Volume 31, Issue 12

Dihydrazido-thiophosphoric acid phenylester as a tridentate chelate ligand forms complexes with bivalent transition metals. The compounds [Ni(II)(L) 2 ]Cl 2 , [Zn(L) 2 ]Cl 2 and [Cd(L)Cl 2 ] are prepared and characterized by elemental analysis, IR, Raman, UV/VIS spectra and X-ray powder diagrams. The nickel possesses a slightly distorted octahedral coordination. The nickel(II) complex can be transformed to a carbon free inner complex salt of the formula [Ni(II){(NH 2 -NH) 2 Ρ(S)O-} 2 ] by hydrolysis.

The synthesis and the crystal data of the oxychlorides of Er, Tm, Yb and Lu are reported. All compounds are isostructural, crystallizing in the rhombohedral SmSJ-type arrangement. The range of existence of the two structure types occurring with the rare earth oxychlorides is briefly discussed on the basis of electrostatic calculations.

The electrochemical synthesis of phenols of alkylated arenes is described with special consideration of added metal salt redox pairs.

In the quaternary system H–Nb 2 O 5 –WO 3 –NbO 2 F the phase WNb 15 O 40 F was prepared in form of light-yellow needles. The compound crystallizes in the monoclinic system with the unit cell dimensions a = 22.254 A, b = 3.829 A, c = 20.298 A and β = 114.29°, space group C 2. Electron optical investigations showed the crystal structure containing 5 x 3 x co-blocks of Nb—(O, F)-octahedra, with metal atoms in tetrahedral positions located at the junctions of every four blocks. X-ray investigations showed a range of homogeneity between (O, F)/ (W, Nb) = 2.556 < 2.563 (WNb 15 O 40 F) < 2.571. The hypothetical phase WNb 18 O 47 F 2 with 6 x 3-blocks was found as a microdomain by electron microscopy.

Usually the Jahn-Teller effect of Cu 2+ in a regular octahedral host lattice site leads to a tetragonal elongation with a small o-rhombic component. If the relevant crystallographic site is slightly tetragonally compressed however in the host lattice structure already – as in Ba 2 ZnF 6 – the Jahn-Teller effect may stabilize this distortion symmetry as well. This can be deduced from the EPR-spectroscopic g n -values of 1.99 for the mixed crystals Ba 2 Zn 1-x Cu x F 6 up to x = 0.3. The angular overlap parameters obtained from the ligand field spectra suggest in addition, that the tetragonal compression of the CuF 6 polyhedra is considerable, with CuF distances of about 1.90 Å (2 x) and 2.14 Å (4 x), respectively. Increasing cooperative elastic interactions between the CuF 6 polyhedra in the (001) planes at larger Cu 2+ -concentrations induce tetragonally elongated octahedra (with a small o-rhombic component) in antiferrodistortive order at x ≥ 0.6. This cooperative Jahn-Teller order, which is characteristic for Ba 2 CuF 6 , can be verified simply by acentric displacements of the F-.ligands connecting two Cu 2+ -ions in the (001) planes.

Deep red heteropolyvanadates of phosphorus(V) n M 2 O:P 2 O 5 : 13 V 2 O 5 · aq (n = 3, 5, 6; M = Na, K, Rb, Cs, NH 4 ) and n M 2 O: P 2 O 5 : 14 V 2 O 5 · aq (n = 4, 7; M = K, Rb, Cs, NH 4 , (n-C 4 H 9 ) 4 N) were prepared. Recrystallization of 1: 13- and 1: 14-heteropolyvanadates and determination of molecular weight by ultracentrifuge technique in solutions from V 2 O 5 and NaH 2 PO 4 indicate 1: 14-heteropolyvanadate ions to be stable species over a wide range of pH, while 1: 13-heteropolyvanadate ions are only stabilized in higher acidified solutions containing H 2 PO 4 - or as slightly soluble salts. Wide line 1 H NMR spectra are interpreted in terms of OH groups and H 2 O of cristallization, the isolated heteropolyvanadates of both series consisting of protonated anions; the basicity of heteropolyvanadic acids of phosphorus(V) is unknown.

Ca 3 Al 2 Ge 2 , Sr 3 Al 2 Ge 2 and Ba 3 Al 2 Ge 2 have been prepared and their structures determined. They crystallize orthorhombicly in an ordered variant of the Ta 3 B 4 structure type with the following constants : Ca 3 Al 2 Ge 2 : a = 4.08(1) Å, b = 18.54(2) Å, c = 4.58(1) A, Sr 3 Al 2 Ge 2 : a = 4.22(1) Å, b = 19.21(2) Å, c = 4.86(1) A, Ba 3 Al 2 Ge 2 : a = 4.34(1) A, b = 19.82(2) Å, c = 5.09(1) A.

The magnetic susceptibilities of the binuclear oxobridged iron(III)-porphyrins [Fe(TTP)] 2 O (2 d), [Fe(OÄP)] 2 O (3 b) and [Fe(OÄPMe 2 )] 2 O (4b) have been determined over the temperature range 4-300 K. The measured susceptibilities of [Sc(TTP)] 2 O (2 e) and [Sc(OÄP)] 2 O (3 c) were used as diamagnetic corrections for [Fe(TTP)] 2 O (2 d) and [Fe(OÄP)] 2 O (3 c), respectively, whereas the diamagnetic correction for [Fe(OÄPMe 2 )] 2 O (4b) was calculated from the measured values of H 2 (OÄP) (3d), H 2 (OÄPMe 2 ) (4c) and [Sc(OÄP)] 2 O (3 c). Antiferromagnetic interactions between the Fe m ions can be described in terms of the HEISENBERG—DIRAC—VAN VLECK-model. The relation between exchange coupling parameters J 12 and steric and electronic effects of the substituents is discussed. The anomalous magnetic behaviour of [Fe(OÄP)] 2 O (3 b) between 230 and 250 K is due to a change in crystal structure.

Mixed crystals of the formulae CaGaAlO 4 (1) and CaGa 0.5 Al 1.5 O 4 (2) were investigated by X-ray single crystal work. 1 shows a tetrahedral orientation like that of CaGa 2 O 4 (monokl.), 2 another one of CaAl 2 O 4 . A discussion of the different polyhedral arrangement of the stuffed tridymite structures is given.

35 Cl and 75 As NQR spectra have been recorded for six gold(I) chloride complexes with phosphine, arsine and sulfide ligands. Though no 197 Au–NQR signals were detected, good 197 Au-Mössbauer spectra could be obtained for the same compounds and some homologs. A discussion of the results has shown, that no consistent correlation is evident between the nature of the ligands and the 35 Cl and 75 As quadrupole coupling constants, 197 Au isomeric shifts and quadrupole splittings.

The photoelectron spectrum of H 5 C 6 -Te-CH 3 displays in its low energy region overlapping bands of gas-phase conformers. Depending on the dihedral angle between the plane of the phenyl ring and the tellurium lone pair, the π conjugation amounts to only 0.1 eV and 0.3 eV, respectively. These values are compared to the considerably larger ones found for the analogous phenyl derivatives H 5 C 6 -X-CH 3 with X = O, S and Se.

The well-resolved helium(I) photoelectron spectrum of H 3 C-Se—Se-CH 3 exhibits distinct bands corresponding to 11 of the total 13 valence electron ionizations. The unequivocal assignment is supported by EHMO calculations including spin/orbit coupling. The two selenium lone pair ionizations differ by 0.23 eV; a split observed also for dimethyl disulfide and discussed within a general model for interactions between adjacent lone pairs.

A new simple method is given to analyse potentiometrically titrated and spectrophotometrically measured complex-solutions of the system AH ⇌ A + H 3 O + and n • A + M ⇌ MA n . The absorbance coefficients of the metal complex MA n and the stability constants can be determined for each titration step by construction of the “extinction triangle” in the (two-dimensional) absorbance (E) diagram. It is not necessary to know the absolute pH value of the solution. The titration of 2-nitroso-1-naphthol-4-sulfonic acid/zinc sulfate in water is shown as an example.

Molecular compounds of HgCl 2 with organic donor molecules (dioxane, 1,3,5-trioxane, 1,3,5-trithiane, tetrahydrothiophene, 1,4-cyclohexandione, collidine, benzaldehyde, orthochlorobenzaldehyde, metachlorobenzaldehyde, parachlorobenzaldehyde) and the double salts K 2 HgCl 4 • H 2 O and Rb 2 HgCl 4 • H 2 O were studied by 35 Cl NQR spectroscopy in the temperature range 77 K ≦ T ⪅ 300 K. The results are discussed with respect to the coordination around the Hg atom within the complex. The molecular compound, except those with sulfur-containing donors, seem to adapt an approximately octahedral coordination at the Hg atom. According to the 35 Cl NQR results, HgCl 2 may form dimers and trimers with orthochlorobenzaldehyde and parachlorobenzaldehyde, respectively. Isotypy of K 2 HgCl 4 • H 2 O and Rb 2 HgCl 4 • H 2 O is in accordance with the NQR experiments.

N-methane-sulfonyl-isoindolines substituted in the carbocyclic moiety can be prepared from the corresponding 1,2-bis-[brommethyl]benzenes and methane sulfonamid by cyclisation under basic conditions. The title compounds are interesting precursors for the generation of carbocyclic substituted 2H-isoindoles via base catalysed 1,2-elimination of methane sulfinic acid. By this reaction sequence the sulfonyl residue is simultaneously involved as a protecting group and as a leaving group.

The 13 C NMR chemical shifts of fifteen 6 substituted 2,3-dihydro-1,4-diazepinium salts (cis trimethincyanines) (1) and twelve 2 substituted bis(dimethylamino)trimethinium salts (trans trimethincyanines) (2) have been determined. A comparison of the substituentinduced shifts ( 13 C SCS) of 1 and 2 allows no distinction between steric and electronic effects. In the three 6 п-electron systems 1, 2 and monosubstituted benzenes the 13 C SCS are similar for the substituent bearing carbon atoms. A surprisingly large 4 J FCCNC coupling constant has been observed.

A sample consisting of about 120 organic rearrangement reactions has been quantified in terms general reaction matrices R̃ expressing electron-flow processes. About two thirds of the reactions considered conform to only two distinct R̃-matrices, 80% to five such schemes. The frequency distribution is qualitatively similar to that found for larger, more randomly chosen, sets of organic reactions. Examples of the various electron-flow processes are given. The bearings of the results on synthesis-planning are discussed.

2,5-Diphenyl-tellurophene (1) is metalated with the n-butyl-lithium/TMEDA complex. The reaction of the resulting lithiumorganic compound with electrophilic agents affords 1,4-substituted butadienes (2-8).

The photochemical conversion of 2-sulfinyl substituted benzaldehydes into benzoic acids in a new type of redox reaction is discribed in which a transfer of an oxygen atom, originally attached to sulphur, takes place by insertion into the C-Η bond of the aldehyde function located in ortho position. Influences of substituents at the sulfinyl group in this photoreaction which seems to be limitated to aldehydes are discussed briefly.

The mass spectra of several pyrazaboles of type 1 (R = H) have been studied. The data illustrate that electron impact causes three major fragmentation patterns for the species. Symmetrical cleavage of the pyrazabole followed by further breakdown is common to all compounds. In addition, those pyrazaboles containing H or CH 3 at the C atoms of the pyrazole rings undergo an electron impact-induced rearrangement which appears to result in the formation of a species containing a B 2 N 3 ring as a structural entity; subsequent breakdown leads to a B 2 N 2 ring system. The mass spectra of halo- or pseudohalo-substituted pyrazaboles evidence the ready loss of hydrogen halide as a predominant feature; no rearrangement ions are observed.

The unusual methyl elimination from para-substituted methoxy-methyl benzenes has been elucidated. It can be shown that two entirely different mechanisms contribute to the reaction: i) intramolecular hydrogen transfer onto the benzene ring (π-complex formation) and ii) substituent migration via ring expansion. Alternative mechanisms as for instance transanular protonation of the ester function or substituent migration via valence bond isomers are not involved in the formation of the [M-methyl]+-ions.

2,3-Dichloro 1,4-naphthoquinone reacts with zinc mercaptide to give 6-chloro-l0-trifluoromethyl-5H-benzo[a]phenothiazin-5-one (1). Synthesis of various O, N acylated and alkylated derivatives (2 to 7) and their sulfoxides (8 to 12) have been described.

(2-trans-Hydroxycyclopropyl)trimethylammonium iodide (4) may be obtained by cleavage of the trans-benzyl ether (7) with concentrated aqueous hydrogen iodide. Under the same conditions the corresponding cis-benzyl ether (8) also gives the trans-cyclo-propanol derivative (4). For the course of the reaction, an S N 2-type mechanism with inversion of configuration at the cyclopropane carbon is proposed.

MICHAEL condensation of 2-cinnamoylbenzimidazoles (1 a-h) with ethyl cyanoacetate, cyanoacetamide and acetoacetamide led to the formation of 2(1 H)pyridone derivatives (2 a-c), (3 a-c), 4a-c), and (5 a-c). Compounds (2 a-c) added GRIGNARD reagents at the nitrile group to give 5a-c. CLAISEN condensation of 5 a-c with ethyl acetate gave the corresponding diketo derivatives (6a-c), respectively. Cyclization of 6 b with ethanolic hydrogen chloride gave the 8-azachromone (7). Both 6 and 7 gave the same pyrazole derivative (8) upon the reaction with phenylhydrazine.

Synthesis of several thieno(2,3-b)quinolines is described starting from appropriately substituted 2-oxo-3-vinylquinolines.

The coupling of aryldiazonium salts to malonanilic acid gives formazanes with a phenylcarbamoyl group attached to the C-atom. One of these compounds has been 15 N-labelled. IR and NMR spectroscopic investigations show that the formazanes exist in the solid state and in solution as mono- and bischelated isomers. The influence of solvents on the rate of isomers and on the chemical shifts has been examined. Approximately linear relationships are given between the δ-values of NH-protons, parameters E T and Hammett σ-values.

Experimental details of the syntheses of five peptide fragments, used for the total synthesis of somatostatin, are described. N-Hydroxysuccinimide esters and DCC are used for forming the peptide bonds. The amino acid side chains are protected by trityl, tertbutyloxycarbonyl and benzyl groups.

Bi 2 PdO 4 was prepared and investigated by X-ray single crystal methods (a = 862.3; c = 590.9 pm, space group C 4V 10 —I4 cm). It shows isolated coplanar oxygen polyhedra around Pd 2 + with an identical construction to that of Bi 2 CuO 4 .

Single crystals of β-CaCr 2 O 4 were prepared by solid state reaction (1300°C, 7d) of CaO-Cr 2 O 3 mixture. The so far unknown parameters of the atomic positions show no distortion of the octahedral surrounding [Cr 2 O 4 ] 2 - in respect to other compounds of this type.

The 13 C NMR spectra of a number of nickel complexes of 1,5,9-cyclododecatriene and bicyclo-[2,2,1]-heptene have been studied and it has been shown that detailed structural information can be obtained relatively easily.

The reaction product of N-phenylquinisatine and diazomethane - formulated by EISTERT and DONATH 3b as benzazepine (1) - has the 2,4-dioxo-1-phenyl-1,2,3,4-tetrahydroquinoline-3-spiro-2′-oxirane (2) structure as shown by 13 C NMR spectroscopy.

Depending upon the structure of the starting compounds, seleno-photo-Fries products or cyclization products (phenenthrenequinone or selenoxanthone) are obtained in novel photoreactions from areneselenol esters of aromatic carboxylic acids.

Silicon homologues of the methylidyneclusters have been prepared. The configuration of these complexes has been derived by IR and mass spectrometric measurements.