Volume 57, Issue 9

The title compounds were synthesized from the elements and characterized via single crystal x-ray studies and Raman spectroscopy. In the Zintl phases A 3 As 7 (A = K, Rb, Cs) the As atoms form nortricyclene-analogous anions As 3 7 with As-As distances ranging from 230 to 254 pm. The three compounds crystallizewithdifferent newstructure types containing different packings of theAs7 anions:K3As7 (orthorhombic, Pbca; a=1291.9(8), b = 2544.1(9), c=1537.7(16) pm) shows a double hexagonal close packing (ABAC stacking of planes of hexagonal close packed anions), Rb 3 As 7 (monoclinic, P21/c, a = 757.3(5), b = 1310.2(8), c = 2692.7(18) pm , β= 91.972(12)°) hows a hexagonal close packing (AB) and the Cs compound (orthorhombic, Pbca, a = 1022.8(5), b = 1317.6(7), c = 2195.2(11) pm) a cubic close packing (ABC) (also present in theHT-forms of the three compounds) respectively. The alkaline metalmonoarsenides AAs (A = K, Rb) crystallize with the NaP structure type (A = K/Rb: orthorhombic, P2 1 2 1 2 1 ; a = 661.7(5) / 658.1(8), b = 688.8(6) / 691.6(8), c = 1197.3(10) / 1204.7(10) pm, Z = 8) with approximate fourfold screw axes 41 of As$ chains, whereas the crystal structure of CsAs (hexagonal, P¯62m, a = 1219.7(3), c = 1046.3(2) pm, Z = 18) contains three crystallographically independent three membered rings As 3 3 with As-As distances of 243.0 to 247.5 pm

Bis(N-lithio-trimethylsilylamino)bis(dimethylamino)silane (1) is formed in the reaction of silicon tetrachloride with excess hexamethyldisilazane, followed by halogen substitution using two equivalents of LiN(CH 3 ) 2 , and treatment with two equivalents of n-butyllithium in hexane. 1, found to be dimeric in the solid state, was characterised by single crystal X-ray diffraction (monoclinic, C2/c, a = 1925.2(4), b = 1501.7(2), c = 1389.7(3) pm, β= 101.98(2), Z = 4, C 20 H 60 Li 4 N 8 Si 6 ), and by solid state and solution NMR spectroscopy and mass spectrometry. Further reaction with titanium tetrachloride (molar ratio 1:1) yields orange crystals of the dimer [TiClf(μ 2 -NSi(CH 3 ) 3 ) 2 Si(N(CH 3 ) 2 )μ 2 -Cl] 2 (2) characterised by single crystal X-ray diffraction (triclinic, P1, a = 942.1(4), b = 991.7(4), c = 1222.6(5) pm, α= 90.12(1), β= 94.42(2), γ= 107.64(1)°, Z = 1, C 20 H 60 Cl 4 N 8 Si 6 Ti 2 )

The results of STO-6G valence-bond studies are reported for the six π-electrons of C 2v symmetry N 5 + , with π-electron core charges determined from the valence bond structures. Important types of canonical Lewis structures are calculated to carry either three atomic formal charges, arranged spatially as (+), (-) and (+) , as in or a single (+) atomic formal charge, as in the “long-bond” structure When localized molecular orbitals are used to accommodate bonding electrons between pairs of adjacent atoms, each of these types of Lewis structures, and others, are components of the increased-valence structure whose bond properties are in qualitative accord with experimental estimates of the bond lengths for N 5 + . Consideration is also given to other types of valence bond representations for N 5 + , and the results of MP2 molecular orbital calculations for the hypothetical N 8 2+ are reported. For the latter species, a stable energy minimum with C 2 symmetry is obtained. Its bond lengths are related to those implied by a Lewis-type valence-bond structure

The reaction of 1-phenylgermatrane (1) and 1-phenylazagermatrane (2) with Cr(CO) 6 affords chromium tricarbonyl complexes [N(CH 2 CH 2 O) 3 GeC 6 H 5 ]Cr(CO) 3 (6) and [N(CH 2 - CH 2 NH) 3 GeC 6 H 5 ]Cr(CO) 3 (7). In contrast, the same reaction of Cr(CO) 6 with 1-(9-anthracenyl) germatrane (3) does not proceed. Composition and structures of the 6 and 7 were established by elemental analyses, 1 H and 13 C NMR spectroscopy and mass spectrometry. The crystal structure of 6 is reported

The compound [Cu(NH 2 CH 2 C 6 H 4 N=CHC 5 H 5 N)Cl 2 ] (1) containing the tridentate Schiff base ligand, which is the 1:1 condensation product of pyridine- 2-carboxaldehyde and 2-amino benzyl amine, was synthesised and its crystal structure has been determined. It is monomeric, space group P1, a = 7.704(1), b = 9.308(2), c = 11.228(2) A˚ , α= 68.97(2), β= 82.23(1), γ= 67.70(1)° and Z = 2. The crystal structure of 1 is based on a five coordinate copper centre with trigonal bipyramidal geometry. The six membered chelate ring possesses a half-chair conformation with C7 most out of the plane made by Cu1, N2, N3, C8 and C9. There is a hydrogen bond between Cl2 and an amine hydrogen H2A of a neighbouring molecule related by a centre of inversion

The results of a single crystal X-ray structure determination of monoclinic (MeNH 3 ) 2 SiF 6 are reported: a = 962.3(5), b = 964.4(1), c = 966.4(5) pm, " = 100.03(3)°; V = 883.2(7) Å 3 , Z = 4, space group C2/c; wR 2 = 0.0999 based on F 0 2 of 1291 independent reflections (including H refinement without restrictions). The structure is related to that of (NH 4 ) 2 SiF 6 , but contains the dumb-bells of the cations well oriented along the greater cell diagonals and fixed by one nearly linear and two bi-furcated hydrogen bonds (N...F: 281 and 293 - 305 pm, resp.). The [SiF 6 ] 2- octahedron is nearly undistorted with average bond length Si-F: 167.7 pm (169.9 pm corrected for thermal motion)

The [1+1] cyclocondensation of the bis-PCl species 1,2-bis(benzo-1-methyl-2-chloro- 1,3,2-diazaphosphorin-4-on-3-yl)ethane 1 and 1,3-bis(benzo-1-methyl-2-chloro-1,3,2-diazaphosphorin- 4-on-3-yl)propane 2 with the 1,2-benzenediol bis(trimethylsilyl) ether 3a and 2,3- naphthalenediol bis(trimethylsilyl) ether 3b gave the symmetrical phosphorus-containing largering systems 4 - 7 in moderate yield. The phosphoryl compounds 8 - 11 were obtained by the oxidation of 4 - 7 with (H 2 N) 2 C(:O) H 2 O 2 . Oxidation of 6 and 7 with elemental sulfur furnished the thiophosphoryl compounds (12 and 13). All new compounds formed in the reactions were characterized unambiguously by NMR spectroscopy, mass spectrometry, and elemental analysis. For compounds 6, 9, 10, 11 and 12, X-ray crystal structure determinations were conducted. The compounds with ten-membered rings show approximate (6, 12) or exact (10) twofold symmetry. In each of the compounds 9 and 11 the two six-membered heterocycles are appreciably different; one is approximately planar, whereas in the other, phosphorus lies outside the plane of the other five atoms

Ru 3 (CO) 12 reacts with 1-tert-butyl-2,4-cyclopentadiene (1), 1-trimethylsilyl-2,4-cyclopentadiene (2), 1-tert-butyl-3-methyl-2,4-cyclopentadiene (3), 1,3-di(tert-butyl)-2,4-cyclopentadiene (4), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), 1-tert-butyl-2,3,4,5-tetramethyl- 2,4-cyclopentadiene (6), 1-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (7), 2,5- diphenyl-2,4-cyclopentadiene (8), or 2,3,4,5-tetraphenyl-2,4-cyclopentadiene (9) with formation of the corresponding bis[dicarbonyl(cyclopentadienyl) ruthenium(I)] complexes [RuCp# (CO) 2 ] 2 1a to 9a. The 1 H and 13 C NMR spectra of the new compounds 3a and 5a to 9a as well as the single crystal X-ray structures of 1a, 4a, 5a, 7a, 8a, and 9a are reported and discussed

The reaction of PCl 3 at r. t. with an equimolar amount of NaR* in heptane gives the colorless phosphane R*PCl 2 (1), the colorless diphosphane R*ClP-PClR* (2), the light green diphosphene R*P=PR* (4), the cyclotetraphosphane R* 2 P 4 Cl 2 (6) (not isolated), the light yellow bis(cyclotriphosphanyl) P 6 R* 4 (7), the cyclotriphosphane R* 2 P 3 Cl (8) (not isolated), and the colorless bicyclophosphane P 4 R* 2 (9).With a threefold molar amount of NaR* in tetrahydrofuran the blue violet triphosphanide NaP 3 R* 2 (10), the dark red tetraphosphanide NaP 4 R* 3 (11), and the orange pentaphosphanediide Na 2 P 5 R* 3 (12) are formed from PCl 3 besides the phosphanides NaPR* 2 , Na 2 PR* (isolated), NaP 2 R* 3 and Na 2 P 2 R* 2 . With a four-fold molar amount of KR* in benzene PCl 3 gives the green diphosphanediide K 2 P 2 R* 2 and the red phosphanediide K 2 PR*, and with an equimolar amount of ZnR* 2 in heptane the compounds 1, 2, 4, 7 and 8 are obtained. The compound R*P=PR* (4), the first diphosphene with two silyl substituents, is formed in high yields from the action of Na on R*PCl 2 in heptane at 90 "C. It gives a [2+4] cycloadduct with 2,3-dimethylbutadiene and phosphanides (Na 2 P 2 R* 2 or Na 2 PR*) with Na or NaR*. Bicyclotetraphosphane P 4 R* 2 (9) (structure: two R*P 3 rings with a common edge) is exclusively obtained from Na 2 P 4 R* 2 (formed quantitatively from P 4 and 2 NaR*) and TCNE. 9 may be reduced (Na, THF) with reformation of Na 2 P 4 R* 2 and reacts in the presence of NaR* with formation of dark red NaP 4 R* 3 (11) (structure: P 3 ring with two R* substituents in trans position and one PNaR* substituent). Straightforward syntheses of halogenophosphanes include (i) reactions of ZnR* 2 with PCl 3 or PBr 3 (mole ratio 1 : 2) in heptane to form R*PCl 2 (1) or R*PBr 2 , and (ii) reaction of R* 2 with R*PCl 2 (mole ratio 1 : 2) without a solvent, or of KR* and PCl 3 (mole ratio 2 : 1) in benzene to formR*ClP-PClR* (2). The halogenophosphanes R* 2 P 3 Cl (8) (structure: P 3 ring with two R* substituents in trans position and one Cl substituent) as well as R*2P 4 Cl 2 (6) (structure: P 4 ring with alternating R* and Cl substituents) have not been isolated. The 31 P-NMR spectra and the pathways of formation of the phosphorus compounds are discussed

On exposure of trans-(n-Bu 4 N) 2 [Pt(SCN) 2 (ox) 2 ] to photochemical reduction (n-Bu 4 N) 2 - [Pt(SCN) 2 (ox)] (1) is formed. Further treatment with (SCN) 2 yields (n-Bu 4 N) 2 - [Pt(SCN) 4 (ox)] (2). The X-ray structure determination on a single crystal was performed of [(C 5 H 5 N) 2 CH 2 ][Pt(SCN) 4 (ox)] (triclinic, space group P1̅, a = 9.823(1), b = 14.850(1), c = 15.799(1) Å , α= 74.304(9), β= 86.268(9), γ= 87.455(9)°, Z = 4). Based on the molecular parameters of the X-ray determination the IR and Raman spectra have been assigned by normal coordinate analysis. The valence force constants of the symmetric axis S-Pt-S and of the asymmetrically coordinated S'-Pt-O* axes are f d (PtS) = 1.71, f d (PtS') = 1.92 (1), f d (PtS') = 2.02 (2) and f d (PtO • ) = 2.45 (1) and 2.24 (2) mdyn/Å. Taking into account increments of the trans influence a good agreement between observed and calculated frequencies is achieved. The NMR shifts are δ( 195 Pt) = 1967.7 (1) and 2930.8 ppm (2)

Colourless single crystals of HgSeO 4 were prepared under hydrothermal conditions by reacting yellow HgO in concentrated selenic acid at 250 °C (10 d); yellow crystals of HgSeO 4 HgO and red-brown crystals of HgSeO 4 2HgO were obtained during hydrolysis of the so prepared HgSeO 4 in demineralized water at 200 °C (7 d). All crystal structures were solved and refined from single crystal diffractometer data sets. The structures of HgSeO 4 and HgSeO 4 2HgO are isotypic with the corresponding sulphates. They are based on [HgO 7 ] polyhedra with a [4+3] coordination around the mercury atom and isolated SeO 4 2- tetrahedra for HgSeO 4 , as well as hexagonal [Hg 3 O 2 ] 2+ nets perpendicular to [001] and disordered SeO 4 2- tetrahedra in the interstices of the nets for HgSeO 4 2HgO. The hitherto unknown compound HgSeO 4 HgO crystallizes in a new structure type. The main structural features of this compound are 1 ∞ [O-Hg-O] zigzag chains which extend parallel to [010] and are built of two crystallographically independent Hg and O atoms, isolated SeO 4 2- tetrahedra situated between the chains and [HgOx] polyhedra (x = 6 and 7) connecting both building units via common oxygen atoms

Di(4-fluorobenzenesulfonyl)amine (DFBSA), di(4-chlorobenzenesulfonyl)amine (DCBSA) or di(4-bromobenzenesulfonyl)amine (DBBSA) were co-crystallized with equimolar amounts of pyridine-N-oxide (PyO), dimethyl formamide (DMF) or 1,3-dimethylurea (DMU), respectively, to form the supramolecular complexes DFBSA·PyO (1; triclinic, space group P1 , Z = 1), DCBSA·DMF (2; monoclinic, P2 1 /n, Z = 1) and DBBSA·DMU (3; triclinic, P1 , Z = 1). Throughout the triad, the molecules are ordered into lamellar layers parallel to the xy plane. Owing to the folded conformations of the disulfonylamines, the layers display an inner polar region of oxygen bases and (SO 2 ) 2 NH groups, outer apolar regions of aromatic rings, and interlayer regions hosting the halogen atoms. These arrays mimic the formerly reported structures of a series of ionic metal di(arenesulfonyl)amides. The intralamellar connectivity is governed by conventional hydrogen bonding and weak C-H···O bonds, the former comprising in structure 1 a very strong N-H···O-N interaction [N···O 250,9(2) pm, N-H···O 171(3)°], in 2 an N-H···O=C bond, and in 3 a set of one S 2 N-H···O=C and two N-H(urea)···O=S bonds. A centrosymmetric (PyO) 2 dimer is present in structure 1. The juxtapositions of adjacent layers reflect halogen-specific recognition patterns (1: three short C-H···F sequences, all F···F distances beyond the van der Waals limit dW; 2: one short C-H···Cl sequence and one close Cl ··· Cl contact < dW, all other Cl ··· Cl > dW; 3: four short C-H···Br sequences and one close Br···Br contact < d W , all other Br···Br > d W ). The interhalogen contacts in 2 and 3 are of the type I, as characterized by θ(C-X···X')≈ θ(C'-X' ··· X); the four angles θ lie in the range 166-175°

One new diterpene ester with a tricyclic lathyrane-or myrsinol-type skeleton has been isolated from Euphorbia decipiens Boiss.&Buhse. In addition to one new, the known constituents β-amyrin, β-amyrin acetate, methyl (2,4-dihydroxy-3-formyl-6-methoxy) phenyl ketone (2), and 1,1-bis (2,6-dihydroxy-3-acetyl-4-methoxyphenyl) methane (3) have been isolated from the same source. The structure elucidation of the isolated compounds was based primarily on 1D and 2D-NMR analysis, including COSY, HMQC, HMBC and NOESY correlations. Compound 1 showed inhibitory activity against prolyl endopeptidase, and also analgesic activity

Magnesium isotope effects by ion exchange using monoazacrown (1-aza-18-crown-6) bonded Merrifield peptide resin were investigated. The capacity and distribution coefficient were determined. The separation factors, ( 24 Mg 2+/25 Mg 2+ ) Resin /( 24 Mg 2+/25 Mg 2+ ) Solution , ( 24 Mg 2+/26 Mg 2+ ) Resin /( 24 Mg 2+/26 Mg 2+ ) Solution , and ( 25 Mg 2+/26 Mg 2+ ) Resin /( 25 Mg 2+/25 Mg 2+ ) Solution were 1.0071, 1.0132, and 1.0068, respectively. The heavier magnesium isotopes were enriched in the solution phase, while the lighter isotopes were enriched in the resin phase. It was found that the hydration and isotope mass effects are more significant than that of the complexation