Volume 47, Issue 3

The title compound has been prepared by the reaction o f [WCl 4 (NSeCl)] 2 with PPh 4 Cl in CH 2 Cl 2 solution. It forms red crystals, which were characterized by an X-ray structure determination. Space group P2 1 /c, Z = 4, 3856 observed unique reflections, R = 0.073. Lattice dimensions at 25 °C: a = 2266.0(5), b = 1121.0(2), c = 2013.0(4) pm, β = 109.66(3)°. The structure consists o f PPh 4 + ions and anions [WCl 5 (NSeCl 2 )] 2- , in which the tungsten atom is surrounded in a distorted octahedral way by five chlorine atoms and by the nitrogen atom of the (NSeCl 2 ) 3- ligand. The W = N = SeCl 2 group is characterized by WN and SeN double bonds; the selenium atom has a pseudo trigonal-bipyramidal coordination with the N atom and two lone pairs in equatorial and the chlorine atoms in axial positions.

The Molecular Structures of [2,4,6-(CF 3 ) 3 C 6 H 2 S] 2 (1) [2,4,6-Me 3 C 6 H 2 Te] 2 and [2-Me 2 N-4,6-(CF 3 ) 2 C 6 H 2 Te] 2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P2 1 2 1 2 1 , Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 2 1 /c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).

The coordinating properties of dipod ligands of the type R 2 M′(OCH 2 PMe 2 )x(CH 2 CH 2 PMe 2 ) 2-x (R = Me, Ph; M' = Si, Ge; x = 0 -2) have been investigated by the preparation of the novel cis-M (CO) 4 L complexes (M = Cr, Mo, W). They are obtained under mild conditions in cyclohexane or n-hexane solution by the reaction of the norbornadiene precursors M(CO) 4 NBD with the corresponding ligands. In case of the Ge containing ligands the dilution principle was used to improve the yields of the mononuclear derivatives. The rate of the NBD replacement is mainly determined by the central atom M (Mo > W > Cr) and only little by R, M' or x . The new com pounds have been characterized by analytical (C, H) and spectroscopic investigations ( 1 H, 31 P NMR, IR, MS). The ligand properties are discussed on the basis of spectroscopic data (in particular coordination effects) and the molecular structure of the complexes Cr(CO) 4 [Ph 2 Si(OCH 2 PMe 2 ) 2 ] (12) and Mo(CO) 4 Me 2 Ge(CH 2 CH 2 PMe 2 ) 2 ] (28) obtained by X-ray diffraction studies.

Gas phase thermolyses of the stannylphosphanes Me 3 SnP(CF 3 )NMe 2 (3) and Me 3 SnP(C 2 F 5 )NMe 2 (4) yield the novel amino substituted fluorophosphaalkenes Me 2 N -P = CF 2 (1) (10 to 15% yield) and Me 2 N - P = C(F)CF 3 (2) (90% yield), respectively. In contrast to other derivatives, 1 cannot be prepared by the reaction of the secondary phosphane Me 2 NP(H)CF 3 (9) with secondary or tertiary amines or KOH. 1 and 2 are labile compounds which undergo quick oligomerization above 0 °C to (Me 2 NPCF 2 ) n and (Me 2 NPCFCF 3 ) n , respectively. By thermal degradation of (Me 2 NPCF 2 ) n at 500 to 600 °C the trans- 1 ,3-diphosphetane (Me 2 NPCF 2 ) 2 (11) is formed in high yield. Reaction of 2 with cyclopentadiene leads to the corresponding [2+4] cycloadduct 2-dimethylamino-3-fluoro-3-(trifluoromethyl)-2-phosphabicyclo [2.2.1]-hept-5-ene (12). New compounds were characterized by spectroscopic methods (NMR, MS).

The phase diagrams of the systems of trimethylbromosilane and the isomeric lutidines are shown. The existence of the congruently melting addition compounds (CH 3 ) 3 SiBr ∙ (3,4-lutidine), (CH 3 ) 3 SiBr (3,5-lutidine) and the incongruently melting addition compounds (CH 3 ) 3 SiBr • (2,3-lutidine) 2 , (CH 3 ) 3 SiBr • (2,3-lutidine), (CH 3 ) 3 SiBr (2,4-lutidine), ((CH 3 ) 3 SiBr) 2 • (2,4-lutidine), (CH 3 ) 3 SiBr • (2,5-lutidine) 2 , (CH 3 ) 3 SiBr • (2,5-lutidine), (CH 3 ) 3 SiBr (2,6-lutidine) 2 could be proved.

The aralkyl and aralkoxy mercury(II) compounds 1-(chloromercury(II)methyl)naphthalene (1), bis[1-naphthylmethyl]mercury(II) (2), 1-naphthyl(1-naphthylmethyl)mercury(II) (3), 1,8-bis[chloromercury(II)methyl]naphthalene (4), methylmercury(II)-benzylate (5), methylmercury( II)-1-naphthylmethylate (6) and bis[methylmercury(II)]μ-1,8-naphthalenediyl-bismethylate (7) have been prepared and characterized by means of NMRspectroscopy, mass spectrometry and elemental analysis. The molecular structure of compound 2 has been determined by single X-ray crystallography. The unit cell of 2 contains two crystallographically independent molecules, one of which is disordered. The interatomic distances and angles meet the expectations with Hg ⋯ Hg separations larger than 5.60 Å, indicating the absence of metal metal interactions.

The crystal structure of (AsPh 4 ) 2 [Te(S 2 C = C(CN) 2 ) 2 ] has been determined by X-ray diffrac tion and the electronic structure has been calculated using an effective core potential approach for core electrons of Te and minimal basis-sets for valence electrons of Te and electrons of S, C and N. Te is situated in the center of planar [Te(S 2 C = C(CN) 2 ) 2 ] 2- anions and is coordinated by four sulfur atoms in a trapezoid geometry with Te -S distances of 2.463(4), 2.524(4), 2.819(4) and 2.945(3) Å. The compound crystallizes in the triclinic space group P 1̄ with a = 9.562(5), b = 11.430(6), c = 27.319(20) Å, α = 93.248(2), β = 91.06(2), γ = 112.23(4)° and Z = 2. The trapezoid geometry allows a straightforeward mixing of Te 5 s-and one 5p-orbital giving rise to the formation of sp-hybride orbitals.

The title compounds have been prepared by controlled hydrolysis of CF 3 NCO in NEt 3 . Their 13 C, 19 F and 1 H NMR spectra are reported and their I R gas and I R matrix spectra are discussed in terms of a normal coordinate analysis. The photoelectron spectrum of F 2 C = NH is compared with those of F 2 C = NF and H 2 C = NH revealing a strong fluoro effect. In the solid state F 2 C = NH is aggregated to infinite zig-zag chains by N • • • H hydrogen bonding.

The title compound was obtained by arc melting of the elemental components and subsequent annealing in a high frequency furnace. It crystallizes with the orthorhombic space group Cmmm, a = 779.26(7) pm, b = 1362.0(1) pm, c = 320.62(3) pm, V = 0.3403 nm 3 , Z = 2. The structure was determined from single-crystal X-ray data and refined to a residual of R = 0.021 (692 F values and 21 variables). It is closely related to the NaCl-structure. Three of the seven carbon atoms per formula unit form linear C 3 -units with C-C bond lengths of 134 pm. They are coordinated to ten Sc atoms forming bicapped quadratic prisms. Additional isolated C atoms are located in octahedral voids formed by four Sc and two Re atoms. Together with the Re atoms they form two-dimensionally infinite [Re 2 C 4 11- ] n polyanions. The Re atoms have highly distorted tetrahedral carbon coordination with Re -C bond lengths of 200 and 208 pm corresponding to bond orders of about two. This coordination seems to be compatible with the 18-electron rule. The near-neighbour coordination of the Re atoms is assymmetric. It is suggested that this is due to the space requirements of nonbonding electrons. Samples of Sc 5 Re 2 C 7 are semiconducting and weakly paramagnetic.

By electrochemical oxidation of an aqueous silver perchlorate solution (c(Ag + ) = 2.0 M) a new compound with the formula Ag 20 O 33 H 22 (ClO 4 ) 4 was obtained. The crystal structure has been determined by use of single-crystal diffractometer data (Fd 3̄̄ m , a = 20.234(1 )Å , Z = 8). It contains H 22 O 17 12- clusters, which exhibit close relationships to the structures of gas hydrates. The clusters are linked through a three-dimensional Ag-O-network being similar to that one present in Ag 7 O 8 X.

Trifluoromethanesulfenylfluoride, CF 3 SF, adds to the carbon-sulfur double bond to form fluorinated compounds containing a trifluoromethyldisulfanyl group. Reactions of CF 3 SF with CS 2 ,CF 2 S,CCl 2 S and (CF 3 S) 2 CS are described.

Condensation o f 1-alkyl-2-aminopyridinium halides 1 with PCl 3 in the presence of NEt 3 yields, depending on the 1-substituent, pyridinylidene am inodichlorophosphines 2 or 4H-1,4,2-diazaphospholo[4,5-a]pyridines 3. The products are characterized by 31 P, 1 H and 13 C NMR. Dimethylsulfate methylates the diazaphospholopyridines 3 at N-1.

The reaction of Cp*SiCl 3 with LiAl(PH 2 ) 4 yields the compound Cp*Si(PH 2 ) 3 (1) which rearranges in the reaction mixture at room temperature to give the new 1,3-diphospha-2,4-disilacyclobutane (1,3-diphospha-2,4-diseletane) [Cp*Si(PH 2 )PH] 2 (2). Compound 2 could be isolated in pure form and has been fully characterized by spectroscopic methods.

Silvery reflecting melting cakes of PdS 1-x Se x (0.0 ≤ x ≤ 1.0) have been prepared by annealing mixtures of Pd, S and Se at 873 K in evacuated quartz tubes. The PdS-type mixed crystals are stable only in the ranges 0.0 ≤ .x ≤ 0.2 and 0.9 ≤ x ≤ 1.0, whereas a new phase appears in the intermediate region. The new phase PdS 1-x Se x (0.2 < x < 0.9) crystallizes in the space group P4 2 /mbc and Z = 24. Lattice constants are a = 1126.2(7), c = 683.2(7) pm (PdS 0.6 Se 0. 4) and a = 1130.8(9), c = 685.4(8) pm (PdS 0.4 Se 0.6 ). The relationships between the new structure type and the PtS and PdS structure types are discussed. The infrared reflection spectra of polycrystalline samples of PdS were measured between 10 and 300 K in the frequency range from 30 to 400 cm -1 . Both phonons and plasmons contribute to the spectra. The temperature dependence of the plasmon contribution shows an unusual behaviour which is explained by the assumption of a phonon assisted hopping conductivity mechanism at low temperatures and a Drude-like transport at high temperatures. The normal mode which may be involved in the hopping process is proposed from a normal coordinate calculation using a three-parameter short range valence force field model. The electrical transport data are in general agreement with the optical ones. The infrared spectra of the mixed crystals PdS 1-x Se x (0.2 < x ≤ 1) are discussed.

Electron-and ligand-transfer reactions of low-valent organometallic compounds of titanium and vanadium with N,N-dialkylcarbamates of titanium(IV) are reported. The reaction of VCp 2 (Cp = η 5 -cyclopentadienyl) with Ti(O 2 CNEt 2 ) 4 affords, inter alia, the dimeric vanadium(III) N ,N-diethylcarbamato derivative V 2 Cp 2 (O 2 CNEt 2 ) 4 which has been studied by X-ray diffraction methods. Crystal data; triclinic, space group P1̄ ; a = 10.802(2), b = 11.004(1), c = 8.960(1) Å; α = 112.879(9), β = 102.66(1), γ = 102.42(1)°; V = 902.3(6) Å 3 ; Z = 1; F(000) = 368, ρ calc = 1.282 g cm -3 ; μ = 5.47 cm -1 . It consists of a centrosymmetric dimer, the two vanadium atoms being surrounded by four oxygen atoms of the bridging N,N-diethylcar-bamato groups and by the cyclopentadienyl ligand. The metal atom exhibits a distorted square-pyramidal coordination geometry with the oxygen atoms occupying the basal plane. The reaction of TiCp 2 (CO) 2 or Vmes 2 (mes = η 6 -1,3 ,5 -Me 3 C 6 H 3 ) with Ti(O 2 CNEt 2 ) 4 affords Ti(III) and V(III) N,N-diethylcarbamato derivatives by a simultaneous ligand-and electron-transfer reaction. Magnesium N ,N-diisopropylcarbamate, Mg(O 2 CNPr i 2 ) 2 , has been obtained by a ligand-transfer reaction between MgCp 2 and Ti(O 2 CNPr i 2 ) 3 .

Solid products obtained from calcium hydroxylapatite suspensions in diluted VO 2+ solutions, under different experimental conditions, were investigated by means of X-ray powder diffractometry and IR and ESR spectroscopy. It is demonstrated that the VO 2+ cation cannot be incorporated into the apatite-lattice but is strongly adsorbed on the surface of the material. Different aspects of this adsorption were thoroughly investigated. The ESR spectra suggest an inhomogeneous distribution of the adsorbed species and the generation of O = V (O) 4 moieties, which show a high stability towards oxidation.

The luminescence of aquatic humic substances in water is quenched over a broad range of pH by paramagnetic metal ions like iron(II) and manganese(II). The efficiency dependents on the pH of the solution and rises with increasing basicity; this parallels the complexing of metal ions by humic substances. No quenching of the luminescence is observed by the addition of aluminium(III).

Transparent, ruby red crystals of the new compound K 2 Sn 4 Se 8 were obtained from K 2 Se, Sn and Se by high temperature synthesis. K 2 Sn 4 Se 8 is monoclinic, space-group Cm with a = 6.436(3) Å, b = 18.934(9) Å, c = 7.417(5) Å, β = 96.26(2)°; Z = 2. The crystal structure was refined to a conventional R of 0.022 (R w = 0.018). In K 2 Sn 4 Se 8 the tin atoms have two distinct oxidation states +2 and +4. Sn(IV) is tetrahedrally coordinated by Se, Sn(II) has a pseudo-trigonal bipyramidal coordination MA 4 E which reveals a pronounced stereo-activity of the lone pair of electrons. In the crystal structure the Sn(IV)Se 4 -tetrahedra share common apices, yielding open sheets which are separated from each other by the alkali cations, but connected via the Sn(II) centers.

Transparent yellow single crystals of Na 4 SnSe 4 and K 4 SnSe 4 were prepared by reacting stoichiometric powdered mixtures of the binary compounds Na 2 Se or K 2 Se, Sn and Se at 850 K. Na 4 SnSe 4 is tetragonal, s.g. P4̄2 1 c, with a = 8.165(2) Å, c = 7.268(2) Å, Z = 2. K 4 SnSe 4 is orthorhombic, s.g. Pnma, with a = 14.714(7) Å, b = 10.323(3) Å, c = 8.248(6) Å, Z = 4. The crystal structures were refined to conventional residuals of 0.058 and 0.031, respectively. Both com pounds are characterized as salts with discrete tetrahedral selenostannate anions. Na 4 SnSe 4 is isostructural with Na 4 SnS 4 , K 4 SnSe 4 is of a new type. The observed Sn -Se bond lengths range from 2.494 Å to 2.536 Å.

Ethyl 5-amino-3,4-diphenyl-7H-pyrrolo[2,3-c]pyridazine-6-carboxylate (1), ethyl 5-aminofuro[ 2,3-c]pyridazine-6-carboxylate (2) and 5-aminofuro[2,3-c]pyridazine-6-carboxamide (3), are obtained from 4-cyano-5,6-diphenyl-3(2H)-pyridazinone. 5-Acetamido and 5-chloroacetamido derivatives prepared from 1, undergo cyclization on heating to form 2-substituted pyridazino[4',3':4,5]pyrrolo[3,2-d]oxazin-4(5H)-one (5a, b). The reaction of 1 and 2 with hydrazine gave 6-carbohydrazide derivatives (7 a, b). Compound 3 undergoes condensation with acetyl chloride, chloroacetyl chloride, benzoyl chloride, formamide and carbon disulphide to furnish the corresponding pyrimido[4',5' :4,5]furo[2,3-c]pyridazin-4(3 H)-one derivatives. The reaction of 1 with o-aminophenol gave 3,4-diphenyl-11-oxo-10,11-dihydro-12H -pyridazino[ 4',3' :4,5]pyrrolo[3,2-b][1,5]benzoxazepine.

Phosphono-, phosphino-, and phosphinyl-sarcosine derivatives are obtained from 4-bromo-3-methyl-2,2-bis(trifluoromethyl)-1.3-oxazolidin-5-one (8) via M ichaelis-Arbusov reaction.

LiSr 2 [CoN 2 ] (tetrag., P4 2 /mnm (Nr. 136); a = 524.4(1) pm, c = 730.7(2) pm; Z = 2) was prepared by reaction of mixtures of Li, Sr 2 N and Co (molar ratio 6:3:1) in tantalum crucibles under nitrogen (1 atm) at 850 °C. The crystal structure (α-Li 3 [BN 2 ]-type) contains linear anions [Co 1 N 2 ] 5- (Co-N : 181.0(5) pm) which are isostructural to [Fe 11 N 2 ] 4- (Li 4 [FeN 2 ]) as well as to the maingroup species CO 2 and [BN 2 ] 3- .

The signs o f the coupling constants 1 J(31P≡13C) ( > O ) , J( 31 P 13 C) ( > O ) , 3 J( 31 P 13 C) ( > O ) and 4 J( 31 P 1 H) ( > O ) in tert-butyl-phosphaalkyne (1) were determined by selective 1 H { 31 P} NMR experiments and two-dimensional (2 D ) 13 C/ 1 H heteronuclear shift correlations based on n J( 13 C 1 H ) (n = 1,2,3), confirming the previously assumed positive sign of 1 J( 31 P≡ 13 C) in phosphaalkynes.

Abstrac t By headspace analysis of the essential oil of Vetiver hitherto sixteen not described volatile constituents, mainly monoterpenes, could be identified. For these investigations GC -FID , GC-MS, GC-FTIR and the GC-sniffing-technique were used.

The crystal structure of the title compound was determined at -9 5 °C. It crystallizes in space group P1̄ with a = 577.5(3), b = 820.2(3), c = 1916.6(8) pm, α = 83.34(2), β = 82.83(2), γ = 83.61(2)° and Z = 2. The final R value was 0.034 for 3019 unique observed reflections. The presence of aggregates of four ions (two cations and two an­ ions) in the solid state is observed, with short cat-ion-anion contacts S II ⋯ O (290 pm) and Cl ⋯ O (298 pm). The bond lengths of the 4-dimethylaminopyridinium moiety of the cation suggest a semiquinoid resonance form with a double bond to the nitrogen of the dimethylamino group and two localized double bonds in the ring. The ring, the dimethylamino group (except H atoms) and the Sn atom are coplanar. The S II -N bond length is 170.3 pm, the N -S II -C angle 99.6°. The S II -C bond is approximately perpendicular to the ring plane.

Single crystals of Zn 4 Fe II 5 (PO 4 ) 6 ∙ 4H 2 O were grown by hydrothermal treatment of phosphophyllite (Zn 2 Fe(PO 4 ) 2 ∙ 4H 2 O) in H 2 O at 180 °C. The crystal structure (tricl., P1̄; a = 651.6(4) pm, b = 902.7(4) pm, c = 995.4(4) pm, α = 69.01(5)°, β = 78.19(5)°, γ = 75.33(5)°; Z = 1) can be derived from the Zn 2 (Zn 1-x Fe x )Fe III (PO 4 ) 3 ∙ 2H 2 O structure by reduction of Fe III to Fe II and by filling a "structure hole" with an additional Fe II .

The structures of the lichen chromones galapagin, lobodirin, mollin, and roccellin, specific com­ pounds of Roccellaceae (lichens), have been es­ tablished as 1, 2, 3, and 4, respectively, by NOE difference spectroscopoy.