Volume 51, Issue 8

By reaction of [N(C 4 H 9 ) 4 ] 2 [B 10 H 10 ] with chlorotriphenyltin in acetonitrile at 70°C the 2- (chlorodiphenyltin)-decaborate anion [2-SnCl(C 6 H 5 ) 2 B 10 H 9 ] 2- is formed and can be separated from the starting compound by ion exchange chromatography on diethylaminoethyl (DEAE) cellulose. The X-ray structure of [P(C 6 H 5 ) 4 ] 2 [2-SnCl(C 6 H 5 ) 2 B 10 H 9 ] (monoclinic space group P 2 1 /c with a=17.263(2), b = 13 .045(3), c=26.171(2) Å, β = 102.882(7)°) reveals that the SnCl(C 6 H 5 ) 2 substituent is bonded with a B2-Sn distance of 2.168(4) Å.

The reaction of ClONO 2 with PCl 3 yields POCl 3 and NO 2 + NO 3 - . With AsCl 3 chlorine nitrate forms a compound of the analytical composition “AsCl 2 (NO 3 ) 3 ” in contrast to SbCl 3 , which does not react with ClONO 2 . The reaction of ClONO 2 with AsCl 4 + AsF 6 - was reported to yield As(ONO 2 ) 4 + AsF 6 - . We found no reaction below 273 K. Reaction at 293 K yields NO 2 + AsF 6 - as solid product. SbCl 5 does react, but the reaction yields no reproduceable products.

Myochrysin (sodium aurothiomalate hydrate) and auranofin [2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranosato-S)(triethylphospine)gold(I)] are luminescent in the solid state and in ethanol glasses at 77 K (myochrysin: λ max = 600 nm; auranofin: 618 nm). Aqueous myochrysin and auranofin in acetonitrile undergo a photodecomposition. It is assumed that the luminecence originates from a metal-centered ds excited state with partial ligand-to-metal charge transfer (LMCT) character while the photodecomposition is induced by LMCT excitation.

The crystal structure of Mg(BrO 3 ) 2 ·6H 2 O twinned crystals has been determined by X-ray single crystal diffraction (Pa3̅, a = 1039.56(9) pm). The structure is isomorphic to that of M(BrO 3 ) 2 ·6H 2 O(M = Co, Ni, Cu, Zn) and Ni(ClO 3 ) 2 ·6H 2 O. The Mg(BrO 3 ) 2 ·6H 2 O structure is related to fluorite, with Mg(H 2 O) 6 2+ replacing Ca 2+ and BrO 3 - replacing F - . The water molecules are involved in nearly linear hydrogen bonds to adjacent bromate ions (νOD of matrix isolated HDO: 2458 and 2453 cm -1 ). The intramolecular O-H distances 96.84 and 96.90 pm have been derived from the wavenumbers of the respective OD stretches using a recently established vOD vs. r OH correlation curve. The infrared and Raman spectra show accidental degeneracy of the symmetric and the asymmetric BrO stretching modes, which is common for bromate ions with local C 3v symmetry.

Coarse crystalline (NH 2 ) 2 (O)P-N=P(NH 2 ) 3 is obtained from a NH 3 saturated CH 2 Cl 2 suspension of (NH 2 ) 2 (O)P-N=P(NH 2 ) 3 NH 4 Cl at room temperature. (NH 2 ) 2 (O)P-N=P(NH 2 ) 3 ·NH 4 Cl is synthesized by slow addition of Cl 2 (O)P-N=PCl 3 to a solution of NH 3 in CH 2 Cl 2 at -78 °C. Excess NH 4 Cl is removed by treatment with HNEt 2 followed by extraction with CH 2 Cl 2 . The crystal structure of (NH 2 ) 2 (O)P-N=P(NH 2 ) 3 has been determined by single crystal X-ray methods (P2 1 /c; a = 1462.8(3), b = 944.8(2), c = 1026.9(2) pm, β = 110.69(3)°; Z = 8). In the unit cell there are two crystallographically unique molecules. They form a three dimensional network by intermolecular hydrogen bonding interactions (N-H···N ≥ 313 pm. N-H···O ≥ 293 pm). The investigation of the thermal properties shows decomposition with evolution of NH 3 above 80 °C.

Reaction of malondiamides 1 with oxalyl chloride (2) leads to the formation of 2,3-dioxo-2,3- dihydrofuran hydrochlorides 3 and 2,3-dioxo-2,3-dihydro-furanes 4, respectively. The structure of 3a was established by X-ray diffraction. The β-oxo-dibenzylamides 5 react with 2 regiospecifically to give the 2,3-dioxo-2,3-dihydrofuranes 6. Addition of water in 1,4-position to 6a yields hydroxy-enol 7, which forms bimolecular aggregates via intermolecular hydrogen bonds as shown by X-ray analysis. Intramolecular C,N-bisacylation of β-oxoamides 8 and malondiamides 11 with 2 leads to the pyrrol-2,5-diones 9 and 12. Reaction of the enols 9 and 12 with thionyl chloride leads to 3-chloro-pyrrol-2,5-diones 13. 3-Amino-pyrrol-2,5-diones 15 are obtained from 13 and amines 14, while 1, ω-diamines 16 yield the bispyrrol systems 17. X-ray diffraction analysis of 17g reveals a supramolecular ribbon based on intermolecular hydrogen bonds between two different conformeres of 17g and in addition establishes unequivocally the imid-structures of 9 and 12. Intermolecular cyclisation of 13 with amino-tetrazol 18 gives the azido-pyrrolo-pyrimidine-diones 20, which reacts with triphenylphosphane to give phosphinimines 22. The structure of 22a was established by X-ray diffraction.

Single crystals of Sr 2 (VO) 2 Si 4 O 12 could be obtained by high-pressure high-temperature reaction of a SrSiO 3 /SiO 2 /V 2 O 5 mixture in a modified Belt-type apparatus. The green crystals are orthorhombic, space group Cmcm, with a = 5.3139(3), b = 14.6281(7), c = 7.0329(4) Å and Z = 2. The structure comprises vierer single chains of SiO 4 tetrahedra, the resulting Si 4 O 12 units being connected by VO 5 square pyramids. There is one short distance (V - O = 1.61 (1) Å) within the square pyramid, giving definite evidence to a (VO) 2+ group with a V = O double bond. The crystal structure of microcrystalline Sr 2 (TiO) 2 Si 4 O 12 , obtained by high-pressure hightemperature reaction of a SrSiO 3 /SiO 2 /TiO 2 mixture, was refined by the Rietveld technique. The compound (Cmcm, a = 5.3530(2), b = 14.4864(7), c = 7.0817(3) Å, Z = 2) is isostructural with the vanadium compound.

The synthesis and structural properties of organo-bis-dialkylaminochlorboranes X(BNR 2 Cl) 2, X = R 2 NB(CHCH 3 ) 2 , o-C 6 H 4 , 1-α-C 6 H 4 CH 2 , and 1.8-C 10 H 6 are reported. The steric influence of the alkylamino group and the geometrical situation caused by a chain of sp 2 or sp 3 hybridized carbon atoms control the formation of intramolecular donor-acceptor bonds. In o-(C 6 H 4 )(BNMe 2 Cl) 2 (5) only one amino-boron donor-acceptor bond is observed. The steric influence of the alkyl groups in R 2 NB(CHCH 3 BClNR 2 ) 2 is discernible from the formation of two donor-acceptor bonds in 7a (R = Me), whereas 7b (R = iPr) is a non-bridged species. The reaction of benzomagnesacyclobutene with chlorbis(dimethylamino)borane yields cyclic 1-α(C 6 H 4 CH 2 )(BNMe 2 Cl) 2 (9). 1,8-Dilithionaphthalene reacts with ClB(NR 2 ) 2 (R = Me, Et, iPr) to yield 1,8-(C 10 H 6 )[B(NR 2 ) 2 ] 2 (10a-c), its reaction with BCl 3 gives 1,8-(C 10 H 6 )(BClNR 2 ) 2 (11a: R = Me; 11b: R = Et; 11c: R = iPr). In 11a,b two tetracoordinate boron atoms are observed, in 11c the steric hinderance of the isopropyl substituents prevents donor-acceptor bonding.

Et 2 Sn(O 2 PPh 2 ) 2 has been synthesized by the reaction of (Et 2 ClSn) 2 O with Ph 2 POCl in toluene and by the treatment of (Et 2 ClSn) 2 O or Et 2 SnCl 2 with HO 2 PPh 2 in methanol. The reaction of Et 2 SnO with HO 2 PMe 2 in toluene was used to prepare Et 2 Sn(O 2 PMe 2 ) 2 . An X-ray diffraction study of Et 2 Sn(O 2 PPh 2 ) 2 (space group P1̅, Z = 1, a = 559,9( 1), b = 983,7(1), c = 1262,4(l)pm, α = 81,85( 1 )°, β = 79,79( 1)°, γ = 75,00(1)°; structure refinement with 2662 independent reflections, R = 0.055) shows that the structure is polymeric and the O 2 PPh 2 ligands function as double bridges between the tin atoms leading to the formation of centrosymmetric Sn 2 O 4 P 2 eight-membered rings. The ethyl groups are in trans-position in the resulting octahedral environment around tin. The I. R. and Raman spectra of Et 2 Sn(O 2 PR 2 ) 2 (R = Ph, Me) have been discussed and assigned. The mass spectra of Et 2 Sn(O 2 PR 2 ) 2 show Sn(O 2 PR 2 ) + as the base peak.

Monoglyme forms a molecular 1:1 adduct with AlBr 3 which dissociates into the ions AlBr 2 (DME) 2 + and AlBr 4 - in DME, CH 2 Br 2 and CDCl 3 as solvents. A hexacoordinated Al center is present in the solid adduct AlBr 3 ·diglyme. The oxygen and bromine atoms are arranged in a meriodional configuration as shown by X-ray crystallography. However, in solution dissociation occurs into AlBr 2 (diglym) 2 + and AlBr 4 - . Not unexpectedly, AlBr 3 forms the adduct AlBr 3 ·2THF with tetrahydrofuran. The dioxane adduct AlBr 3 ·diox is polymeric in the solid state and has a chain structure with pentacoordinated trigonal-bipyramidal Al centers. The Br atoms are arranged in a slightly distorted trigonal plane. In solution, the presence of tetracoordinated Al is indicated by 27 AI NMR spectroscopy. AlBr 3 cleaves one of the C-O bonds of 12-crown-4 leading to the dimer of ω-bromo-tetra(ethyleneoxy)aluminium dibromide. This dimer contains pentacoordinated Al centers as proven by X-ray structure analysis. In contrast, the adduct of AlBr 3 with 15-crown-5 is most likely an ionic compound, and is best described as [AlBr 2 (15-crown-5)]AlBr 4 based on 27 Al NMR and IR data.

Red crystals of (TeCl 3 ) 3 MoCl 6 (Cl) are obtained by reacting MoCl 4 with TeCl 4 in a 1:3 molar ratio in a sealed evacuated ampoule at 170°. The crystal structure determination (orthorhombic, space group Cmc2 1 , a = 1541.6(2), b = 1268.1(1), c = 1180.6(1) pm) shows the presence of trigonal-pyramidal [TeCl 3 ] + ions, octahedral [MoCI 6 ] 2- ions, and isolated Cl - ions. The ions are linked by long Te-Cl bridges resulting in distorted TeCl 6 octahedra. The octahedra are connected by joint edges and corners to zig-zag chains running along the polar c axis.

[Methylamino-(N,N′-1,3-propyl-disalicylaldiminato)-Ni(II)-bis-(N-methylsalicylaldiminato)- Ni(II)] was synthesized from the condensation of N,N′-1,3-propyl-disalicylaldimine, salicylaldehyde, methylaminohydrochloride, NaOH and Ni(CH 3 COO) 2 ·H 2 O, and its crystal structure determined. [C 34 H 37 N 5 O 4 Ni 2 ], orthorhombic, space group Pbca, a = 12.330( 1), b = 24.967(2), c = 20.616(2)Å, Z = 8. The dinuclear complex contains two octahedrally coordinated nickel atoms which are linked via three oxygen atoms with an average (Ni-O-Ni) angle of 87.2( 1)° and a Ni···Ni distance of 2.884(1)Å. The coordination is completed by three nitrogen atoms. The nickel(II) centers are ferromagnetically coupled (J = 11.5 cm -1 ) as derived from temperature-dependent magnetic susceptibility measurements in the range 5 - 280 K.

(davaH 2 )[FeCl 4 ] 2 crystallizes at room temperature from aqueous solutions of 2,4-diaminovinamidinium hydrochloride, (davaH)Cl, and FeCl 3 in 3M HCl in the orthorhombic space group Pca2 1 with a=14.108(3), b = 16.502(3), c = 18.919(4) Å, Z=8. The structure consists of diprotonated tricyclic (davaH 2 ) 2+ cations and slightly distorted tetrahedral [FeCl 4 ] - anions. The cations are bent around the central heptacycle forming boat-like units. One of the two independent cations is disordered between two positions. Some interatomic distances N···Cl are interpreted in terms of N-H···Cl hydrogen bonds.

Cl 3 Ti[N(SiMe 2 Cl)(SiMe 2 NH 2 )] is yielded by reaction of TiCl 4 with two molecules ClMe 2 SiNHSiMe 3 . A single crystal structure determination (P 2 1 /n, a = 747.12(2), b = 1294.1(3), c = 1496.7(3) pm, β = 90.30(3)°, Z = 4) shows a planar four-membered ring Ti-N-Si-N as the central feature of the monomers formed by a weak coordinative bond of the NH 2 group to the Ti atoms. The monomers are connected to give dimers via two Cl bridges linked to the Ti atoms.

A [K(18-crown-6)] salt of the (Ph 2 PSe) 2 NH ligand was obtained by reaction of [K(Ph 2 PSe) 2 N] with 18-crown-6 [monoclinic, space group C2/c with the cell parameters a = 20.310(2), b = 8.894(2), c = 22.978(3) Å, β = 114.66(2)°, and Z = 4], The potassium ion has the rare coordination number 10. It is coordinated to the six oxygen atoms of the crown ether and to four carbon atoms, two from each of the two anionic ligands neighboring the cationic moiety.

The organophosphonous-N-(N′,N′,N″,N″-tetramethyl)guanidinide fluorides RP(F)N=C(NMe 2 ) 2 2a (R = t-Bu) and 2b (R = Ph) were synthesized. They are readily oxidized by the urea-H 2 O 2 1:1 adduct and by elemental sulfur, selenium and tellurium to give the compounds 4a/b, 5a/b, 6a/b and 7a/b respectively. Compound 2b undergoes a Staudinger reaction with triphenylmethyl azide to yield the phosphine imide 3. The compounds were characterized by 1 H-, 13 C-, 19 F and 31 P NMR spectroscopy, and 6a/b and 7a/b by 77 Se and 125 Te NMR spectroscopy. The structures of the sulfur compound 5b and the selenium compound 6a were confirmed by X-ray crystal structure analysis. Both molecules exhibit short P-N-bonds [158.9(2) pm and 159.8(3) pm] consistent with partial double bond character even though the P(:S) and the P(:Se) bonds are not longer than a normal double bond.

The first crystallographic study on an aromatic analogue of the antileukemic agent methylglyoxal bis(amidinohydrazone) (MGBG) is reported. Thus, the crystal and molecular structures of two different geometrical isomers of phenylglyoxal bis(amidinohydrazone) (PhGBG) sulphate were determined by single-crystal X-ray diffraction. Crystals were prepared by recrystallizing PhGBG sulphate using either water or aqueous ethanol (volume ratio ethanol:water 1:4) as the solvent. Depending on the solvent, different types of crystals were obtained although the PhGBG sulphate employed was in the both cases from the same synthesis batch that had been prepared according to classical methods from the corresponding glyoxal. When a crystal obtained from water was studied, PhGBG was found to exist solely in the form of the anti-anti isomer. e. the same isomer that has been observed in the cases of all mono- and dialkylglyoxal bis(amidinohydrazones) so far studied. However, when PhGBG sulphate was recrystallized from 20 % aqueous ethanol, the crystals obtained consisted of a different geometrical isomer. In this anti-syn isomer the carbon-nitrogen double bond closest to the phenyl group had the syn configuration. In the anti-syn isomer, there is an internal hydrogen bond between the two amidinohydrazone moieties, which may markedly contribute to the stabilization of the isomer. The anti-syn isomer of PhGBG is analogous to the only isomer of trifluoromethylglyoxal bis(amidinohydrazone) so far observed. PhGBG sulphate constitutes the first case in which two different geometrical isomers of a bis(amidinohydrazone) have been observed. In the case of the much studied aliphatic mono- and dialkylglyoxal analogues, isomerization of the bis(amidinohydrazone) backbone has never been observed. The structural flexibility of the bis(amidinohydrazone) chain of PhGBG is obviously attributable to the electron-withdrawing resonance effect and perhaps also to the inductive and hyperconjugative effects of the phenyl group. The obviously facile isomerization of PhGBG may markedly influence the biochemical properties of the compound.

Reaction of o- and p-alkyl substituted dithiobenzoic esters 5 with LDA and methyl iodide lead to the formation of the 1,2-bis(methylthio)stilbenes 9/10 and 16 by reductive dimerisation. The p-methyl dithiobenzoic ester 15b, however, suffers a Claisen condensation with lithium hexamethyldisalazane to yield the stilbene derivative 17. Even the o-methyldithiobenzoic acid 19 is reductively dimerized by LDA giving after methylation a mixture of the stilbenes 9a/10a and 20.

The secondary phosphines R(Ar*)PH(R = Me, iPr, Ph, Mes, Ar*) (2a-2h) with bulky aromatic substituents Ar* (Ar* = 2,3,6-R′ 3 C 6 H 2 , R′ = iPr, tBu) are obtained in good yields by reaction of RPCl 2 , PCl 3 , PBr 3 or Ar*P(Cl, Br) 2 with 2,4,6-tBu 3 C 6 H 2 Li or 2,4,6- iPr 3 C 6 H 2 MgBr and subsequent reduction of the intermediate halophosphines R(Ar*)PX(X = Cl, Br) with LiAlH 4 . The X-ray structural analysis of Ph(2,4,6-iPr 3 C 6 H 2 )PH (2g), space group P 1 , shows P-C-distances of 1.824(1) and 1.838(1)Å. The lithium derivatives of 2a-2c are monomeric in solution as indicated by the 1 :1 :1 : 1-quartet 7 L i - 31 P fine structure of the 31 P {1H} NMR signals at low temperatures. 2a-2c and 2f-2h form Ni(0) and Fe(0) complexes (CO) 3 NiL (6a-6f) and Fe(CO) 4 L (7a-7d), respectively. The Tolman electronic parameters of the bulky ligands are almost identical. Within the series 2a-2h the spatial shielding of the P atoms has been estimated using advanced molecular modeling techniques. The bulky ligand 2c forms coinage metal complexes [C u(CH 3 CN) 2 (2c) 2 ] [PF 6 ] (8), Cu 2 Cl 2 (2c) 2 (9) and Cl-Au(2c) (10). While 10 is monomeric in solution, in the solid state it forms pairs of head to tail oriented monomers with almost linear Cl - Au - P skeletons (Cl - Au - P 175.47(9)°) as shown by an X-ray structural analysis.

Reaction of [Ph 4 P] 2 WS 4 with NiCl 2 in methanol solution in the presence of NaOCH 3 leads to the formation of [Ph 4 P] 2 [S 2 W(μ-S) 2 Ni(S 2 )] (I). A similar reaction between (NH 4 ) 2 WS 4 and NiCl 2 under O 2 atmosphere in the presence of Ph 4 PCl or n Bu 4 NCl affords [Ph 4 P] 2 {[(S 2 )W(O)(μ-S) 2 ] 2 Ni} (Ila) and [ n Bu 4 N] 2 {[(S 2 )W(O)(μ-S) 2 ] 2 Ni} (lIb). Under argon the same reaction gives [Ph 4 P] 2 [Ni(WS 4 ) 2 ] (IlIa) and [ n Bu 4 N] 2 [Ni(WS 4 ) 2 ] (Illb). [Ph 4 P] 2 [Ni(WOS 3 ) 2 ] (IV) and [Ph 4 P] 2 [Ni(WO 2 S 2 ) 2 ] (V) can be prepared from the reaction of [Ph 4 P] 2 WOS 3 and [Ph 4 P] 2 WO 2 S 2 with NiCl 2 . Treatment of (NH 4 ) 2 WS 4 with CuCl in the presence of PPh 3 in boiling pyridine produces W(μ-S) 4 Cu 2 (PPh 3 ) 3 (VI), which can further react with excess PPh 3 to give W(μ-S) 4 Cu 2 (PPh 3 ) 4 ·py (VII). Complex I crystallizes in the space group P2 1 /n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Å; β = 110.24(3)° and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(μ-S) 2 Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Å; β = 128.00(3)° and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.

Single crystals of NaBa 3 RuO 6 (I) and NaBa 3 IrO 6 (II) have been prepared by crystallization from melts in closed silver tubes. The crystal structures were investigated by X-ray techniques. Both compounds crystallize with trigonal (rhombohedral) symmetry, space group D 6 3d -R3̅c, I: a = 10.107(2), c = 11.872(2) Å, II: a = 10.128(2), c = 11.905(2) Å, Z = 6. I and II are isostructural to the Sr 4 PtO 6 type.

Dimethylsulfide reacts with (triphenylphosphine) gold(I) trifluoromethanesulfonate to give quantitative yields of the mixed ligand complex [(Ph 3 P)Au(SMe 2 )] + O 3 SCF 3 - (1). The structure of compound 1 has been determined by an X-ray crystal structure analysis. The lattice contains independent anions and (monomeric) cations, which have a linear P-Au-S axis. Attempts to produce a binuclear. dicationic complex through addition of a second equivalent of [(Ph 3 P)Au] + failed and lead to decomposition products including [(Ph 3 P) 2 Au] + O 3 SCF 3 - .

A new bisphospholane, BDPB, derived from 1,2-bisphosphanobenzene and tartaric acid as well as the complex [Rh(COD)(BDPB)]PF 6 were synthesized. The strong binding of BDPB to metals and the presence of four functional groups in the periphery of the molecule make this bisphospholane a good starting point for new expanded bisphosphanes.

The compounds BaPdAs 2 (a = 4.678(1), b = 17.330(2), c = 4.574(1) Å), BaPdSb 2 (a = 4.877(1), b = 18.583(2), c = 4.889(1) Å) and BaPtAs 2 (a = 4.660(1), b = 17.119(2), c = 4.608(1) Å) were prepared by heating mixtures of the elements and investigated by X-ray methods. They are isotypic and crystallize in the CeNiSi 2 -type structure (Cmcm), also called the BaCuSn 2 -type.