Volume 50, Issue 6

The phosphonic acid anhydrides of the general formula [RPO 2 ] n have been prepared with R = Me, Et, i-Pr, t-Bu, and Ph from the corresponding phosphonic acids and their chlorides and esters. Mass spectrometric data indicate that the trimers are the dominant oligomers for all five systems. According to their NMR spectra, the methyl and t-butyl compounds have a symmetrical (C 3v ) structure with equivalent RP groups, while the ethyl, i-propyl and phenyl homologues have the C s structure with non-equivalent PR groups in the ratio 1:2.

The reaction of tris[(tri- t butyl-phosphine)gold(I)]oxonium tetrafluoroborate with close to stoichiometric quantities of ammonia in dichloromethane at -78 °C affords tetrakis[(tri- t butyl-phosphine)gold(I)]ammonium tetrafluoroborate, the structure of which has been determined by single crystal X-ray diffraction. The cation features a strongly distorted NAu 4 tetrahedron with four short and two longer Au -Au edges. - With a large excess of ammonia, only partially aurated ammonium salts are formed, as suggested by detailed NMR spectroscopic and mass spectrometric studies. These partially aurated intermediates have not been isolated. Slow decomposition processes in these solutions lead to the precipitation of bis(tri- t butyl-phosphine)gold(I) tetrafluoroborate. The structure of the bis(chloroform) solvate has also been determined. The crystals contain two independent C 3 -symmetrical cations with similar structures.

The crystal and molecular structure of the complex [Cu(Dipy){NDA}Cl] · H 2 O , where (NDA) = {ONC(CONH 2 ) 2 } − anion (space group P 1̄, triclinic, with a = 7.834(1), b = 9.923(1), c = 9.952(1)Å, α = 93.60(1), β = 93.65(1), γ = 92.72(1)°, Z = 2) has been determined from X-ray diffraction data. The structure was refined to R = 0.029 for 2243 reflections with I>3σ(I). The coordination polyhedron of Cu 2+ can be described as a distorted square pyramid with a chlorine atom in the apex, and with the central atom situated 0.258(3) A above the base of the pyramid towards the chlorine atom. The complicated system of hydrogen bonding involving the water of crystallization connects copper complex units in to the chains in the c direction.

Single crystals of KMg 3 Pd (AsO 4 ) 3 have been p repared by solid state reactions below the melting point of the reaction mixture. This compound crystallizes isotypic to the mineral Johilleriteo with monoclinic symmetry, space group C 2h 6 -C 2/c , a = 12.098(3) Å, b = 12.853(5) Å , c = 6.688(3) Å, β = 112.92(3)°, Z = 4. The crystal structure is characterized by AsO 4 tetrahedra, isolated planar but twisted PdO 4 polygons, MgO 6 octahedra and a 2+4+2- coordination of potassium . From the point of view of crystal chemistry KMg 3 Pd (AsO 4 ) 3 both belongs to the arsenates and oxopalladates(II).

Single crystals of CuCdVO 4 have been prepared by CO 2 -LASER techniques. X -ray investigations of the black single crystals led to orthorhombic symmetry, space group D 2h 17 -Cmcm , a = 5.921(1), b = 9.065(4), c = 6.633(2) Å, Z = 4. CuCdVO 4 represents the first example of a quaternary oxide containing cadmium and copper(I). Compared to AgCdVO 4 , CuCdVO 4 shows a different linkage of the VO 4 and CuO 4 tetrahedra, explaining the missing isotypy of these com pounds.

Single crystals of Rb 0.6 K 0.4 CuMo 3 O 10 have been prepared by crystallization from melts and investigated by X-ray diffractometer technique. They crystallize with orthorhombic symmetry, space group D 2h 16 -Pnma , a = 8.606(2), b = 7.595(3), c - 13.660(7) Å, Z = 4. The crystal structure of Rb 0.6 K 0.4 CuMo 3 O 10 is characterized by the rare octahedral coordination of molybdenum and is related to (NH 4 ) 2 Mo 3 O 10 with respect to the one-dimensional 1 ∞ [Mo 3 O 10 ]- chains.

Single crystals of Ag 0.5 Cu 3 V 0,5 Mo 2,5 O 12 have been prepared by crystallization from melts and investigated by X -ray methods. They crystallize with triclinic symmetry, space group C i 1 -P 1̄ , a = 6.797(6), b = 8.575(6), c = 9.897(7) Å, α = 103.47(6), β = 103.69(6), γ = 101.48(6)° and Z = 4. The crystal structure is characterized by chains of edge-sharing CuO 6 octahedra and CuO 5 pyramids. Special features of this com pound are the square planar surrounding of Ag + by O 2− and a statistical distribution of molybdenum and vanadium at one point position.

β-Tetraphosphorus-trichalcogenide hydrides have been detected in the reaction mixtures of β-P 4 S 3 X 2 (X = Cl, Br, I) with (CH 3 ) 3 SnH in CS 2 solutions. In the first step of the reaction the configuration of the hydrogen accepting phosphorus atom is inverted and the compound β-P 4 S 3 X exo H endo is formed, as the main product. Two further isomers β-P 4 S 3 Cl exo H exo and β- P 4 S 3 H exo H endo w ere found in low concentrations. The second nucleophilic substitution is slow and the configuration at the second hydrogenated phosphorus atom can be retain ed or inverted. Two products, β-P 4 S 3 H exo H endo and β -P 4 S 3 (H endo ) 2 , are observed.

Ab initio calculations at the MP2/6-311 G **//MP2/6-311 G** level show that the all-trans, cis-trans and all-cis rotamers of H 2 S 4 are practically of identical energy. Their vibrational wavenumbers are also practically identical and in agreement with the observed infrared and Raman spectra of dissolved H 2 S 4 . On rotation about the central bond of H 2 S 4 the torsional barriers are found to be 32.0 (cis -barrier) and 26.6 kJ mol -1 (trans-barrier). The geometries of the two transition states with τ SSSS = 0° and 180° can be explained by hyperconjugation between the lone pairs at the terminal sulfur atoms and the σ * molecular orbital of the central bond.

Li 2 P(2,4,6-Me 3 C 6 H 2 ) reacts with Cp°MoCl 2 (PMe 3 ) 2 (Cp° = C 5 Me 4 Et) with reductive cleavage of the Mo -Cp° bond to yield MoCl 2 (PMe 3 ) 2 (1). The reaction of the Mo(II) derivative MoCl 2 (PMe 3 ) 4 with two equivalents of KPPh 2 (dioxane) 2 yields [Mo(μ-PPh 2 )(PPh 2 )(PMe 3 )] 2 (2). Both have been characterized by X-ray crystal structure determination.

The title compounds were prepared by reaction of the elemental components. They crystallize in a new structure type, which was determined from single-crystal X -ray data of CeCrSb 3 : Pbcm, a = 1310.8(3), b = 618.4(1), c = 607.9(1) pm, Z = 4, R = 0.029 for 648 structure factors and 32 variable parameters. The structure of the antimonide CeVSb 3 is isotypic: a = 1319.0(2), b = 623.92(8), c = 603.03(8) pm , R = 0.041 for 477 structure factors and 32 variables. The transition metal site and one of the three antimony sites were found to have partial occupancies resulting in the exact compositions CeV 0,91(1) Sb 2,916(4) and CeCr 0,901(9) Sb 2,909(4) . The structures contain fractional Sb -Sb bonds with distances varying between 301,5 and 316.4 pm. The transition metal atoms have octahedral antimony coordination. These TSb 6 octahedra share faces resulting in linear infinite strings with V - V and Cr - Cr bond distances of 301.5 and 304.0 pm, respectively. The structure of these com pounds contains building elements, which are also found in antimonides with ThCr 2 Si 2 , CaBe 2 Ge 2 , and HfCuSi 2 type structures.

The title compounds have been prepared by annealing cold-pressed pellets of the binary nitrides LnN and CrN. Well developed crystals were obtained by recrystallization of the binary or prereacted ternary nitrides in a Li 3 N flux. Their structures were determined from single-crystal diffractometer data. C e 2 CrN 3 has a U 2 CrN 3 type structure: Immm , a = 379.0(1), b = 340.4(1), c = 1251.7(2) pm, Z = 2, R = 0.012 for 383 structure factors and 16 variables. The atomic positions of this structure are similar to those of U 2 IrC 2 and K 2 NiF 4 . The structure may be rationalized to a first approximation with the formula (Ce +4 ) 2 [CrN 3 ] 8− . The chromium atoms are in a distorted square-planar nitrogen coordination. The CrN 4 -squares are linked via corner-sharing nitrogen atoms, thus forming infinite, straight - N - CrN 2 - N - CrN 2 - chains. The cubic structure of La 3 Cr 10−x N 11 (a = 1298.2(1) pm ), Ce 3 Cr 10−x N 11 (with a small homogenity range; a = 1284.3(1)-1286.1(3) pm ), and Pr 3 Cr 10−x N 11 (a = 1289.1(2) pm ) was determined for the lanthanum compound: Fm 3̄ m , Z = 8, R = 0.027 for 189 F values and 18 variables. One chromium site was found to have an occupancy of only 80.9(5)% resulting in the composition La 3 Cr 9.24(1) N 11 . The nitrogen atoms occupy four atomic sites. Three of these have octahedral environments (6 La, 3 La + 3 Cr, 2 La + 4 Cr), the fourth one is surrounded by eight chromium atoms forming a cube. The chromium atoms are tetrahedrally coordinated by nitrogen atoms, and these CrN 4 -tetrahedra are linked via common corners and edges to form a three-dimensionally infinite polyanionic network. In addition the chromium atoms with oxidation numbers of about 2 to 3 form numerous Cr - Cr bonds, which allow to rationalize the Pauli paramagnetism of the compound.

The complexes 18 C 6 · 2 HN (SO 2 -2 -Naphthyl) 2 (2a) and 18 C 6 · 2 i PrOH · 2 HN (SO 2 Ph) 2 (3e) were obtained by co-crystallization of 18-crown-6 (18 C 6) with the appropriate di(arenesulfonyl) amine from isopropanol solutions at temperatures ≥20 °C (for 2a) or at - 20 °C (for 3e). Both structures contain isolated formula units displaying crystallographic inversion symmetry. The conformation of the crown rings is characterized by the torsion angle sequence g + g + aag − g + ag + ag − g − aag + g − ag − a, unprecedented in solid-state structures of 18C 6 complexes. The six ether oxygen atoms and four out of twelve carbon atoms of the ring are coplanar within ± 7 pm. In 2a (triclinic, space group P 1̄) , the disulfonylamine molecules are linked to the oxygen atoms of the g ± g ∓ g ∓ units via N -H ··· O hydrogen bonds ( H ··· O 201 pm, N - H ··· O 161°). In 3e (triclinic, space group P 1̄ ) , each amine is N - H ··· O bonded to an isopropanol molecule (H ··· O 193 pm , N - H ··· O 175°) that is connected to a crown oxygen atom of the same conformational type as indicated above for 2a (H ··· O 198 pm, O - H ··· O 166°).

The reaction of (η 5 -C 5 H 4 SiMe 3 ) 2 TiCl 2 (1) with HO(CH 2 ) n C ≡ CR (2a: n = 1, R = H; 2b: n = 1, R = CH 3 ; 2c: n = 1, R = CH 2 OH ; 3: n = 2, R = H; 4: n = 4, R = H) affords in toluene at 25 °C in the presence of NEt 3 the monoalkyne-ol substituted titanocenes (η 5 -C 5 H 4 SiMe 3 ) 2 Ti(Cl)[O(CH 2 ) n C ≡ CR] (5a: n = 1. R = H; 5b: n = 1, R = CH 3 ; 5c: n = 1, R = C H 2 OH; 6: n = 2, R = H; 7: n = 4. R = H ). Compound 5c reacts with one equivalent of 1 in the presence of NEt 3 to yield (η 5 -C 5 H 4 SiMe 3 ) 2 (Cl)Ti-OCH 2 C ≡ CCH 2 O -Ti(Cl)(η 5 -C 5 H 4 SiMe 3 ) 2 (8). In addition, compound 8 can be synthesized directly by treatment of (η 5 - C 5 H 4 SiMe 3 ) 2 TiCl 2 (1) with 0.5 equivalents of HOCH 9 C≡CCH 2 OH (2c) in the presence of NEt 3 . The reaction of (η 5 -C 5 H 4 SiMe 3 ) 2 Ti(Cl)(OCH 2 C ≡ CCH 3 ) (5b) with Co 2 (CO) 8 (9) yields (η 5 -C 5 H 4 SiMe 3 ) 2 Ti(Cl)[(η 2 -OCH 2 C ≡ CCH 3 )Co 2 (CO) 6 ] (10). Treatment of 5b or 10 with HCl (aq) (11) leads to the formation of (η 5 -C 5 H 4 SiMe 3 ) 2 TiCl 2 (1) and HOCH 2 C ≡ CCH 3 (2b) (reaction of 5b with 11) or (η 5 -C 5 H 4 SiMe 3 ) 2 TiCl 2 (1) and [(η 2 -HOCH 2 C ≡ CCH 3 )Co 2 (CO) 6 ] (12) (reaction of 10 with 11). All compounds have been characterized by analytical and spectroscopic data (IR , 1 H, 13 C NMR, MS) and (η 5 -C 5 H 4 SiMe 3 ) 2 Ti(Cl)(OCH 2 C ≡ CCH 3 ) (5b) by X -ray analysis.

The new compounds Y 7 I 12 C 2 N and Ho 7 I 12 C 2 N have been prepared by reaction of stoichiometric amounts of the metals (RE), REI 3 , REN and C in closed Ta capsules at 1150 and 1120K, respectively. Pure samples of the compounds were obtained after 5 days annealing time. The crystals with xenomorphic shape are olive-green (Y 7 I 12 C 2 N) or red-brown (Ho 7 I 12 C 2 N) in colour and sensitive to air and moisture. Y 7 I 12 C 2 N crystallizes in the space group P 1̄ (No. 2) with lattice constants a = 971.24(7), b = 1030.38(7), c = 1673.58(11) pm and α = 101.366(5), β = 92.758(5), γ = 112.799(5)°. According to Guinier photographs Ho7I12C2N is isotypic with the lattice consiants u - 968.8(3), b = 1028.7(3), r. = 1667.8(5) pm and α = 101.31(2), β = 92.78(2), γ = 112.80(1)°. In the structure the C atoms are present as C 2 units with a C -C distance of 144 pm. These C 2 units are octahedrally coordinated by Y atoms (o 1 ). The N atoms are in the center of Y 4 tetrahedra, which are linked via a common edge to form double tetrahedra (t 2 ). By condensation of N-centered double tetrahedra (t 2 ) with a C 2 -centered Y octahedron (o 1 ) the characteristic units o 1 t 2 o 1 are formed. The I atoms coordinate all free edges and corners of these units and connect them via I i - I a contacts parallel [100] and [001]. The compounds are semiconducting. Ho 7 I 12 C 2 N exhibits Curie-Weiss behaviour with θ = 15(1) K and μ eff = 10.5(1) μ B .

Trimethylsilyl phosphines Ph(R)PSiMe 3 (R = Me, Et, Pr, Bu, iBu, and C 5 H 11 ) react with acrylic esters CH 2 = C(R′)CO 2 Me(R′ = H, Me) to give the O-silylated phosphinoketenacetals Ph(R)PCH 2 C(R′)=C(OSiMe 3 )OMe 1-6, 15 and 16. By contrast, the reactions of the sterically demanding silyl phosphines R 2 PSiMe 3 (R = iPr, tBu) with CH 2 = CHCO 2 R′ (R′ = Me, Et) result in the formation of mixtures of the corresponding phosphinoketenacetals 7-10 and the 1,2-addition products R 2 PCH 2 CH(SiMe 3 )CO 2 R′ 11-14. The ratio of the two isomers depends on the solvent and on the reaction temperature. β-Substituted acrylic acid esters such as methyl trans-crotonate or methyl trans-cinnamate react only very slowly (yielding a mixture of compounds) or do not react at all. NMR spectra and NOE measurements reveal that only the Z-isomer of the O-silylated phosphinoketenacetals is formed. On the basis of these results a plausible reaction mechanism is proposed. The phosphinoketenacetals react with H 2 O to afford the phosphinoesters R(R′)PCH 2 CH 2 CO 2 R″ 17-22, and with D 2 O to give the deuterated species R(R′)PCH 2 CHDCO 2 Me 23 and 24.

Chloro-N,N-dimethylamino- and chloro-N,N-diisopropylamino-2.2,2-trichloro-tert-butoxyphosphine are demonstrated as reagents in the automated solid-phase oligonucleotide syntheses.

Partial but regio- and stereoselective dechlorination takes place if polychlorinated oligocyclic insecticides (Diels-Alder adducts and dimers of hexachlorocyclopentadiene) are electrolysed in methanol solution at lead cathodes. The products are detected and identified by GC/MS, IR and NMR spectroscopy. The structure of the product 2 formed from Mirex ® is confirmed by an X-ray structural analysis.

The heterocycles Et [R 3 = Me: A; R 3 = C(Me)=CH 2 : B] react with 2-aminoethanethiol (1) by elimination of MeNH 2 to give the monocyclic [R = Me: 3a; R = C(Me)=CH 2 : 3b] and the thermically more stable bicyclic compounds [R = Me: 4a; R = C(Me)=CH 2 : 4b], 4a crystallizes in the monoclinic space group P2 1 /c [lattice constants (at 120 K) a = 9.3239(10), b = 8.9225(11), c = 17.3958(23) Å; β = 92.207(9)°] with a folded bicyclic ring system. cis-ClB(Et)C=C(Me)Si(Me 2 )Cl (C) and Na 2 -1BEt 3 (prepared from 1 and NaHBEt 3 ) form by elimination of MeNH 2 preferentially 3a and minor amounts of 4a. A reacts with o-aminothiophenol (2) via (5) to (6) and the products 7-10.

Crystal structure analyses of (rhodochlorinato-15-acetic trimethyl ester)copper(II) 3 and (3 1 , 3 2 -didehydro-rhodochlorinato-15-formic acid trimethyl ester)copper(II) 4 reveal intriguing multiple macrocycle conformations of the metallochlorins in the crystal. The observed conformations range from almost planar macrocycles to distorted macrocycles with individual atoms being displaced up to 0.72 Å from the mean plane. The nonplanar macrocycles show a S 4 -ruffled macrocycie distortion with significant distortions for the meso-carbons and tilting of the Cb- Cb axes. A comparison with the related free base porphyrins rhodoporphyrin-15- acetic acid trimethyl ester 5 and rhodoporphyrin dimethyl ester 6 shows that the conformational distortion is due to the mixing of metal and substituent effects, hydroporphyrin character, and packing forces. Crystal data: 3, monoclinic, P2 1 , a = 12.096(4) Å, b - 14.307(4) Å, c = 22.343(9) Å , β = 104.94(4)°, Z = 4 (2 indep. mol.), R = 0.069 for 8141 reflections with I > 2.0σ(I); 4, triclinic, P 1, a = 10.528(3) Å . b - 10.646(4) Å, c = 34.026(13) Å, α = 89.81(4)°, β = 88.72(3)°, γ = 60.38(2)°, Z = 4 (4 indep. mol.). R = 0.073 for 9446 reflections with I > 2.5σ(I); 5, triclinic, P 1̄, a = 9.591(2) Å, b = 12.959(4) Å, c = 13.453(4) Å, α = 105.86(2)°, β = 92.67(2)°, γ = 96.12(2)°, Z = 2, R = 0.060 for 4990 reflections with I > 2.5 σ(I); 6, triclinic, P 1̄, a = 8.908(4) Å, b = 12.895(5) Å, c = 13.482(6) Å , α = 102.74(3)°, β = 90.38(4)°, γ = 91.84(3)°, Z = 2, R = 0.089 for 3369 reflections with I > 2.0σ(I).

Reaction of lithium(neomenthylcyclopentadienid) 3 with dimethyldichlorosilane gives dimethylbis[3-(neomenthyl)cyclopentadienyl]silane 4 regioselectively as a mixture of double bond shift isomers (57% isolated). Deprotonation with 2 equiv. of butyllithium followed by treatment with zirconiumtetrachloride furnished a mixture of the three {dimethylsilylenbis[η 5 -3-(neomenthyl)cyclopentadienyl][zirconium dichloride diastereomers from which the pure meso-like isomer 6e [p -R (1′S ,3 ′R ,4 ′R),p -S (1′S ,3 ′R ,4 ′R)] was isolated by fractional crystallization. Complex 6 c was characterized by an X-ray crystal structure analysis. Its D 1 - Zr - D 2 angle of 126.8° is very similar as observed in bis(η-cyclopentadienyl) zirconium dichloride (D 1 and D 2 denote the centroids of the cyclopentadienyl rings). The homogeneous 6c/methylalumoxane Ziegler-type catalyst produces polypropylene of low molecular weight (M η ≈ 670 at ambient temperature). Related catalyst systems may find interesting applications in organic synthesis.

TlAg 6 O 8 ClO 4 has been synthesized for the first time by electrocrystallization. It is isostructural to silver clathrate salts like Ag 7 O 8 NO 3 , thus containing octacoordinated thallium(III) with d (Tl-O ) = 246 pm (Fm 3̄m , a = 1002.3(2) pm). The title compound shows temperature-independent paramagnetism, which appears to be caused by delocalization of unpaired electrons from Ag(II) into the conduction band.