Volume 46, Issue 12

Under exclusion of air the thioether and thiol complexes [Ru(SRR′)(PPh 3 )′S 4 ′] (′S 4 ′ 2- = 1,2-bis(2-mercaptophenylthio)ethane (2—)) easily react with CHCl 3 yielding [Ru(Cl)(PPh 3 )(′S 4 ′—CHCl 2 )] in which one thiolato atom of the ′S 4 ′ ligand is diastereospecifically dichloromethylated. In the presence of air, however, [Ru III (Cl)(PPh 3 )′S 4 ′] is formed. The molecular structures of [Ru(Cl)(PPh 3 )(′S 4 ′-CHCl 2 )] · 2CHCl 3 and [Ru III (Cl)(PPh 3 )′ bu S 4 ′] have been determined by X-ray crystallography. ′ bu S 4 ′ 2- (= 1,2-bis(3,5-di(t-butyl)-2-mercaptophenylthio)ethane(2-)) is the t-butyl derivative of the ′S 4 ′ ligand. Reasons for observed diastereospecifity of alkylation are discussed.

[Ni(′N H S′ 4 )] 2 (′N H S′ 4 2- = 2,2′-bis(2-mercaptophenylthio)diethylamine(2-)) was synthesized from Ni(ac) 2 and Na 2 —′N H S′ 4 and characterized by X-ray structure analysis. In the solid state [Ni(′N H S′ 4 )] 2 contains two pseudooctahedral [Ni(′N H S′ 4 )] fragments bridged via thiolate donors, in DMF solution at 110 °C it dissociates into mononuclear entities. The product of the template reaction between [Ni(′S′ 2 ) 2 ] 2- (′S′ 2 2- = 1,2-benzenedithiolate) and (BrC 2 H 4 ) 2 NH was shown to contain an as yet unidentified by-product in addition to [Ni(′N H S′ 4 )] 2 . Pure [Ni(′N H S′ 4 )] 2 does not react with pyridine, but the template product forms [Ni(Py) 2 (′S′ 2 )] which has a square planar coordination geometry with the pyridine rings perpendicular to the NiS 2 N, plane. Investigation of the template formation of [Ni(′N H S′ 4 )] 2 provided evidence that the reaction of [Ni(′S′ 2 ) 2 ] 2- with (BrC 2 H 4 ) 2 NH involves radicals, suggesting a radical chain reaction mechanism.

In order to elucidate specific properties of nickel sulfur complexes, redox and addition-elimination reactions of [Ni(′OS 4 ')] 2 , [Ni(′N H S 4 ')] 2 , [Ni(′S 5 ')], [Ni('S 4 —C 5 ')], and [Ni('S 4 —C 3 ')] were investigated ('OS 4′ 2 ' = 2,2'-bis(2-mercaptophenylthio)diethylether(2—), 'N H S 4 ' 2 - = 2,2'-bis(2-mercaptophenylthio)diethylamine(2—), 'S 5 ' 2- = 2,2'-bis(2-mercaptophenylthio)diethylsulfide(2—), 'S 4 -C 5 ' 2- = 1,5-bis(2-mercaptophenylthio)pentane(2—), 'S 4 —C 3 ' 2 - = 1,3-bis(2-mercaptophenylthio)propane(2—)). Cyclovoltammetry proves the complexes to be redox inactive between —1.4 and +0.8 V vs. NHE. Above +0.8 V the complexes are irreversibly oxidized, below —1,4 V desalkylation takes place and [Ni(′S,′)2] 2- is formed. An X-ray structure analysis was carried out of (NMe 4 ) 2 [Ni(′S 2 ') 2 ], which shows a planar anion with the Ni center in a nearly perfect square planar coordination. Distances and angles are practically identical to those in the [Ni(′S 2 ') 2- ] monoanion. The complexes coordinate only phosphines as coligands, but thioether donors simultaneously decoordinate and, dependant of reaction temperature, mono- or trisphosphine complexes are formed. [Ni(′S 4 —C 3 ')(PMe 3 )] was characterized by X-ray structure analysis and exhibits a square pyramidal coordination geometry.

Chlorodiisopropylphosphane reacts with hexachlorodisilane to give diisopropyl(trichlorosilyl)phosphane which reacts with the educt chlorophosphane to produce tetraisopropyldiphosphane. Tetraisopropyldiphosphane reacts with hexachlorodisilane to provide diisopropyl(trichlorosilyl)phosphane. With di-tert-butylchlorophosphane and tetra-tert-butyldiphosphane, the corresponding reactions leading to di-tert-butyl(trichlorosilyl)phosphane are much slower; while the product does not react further with di-tert-butylchlorophosphane, it does with chlorodiisopropylphosphane. A stable 1:1 complex is formed from di-tert-butyl(trichlorosilylphosphane) with silver bromide. Products are characterized on the basis of analytical and 1 H, 13 C, 29 Si and 31 P NMR data.

The predominant complex species formed between inosine and vanadate in aqueous media is binuclear and biligate (δ( 51 V) = —523 ppm; the formation constant at pH 7.9 and an ionic strength I = 1 M is K 4 = 2.2(1) · 10 7 M -3 ), with essentially a pentagonal-bipyramidal geometry around vanadium, coordination through two adjacent (2′ and 3′) ribose oxygens, and dimerization via alkoxo bridges. The complexation depends upon concentration, pH, temperature, and solvent. The pH range of 7.1-8.8 has been studied. In dry dmso, the geometry of the vanadate-inosine complex is probably octahedral (δ( 51 V) = - 494 ppm). Adenosine (Ad) shows a behaviour very much comparable to inosine in aqueous media (K 4 = 2.5(1) · 10 7 M -3 ), but higher equilibrium concentrations of a 1:2 complex (VAd 2 ) n have been detected in this case. There is evidence (by 1 H NMR) for participation of the NH, group of the base in coordination. The overall formation constant for the complexes formed between vanadate and guanosine in water amounts to ca. 24 M -1 .

The crystal structure and the X—X difference electron density distribution of 1,3-bis(diisopropylamino)-1,3,dihydro-1,3-diborete (1) has been determined at the temperature of 107 K. Both π-electrons of the folded aromatic four membered ring system (folding angle 47.6°) are uniformly distributed on the four ring bonds with equal lengths (B—C 1.524 A). These bonds are significantly bent.

The reaction of tungsten hexachloride with Se 4 N 2 leads to [WCl 4 (NSeCl)] 2 , which reacts with pyridine to form [WCl 4 (NSeCl)Py], and with tetraphenylphosphonium chloride to form PPh 4 [WCl 5 (NSeCl)], which was characterized by an X-ray structure determination. Space group P2 1 , Z = 2, 1657 observed unique reflections, R = 0.074, wR = 0.061. Lattice dimensions at —80 C: a = 710.7(1), b = 2217.9(4), c = 953.6(2) pm; β = 111.93(3) . The [WCl 5 (NSeCl)] - ion possesses an almost linear WNSe group with bond lengths WN = 188 pm, corresponding to a double bond, and NSe = 200 pm.

The reaction of [FeI 2 L 2 ] (1; L = SC(NMe 2 ) 2 ) with KSR (R = 2,4,6-i-Pr 3 C 6 H,) yields [Fe(SR) 2 L 2 ] · PhMe (2). Oxidation of the thiolate ligands of 2 with ((Me 2 N) 2 CSSC(NMe 2 ) 2 ) 2+ affords the cationic complexes [Fe(SR)L 3 ] + and [FeL 4 ] 2+ , which were isolated as tetraphenylborate salts. A mixed ligand neutral iron sulfur cluster [Fe 4 S 4 (SR) 2 L 2 ] (3) has been synthesized by the reaction of 2 with elemental sulfur. 3 is a precursor for cationic clusters which are obtained via the above-mentioned oxidation. The structures of 2 and 3 were determined from single crystal X-ray diffraction data. 2 crystallizes in the monoclinic space group C2/c with a = 1807.8(1), b = 1000.6(1), c = 2946.0(2) pm, β = 101.16(1), V = 5227.6 × 10 6 pm 3 , Ζ = 4, R = 0.067. The complex exhibits C 2 -symmetry and a distorted tetrahedral coordination of Fe(II) (S–Fe–S angles between 101.7 and 125.7). The Fe–S thiourea and Fe–S thiolate bond lengths were found to be 240.3(2) and 231.5(1) pm, respectively. 3: triclinic, P1, a= 1020.2(2), b = 1035.3(2), c = 1402.1(2) pm, α = 73.50(1), β = 70.47(1), γ=84.38(1),V= 1338.2 × 10 6 pm 3 ,Z= 1, R = 0.039. 3 shows a slightly compressed Fe 4 S 4 core structure. The Fe– Fe distances range from 269.1 to 278.1 pm. The shortest and longest distances are observed between those Fe atoms which have two thiourea and two thiolate ligands, respectively.

Cobalt sulfate heptahydrate (d-14), CoSO 4 ·7D 2 O, M r = 294.99, monoclinic, P2 1 /c, a = 1404.8(1), b = 649.41(6), c= 1092.5(2) pm, β = 105.232(8), V = 961.66·10 6 pm 3 , Z = 4, D x = 2.073 Mg· m -3 , λ(MoKa) = 71.073 pm, [(sin θ)/λ] max = 0.7035· 10 -2 pm -1 , μ = 20.26 cm -1 , F(000) = 580, T = 298 K, R(F) = 0.0264 for 2339 observed unique reflections. CoSO 4 ·7 D 2 O is shown to be isotypic to FeSO 4 · 7 H 2 O (Melanterite). The deuterated compound is stable at ambient conditions in contrast to the normal hydrate. Its structure is built up by [Co(D 2 O) 6 ] 2+ octahedra, SO 4 2- tetrahedra, and “lattice” water molecules. One water molecule, which is almost exactly trigonally planar coordinated in its average position, exhibits a distinct oxygen disorder. The “lattice” water molecule accepts two strong hydrogen bonds and donates a linear and a bifurcated one. The hydrogen-bond lengths (O···O distances) are in the range 271-302 pm.

High yields of bisphthalocyaninates of lanthanum and cerium have been obtained in the strongly exothermic reaction of the dehydrated lanthanoid acetates with molten 1,2-dicyanobenzene in the presence of potassium hydroxide or methylate. Salts of the type (cat)[M(Pc(2—)),] (M = La, Ce) with different cations (cat + = K, Bu 4 N, PNP, TDOA) have been isolated. The corresponding “Hydrogen salts” are obtained by thermal decomposition of (Bu 4 N)[M(Pc(2—)) 2 ] at T > 350 C. The dimeric structure is confirmed by negative fast atom bombardement mass spectra. The redox properties have been investigated by cyclovoltammetry and UV, VIS, MIR, FIR and resonance Raman (RR) spectra are reported. Electronic transitions between 2000 and 3000 cm -1 are observed in the low temperature RR spectra of (Bu 4 N)[Ce(Pc(2—)) 2 ] being RR enhanced at 470 nm. From the assignment to the higher transitions within the symmetry split 5 F 5,2, , 2 F 72 manifolds of the f 1 ground state of Ce 3+ the crystal field parameters ζ 4f = 610.5, B 40 = 242.2 and B 60 = 4.1 cm -1 have been determined.

The reaction of bifunctional neutral phosphenium ion complexes, containing a carbon-carbon triple bond next to a phosphorus-molybdenum multiple bond, with carbenes and to carbene isolobal organometallic fragments is discussed. So, the reaction of (R)(PhC=C)P=MoCp′(CO), (R = 2,4,6-′Bu 3 C 6 H 2 O; Cp′ = η 5 -C 5 H 5 : la; Cp′ = η 5 -C 5 Me 5 : 1b) with CH 2 ,Ν 2 (2) yields the three membered heterocyclic compound (3). 3 reacts with Co 2 (CO) 8 to afford complex (5) in which the phenylethynyl building block is η 2 -side-on coordinated to a Co 2 (CO) 6 fragment. Similar to the reaction of 1 with 2, 1 forms with Fe 2 (CO) 9 (6), compound (7). In 7 the PMo double bond is coordinated in a η 2 fashion to the 16-electron organometallic fragment Fe(CO) 4 . Using an excess of 6 and a higher temperature, the phosphorus-alkynyl-carbon σ-bond is cleaved, and cluster MoCp*Fe 3 (CO) 8 η 3 -PR)(C≡CPh) (8) is formed. The reaction of 1 with Cr(CO) 5 (THF) yields 10, a complex, in which the PhC≡C ligand is η 2 -coordinated to Cp′(CO) 2 Mo, and the Cr(CO) 5 group forms a dative bond with the phosphorus atom. All new compounds have been characterized by analytical as well as by spectroscopic data (IR, 1 H, 31 P, 13 C NMR, MS), compound 10 by an X-ray analysis.

The melting diagram of the superacid system SbF 5 —CF 3 SO 3 H as well as of SbF 5 —HF has been studied by DTA and the crystal structure of one newly found low-melting adduct in each case determined. The adduct SbF 5 · CF 3 SO 3 H (m.p. — 1°C, monoclinic, space group P21/c, Z = 4 formula units per unit cell) is composed of complex molecules F 5 SbOS(CF 3 )(O)OH which are linked by strong hydrogen bonds O-H ···F to infinite chains. The adduct SbF 5 · 7HF (melting incongruently at —75°C, monoclinic, I 2/m, Z = 2) is a fluoronium salt, (H 7 F 6 )SbF 6 . The novel H 7 F 6 + cation is formed as an unbranched chain by very strong hydrogen bonds between the respective F atoms, which become weaker from the center to the ends. A further hydrogen bond of this kind, between the cations and the octahedral SbF 6 - anions, again leads to a one-dimensional polymer.

Vibrational spectra of the title compounds have been measured and assigned based on the symmetry D ∞h of linear [BN,] 3- units. The (B–N) force constants and bond orders have been calculated and compared with those of isoelectronic molecules and ions.

An X-ray single crystal structure determination (monoclinic, space group P2 1 /c, a = 573.6(2), b = 489.2(1), c = 574.8(2) pm, β = 108.07(2), Z = 2; wR = 0.038 for 380 reflections) shows that NaMnF 4 crystallizes in the same layered structure type as LiMnF 4 . In the quadratic layers the Mn-F-Mn bridges are strongly asymmetric, due to the Jahn-Teller effect, leading to an antiferrodistortive order of elongated octahedra. The bridging angle is 138.4°. The Na + ions are 6-coordinated as well. The common structural arrangement of both [MnF 6 ] and [NaF 6 ] octahedra shows topological relation to the rutile structure. In the magnetic measurements performed on powder samples NaMnF 4 behaves as an antiferromagnet with a weak ferromagnetic component below 13 K. By neutron diffraction on powder (4-70 K) a magnetic cell doubled along the α-axis is found and below a Neel temperature of T N = 13 K the magnetic structure shows colinear antiferromagnetic arrangement of the spins pointing slightly (16) out of the layer plane. The resulting magnetic moment is 3.52 μ Β .

Se 5 S in CS 2 solution at 20°C spontaneously decomposes to give a mixture of 8 selenium-rich cyclic molecules which have been identified by reversed-phase HPLC and 77 Se NMR spectroscopy as Se 6 , Se 7 , Se 8 , Se 6 S, Se 7 S, 1,2-Se 6 S 2 , 1,5-Se 6 S 2 , and 1,4-Se 4 S 2 . NMR spectra of Se 5 S, Se 7 S, and 1,5-Se 6 S 2 have been measured for the first time; Raman spectra of solid Se 5 S and Se 7 S as well as crystal data of Se 7 S are reported in addition. A mechanism based on nucleophilic attack on Se 5 S is proposed for the formation of the products.

Complexes of the type Fe 2 (CO) 6 (μ-RNS) [R = H (la), t Bu (lb), SiMe 3 (lc), Si'BuMe 2 (1d), SnMe 3 (le)] have been studied by multinuclear magnetic resonance ( 1 H 13 C, 14 C, 14 N, 15 N, 17 O, 29 Si, 119 Sn) with emphasis on natural abundance 15 N NMR measurements. By application of various polarization transfer techniques 1 J( 57 Fe 15 N) (6.1 Hz) in la has been determined for the first time, together with the isotope-induced shift 1 Δ 34/32 S (-36 ppb). Compound ld has been prepared via the reaction between Me 2 t BuSiCl and Fe 2 (CO) 6 (μ-NaNS) (lf), available from la and sodium.

[Hg 2 (o-NH 2 C 6 H 4 CN)2](NO 3 ) 2 is formed by the reaction of o-aminobenzonitrile with dimercury(I)-dinitrate in methanol. It crystallizes in the monoclinic space group P 2/c with a = 8.6819(5)Å, b = 5.3696(6)Å, c = 19.7645(8)Å, β = 95.138(12)° and Ζ = 2. The crystal structure has been determined by single crystal X-ray diffraction with applied gaussian absorption correction and refined to an R w -value of 0.027. The Hg 2 2+ -ion is coordinated to both amino nitrogen atoms. Strong hydrogen bonds and bridging nitrate ions lead to chain structure.

The title compounds were obtained by the reaction of cobaltocene with ozone in acetonitrile at -40°C. Their crystal structures were determined by X-ray diffraction. [Co(C 5 H 5 )2]NO 3 : orthorhombic, space group Pnma, a = 1566.4(3), b = 831.6(2), c = 765.7(1) pm, Z = 4, R = 0.055 for 587 observed unique reflexions. [Co(C 5 H 5 ) 2 ] 2 [Co(NCO) 4 ]: monoclinic, P 2,/c, a = 1792.6(8), b = 2079.2(9), c = 1311(1) pm, β = 99.18(6)°, Ζ = 8, R = 0.067 for 2994 reflexions. Both compounds contain sandwich-type cobalticenium ions. The cyanato group of the [Co(NCO) 4 ] 2- ions are bonded to Co via their N atoms with CoNC angles ranging between 160 and 173°.

The reaction of (Ph 3 P) 2 PtC 2 H 4 with the divinyldisiloxane (CH 2 =CHSiMe 2 ) 2 O in toluene yields Pt{(η 2 -H 2 C=CHSiMe 2 ) 2 O}PPh 3 , which has been characterized by IR, 1 H, 13 C, 31 P NMR and MS spectra. The crystal structure was determined by X-ray diffraction: space group C2/c, Z = 16, a = 5534.2(9), b = 842.6(2), c = 2383.1(2) pm, β = 103.73(1)°, R/R w = 0.047/0.052. It shows a three-coordinate platinum atom with one phosphine and one sym-tetramethyldivinyldisiloxane ligand acting as a chelating bidentate η/ 2 -ligand to give a chair conformation of the six-membered PtC 2 Si 2 O-ring system.

Reaction of [Cu(PPh 3 ) 2 (NO 3 )] (1) in acetone with bis(diphenylphosphino)amine (dppa, 2) yields [Cu(dppa)(PPh 3 ) 2 ] + NO 3 - (3a). [Cu(dppa)(PPh 3 ) 2 ] + PF 6 - (3b) has been synthesized by metatheses of 3a with NH 4 PF 6 . The salt [Cu(dppm)(PPh 3 )2] + PF 6 - (5b) has been prepared by an one batch reaction of [Cu(PPh 3 ) 2 (NO 3 )] (1), bis(diphenylphosphino)methane (dppm, 4) and NH 4 PF 6 in methanol, because [Cu(dppm)(PPh 3 ) 2 ] + NO 3 - (5a) could not be isolated by the direct reaction of 1 with 4. The IR, Raman, 31 P{ 1 H} NMR, 1 H{ 31 Ρ} NMR as well as the conductivity data are reported and discussed together with the X-ray crystal structure of 3a · 1.8 (CH 3 ) 2 CO. The structure consists of copper atoms coordinated tetrahedrally by two PPh 3 ligands and the chelating dppa ligand and features a highly strained four-membered ring. The distorted tetrahedral cations are hydrogen bridged to the nitrate anions. The colourless needles of 3a· 1.8 (CH 3 ) 2 CO crystallize in the monoclinic space group C 2/c, with the lattice constants a = 4189.2(27); b = 1223.7(8); c = 2717.8(15) pm;β = 113.16(4)°.

1,2,4,5-Tetramethylimidazole (3) is obtained by metalation of 2,4,5-trimethylimidazole (2) with sodium in liquid ammonia and subsequent addition of methyl iodide. 3 reacts with Lewis acids to form the compounds Me 4 C 3 N 2 · BH 3 (8) and Me 4 C 3 N 2 · E + (4, 5, 7, 10; E = Me, H, SiMe 3 , C(O)Me). The X-ray structure reveals the ionic nature of pentamethylimidazolium iodide (4) in the solid state.

Depending on the keto-enol equilibrium 1 ⇄ 2 reduction of the esters and the amides 1/2 a—g with Zn(BH 4 ) 2 /ZnCl 2 attacks either at the CO or at the CO 2 R group. A high diastereoselectivity (98:2 or more) is observed for the formation of the β-hydroxy compounds 3a,b,c,e,f in favour of the erythro forms. As to the structure determination of 3, different steric effects and different intramolecular hydrogen bonding have to be considered, leading to different rotameric populations.

4-Aroyl-6-phenylpyridazin-3(2 H)-ones (4a—c) were synthesized by the oxidation of the corresponding 4-arylmethyl-6-phenylpyridazin-3(2H)-ones (3a—c) using sodium dichromate in glacial acetic acid. The reactions of 4a—c with hydrazine hydrate and hydroxylamine hydrochloride proceeded smoothly to give the corresponding hydrazones (5) and oxime (6). 4a—c reacted with dimethyl sulphate to give 4-aroyl-2-methyl-6-phenylpyridazin-3(2 H)-ones (7a—c), respectively while their reaction with phosphorus oxychloride gave 4-aroyl-3-chloro-6-phenylpyridazines (9a—c), respectively.

In order to determine the effect of tetravalent cations on the inorganic phase of hard tissues, a model study has been undertaken, investigating a series of fluoroapatites in which part of the Ca(II) ions were substituted by Th(IV), Zr(IV) or Hf(IV). Diffractometric and vibrational spectroscopic studies show that low concentrations of the incorporated metals neither affect the crystallographic characteristics nor the strength of the P—O bonds of these apatitic materials.

The colourless compound K 3 O(CN) has been prepared. The characterization by X-ray powder methods leads to a cubic primitive lattice (Pm 3m) with a = 520(2) pm (Z = 1). The structure is related to the anti-perovskite type.

(±)-(10- 2 H, 11- 2 H 2 , 12- 2 H 3 )Jasmonic acid has been synthesized starting from racemic jasmonic acid via 2-formylmethyl-3-methoxycarbonylmethylcyclopentanone by reaction with (1- 2 H, 2- 2 H 2 , 3- 2 H 3 )propylidene-triphenylphosphoran followed by sponification of the labelled methyl jasmonate.

Starting from 1,3-dithiolo[4,5-b][1,4]dithiin-2-thione, the title thione was prepared by a fourstep sequence (lithiation with lithium diisopropylamide, addition of Se, treatment with ZnCl 2 in the presence of n-Bu 4 NBr, and alkylation with 1,2-dibromoethane). Self-coupling as well as cross-coupling with similar compounds via triethyl phosphite afforded new tetrathiafulvalenes, precursors of conducting salts.

The adducts CF 3 S(O)F · MF 5 (M = As, Sb) and (CF 3 ) 2 SO · SbF 5 have been prepared by reaction of the sulfuranes CF 3 S(O)F and (CF 3 ) 2 SO with AsF 5 and SbF 5 in liquid HF, and characterized by Raman and 19 F NMR spectroscopy.