± 0.8 pm, b = 2076 ± 3 pm, c = 855.1 ± 0.8 pm, β = 91.2 ± 0.1°. One half of the Sb atoms form ψ-tetrahedra with three neighbouring selenium atoms, the other half forms ψ-trigonal bipyramids with four selenium atoms. These polyhedra are connected by common corners and edges to twisted chains which are ordered to sheets with Ba ions between them

In the systems Li-M-X = (M = Y, Gd; X = Si, Ge) the compounds LiYSi, LiYGe and LiGdGe were prepared. Their crystal structures were determined by X-ray investigations. They crystallize hexagonally (space group P 6̄2m), and a C22-(Fe 2 P-type) lattice was found

New mixed-valence-compounds with Sb(III) and Sb(V) of the structure (RH + ) 8 (Cl - ) 4 SbCl 6 3- SbCl 6 - with R equal CH 3 CH(NH 2 )CH 3 , CH 3 CH(NH 2 )CH 2 CH 3 , CH 3 CH 2 CH 2 NH 2 , and CH 3 CH(CH 2 NH 2 )CH 3 are reported. Different methods of preparation for these compounds are described. Compounds with the structure (RH + ) 8 (Br - ) 4 SbCl 6 3- SbCl 6 - are obtained with R = CH 3 CH(NH 2 )CH 2 CH 3 and CH 3 CH(NH 2 )CH 3 . All compounds are characterised, their formation is discussed

(C 6 H 5 ) 4 P + IBr 2 - is isostructural with (C 6 H 5 ) 4 As + I 3 - , crystallizing in the space group P2/n with a = 1476, b = 767, c = 1025 pm and β = 91.4°. The crystal structure was refined from X-ray diffraction data to a residual index of R = 0.036. The IBr 2 - ion is situated on a two-fold rotation axis so that it apparently is symmetrical with I-Br distances of 269.5 pm. Nevertheless, it cannot be excluded that the two I-Br bonds could be as different as 252 and 287 pm with anions randomly adopting one of two orientations

A new compound, BeGa 2 O 4 , was prepared by high temperature reaction between BeO and Ga 2 O 3 . X-ray single crystal investigations show a hitherto unknown structure type of M 2+ M 2 3+ O 4 compounds. BeGa 2 O 4 crystallizes with hexagonal symmetry a = 775.0 and c = 298.0 pm, space group C 2 6 h-P6 3 /m. Be 2+ and Ga 3+ are statistically distributed and are surrounded by O 2- -tetrahedra

Photolysis of CpFe(CO) 2 R complexes [R = Me (1a), Et (1b), Ph (1c)] in hydrocarbon solvents results in loss of the group R and formation of the binuclear compound [CpFe(CO) 2 ] 2 (2). In the case of 1a, the photogenerated methyl group reacts to give methane by intramolecular hydrogen abstraction from the Cp ring, or by intermolecular hydrogen abstraction either from the solvent or another methyl group. The photoinduced dealkylation of the ethyl compound 1b is explained by β-elimination (to give ethylene) and subsequent reaction of the hydrido intermediates thus formed with unchanged 1b (to give ethane). The photolysis of 1c leads to phenyl groups which abstract hydrogen from the solvent to give benzene; a noticeable amount of diphenyl is also observed if benzene is used as a solvent. In the presence of potential two-electron ligands L [L = PMe 3 , P(OMe) 3 ], only the carbonyl groups of CpFe(CO) 2 Me (1a) are photolabile, and substituted derivatives of the type CpFe(CO)(L)Me [L = PMe 3 (3a), P(OMe) 3 (4a)] and CpFe(L) 2 Me [L = P(OMe) 3 (5a)] are formed. The photoinduced reaction of CpFe(CO) 2 Me (1a) and diphenylacetylene in solution gives metallocyclic derivatives containing either one or two diphenylacetylene units. On the basis of the IR, the 1 H and 13 C NMR, and the mass spectra, the complex CpFe(CO)(Ph 2 C 2 -COMe) (6a) is assigned a structure containing a vinyl-ketone unit in a five-membered metallocycle, while in CpFe(Ph 4 C 4 -COMe) (7a) a tetraphenylbutadienyl group appears to be incorporated into a seven-membered metallocycle

The 11 B nuclear magnetic resonance spectra of sodium, potassium and ammonium polyborates in aqueous solutions, - as a function of concentration and pH - , provide information of the hydrolysis equilibria. Two 11 B NMR lines are observed in aqueous solutions of Na[B 5 O 6 (OH) 4 ], K[B 5 O 6 (OH) 4 ] and NH 4 [B 5 O 6 (OH) 4 ]. Only one 11 B NMR line is recorded in aqueous solutions of (NH 4 ) 2 [B 4 O 5 (OH) 4 ] and Na 2 [B 4 O 5 (OH) 4 ]. The results of the 11 B NMR spectra are discussed and compared with the results obtained from Raman studies of aqueous polyborate solutions

The metathetic rearrangement of boron heterocycles containing an O - B (R) - O group with trivalent boron leads to oligomeric and/or polymeric ring systems. The equilibrium between the rings of different size is disturbed when crystallisation takes place. It is most probable that the monomeric rings can build up associated molecular structures with tetravalent boron atoms thus inhibiting the metathesis. But the rearrangement mechanism again rules the behaviour of the substances after melting the crystals

Alkylamino- and formyl alkylamino-cyano Schiff's base, biphenyl and phenylbenzoate liquid crystals were synthesized. The mesomorphic behaviour of these compounds is described. The introduction of the formyl group in the higher homologues lead to the disappearance of the mesophase. The alkylamino and formylalkylamino substituents are strong electron donating groups and lead to nematic phases with remarkably high positive dielectric anisotropy

Cis-dicarbonyl complexes of Fe(II) with o-benzenedithiolate and o-methylthiobenzenethiolate ligands react with PMe 3 yielding [Fe(CO) 2 (PMe 3 ) 2 (C 6 H 4 S 2 )] and [Fe(CO)(PMe 3 )(CH 3 S-C 6 H 4 -S) 2 ], respectively. The reaction of [Fe(CH 3 S-C 6 H 4 -S) 2 ], accessible only in solution, with PMe 3 affords the labile [Fe(PMe 3 ) 2 (CH 3 S-C 6 H 4 -S) 2 ], which with CO rapidly yields the monocarbonyl complex [Fe(CO)(PMe 3 )(CH 3 S-C 6 H 4 -S 2 )]. The anion [Fe(CO) 2 (C 6 H 4 S 2 ) 2 ] 2- , hitherto accessible in solution only, could be precipitated in the presence of NaBH 4 as (NMe 4 ) 2 [Fe(CO) 2 (C 6 H 4 S 2 ) 2 ]

The preparation of sixteen new etherate, pyridine and aniline compounds of complex halo and pseudohalo acids of Zn(II) is reported. The study of some physical and chemical properties as well as the UV and IR spectra of these compounds are discussed. Tetrahedral structures are proposed for all compounds in the solid state

Phenoxy-thiophosphoryl-dihydrazide C 6 H 5 OP(S)(NH-NH 2 ) 2 (1a) and phenoxy-phosphoryl- dihydrazide C 6 H 5 OP(O)(NH-NH 2 ) 2 (1b) react with tetraalkyl-1,3-dichloro-disiloxanes to give the 1-oxa-3,5-diaza-4-phospha(λ5)-2,6-disila-cyclohexanes 2a-2d. Their 1 H NMR, 31 P NMR, IR, and Raman data are given

The reactions of a series of six-membered ring cyclic phosphines (10-phenylphenoxaphosphine, 10-phenylphenothiaphosphine, and the related sulphone) with styrene oxide in ethanol result in the formation of styrene and the corresponding cyclic phosphine oxide, indicating that betaine collapse is rapid compared to alternative routes involving the formation of vinylphosphonium salts. This conclusion is supported by studies of the rates of alkaline hydrolysis of the related methylphosphonium salts which give rise to ringopened products. These salts undergo hydrolysis significantly faster than the acyclic salt methyltriphenylphosphonium iodide, due to the electron-withdrawing effect of the oxygen, sulphur or sulphone grouping in the six-membered ring

The preparation of 5-(2-thienyl)dibenzophosphole (1) is reported. It readily forms quaternary salts with iodomethane, diiodomethane and benzyl bromide, and also forms a complex with nickel(II) bromide. The methyl- and benzyl-quaternary salts (2, R = Me or PhCH 2 ; X = I or Br) undergo hydrolysis with preferential cleavage of the 2-thienyl group, forming the cyclic oxides (3, R = Me or PhCH 2 ). The iodomethyl salt (2, R = CH 2 I, X = I) undergoes hydrolysis to give a mixture of products, which include the ring-expanded structure (8, R = 2-thienyl). The dibenzophosphole also reacts with ethylpropiolate and water in THF solution with ring-expansion to give the dibenzo[b,d]phosphorin (9)

The 2-methylthio-ethoxycarbonyl (Mtc) amino protecting function of dipeptide esters (3) is converted into 2-thiocyanato-ethoxycarbonyl derivatives (6) b y treatment with cyanogen bromide. This behaviour of the Mtc-group contrasts with the cleavage of the N-acyl methionyl peptides, due to the differing nucleophilicity of the respective carbonyl oxygens

Phases of composition Ca 10-z ;Na z (PO 4 ) 6-z ;(SC) 4 ) x F 2 , obtained during the substitution of PO 4 3- by SO 4 2- ions in the Ca 10 (PO 4 ) 6 F 2 lattice have been investigated by means of X-ray and IR spectroscopic methods. The stepwise introduction of SO42- ions produces an increasing distorsion of the lattice, although the parameters of the "pseudo-hexagonal" unit cell are practically invariant. The not well defined IR spectra are greatly dependent of the oxoanion present in largest concentration

Direct irradiation of each of N-a- and /3-phenethyl toluidine in carbon tetrachloride solution leads t o homolysis of the phenethyl-nitrogen bond forming phenethyl and arylamino free radicals. The fates of such radicals are discussed in terms of the identified products. Thermolysis of the title compounds either alone or in presence of aromatic solvents such as isoquinoline or ß-naphthol leads, in addition to the products obtained from photolysis, to partial attack of the so formed radicals on the solvent nuclei forming simple substitution products or polynuclear compounds of the indole, acridine and carbazole series

The isomerizations following the singlet excitation of 1,2,3,5-exo-6-pentamethyl-4- methylene-bicyclo[3,1,0]hex-2-ene (exo-1) and 1,2,3,5-endo-6-pentamethyl-4-methylenebicyclo[3,1,0]hex-2-ene (endo-1) are studied quantitatively. Besides an reversible endo-exo - isomerization exo-1 and endo-1 form hexamethylbenzene via 1,2,3,4,6-pentamethyl-5- methylene-cyclohexa-l,3-diene as an isolable intermediate

The syntheses of some silylcoumarins of the formulae 7-HOC 9 H 4 O 2 -4-(CH 2 ) n SiMe 2 (F) [n = 3 and 4], and 7-HOC 9 H 4 O 2 -4-C 6 H 4 (CH 2 ) n SiMe 2 (F)-4' [n= 1, 2 and 3] are reported

The anions derived from the seven-membered 2-methyl-diketone (3) and the enolether (4) were alkylated resp. acylated to the 2-methyl-4-phenyl-l-benzothiepins (6), (7) resp. (8). Compound 4 could also be obtained by C-methylation of the enolether (2). The thermal decomposition of the 2-methyl-4-phenyl-l-benzothiepins yielded exclusively sulphur and the corresponding I-methyl-3-phenyl-naphthalenes (9), (10) resp. (11).

4' -Nitro -4-aminodipheny lsulphide (1a) and/or 2'-nitro-4-amino-diphenylsulphide (1b) react with chloroacetylchloride giving 4-chloroacetylamino-diarylsulphides (2a, b) which undergo facile reaction with different amines and hydrazine yielding the 4-glycylamino and 4-hydrazinoacetylaminodiphenylsulphides (3) and (5). Two moles of 2 react with one mole of piperazine and/or hydrazine to give 1,4-Bis(p-N-(p'-nitrodiphenylsulphido)(amino- carbonylmethylene)piperazino (4) and 1,2-Bis(p-N-(o'-nitro-diphenylsulphido)(aminocar- bonylmethylene)hydrazine (6). On condensation of 5 with aromatic aldehydes yielded new Schiff bases (7). Oxidation of 3, 4, 6 and 7 using H 2 O 2 /CH 3 COOH mixtures furnished the corresponding diarylsulphones 8, 9, 10 and 11, respectively. The biological activity of some of the prepared compounds were screened against some strains of bacteria

4-Bromoxanthotoxin reacts with cyanoacetamide to form 4-bromo-o,6-dihydroxantho- toxin, which on hydrolysis with cold hydrochloric acid leads to the formation of cyano- acetic acid derivative, but hydrolysis by boiled hydrochloric acid gives the acetic acid derivative. Thio-, and 4-nitroxanthotoxin reacts with malononitrile in presence of piperidine by addition to give thio- and 4-nitro-5,6-dihydroxanthotoxin-5-[1',3 , ,3'-tricyano-2-amino- propene-(2)] respectively, while in presence of ammonia leads to the formation of 5- malononitrile derivatives. The reaction of hydrazine and phenyl hydrazine with thio- and 4-bromothioxanthotoxin leads to the formation of the hydrazones. Also thio- and 4-bromothioxanthotoxin reacts with anhydrous aluminium chloride in benzene by cleavage of the furan ring and the formation of 6-(1,2-diphenylethyl)-7,8- dihydroxythiocoumarin and 5-bromo-6-(1,2-diphenylethyl)-7,8-dihydroxythiocoumarin, respectively

The new compound Sr 2 Sb 3 crystallizes in the monoclinic system with a = 667.0(5) pm, 6 = 1297.3(5) pm, c = 1520.8(5) pm, β = 90.09(3)°, space group P2 1 /c. The structure is characterized by Sbe-chains, the compound be­longs to the Zintl-phases

The X-ray structure determination of YLiSn showed that Li and Sn form a weakly distorted Wurtzit-type lattice, whose octahedral lacunas are occupied by Y. The lattice constants of the hoxagonally crystallizing compound are a = 929.6 pm and c = 734.6 pm, space group P 6 3 mc, Z = 8

K 2 PdAs 2 was prepared from the elements. It crystallizes orthorhombically , space group Cmcm, a = 653.6 pm, b =1412.1 pm, c = 602.5 pm, forming infinite Pd-As 2 -zig-zag-ribbons and conforming to a filament

X-ray investigations on the ternary compound CeLi 2 As 2 showed it to crystallize in the trigonal CaAl 2 Si- 2 -structure, space group P3̄m1-D 3 3 d- The cell parameters are: a = 431,1 pm, c = 698,4 pm, c/a = 1,62