Band 43, Heft 1

The title compound has been prepared by the reaction of N-trimethylsilyl-iminotriphenylphos-phorane with copper(II) chloride in boiling CCl 4 /C 2 H 5 OH, and forms moisture sensitive crystals, which are green in transmittance and black in reflexion. [Me 3 SiNPPh 3 · CuCl 2 ] 2 was characterized by its IR spectrum as well as by a crystal structure determination (4197 observed, independent reflexions, R = 0.049). The lattice dimensions are at 20 °C: a = 1102.7. b = 1407.3. c = 1560.2 pm; β = 94.27°; space group P2 1 /n with two formula units in the unit cell. The complex consists of centrosymmetric, dimeric molecules with a planar Cu 2 Cl 2 ring (Cu-CI bond lengths 229 and 231 pm). A terminally bonded CI atom (Cu-CI = 221 pm) and the N atom of the Me 3 SiNPPh 3 ligand (Cu-N = 198.5 pm) complete the coordination number four of the nearly planar surroundings of the Cu atoms.

The title compounds Ph 3 PNPh · CuCl (1) and (Ph 3 P) 2 N 2 C 4 O 2 (NMe) CuCl (2) have been prepared by the reactions of CuCl with the corresponding phosphoranimines Ph 3 PNPh and 2.3-bis(triphenylphosphoranylideneamino)maleic acid N-methylimide, respectively. Both com-plexes were characterized by their IR spectra as well as by crystal structure determinations. Ph 3 PNPh · CuCl (1): space group P1, Z = 4, 3639 independent observed reflexions, R = 0.038. Lattice dimensions (18 °C): a = 1047.6; b = 1251.5; c = 1755 pm; α = 103.43°; β = 97.24°; γ = 101.30°. The compound forms monomeric molecules; the asymmetric unit contains two crystallo-graphically independent molecules. The CuCl molecule is bonded via the N atom of the phos-phoranimine. Bond lengths: Cu-N = 189 pm; Cu-CI = 209 pm; bond angle N - Cu - CI = 177°. (Ph 3 P) 2 N 2 C 4 O 2 (NMe) · CuCl (2): space group Pbca, Z = 8, 5611 independent, observed reflexions, R = 0.069. Lattice dimensions (25 °C): a = 1224.3; b = 1962.5: c = 2994.0 pm. The compound forms monomeric molecules with the CuCl molecule bonded via one of the N atoms of the phosphoranimine groups. Bond lengths: Cu - N = 194 pm; Cu-CI = 212 pm; bond angle N-Cu -CI -175°.

W 2 NCl 7 has been prepared by the reaction of tungsten pentachloride with the bromide of Millon's base, [Hg 2 N]Br, in boiling CCl 4 . The product forms a dark brown, moisture sensitive crystal powder (μ eff = 0.7 B.M. at 21 °C). With phosphoryl chloride, the complex W 2 NCl 7 ·2 POCl 3 is formed. The reaction with chlorine leads to the mixed-valenced W(V)/W(VI) complex W 2 NCl 8 (μ eff = 0.5 B.M. at 22 °C), which reacts with tetraphenylphosphonium chloride in CH 2 Cl 2 to form (PPh 4 ) 2 [W 2 NCl 10 ] ·2CH 2 Cl 2 . The reactions of W 2 NCl 7 with PPh 4 Cl in molar ratios in CH 2 Cl 2 solution lead to several complexes; one of them was identified bv X-ray diffraction methods to be (PPh 4 ) 2 [W 3 Cl 9 (μ 3 -N)(0)(μ 2 -NCl)] 2 ·1,5 CH 2 Cl 2 , which forms black crystals. The compound crystallizes monoclinically in the space group P2 1 /n with two formula units per unit cell (7318 observed, independent reflexions, R = 0.083). The lattice dimensions are (20 °C): a = 994.4; b = 2673; c = 1518.2 pm; β = 101.00°. The compound consists of PPh 4 ⊕ cations and centrosymmetric anions [W3Cl 9 (μ 3 -N)(O)(μ 2 -NCl)] 2 2⊕ . The tungsten atoms form a scalene triangle with WW bond lengths of 282 and 278 pm, respectively. The hypothenuse of this triangle is a nearly linear W - N -W bridge with WN distances of 199 and 182 pm. One of the WW edges is bridged by a μ-NCI group with WN bond lengths of 196 und 189 pm. respectively.

The preparation and crystal structure of the first octasulfide is described. The reaction of triethylamine, sulfur and dihydrogen sulfide in a solution of formamide yields orange-red crystals of bis(triethylammonium)octasulfide. The crystals are orthorhombic, space group Pbcn. with 4 molecules per unit cell. The cell constants are a = 23.709(4) Å. b = 13.276(4) Å. c = 7.388(2) Å. The chains of sulfur, S 8 2- , do not show the common helical all-trans conformation, but a mixed sequence with the signs of the dihedral angles (++−++ and −−+−−).

Acetal complexes of the type (OC) 5 MnCH(XR) 2 , RX = PhO (1a), (RX) 2 = 1,2-dioxybenzene (1b), (RX), = S-(CH 2 ) 3 -S (2) and (5) were synthesized. Glyoxyloyl acetal derivatives (OC) 5 MnC(O)CH(XR) 2 , RX = PhO (3a), (RX) 2 = 1,2-dioxybenzene (3b), (RX) 2 = S-(CH 2 ) 3 -S (4) were obtained by the action of NaMn(CO) 5 upon the corresponding acid chlorides or anhydrides, la can be transformed to 3a by CO insertion, 1a has been characterized by an X-ray structure determination.

The synthesis of the trimethylsilyl derivatives of the PH-functional methylenebisphosphanes, R 2-n (Me 3 Si) n P-CH 2 -PR(SiMe 3 ) (R = Me, iPr, tBu, Ph, 2.4.6-Me 3 C 6 H 2 ; n = 0.1) is reported. In the Li-phosphides R 2-n Li n P - CH 2 - PLiR used as reactive intermediates, a monomer-oligomer association equilibrium causes a rapid Li-exchange as indicated by the solvent and temperature dependent 31 P{ 1 H} and 7 Li NMR spectrum of (iPr) 2 P-CH 2 -P(iPr)Li in various solvents (Et 2 O, THF and MTHF) in the temperature range from 30 to -110 °C. For the syntheses of the Me-and Ph-substituted PH-functional methylenebisphosphanes R 2 P-CH 2 -PRH and RHP-CH 2 -PRH (R = Me, Ph) the chlorophosphane CKP -CH 2 -PCl 2 is used as a starting material. Bifunctional substituents (Ph -N̍-N̍ -Ph and Me -N̍-CO-N̍-Me) are employed for the first time as protecting groups to block one or two PCl-functions in Cl 2 P-CH 2 -PCI 2 ,. Cleavage of the PN-bonds in the five membered ring systems (R = Me, Ph) with HCl affords the P-substituted methylenebis-chlorophosphanes RClP-CH 2 - PClR in satisfactory yields. The compounds have been characterized by 1 H, 13 C{ 1 H} and 31 P{ 1 H} NMR spectroscopy. With-in homologous substitution series of methylenebisphosphanes, e.g. R 2 P-CH 2 -PR 2-n H n the coupling constants 2 J(PP) seem to reflect conformational changes at the PCP-skeleton.

t-Butyloxytin(II) chloride (1) is prepared from SnCl 2 and KO-z-Bu at -60 °C in tetrahydrofuran. Above -30 °C a reversible dismutation into SnCl 2 and [(t-BuO) 2 Sn] is observed in THF. For this process Δ G = +38 kJ/mol is estimated from NMR data. Compound 1 is a centrosymmetric dimer in the solid state with bridging O atoms (Sn-O 2.153(2)/2.156(2) Å, O-Sn-O 73.0(1)°, Sn-O-Sn 107.0(1)°). Due to the acute intraring bond angles at Sn. the O···O distance across the four-membered ring is relatively short (2.563(3) Å). The dimers are very loosely connected to chains by bridging THF molecules.

Trimethylsilylethine (1) has been prepared from C 2 H 2 , sodium and Me 3 SiCl in anisole. The product can be converted into a Grignard reagent Me 3 SiC≡CMgCl using iPrMgCl. This reagent yields the compounds Me 3 SiC≡CSiH 3 , (Me 3 SiC≡C) 2 SiH 2 , (Me 3 SiC≡C) 3 SiH, and (Me 3 SiC≡C) 4 Si (2-5) when treated with equivalent amounts of H 3 SiBr, H 2 SiBr 2 , HSiCl 3 , or SiCl 4 . respectively. The new silanes have been characterized by NMR data. The crystal structure of (Me 3 SiC≡C) 4 Si has been determined by single crystal X-ray diffraction. It shows the expected tetrahedral geometry at he central silicon atom with four linear SiC≡CSi linkages.

The reaction of LiAlH 4 with dimethylamine has been studied in THF, diglyme and diethyl ether solution covering the molar ratios 1:0.5 to 1:4. In all cases the stoichiometric amount of H 2 s evolved. With the exception of LiAl[N(CH 3 ) 2 ] 4 all other members of the series LiAlH 4-n [N(CH 3 ) 2 ] n cannot be isolated. They are in equilibrium with one another in solution, these equilibria are independent of the solvent used. The structure of compound LiAl[N(CH 3 ) 2 ] 4 · 2(OC 4 H 8 ) has been determined by X-ray diffraction. The anion acts as a bidentate ligand to Li which is also bonded to the oxygen atoms of two THF molecules.

The iminoboranes RB≡NR′, 2a-f, are formed by the elimination of Me 3 SiHal from the corresponding aminoboranes 1a-f. Stabilization occurs either through cyclodimerisation (→3b-d,f), cyclotrimerisation (→4e), bicyclotrimerisation (→5b) or cyclotetramerisation (→6a). Trialkylboranes BX 3 are added to give the diboryl amines . 7a-f. The Δ 2: -tetraazaborolines . 8a-f, are the (3+2)-cycloaddition products from 2a-f and azides X′N 3 . A CH-bond of cyclopentadiene adds to one of the BN bonds of 2f, giving a mixture of the corresponding 1,3- and 1,4-cyclopentadienyl boranes. 9f, 9′f.

The new compound Na 8 SnSb 4 has been prepared from appropriate mixtures of the elements at 700 °C in evacuated silica ampoules coated with glassy carbon. The structure has been determined by single crystal X-ray diffraction data (cubic, space group Fd3m, a - 1481.6(3) pm, Z = 8, R = 0.044 for 263 reflections). There are isolated tetrahedral SnSb 4 8- units (bond length Sn -Sb = 284.3 pm), proving the compound to belong to the Zintl phases.

The reaction of Ph 3 AsCl 2 (1) and N(SiMe 3 ) 3 (2) yields [Ph 3 As-N-AsPh 3 ] + Cl (3) as a crystal­line white solid, soluble in CH 3 OH and acetone. 3 might be used to stabilize unusual anions. It crystallizes as a 1:1 toluene adduct in the space group C2/c with a - 1585.3(3). b = 1058.7(2). c = 2266.3(4) pm. β = 94.40(2)° and Z = 4. The cation in 3 lies on a crystallographic two-fold axis with As-N-As 123.9(1)°. As-N 174.9(3). and As-C 196.7(5). 197.6(5). 193.2(5) pm.

The synthesis of 3-tert-alkyl-3-oxo-1-arninopropane-1,1-diphosphonic acids and of 3-tert-alkyl-3-oxo-prop-1-ene-1,1-diphosphonic acids as two new groups of metal complexing agents and their chemical properties are described. Evidence is given for their suggested structures. In addition, the first known example of a diphosphonic acid with a cyano group attached to the geminal carbon atom was prepared from 3-oxo-1-aminoalkane-1,1-diphosphonic acids and 3-terr-alkyl-3-oxo-1-hydroxypropane-1,1-diphosphonic acids from 3-oxo-1-aminopropane-1,1-diphosphonic acids.

Crystal and molecular structure analysis of the electron rich title compound exhibits an undistorted, yet sterically shielded tetra(primary alkyl)-substituted double bond system with alternating anti-periplanar CH 2 SiMe 3 substituents. The diastereotopic methylene protons have been located and their position correlated to the 1 HNMR data and to the ESR hyperfine coupling constants of the corresponding radical cation. In contrast to the highly inert all-carbon derivative, tetraneopentylethene, the more electron-rich and more flexible organosilicon title compound reacts with bromine. Close to orthogonal arrangement between the C-C(H 2 )-Si planes and the ethene plane ensures effective, fourfold σ/π-hyperconjugation.

The title compound crystallizes in the triclinic space group P1̅ with lattice parameters a = 13.129 Å, b = 14.156 Å, c = 14.843 Å and α= 88.34°, β = 74.43°, γ = 70.86°. The polyanion evidently is the predominant species in pseudometatungstate phases the exact composition of which has not previously been determined.

Through careful acidification of the aqueous solution of [OsO 2 (OH) 4 ] 2- in the presence of CN - or 13 CN - with acetic acid, [OsO 2 (CN) 4 ] 2- or [OsO 2 ( 12 CN) 4 ] 2- are formed, respectively. The reaction of Os 18 O 4 and tetrabutylammonium cyanide with glacial acetic acid in anhydrous methanol yields [Os 18 O 2 (CN) 4 ] 2- . The shifts of the infrared and Raman bands of the isotopically labelled complexes are in good agreement with Teller-Redlich calculations. The degenerate E modes, expected for tetragonal symmetry, are split by approx. 15 cm -1 , indicating an orthorhombic distortion of the complex ion in the solid state. Therefore, all the observed IR- and Raman frequencies are assigned according to point group D 2h . For the complex containing an 18 O=Os= 18 O axis, the symmetry is lowered to C 2v , and the rule of mutual exclusion is restricted. This results in a weak absorption in the infrared spectrum of the Raman active symmetric OsO stretching vibration and vice versa a weak band in the Raman spectrum for the antisymmetric infrared active mode.

SrC 4 O 4 ·3 H 2 O, type III. was obtained in an aqueous silica gel besides crystals of SrC 4 O 4 -3 H 2 0. type I. X-ray crystal structure analysis showed close relationship to BaC 4 O 4 -3H 2 0. but no isotypism. Sr 2+ is coord|inated by four water molecules and four oxygen atoms of the squarate dianion. The connection of Sr 2+ with C 4 O 4 2- leads to layers. The geometry of C 4 O 4 2- is typical for delocalized π-systems. The O squarate atoms are not equally bound to Sr 2+ . One O squaralc atom (0(4)) is bound to two Sr 2+ , two (O(1). O(2)) are bound to one Sr 2+ , respectively, and the fourth O squaratc atom (0(3)) shows no bonding contact to Sr 2+ . These differences are compensated for by intermolecular hydrogen bonds which involve O(3) three times, O( I) and O(2) once each, but not O(4).

9,9-Dimethyl-9-silaacridane 3a was synthesized by ringclosing reactions of N-trimethylsilyl-bis(2-halogenophenyl)amines with dichlorodimethylsilane and acid cleavage of the silyl groups (eqs (6-9)). Syntheses of N-organyl-substituted 9,9-dimethyl-9-silaacridanes 13 occurred by ring closure of N-organyl-bis(2-halogenophenyl)amines 12 with dichlorodimethylsilane. organyl groups here being dimethylaminoethyl. pyrrolidinoethyl, piperidinoethyl, 3-dimethylamino-2-methyl-propyl and (1-methylpiperidin-3-yl)methyl. 13 were transformed to their hydrochlorides and methoiodides 14. Structures of 13 are compared with those of analogous compounds bearing aminopropyl-side chains and discussed in the light of psychopharmacological effects of tricyclic ring systems.

Bis(oxamido)trisulfane was obtained first as a by-product in the synthesis of 3,4-dihydroxy- 1,2,5-thiadiazole, later in direct syntheses from 3,4-diethoxy-1,2,5-thiadiazole. Reaction with anhydrous CuCl 2 gave bis(oxamido)trisulfane copper(II). Bis(oxamido)trisulfane is monoclinic P2 1 /n, a = 8.975(2) A. b = 8.875(1) Å, c = 12.781(2) Å. β = 94.40(2)°, V = 1015.05(4) Å 3 , Z = 4, M r = 270.31, D x = 1.76 g cm -3 , MoK α,λ = 0.7107 Å, μ = 7.0 cm -1 , wR = 0.038 for 1371 observed independent reflections. Bis(oxamido)trisulfane copper(II) is triclinic PI, a = 5.279(1) Å, b = 11.388(3) Å, c = II.943(4) Å, a = 89.08(2)°, β = 82.62(2)°, γ = 86.44(2)°, V = 710.8(3) Å 3 , Z = 2, M r = 331.83, Dv = 1.56 gcm -1 , MoK α,λ =0.7107 Å, μ = 19.89 cm -1 , wR = 0.039 for 1974 observed independent reflections.

Organodisulfide radical cations R 2 S 2 ′ ⊕ and R 2 C 2 S 2 ′ ⊕ can be generated from aliphatic as well as aromatic cyclic polysulfides in AlCl 3 /H 2 CCl 2 solutions and characterized by their ESR spectra. Examples presented are the oxidations of 1,2,3-trithiolanes to 1.2-dithiolane radical cations, in which energetically favored planarized 3 electron/2 center bonds are formed.

2,7-Di-tert-butyl-2,7-dihydro-benzo[ 1,2-c:3,4-c′]dipyrrole (2b) and 2,5,8-Tri-tert-butyl-5.8-di-hydro-2H-benzo[1,2-c:3,4-c′:5,6-c″]tripyrrole (3b) have been prepared by acetolysis of the cor-responding tri-and tetracyclic N-oxides, isolated in crystallinic form and characterized by spectroscopic data. The scope of the N-oxide route is documented and the existence of benzoannellated pyrroles is proofed. The stabilizing effect of the tert-butyl group is presumably sup-ported by the vicinal annellated heterocycles.

The unit cell of TlBrI 2 (4-methylpyridine-N-oxide) 2 is orthorhombic, space group Pnna. with a = 1126.9(3),b = 919.8(2),c = 1210.4(3) pm.and Z = 4. The structure consists of discrete TlBrI 2 (4-methyl-pyridine-N-oxide) 2 molecules which have a distorted trigonal-bipyramidal geometry. The thallium atom is coordinated to two iodine atoms and a bromine atom in equatorial positions, and by two 4-methyl-pyridine-N-oxide ligands in the axial positions.

The quantitative elimination of chlorine and bromine from acidic aqueous solutions was achieved through extraction with a dilute solution of styrene in CCl 4 .