Volume 53, Issue 7

The new compound [(Crypt-2.2.2)H 2 ]I 8 has been prepared by the reaction of [(Crypt-2.2.2)H 2 ](I 3 ) 2 with iodine in methanol. It crystallizes in the orthorhombic space group Pbcn with a = 11.476 (2), b = 13.589 (2), c = 22.888 (2) Å and Z = 4. The crystal structure has been refined to R F = 0.031 for 1618 reflections. It may be described as a layerlike packing of octaiodide anions I 8 2- and diprotonated 2.2.2-Crypt as cations. The non planar octaiodide anion is built up from two triiodide groups and a bridging iodine molecule. Tris(1, 10-phenanthroline)nickel(II) octaiodide bis(chloroform) crystallizes in the monoclinic space group P2 1 /n with a = 11.683 (8), b = 21.717 (8), c = 20.752 (5) Å, β = 95.03 (5)° and Z = 4 formula units. The crystal structure has been refined to R F = 0.058 for 3894 reflections. The structure consists of two chloroform molecules, octahedrally coordinated complex cations [Ni(phen) 3 ] 2+ and nonplanar octaiodide anions I 8 2- each composed of two asymmetric triiodide units I 3 - weakly associated with an elongated bridging iodine molecule I 2 . The already known structure of bis(N-methylurotropinium) octaiodide, (UrMe) 2 I 8 , has been verified and more accurate crystal data have been collected. The crystal structure has been refined to R F = 0.045 for 1908 reflections. The compound crystallizes in the monoclinic space group P2 1 /c with a = 11.302 (2), b = 9.850 (2), c = 14.188 (2) Å , β = 92.59 (1)° and Z = 2. The anion has the shape of a stretched Z. The structure of bis(N-ethylurotropinium) octaiodide (UrEt) 2 I 8 has been determined and a new configuration (I 3 - , I 5 - ) for octaiodide ions between Z (I 3 - · I 2 ·I 3 - ) and a “broken” configuration (I 3 - , I 5 - ) has been observed. The compound crystallizes in the triclinic space group P1̄ with a = 9.741 (3), b = 11.815 (3), c = 15.426 (3) Å, α = 91.80 (2), β = 107.14 (2), γ = 90.04 (2)° and Z = 2. The crystal structure has been refined to R F = 0.037 for 3657 reflections.

Gold(I) complexes of overall formula LAuCl (L = various methylpyridines) are non-conducting in acetone. X-ray structure analyses show that the solid state structure of the cor­ responding complex 1 (L = 2-picoline) is molecular; the 3-picoline derivative 2 is however ionic (L 2 Au)+(AuCl 2 ) - . 3-Picoline forms a molecular complex LAuC 6 F 5 (3) and also the ionic (L 2 Au) + (SbF 6 ) - (4). Complexes 1, 2 and 4 display short Au ··· Au contacts, leading to chains of gold atoms; additionally, complexes 3 and 4 show weak Au ··· F contacts. The (3-picoline)-gold(III) complex trans-(L 2 AuCl 2 ) + (SbF 6 ) - (5) was obtained as a by-product; it too contains short Au ··· F contacts.

The lithium hydridosilylamides Me 2 (H)SiN(Li)R (1: R = CMe 3 , 2: R = SiMe 3 ) were allowed to react either with the non-enolizable carbonyl compounds CH 2 =C(Me)CHO, PhCHO and Ph 2 CO followed by trapping with chlorotrimethylsilane (A), or with mixtures of these carbonyl compounds and chlorotrimethylsilane (B). In the second case the course of the reactions is determined by the carbonyl compound. The composition of the reaction mixtures is nearly the same according to A and B. Main products in the reactions with the aldehydes are the corresponding imines R′CH=NR (R′ =CH 2 =C(Me), Ph) 3 , 4 , 8 ,9 formed by addition of the hydridosilylamides to the C = O group of the aldehydes and subsequent LiOSiMe 2 H elimination. Partial hydrosilylation of the aldehydes by the hydridosilanolate followed by the trimethylsilylation yields the alkoxydisiloxanes R'CH 2 OSiMe 2 OSiMe 3 6 , 11. In some cases 2 partially reacts under hydrosilylation to give the alkoxydisilazanes R'CH 2 OSiMe 2 NHSiMe 3 7,12. The hydrosilylation is the preferred reaction of 1 and 2 with benzophenone. The compounds Ph 2 CHOSiMe 2 NHR 13, 14 are obtained. This difference in the reaction behaviour of 1 and 2 towards the aldehydes and benzophenone is mainly due to steric reasons. Depending on the conditions the imines Ph 2 C=NR 20, 21 may be formed. Ph 2 CHOSiMe 2 OSiMe 3 (22) is a secondary product of imine formation. In all reactions of 1 and 2 with the carbonyl compounds the corresponding alkoxysilanes R'CH 2 OSiMe 3 (5: R' = CH 2 =C(Me), 6 : R' = Ph) and Ph 2 CHOSiMe 3 (15) are generated. Compounds resulting from a reaction of 1 and 2 with chlorotrimethylsilane are produced to minor extent, but only if the molar ratio of amide to carbonyl compounds is not greater than one. The formation of a silanimine intermediate in reaction according to B is not observed.

The twelve title compounds have been prepared for the first time. Their CaCr 2 Al 10 -type structure (P4/nmm, Z = 4) was refined from single-crystal X-ray data for the three representatives TbMnAl 10 (a = 1274.3(2) pm, c = 511.4(2) pm, R = 0.025 for 680 structure factors F and 43 variable parameters V), CeRe 2 Al 10 (a = 1295.5(5) pm, c = 517.2(4) pm, R = 0.054 for 810 F and 46 V), and SmRe 2 Al 10 (a = 1291.5(2) pm, c = 516.5(1) pm, R = 0.021 for 622 F and 46 V). The atomic positions of the lanthanoid and transition metal atoms are fully occupied. Significant deviations from the full occupancies were observed for two aluminum sites in TbMn 2 Al 10 and for all five aluminum sites of the two rhenium-containing compounds, resulting in the compositions TbMn 2 Al 9.63(2) , CeRe 2 Al 9.52(8) , and SmRe 2 Al 9.16(9). The cell volume of CeRe 2 Al 10 and to a smaller extent also that of CeMn 2 Al 10 indicate mixed or intermediate +III/+IV valencies of the cerium atoms in these compounds. The structural relationships between the three closely related body-centered tetragonal structures of ThMn 12 , CeMniAl 8 , DyFe 6 Al 6 and the primitive tetragonal structure of CaCr 2 Al 10 are briefly discussed.

The effect of reduced oxygen species on the partial oxidation of methane to methanol was examined with nitrite melts. The experimental results support the suggestion that the formation of methanol or C 2 compounds depends on different reduced oxygen species, as observed in our previous work using nitrate melts. It has been suggested that the partial oxidation of methane proceeds to CH 3 OH or C 2 compounds via parallel pathways. This suggestion was verified by increasing the oxygen concentration to carry out the partial oxidation of methane in 25 mol% NaNCO 3 -75 mol% KNO 3 melts. A methanol selectivity of 8.2% and a methanol yield of 0.43% were observed with CH 4 /O 2 = 15/1 at 575 °C, whereas with CH 4 /O 2 = 7/1 methanol selectivity and yield increased to 23.7% and 1.1%, respectively. The results further confirm the contribution of the superoxide ion O 2 - on methanol formation.

The new macrocyclic complexes of composition Rb(18-crown-6)AuX 4 (X = Cl (1) and CN (2)) have been prepared and characterized by X-ray crystallography (1: monoclinic, space group P2 1 /n, with a = 8.747(1), b = 8.366(1), c = 15.404(1) Å; β = 104.37(1)°, V = 1092.0(3) Å 3 , Z = 2; final R1 =0.025 for 2030 independent reflections used; 2: monoclinic, space group P2 1 /c, with a = 14.765(3), 6 = 17.134(3), c = 8.855(2) Å; β = 90.20(1)°, V = 2240.2(8) Å 3 , Z = 4; final R1 = 0.080 for 2034 independent reflections used). Both structures consist of Rb(18-crown-6) + cations (A) and complex aurate(III) anions AuX 4 - (B). Complex 1 has a linear polymeric array -A-B-A-B-(Rb-Cl 3.604(3), 3.654(3) Å) with the rubidium ions disordered 0.276(2) Å above and below the crown ether plane (Rb-O 2.819(5)-2.884(5) Å, av. 2.846(5) Å). The positioning of the rubidium atom away from the center of the 18-crown-6 is effected by the packing of the Rb(18-crown-6) + and AuCl 4 - moieties, and by the resemblance in the charge and symmetry of the cationic and anionic parts of the structure. Complex 2 has a zig-zag polymeric array -A-B-A-B-(Rb-N 2.92(2), 2.94(1) Å) with orthogonal disposition of Rb(18-crown-6) + and Au(CN) 4 - planes. The rubidium atom is situated 0.90(2) Å above the mean plane of the macrocyclic oxygen atoms (Rb-O 2.93(5)-3.15(4) Å) and adopts a typical “sunrise coordination”.

Dioxomolybdenum(VI) complexes have been synthesized by ligand exchange reactions of Mo(CO) 6 , Mo(NO) 2 (acac) 2 and MoO 2 (acac) 2 with tridentate diacidic ligands. X-ray structure analyses were performed on single crystals. The complexes salicylaldehyde-2-hydroxyanilato(2-)-triphenylphosphaneoxide-dioxomolybdenum(VI) (1b) and 2,2'-dihydroxy-azobenzenato(2-)-triphenylphosphaneoxide-dioxomolybdenum(VI) (2) are isomorphous. In all chelates the Mo atom is in a distorted octahedral environment. Structural data: Salicylaldehyde-2-hydroxyanilato(2-)-tetrahydrofurane-dioxomolybdenum (VI) (1a): a = 23.381(6) Å, b = 6.756(2) Å, c = 28.380(8) Å, β = 124.47(2)°; Salicylaldehyde-2-hydroxyanilato(2-)-triphenylphosphaneoxide-dioxomolybdenum (VI) (1b): a = 9.4208(14) Å, b = 30.550(5) Å, c = 10.461(2) Å, β = 111.005(17)°; 2,2′-Dihydroxy-azobenzenato(2-)-triphenylphosphaneoxide-dioxomolybdenum(VI) (2): a = 9.392(2) Å, b = 31.012(13) Å, c = 10.350(2) Å, β = 110.968(17)°; Salicylaldehyde-salicylhydrazonato(2-)-triphenylphosphaneoxide-dioxomolybdenum(VI) (3): a = 9.321(2) Å, b = 12.048(2) Å, c - 13.858(3) Å, α = 101.90(2)°, β = 94.94(2)°, γ = 105.479(17)°.

The structures of twelve dihalogeno(diphosphine)nickel complexes of the general formula [NiX 2 (PR′ 2 R′) 2 ] (X = Cl, Br and I; R′ resp. R″ = -C 2 H 5 or -C 6 H 5 ) were analyzed in solution by differential puls polarography and 1 H-NMR spectroscopy as a function of temperature.

Diethylchlorotin dimethylphosphinate has been synthesized by treating (Et 2 ClSn) 2 O with HO 2 PMe 2 in toluene. Single crystal X-ray analysis shows that O 2 PMe 2 groups behave as bidentate bridge ligands between Et 2 ClSn units leading to a polymeric chain structure in which the tin atoms exhibit a distorted trigonal bipyramidal geometry with the oxygen atoms in the axial positions. The Sn-Cl bond lies on a C 2 axis of symmetry in the (C 2v ) OCClSnCO unit. Et 2 ClSnO 2 PMe 2 crystallizes in the monoclinic space group C2/c (a = 877.9 (2), b = 1907.8 (4), c = 695.5 (1) pm, β= 106.72 (2)°, Z = 4 and R = 0.043). The characteristic IR bands of Et 2 ClSnO 2 PMe 2 are assigned and the mass spectrum is reported and discussed.

[N(CH 3 ) 4 ] 2 SeO 4 and [N(CH 3 ) 4 ] 2 CrO 4 have been investigated by Infrared and Raman spectroscopy, coupled thermogravimetric and differential thermal analysis combined with mass spectroscopy of the evolved gases and temperature dependent X-ray diffraction. The crystal structure of [N(CH 3 ) 4 ] 2 SeO 4 has been determined from single crystal data (cubic, Fm3̄m. a -11.1077(7) Å, Z = 4) and reveals [N(CH 3 ) 4 ] + cations and SeO 4 2- anions to be arranged in a Li 2 O -type of structure. While the cation framework of regular tetrahedra is orientationally fixed, the selenate anions are disordered. Powder diffraction data show [N(CH 3 ) 4 ] 2 CrO 4 to be isostructural (cubic, Fm3̄m, a = 11,039(1) Å, Z = 4).

Single crystals of synthetic francoanellite K 3 Al 5 (HPO 4 ) 6 (PO 4 ) 2 -12H 2 O could be obtained for the first time by topochemical dehydration of taranakite crystals. An X-ray structure determination showed francoanellite to be the mineral with the second longest crystallographic axis described hitherto. Crystal data: space group R3c, a = 869.0(2), c = 8227(1)pm, Z = 6 , R g = 0.042. Francoanellite is a layer structure mineral having six layers of composition [K 3 Al 5 (HPO 4 ) 6 (PO 4 ) 2 (H 2 O) 12 ], connected by hydrogen bonds. The rigid layer is formed by columns of corner sharing hydrogen phosphate tetrahedra and AIO 6 -octahedra which are inter­ connected by additional six-coordinated Al ions. In trigonal holes of the layer orthophosphate ions are situated. The structure of francoanellite is very similar to the structure of taranakite K 3 H 6 Al 5 (PO 4 ) 8 · 18H 2 O which has planar water interlayers between the Al-phosphate layers. A neutron scattering experiment with subsequent Rietveld refinement of the powder pattern gave the H-atom positions. Hydrogen bonds in francoanellite are formed within the rigid layers and between them. During the reaction taranakite → francoanellite crystals in an intermediate stage of dehydration could be obtained. From the c-axis of 8858 pm and one-dimensional electron density projections it can be proposed that in these crystals every second water interlayer was lost and a first order staging product of the deintercalation of water from taranakite was formed.

The carbene adducts 3a-c (R 1 = Me, Et, iso-Pr; R 2 = Me) are formed from the 2,3-dihydro-imidazol-2-ylidenes 1a-c and 1,2-dichloroethane as air-sensitive solids in good yields. The compounds exhibit a reactive Cl-Cl bond. Benzene is chlorinated by 3a,b to give chlorobenzene and the imidazolium salts 10a,b under mild conditions. 3c acts as a chloride donor to give with AICI 3 and SO 2 the 2-chloroimidazolium salts 12c and 13c (X = AlCl 4 , SO 2 Cl). On hydrolysis, the less reactive hydrate salt 14c is formed from 3c. The X-ray structures of 10a and 14c are reported.

Beryllium succinate dihydrate [Be(C 4 H 4 O 4 )](H 2 O) 2 is formed in the reaction of equimolar quantities of beryllium sulfate, succinic acid and barium hydroxide in aqueous solution at pH 3.2. Sodium, potassium, and ammonium bis(succinato)beryllates M 2 [Be(C 4 H 4 O 4 ) 2 ] are obtained using the same reagents in the molar ratio 1:2:1 and adjusting the pH to 6.3-6.5 with NaOH, KOH or concentrated aqueous ammonia, respectively. The corresponding potassium bis(maleato)beryllate is prepared similarly and obtained as a crystalline monohydrate, the structure of which has been determined by X-ray methods. The lattice contains spiro-bicyclic dianions with the Be atom chelated by two dicarboxylate ligands. The compounds undergo slow hydrolysis in water as shown by time-and pH-dependent 9 Be NMR spectroscopy. In the neutral region (pH 6.5-6.9) the maleinato complexes are in an equilibrium with trinuclear compounds M 3 {[Be(C 4 H 2 O 4 )OH] 3 } as the predominating species, while in acid solution (at pH 1.3) only the aquo complex [Be(H 2 O 4 ] 2+ remains. In the intermediate pH region various complexes of the above types coexist, with only very slow ligand exchange (on the NMR time scale).

The novel sulfinamides RS(O) -N(SO 2 Me) 2 , where R = Me (1a) or CCl 3 (1b), were obtained by treating the corresponding sulfinyl chlorides with Me 3 SiN(SO 2 Me) 2 or AgN-(SO 2 Me) 2 , respectively. A presumedly ionic 1:1 adduct of 1b with 4-dimethylaminopyridine was isolated and analytically characterized. In the crystals of 1a (monoclinic, space group P2 1 /c) and 1b (monoclinic, P2 1 /c) , the molecules feature approximately planar NS 3 moieties, unusually long S(O) -N bonds and, in the case of 1b, an extremely long S(O) -C bond [for la and 1b, in order: sum of bond angles at nitrogen 359.5 and 357.1°, S(O) -N 178.2(2) and 173.6(2) pm, S(O) -C 178.8(2) and 194.1(2) pm]. In both molecular structures, an attractive S(O) ··· O 1,4-interaction leads to a 7.3° discrepancy in the S(O) -N -SO 2 angles. The crystal packing of 1a displays a tape (double-chain) motif generated by two prominent intermolecular C -H ··· O interactions involving one MeSO 2 group and the sulfinyl oxygen atoms of two adjacent molecules, whereas in 1b the molecules are associated into parallel chains via a bonding Cl ⋯ O(sulfonyl) interaction.

The product of the reaction of 1,2,3,4-tetrahydroquinoline (1) with 2-naphthol (2) and form aldehyde reported as the N -substituted tetrahydroquinoline 3 show s really the structure of the phenylogous bis-substituted tetrahydroquinoline 4. The function of 1, 6 -methyl-1,2,3,4-tetrahydroquinoline (9) and 1-methyl-1,2 ,3 ,4 -tetrahydroquinoline (17) as amines or C -nucleophilic compounds in Mannich condensations were examined .

New isomeric trialkoxybenzylamine resins are developed coupling phthalimidomethyl-3,5-dimethoxyphenols to the Merrifield resin, followed by subsequent treatment with hydrazine. The generated benzylamine function allows DCC coupling w ith the carboxyl function of amino acids and peptides which are removed as amides after treatment with trifluoroacetic acid. These new trialkoxybenzylamine resins allow expeditious syntheses of peptide amides and glycopeptide amides as is demonstrated for muramyl peptides and analogues.

Bivalent oxidation of 3,5-di-tert-butyl-hydroquinone monoesters leads to phenoxenium ions, which can transfer an acyl group to nucleophiles. Based on this principle, dipeptides, glyco-amino acids and N-sulfonyl-amino acids were synthesized from hydroquinone esters of amino acids and p-toluenesulfonic acid. For this reaction, direct anodic and indirect mediated oxidation, as well as chemical oxidation with NBS or trisarylammoniumyl salts, was used. The mechanism of the acyl transfer is discussed in terms of a direct and/or a mediated process. A spirocyclic key intermediate was isolated and its molecular structure determined by X-ray crystallography.

T etrakis-μ-acetato-bis(acetonitrile-N )-dicopper( II) bisacetonitrile (1) was syn thesized and characterized by IR spectroscopy and by an X-ray structure determination [Space group P2 1 /n, Z = 2, lattice dimensions at - 70 °C: a = 1064.2(1), b = 1018.4(1), c = 1088.3(1) pm, β = 101.59(1)°, R 1 = 0.048]. A ccording to the structural data the blue compound consists of centrosymmetric dimers [Cu 2 (OAc) 4 (NCMe) 2 ] and noncoordinated acetonitrile molecules.

The reaction of Me 3 SiI with (Me 3 SiO) 2 P(O)H leads to tris(trimethylsiloxy)phosphonium iodide (Me 3 SiO) 3 PH + I - which has been characterized by vibrational and NMR spectroscopy.