Band 33, Heft 5

The formerly unknown spiro systems C-F (Scheme I) with silicon in the spiral center and C, Si, N and O in the framework were synthesized via reactions 2-6 and confirmed in their structure by elemental analysis and spectroscopic data (Table I).

The inorganic ring systems BNCO 2 Si 2 (B) and BCO 3 Si 4 (E) were prepared for the first time via equations (1) and (5), system BCO 3 Si 2 (C) enlarged by preparation of compound C 1 via eq. (4). Synthesis of a system BCO 2 Si 2 (D) failed as well as preparation of five and seven membered building units VI and VIII. For bis(trimethylsiloxy)phenylborane (IX) detailed and additional information about preparation, properties and structure analysis is given. Compound VTI, C 5 H 15 NOSi, was obtained for the first time via eq. (7) and described in its properties.

The new ternary tin(II) sulfide iodide Sn 4 SI 6 was prepared by annealing of stoichiometric amounts of SnI 2 and SnS at 280 °C. The structure of this compound was determined from three-dimensional X-ray data. The cell parameters for the monoclinic phase are a = 14.129, b = 4.425, c = 25.15 Å, and β = 93.42°; space group C2/m (No. 12), Z = 4. Parts of the structure are built up of the Snl 2 structure.

K 2 PtS 15 can be synthesized from solutions of potassium polysulfide and hexachloro-platinic acid. X-ray investigations on single crystals revealed its structure. Similar to the ammonium salt (NH 4 ) 2 PtS 15 2 H 2 O, the Pt-atom of the PtS 15 2- anion is found in an octahedral environment consisting of three bidentate five-membered sulfur chains.

Dimethylstibonium trichloride (CH 3 ) 2 SbCl 3 exists in two isomeric forms. In the dimeric "covalent" one, [(CH 3 ) 2 SbCl 3 ] 2 , two formula units are bridged by chlorine, building a fourmembered ring. It crystallizes in the orthorhombic space group Pnma with lattice constants a = 1212.9, b = 1910 and c = 610.2 pm. The mean value of bond length from antimony to the terminal chlorine atoms is 235.5 pm, to the bridging chlorine atoms 280.0 pm and the averaged Sb-C distance is 213.3 pm. The second form [(CH 3 ) 4 Sb] + [SbCl 6 ] - is an ionic one and crystallizes in the triclinic space group P1̅ with lattice constants a = 715.6, b = 744.2, c = 1415.2 pm, a = 90.01, β = 93.39 and γ = 106.4°. The mean values of bond lengths are Sb-C 211.5 pm and Sb-Cl 238.2 pm. The tetrahedrical as well as the octahedrical coordination polyhedra are only slightly distorted.

The title compounds have been prepared in high yields from equimolar amounts of methanol and the ylides 1-methyl-1-methylene-phospholane and -phosphorinane, respectively. On the basis of a variable temperature 1 H, 13 C, and 31 P NMR study the compounds have been assigned a molecular structure with a pentacovalent phosphorus atom in a trigonal bipyramidal configuration and the methoxy group in an axial position. The molecules are fluxional on the NMR time scale and rapid ligand scrambling is observed at room temperature, predominantly affecting the ring systems. At elevated temperatures an irregular, intermolecular exchange of methoxy groups and CH 3 P-protons is observed, which is a consequence of a retro cleavage to form ylide and methanol. This process is faster with the phosphorinane than with the phospholane.

N-(Trichlorogermyl)trimethylphosphinimine crystallizes in the triclinic space group P1̅ with a = 12.49(2), b = 12.54(3), c = 6.66(1) Å,a = 100.96(10),β = 91.45(14), γ = 102.77(15)°. The structure was solved by Patterson and difference syntheses and refined to R = 0.063 for 2867 independent reflections. In the unit cell there are two symmetry related monomers containing tetracoordinated Ge and one crystallographically centrosymmetric dimer with a planar four-membered [GeN] 2 ring exhibiting trigonal-bipyramidal pentacoordinated Ge and trigonal N. Significant differences are observed in the bond lengths from pentacoordinated Ge to its equatorial and axial ligands: Ge-N eq 1.837(7), Ge-N ax 1.972(7), Ge-Cl eq 2.176(2) and 2.170(2), Ge-Cl ax 2.345(3) Å. The Ge-N eq distance is similar to that observed in tetracoordinated derivatives [1.81-1.87 Å], whereas the Ge-N ax distance is 0.22 Å shorter than that observed for the axial N→Ge coordinate bond in hitherto known pentacoordinated derivatives [2.19-2.24 Å]. The very short Ge-N bond length of 1.737(8) Å in the monomer which is 0.07 Å shorter than in other tetracoordinated derivatives may be indicative of the involvement of a (p→d)π component.

By anodic oxidation of naphthalene in H 2 CCl 2 /O.O2m Bu 4 NPF 6 at -45 °C dark red-violet crystals of (C 10 H 8 ) 2 PF 6 can be obtained by electrocrystallisation. They are stable at low temperatures, however, decompose on warming. In solution and in the polycrystalline state these radical cation salts show only narrow e.p.r. signals without h.f.s. The specific conductivity of a polycrystalline pellet at room temperature was determined to be 0.12 ±0.046 Ohm -1 cm -1 . The structure determination of (C 10 H 8 ) 2 PF 6 yielded the tetragonal space group P4 2 /n, Z = 2, a = b = 1156(2), c = 640(1) pm. Patterson synthesis and difference Fourier analyses showed the compound to have a columnar stacking of C 10 H 8 units the long molecular axes of which are twisted alternately by 90° around a screw axis in c-direction, and the molecular planes of which are 320 pm apart. The PF 6 - ions have four nearest C 10 H 8 neighbours lying in pairs in parallel planes 63 pm above and below that plane of PF 6 - perpendicular to the c-axis and containing a PF 4 group. This is the first established case for a columnar structure of a pure hydrocarbon radical cation. (C 10 H 8 ) 2 AsF 6 is isomorphous.

A series of new phosphorus (III) compounds containing the hexafluoroisopropoxide group has been synthesised by reacting halophosphines with lithium hexafluoroisopropoxide. The phosphites Bu t PX[OCH(CF 3 ) 2 ] (where X = F, Cl), Bu t MeP[OCH(CF 3 ) 2 ] and C 6 H 5 PF[OCH(CF 3 ) 2 ] each contain a chiral center at phosphorus.

The ionic conductivity of some polycrystalline samples of the general formula Lil · yXI(y = 1/4 or 1/10) X = Rb + , NH4 + , N(CH 3 ) 4 + , NEt 4 + ) is measured. These mixtures generally exhibit higher activation energies for ionic movement than pure lithium iodide. At temperatures above 50 °C, the overall conductivity is higher them that of pure lithium iodide.

14 N chemical shifts of a series of cyclic and noncyclic aminophosphines are reported. The nuclear shielding of nitrogen decreases with increasing number of halogen substituents at phosphorus as well as with increasing number of phosphinyl groups attached to nitrogen. In addition to the influence of electronegativity PN(π)-interactions may account for the observed shielding. Steric effects are discussed.

Fluorosilanes react with lithium amides and organolithium compounds to give aminofluorosilanes. (Lithioamino)fluorosilanes are formed by the reaction of aminofluorosilanes with butyllithium depending on the steric influence and molecular stabilization of the ligands. These lithium salts react with halogensilanes and trimethyltin chloride with substitution. By LiF elimination the lithioaminofluorosilane C 6 H 5 -SiF-NLiC(CH 3 ) 3 -N(p-C 6 H 4 CH 3 Si(CH 3 ) 3 ) cyclisizes through a (2+2)cycloaddition and SiC-H-cleavage.

Fluorosilanes, chlorodiorganylboranes and chlorotrimethylstannane react with lithiated cyclotrisilazanes under LiF elimination and substitution. Mixed substituted compounds are obtained by the reaction of lithio-fluorosilyl-cyclotrisilazanes with other fluorosilanes. Ring coupling is achieved by the reaction of lithio-hexamethylcyclotrisilazane with 2-chloro-1,3,4,5,6-pentamethylborazine. The reaction of a fluoro(methylamino)silylsubstituted cyclotrisilazane with butyllithium leads to a system consisting of two hexamethyleyclotrisilazanes connected through a diazadisilacyclobutane ring.

From acidified sodium molybdate solutions mixtures of two polymolybdates are precipitated by addition of tetraphenylphosphonium ions. The pure compounds obtainable by separation with selective organic solvents were identified analytically and by their vibrational spectra as octamolybdate, [P(C 6 H 5 ) 4 ] 4 Mo 8 O 26 , with "Lindqvist structure" and as hexamolybdate, [P(C 6 H 5 ) 4 M O6 0 19 . They are characterized by their UV-VIS spectra and X-ray powder patterns. The precipitation of the hexamolybdate from strong acidic solution can be used analytically for the determination of molybdenum.

The title complex 4 was prepared from η-C 3 H 5 Co(CO) 3 and η-C 5 H 5 (CO)Co-P(CH 3 ) 2 H. It completes the series of PR 2- and AsR 2- bridged homodinuclear complexes C 2 (CO) 7 C 5 H 5- As(CH 3 ) 2 , Mn 2 (CO) 6 C 5 H 5 As(CH 3 ) 2 , and Fe 2 (CO) 5 C 5 H 5 P(CH 3 ) 2 . Its crystal structure analysis reveals the systematic variation of the ligand distribution along the series which depends only on the number of ligands present and not on given coordination geometries. The metal-metal bond length in 4 is mainly determined by the stereochemical require-ments of the bridging phosphido ligand.

Synthesis, properties and reactions of [(OC) 5 W] 2 N 2 H 2 , [(OC) 5 W] 2 N 2 H 4 , (OC) 5 WN 2 H 4 , (OC) 5 WNH 3 , [(OC) 4 PØ 3 W] 2 N 2 H 4 , [(OC)4PØ 3 WN 2 H 4 ], [(OC) 5 W-N 2 H 2 -W(CO) 4 PØ3], [(OC) 5 W-N 2 H 2 -W(CO) 4 P(CH 3 ) 3 ] and [(OC) 5 WNHCH 3 NHC 6 H 5 ] are reported. The hydrazine complexes are synthesized by ligand exchange from the corresponding tetra-hydrofuran complexes. Oxidation by various oxidizing agents yields the diazene complexes, in most cases very low yields. Substitution of CO by phosphanes leads to reduced stability of the compounds. All complexes undergo base catalysed H-D exchange yielding the corresponding ND derivatives; the diazene complexes show a much faster exchange than the corresponding hydrazine and ammonia complexes, which is explained by the higher acidity of the N 2 H 2 protons. The diazene complexes disproportionate under base catalysis to hydrazine and dinitrogen compounds, the latter of which loose the N 2 ligand immediately. The diazene ligand of [(OC) 5 W] 2 N 2 H 2 cannot be alkylated by reactions with (CH 3 ) 2 SO 4 , LiCH 3 or CH 2 N 2 ; instead, LiCH 3 as well as CH 2 N 2 cause disproportionation to N 2 H 4 and N 2 complexes. UV irradiation of [(OC) 5 W] 2 N 2 H 2 in THF leads to substitution of CO by THF. The THF complexes can be converted to the phosphane substituted diazene complexes. The IR, UV-VIS and 1 H NMR spectra of the (OC) 5 W complexes are nearly identical to those of the analogous Cr and Mo compounds. The unsymmetrical phosphane diazene complexes, however, show a quartet of the N 2 H 2 protons in the 1 H NMR spectra with coupling constants of 25-26 Hz for the protons on the NN double bond. This value points to a trans configuration of the diazene ligand and its complexes respectively.

For possible antiparasitic activity, benzo-benzothiopyranoquinoline-6-malonaldehyde was synthesized and condensed with hydrazine hydrate, Phenylhydrazine and/or 0-phenylenediamine. This afforded pyrazole, phenylpyrazole and diazepin derivatives respectively.

The nitrile infrared intensities of a series of a,β-diaryl cyanoethylenes were juxtaposed to the associated substituent constants, HMO and SCF-MO indices and fair to excellent correlations were established. The competitive resonance of the nitrile group with alpha-and beta-aryl substituents is discussed. HMO calculations were used to estimate the steric hindrance to conjugation caused by polycyclic substituents and SCF-MO calculations were made to obtain uniform predictions of nitrile intensities and frequencies for hetero-cyclic derivatives of acrylonitrile.

Most of the polyacid salts A x M y O z of the transition elements M = Ti, V, Nb, Mo, W, U with layer structure can exchange the alkali or earth alkali ions A for other suitable cations. Especially suited are large organic ions such as alkylammonium ions whose large layer separation makes the interlayer cations accessible for the exchange reaction.

Tetramethylstiboniumtetrachlorogallate crystallizes in the hexagonal space group P6 3 mc with two formula units per cell. The lattice constants are a=b = 768.8 pm and c= 1251.2 pm. The structure shows isolated cationic and anionic tetrahedra, which are only slightly distorted. The averaged bond lengths are: Sb-C 212.6 pm and Ga-Cl 217.2 pm. In good agreement with the short Ga-Cl distance (the shortest of all compounds ((CH 3 ) n GaCl 4-n ) - ; n = 1-3) are the measured ionization energies of Ga-3d-electrons and the calculated Pauling Qp-values.

Au 7 P 10 I can be prepared by chemical transport with iodine in a temperature gradient 900 °C→ 450 °C. The crystal structure has been determined. The compound shows metallic conductivity; its thermal stability has been studied.

Dimethyl-trimethylphosphinimino-methylene-phosphorane, (CH 3 ) 3 P=N-P(CH 3 ) 2 = CH 2 was found to react with ethylene oxide to form a 1:1 adduct, that was identified as 2,2-dimethyl-2-trimethylphosphinimino -1,2λ 5 -oxaphospholane. According to its 1 H, 13 C, 31 P NMR spectra it is assigned a rigid trigonal bipyramidal structure with nitrogen and oxygen atoms in axial positions.

Some properties of alkylsulfonyl hydroxylamines CH 3 (CH 2 ) n SO 2 NH0H (n = 1. 2. 3), prepared by reaction of the sulfonyl chlorides and hydroxylamine, are reported.