Volume 50, Issue 7

The reaction of [2.2.2]cryptand, 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo- [8 .8 .8 ]hexacosane, with mercuric thiocyanate yields crystals of [Hg(cryptand 222 )][{Hg(SCN ) 3 } 2 ]. The compound crystallizes monoclinically, space group C2/c, Z = 4, a = 2478.3(12), b = 1540.4(4), c = 1049.4(3) pm, β = 108.77(3)°. In the cation the mercury atom is 8 -coordinated by six oxygen and two nitrogen atoms with distances Hg -N 220(2) pm and Hg -O 268.8(9) pm (mean value). The polymeric anion consists of infinite chains -Hg -SCN -Hg - with bond distances Hg-S 254.2(4) and Hg-N 257(2) pm. Each Hg atom carries two additional terminal SCN ligands, with a mean Hg-S distance o f 244( 1) pm; the distance from Hg to the N atom of an SCN ligand of a neighbouring Hg atom is 300(2) pm, probably indicating an additional, although weak bonding.

trans-mer--Trichlorobis(diethylphenylphosphine)phenylnitrene rhenium(V), [Re(NPh)Cl 3 - (Et 2 PhP) 2 ], has been synthesized from [ReOCl 3 (Et 2 PhP) 2 ] and N-trimethylsilylaniline, while trans-mer-trichlorophenylnitrenebis (triphenylphosphine) rhenium(V), [Re(NPh)Cl 3 (Ph 3 P) 2 ] has been obtained via a novel route, from (Bu 4 N)[ReOCl 4 ] and N-trimethylsilylanilin. The products were studied by mass spectrometry, IR spectroscopy and X-ray diffraction. trans-mer-[Re(NPh)Cl 3 (Et 2 PhP) 2 ] crystallizes in the monoclinic space group P2 1 /n with a = 1498.5(3), b = 1068.6(1), c = 1784.0(4) pm and β = 91.28(1)°, Z = 4. The rhenium atom exhibits a distorted octahedral coordination with the phosphine groups in trans positions, and the Cl ligands in a meridional arrangement. The Re ≡N -C moiety is linear with a bond angle o f 169,4(5)°and a Re= N bond length o f 171.8(6) pm. [Re(NPh)Cl 3 (Ph 3 P) 2 ]· 0.5 CHCI 3 crystallizes in the triclinic space group P 1̄ with a = 1232.1 (4), b= 1431.6(5), c = 2236.6(8) pm, a = 89.19(2)°, β = 80.50(2)°and γ = 88.26(2)°, Z = 4. The asymmetric unit contains two symmetry independent complex molecules of approximately the same structure, with Cl atoms meridionally arranged and the phosphine groups in trans positions. The coordination geometry is a distorted octahedron. The almost linear Re≡N -C moieties have Re≡N bond lengths of 170.2(7) and 170.8(7) pm, respectively, and Re≡N -C angles of 173.3(6)°and 175.0(7)°.

The title compound (S,S)-2, has been obtained by reduction with Li[AlH 4 ] of the cyclopentane- 1,2-diyl-bis(1′,3′,2′-dioxaphospholane) (1S ,2S)-trans-C 5 H 8 [P(OCH (CO 2 Pr-i)- (R) - ) 2 ] 2 , (S,S)-1, which itself was isolated in diastereomerically pure form (X-ray structure analysis) from the reaction between rac, trans-C 5 H 8 (PCl 2 ) 2 and (2R,3R)-(+)-diisopropyl tartrate. Cleavage of (S,.S)-1 withPCl 3 yielded an unseparable mixture of (1S,2S)-trans-C 5 H 8 (PCl 2 ) 2 and (4R.5R) -ClP [OCH(CO 2 Pr-i)-] 2 .

The bis(dicyclohexylphosphines) trans-C 5 H 8 (PCy 2 ) 2 (1) and trans-C 7 H 10 (PCy 2 ) 2 (11) (C 5 H 8 = cyclopentane-1,2-diyl, C 7 H 10 = norbornane-2,3-diyl) were prepared by treatment of the bis(dichlorophosphines) trans-C 5 H 8 (PCl 2 ) 2 and trans -C 7 H 10 (PCl 2 ) 2 with CyMgBr. Oxidation with H 2 O 2 in acetone gave the corresponding P,P′-dioxides, trans- C 5 H 8 [P(O)C y 2 ] 2 (2) and trans-C 7 H 10 [P(O)Cy 2 ] 2 (12) respectively. Effective optical resolution of 2 was achieved using (2S,3S )-(+)-di-O-benzoyl tartaric acid as a resolving agent. Heating (+)-2 and (-)-2 in neat Ph 2 SiH 2 gave enantiopure 1. Reactions of 1 and 11 with (cyclo-C 8 H 12 )Pt(CH 2 CMe 3 ) 2 afforded the dineopentyls [transC 5 H 8 (PCy 2 ) 2 ]Pt(CH 2 CMe 3 ) 2 , 3, and [trans-C 7 H 10 (PCy 2 ) 2 ]Pt(CH 2 CMe 3 ) 2 (13). These were further derivatized to [trans- C 5 H 8 (PCy 2 ) 2 ]PtH (CH 2 CMe 3 ) (5), and [trans-C 7 H 10 (PCy 2 ) 2 ]PtH (CH 2 CMe 3 ) (15) by consecutive acidolysis (HCl or (1S)-(+)-camphor-10-sulphonic acid) and treatment with Na[BH (OMe) 3 ] of the acido(organo) intermediates [trans-C 5 H 8 (PCy 2 ) 2 ]PtCl(CH 2 CMe 3 ) (4) and [trans-C 7 H 10 (PCy 2 ) 2 ]Pt[O 3 SCH 2 C 9 H 13 (O ) -(+ ) ]CH 2 CMe 3 (14) (mixture of four diastereoisomers), so obtained. Thermolysis of 5 in cyclo-C 6 H 12 /PhC 2 H, C 6 H 6 , or Me 3 SiOSiMe 3 led to smooth formation of [trans -C 5 H 8 (PCy 2 ) 2 ]PtH (R ), R = C 2 Ph (6 ), C 6 H 5 (8), CH 2 SiMe 2 OSiMe 3 (9), and [trans -C 5 H 8 (PCy 2 ) 2 ]Pt(η 2 -PhC ≡CH ) (7), respectively. Reactions of enantiopure complex 5, prepared from (cyclo-C 8 H 12 )Pt(CH 2 CMe 3 ) 2 and resolved bis(phosphine) 1 via (+ )-/(-)-3 and (+)-/(-)-4, with 2,2′-dimethylbinaphthyl and 2 ,2′ -di-t-butylbiphenyl ( 2 equiv. in cyclo-C 6 H 12 at 68 °C) resulted in little optical induction.

In a systematic search for supramolecular complexes involving all combinations of the cyclic polyethers 12-crown-4 (12C4), 15-crown-5 (15C 5), 18-crown-6 (18C 6) and dibenzo- 18-crown-6 (DB -18C6), and the geminal di- or trisulfones H 2 C(SO 2 Me) 2 , H 2 C (SO 2 Et) 2 and HC (SO 2 Me) 3-n (SO 2 Et) n (n = 0 -3 ) , only the following four complexes could be isolated and unequivocally characterized by elemental analysis and 1 H NMR spectroscopy: [(12C4){H 2 C (SO 2 Et) 2 } 2 ] (3), [(18C6){H 2 C (S O 2 Me) 2 }] (4), [(DB -18C 6){H 2 C (SO 2 Et) 2 }] (5) and [(D B -18C 6) 2 {HC (SO 2 Me )(SO 2 Et) 2 } 3 ] (6). The structure of 3 (triclinic, space group P1̄) consists of crystallographically centrosymmetric formula units, in which the disulfone molecules are bonded on each side of the ring by two C -H ··· O(crown) interactions originating from the central methylene group (H···O 213 pm) and from the methylene group of one EtSO 2 moiety ( H ··· O 237 pm). Formula units related by translation are connected into parallel strands by a third type of reciprocal C -H ···O bond (H ···O 232 pm) between the second H atom of the central methylene group and a sulfonyl oxygen atom of the adjacent unit. The structure of 4 (monoclinic, space group C2/c) showed severe disorder of the crown ether and could not be refined satisfactorily. Compounds 5 and 6 crystallized as long and extremely thin fibres, indicative of linear-polymeric supramolecular structures; single crystals for X-ray crystallography were not available.

By reaction of [N(C 4 H 9 ) 4 ] 2 [B 6 H 6 ] with iodomethyl-trimethylsilane in acetonitrile a solution with trimethylsilylm ethyl-closo-hexaborate(1-)anions, [B 6 H 6 (CH 2 Si(CH 3 ) 3 )] - , is formed. The crystal structure of [P(C 6 H 5 ) 4 ][B 6 H 6 (CH 2 Si(CH 3 ) 3 )] has been determined by single crystal X-ray diffraction analysis; monoclinic, space group P2 1 /n with a = 16.140(2), b = 11.646(8), c = 16.731(3) Å, β 109.664(11)°. The 11 B NMR spectrum reveals features of a mono hetero substituted octahedral B 6 cage. The 13 C NMR spectrum exhibits a quartet at +0.18 ppm with 1 J(C,H) = 118 Hz for the three methyl groups and a weak multiplet at -0.65 ppm for the methylene bridge due to quadrupole coupling with the boron atoms. In the 29 Si NMR spectrum a decet at +2.25 ppm with 2 J(C,H ) = 6.9 Hz is observed. The B -C stretching vibration is observed at 1155 cm -1 in the IR and Raman spectrum.

By electrochemical oxidation of [B 6 H 6 ,]2 in the presence of nitrite ions and of the base DBU in dichloromethane solution apart from [B 6 H 5 (NO 2 )] 2- and [B 6 H 5 (NO)B 6 H 5 ] 3- the dinitro anion cis-[B 6 H 4 ( NO 2 ) 2 ] 2- is formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structure of the Cs salt has been determined from single crystal X-ray diffraction analyses. cis-Cs 2 [B 6 H 4 ( NO 2 ) 2 ] is tetragonal, space group P4̄2 1 m with a = 10.0656(4), c = 11.0127(13) Å. The 11 B NMR spectrum is consistent with a disubstituted octahedral B 6 cage with local C 2v symmetry. The IR and Raman spectra exhibit characteristic NO 2 , B - H and B 6 vibrations.

Hexabromostannate(IV) in acetonitrile undergoes a photochemical reductive elimination according to the equation [SnBr 6 ] 2- →[SnBr 3 ] - + Br 3 - with ϕ= 0.06 at λ irr = 313 nm. The formation of [SnBr 3 ] - takes place also by irradiation of [Ru(SnBr 3 ) 5 Br]4- in acetonitrile with visible light. This photosubstitution occures with ϕ > 0.09 at λ irr = 436 nm.

Organo-substituted 1,3,5-hexahydrotriazine complexes of the type (RNCH 2 ) 3 Mo(CO) 3 (R = CH 3 , i - C 3 H 7 and CH 2 C 6 H 5 ) are obtained by ligand displacement from η 6 -C 7 H 8 Mo(CO) 3 in high yields. These products have been characterized by 1 H, 13 C, 95 Mo NMR, IR as well as mass spectroscopy and contain an electron-rich Mo(C O) 3 center bonded to the 1,3,5-hexahydrotriazine 6e donor via three Mo -N bonds. Oxidation of the Mo 0 complex 1,3,5-(CH 3 NCH 2 ) 3 Mo(CO) 3 with H 2 O 2 under carefully controlled conditions allows isolation of 1,3,5-(CH 3 NCH 2 ) 3 MoO 3 containing a Mo VI center. Chemical and spectroscopic properties of these complexes are compared with those of related Mo complexes with neutral macrocyclic ligands containing N 3 donor sets.

Chiral tripod-ligands of the type 5 are easily accessible in four steps starting from the dibromide 1. The cleavage of the oxetane 4 b by LiPPh 2 yielding the tripod-ligand 5 can be modified enantioselectively by the addition of (-)-sparteine.

The crystal structures of two silylated phosphanimines have been determined. Me 3 SiNPPh 3 : Space group P 1̃, Z = 2, structure refinement with 2907 observed unique reflections with F o > 5 σ(F o ), R = 0.052. Lattice dimensions at 19 °C: a = 876.6(1), b = 1125.8(1), c = 1151.2(1) pm, α = 61.71(1)°, β = 88.08(1)°, γ = 87.18(1)°. The compound forms monomeric molecules with a SiNP bond angle of 140.2° and bond lengths PN of 154.2 pm and SiN of 168.6 pm which correspond with PN double and SiN single bonds. Me 3 SiNPPh 2 - C 2 H 4 -PPh 2 N SiMe 3 : Space group P3 1, Z = 3, structure refinement with 4251 independent reflections, R = 0.061 for 3587 reflections with I > 2σ(I). Lattice dimensions at - 80 °C: a = b = 1591.4(1), c = 1165.8(1) pm. The compound forms monomeric molecules with a c/s-conformation of the PNSiMe 3 groups. Bond angles and bond lengths (average) are SiNP = 140.8°, PN = 153.8 pm, SiN = 165.6 pm.

The triple decker complex [{(η 5 -Cp*)Co} 2 -μ-{η 4 : η 4 -toluene}] 1b exhibits an unusual reactivity towards a variety of organic ligands, 1b reacts with CO, ethene, butadiene, H 2 , Al 2 O 3 , hexafluorobenzene, 1.5 Cod, 2-butyne, phenanthrene, naphthalene and the dinuclear Ni cluster [{(η 5 -Cp)NiP(C 2 H 5 ) 3 } 2 ] to form mainly mononuclear organocobalt complexes. Reaction of 1b with NO and the diazoalkanes di-t-butyl-diazomethane and 2-diazo-1,1′,3,3′-tetramethylcyclohexane results in the formation of the dinuclear complexes [{(η 5 -Cp*)CoNO} 2 ], [{(η 5 -Cp*)(di-t-butyl-diazomethane)Co} 2 ] and [{(η 5 -Cp*)(2-diazo-1,1′,3,3′-tetramethylcyclohexane) Co} 2 ], respectively. In the reaction of 1b with elemental sulfur the formation of a tetranuclear Co-sulfide cluster is observed. In the majority of the reactions studied, l b looses its toluene ligand already at room temperature indicating an unusual high and hitherto unprecedented reactivity of an arene triple decker complex.

Li 10 N 3 Br has been prepared by the reaction of Li 3 N and dry, OH-free LiBr. It is found to be the most nitride rich compound in the quasi-binary system Li 3-2x N 1-x Br x . The previously unknown structure of the title compound has been solved from neutron powder diffraction data recorded using the flat-cone and powder diffractometer E2 at the Berlin BER II reactor. Li 10 N 3 Br crystallizes in the hexagonal space group P6̄m2 (No. 187), a = 741.3(1) pm, c = 386.57(3) pm, with one formula unit per unit cell. The structure is closely related to Li 3 N (space group P6/m m m , a = 364.8(1) pm, c = 387.5(1) pm). It comprises roughly pentagonal bipyramidal Li 7 N units which share edges and vertices to give a three-dimensional Li 10 N 3 network. The Li atoms in axial positions are in an almost linear coordination with the central N atom. The Li atoms in the equatorial positions are surrounded either by N atoms in an ideal trigonal coordination or by N and Br atoms in a distorted tetrahedral coordination. The Br atoms are situated in the large trigonal prismatic holes formed by the Li atoms.

Mixed potassium -ferrous ferrocyanide and its Ru II and Os II analogs have been synthesized tribochemically by grinding Fe (SO 4 )·7H 2 O with the equivalent amount of K 4 [Fe(CN ) 6 ]·3H 2 O and the Ru II and Os II compounds. Their XRD powder patterns and Mössbauer and IR spectra were recorded and interpreted. The role of hydration water on the feasibility of the tribochemical synthesis is discussed.

The title compound was prepared by the reaction of the elemental components in a tantalum tube. EuAgGe (single crystal. X-ray, Imma, a = 467.0(1), b = 740.0(1), c = 798.1(1) pm, V = 0.2758(1) nm 3 , Z = 4, wR2 = 0.0371, 474 F 2 values and 13 variables) crystallizes with the orthorhombic structure of CeCu 2 . The europium atoms occupy the cerium positions, while the silver and germanium atoms are randomly distributed on the copper positions. The crystal structure of EuAgGe is discussed together with the structures of EuAg 2 and EuAuGe.

The first fluorine-containing cryptand F 3 -TREN 4 for the complexation of anions was prepared in the 3 + 2-condensation reaction of 2-fluoro-1,3-phthalaldehyde 3 with tris(2-aminoethyl) amine and subsequent reduction with NaBH 4 . Upon incorporation of anionic guests 4 ·6HClO 4 experiences shifts of its 19 F NMR resonances and thus demonstrates the advantages of studying host-guest association by 19 F NMR spectroscopy.

Alkyl-1-thio-α/β-D-gaIactopyranosides (hexyl-dodecyl, 1a - g ) have been O-diethylborylated and then reduced with tetraethyldiboranes(6) in the presence of 9-methylsulfonyloxy- 9-borabicyclo[3.3.1]nonane (MSBBN) catalyst to give 1-alkylthio-1-deoxy-D-galactitols 3a -g after deprotection. 3 exhibit the smectic A liquid crystalline phase on melting.

Several (aminoalkyloxymethyl)dimethylphosphine oxides with the formula (CH 3 ) 2 P(O)CH 2 ORNH 2 have been synthesized via the Williamson reaction from (chloromethyl) dimethylphosphine oxide and sodium alcoholates of amino alcohols. The new compounds were characterized by analytical methods, IR, 1 H NMR, 31 P NMR spectroscopy and by mass spectrometry.

The structure of the hexasaccharide 1 has been examined by a spectroscopic investigation using one- and two-dimensional NMR spectroscopy All 1 H and 13 C signals of the saccharide part were assigned. NOESY and ROESY experiments allowed to discuss the flexibility of the molecule.

Polystyrene-polyethylene glycol (PS-PEG) tentacle polymers with loadings of up to 60/<μmol/g were used for standard oligonucleotide synthesis. As these resins are easy to handle and stable under reaction and cleavage conditions they may be used alternatively to controlled pore glass (CPG) as the most commonly used solid support for oligonucleotide synthesis. However, structural and chemical properties of the PS-PEG resins require modified conditions to guarantee syntheses with high coupling efficiencies. Oligonucleotides (ODN ) of various sequences and lengths have successfully been synthesized using HPLC and capillary electrophoresis (CE) for purity control. Additionally, electrospray mass spectrometry (ES-MS) was used for product identification.

The structure and stereochemistry of arthogalin from the liehen Arthothelium galapagoense has been elucidated as the cyclic depsipeptide 1′.

A new monodesmosidic spirostanol glycoside extracted from the fresh leaves of Cestrum nocturnum was identified as spirost-5-ene-3-ol, [3β,25R]-3-O-[{α-L-rhamnopyranosyl-(1→4)- α-L-rhamnopyranosyl-(1→2)}-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside. The name proposed for this saponin is nocturnoside B. The structure elucidation was done on the basis of 1 D and 2 D spectroscopic studies [DEPT. HeteroCOSY, HMBC, COSY-45°, HOHAHA ] and chemical analysis.

The structure and relative stereochemistry of lepranthin from the lichen Arthonia impolita has been elucidated as 1 by NMR spectroscopy and X-ray analysis.

Different pathways to Ru-complexes are described using the hitherto unknown S-type terpyridines 3 and the known U-type ligands 4. The resulting hexafluorophosphates 6 and 7 have been spectroscopically characterized by 1 H NMR and IR data and also by mass spectrometry and cyclic voltammetry.

The phosphonium salts 4 are versatile reagents for the synthesis of 1,2,3-thiadiazoles 6 with unsaturated side chains. The preparation starts with the α-chloroketones 1 which are transformed in a stepwise process to the phosphonium salts 2 and 3. The reaction with SOCl 2 leads to a regioselective ring closure 3 → 4 . Subsequent Wittig reactions yield the monomers 6, which exhibit with the exception of 6ac a high tendency for a thermal polymerization. Cleavage of the ester groups in 6ca and 6 cd generates the carboxylic acids 7ca and 7 cd which possess a higher stability.

Improvements in the detection of 13 C(CO) resonances by using polarization transfer techniques, based on long-range coupling constants n J( 13 C(CO) 1 H) = 1 ±0.1 Hz (n > 3), are reported. Coupling constants between 13 C(CO) and other rare spin-1/2 nuclei have been observed, and longrange 13 C(CO)- 1 H coupling have been traced by two-dimensional (2D ) 13 C/ 1 H heteronuclear shift correlations (HETCOR). Seven tricarbonyliron complexes 1 to 5 serve as examples in which the [Fe(CO) 3 ] fragment is linked to cyclic dienes (siloles: 1a, b; 1,1′-spirobisilole: 2), and to cyclic heterodienes derived from substituted 2,5-dihydro- 2,5-silaboroles [1-aza (3a, b); 1-thia (4); 1-selena (5)]. In the case of complex 5, it was possible to resolve the 77 Se satellites with 2 J( 77 Se 13 C(CO )) = 4.4 Hz. In 2D 13 C (CO )/ 1 H HETCOR experiments it was shown that polarization transfer originates mainly from C-methyl groups [ 4 J( 13 C(CO)/ 1 H (M ))], adjacent to the “terminal” carbon atom(s) of the cyclic diene or heterodiene system which are linked to the [Fe(CO) 3 ] fragment.

As found by X-ray structure analysis (tBuO) 4 AlSnCl (1) is monomeric in the crystal and has a central AlO 2 Sn four-membered ring (Sn -O 2,153(5) Å , Al-O 1,807(7)Å). The corresponding iso-propyl derivative 2 reacts with SnCl 2 to yield a coordination polymer (iPrO) 4 AlSn 2 Cl 3 3 incorporating a new trigonal bipyramidal Sn 2 Cl 3 + cation [angles at tin from 67,18(5) - 83,90(5)°]. 3 reacts with moisture to give the compound [(iPrO) 5 Cl 2 Al 2 ] 2 O 2 Sn 4 Cl 2 (4) which has a central O 2 Sn 4 Cl 2 -cluster of approximately D 2h symmetry with four-coordinate η 4 -bridging chlorine atoms.

PPh 4 [SnCl 3 ] reacts with Na 2 S 4 in acetonitrile to give the title compound as one of the products. Its crystal structure was determined by X-ray diffraction (R = 0.071 for 3288 reflexions). Crystal data: monoclinic, P2 1 /C, Z = 4, a = 1301.2(3), b = 1139.1(2), c = 3476.2(7) pm, β = 97.82(3)°· (PPh 4 ) 2 [Sn(S 4 ) 3 ] is isotypic with (PPh 4 ) 2 [Sn(Se 4 ) 3 ] and contains [Sn(S 4 ) 3 ] 2- ions in which three tetrasulfido groups are chelating an octahedrally coordinated tin atom.

The title compound was prepared by hydrogenolytic deprotection of the corresponding Nbenzyl derivative, which had previously been synthesized by a Picted-Spengler condensation of the corresponding arylethylamine. It crystallizes from dichloromethane/methanol in the orthorhombic system, space group P2 1 2 1 2 1 ; a = 1305.7(2), b = 1400.3(3), c = 727.4(1) pm. Hydrogen bonds between Cl and OH and NH 2 groups cause a threedimensional arrangement.