Volume 47, Issue 12

The new thiophosphonium compounds (CH 3 )„P(SCH 3 )Cl 3-n + Cl - (n = 1-3) are prepared by reaction of methylphosphines (CH 3 )„PC1 3 _„ (n = 1-3) with CH 3 SC1 in CH 2 C1 2 . CH 3 P(SCH 3 )Cl 2 + Cl - reacts with A1C1 3 or SbCl 5 to give the tetrachloroaluminate and the hexachloroantimonate, respectively. Likewise (CH 3 ) 2 P(SCH 3 )Cl + SbCl 6 - is formed from the chloride and SbCl 5 . All compounds are characterized by vibrational and NMR spectroscopy. CH 3 P(SCH 3 )Cl 2 +SbCl 6 - crystallizes in the monoclinic space group P2 1 /n with a = 929(2), b = 1095(2), c = 1436(3) pm, β = 93,1(2)° and Z = 4. (CH 3 ) 3 PSCH 3 + I - crystallizes in the same space group with a = 705,2(4), b = 1360,6(8), c = 941,8(4) pm, β = 93,85(4)° and Z = 4.

The vibrational spectra of all members of the fluorophosphonium cation series are reported, including the protonated and deuterated species PX 4-n F n + (X = H, D; n = 0-4). The unequivocal assignment of the vibrations follows from the isotopic shifts and by means of force field calculations. Furthermore, the force constants are discussed for the complete series.

The IR and Raman spectra of the ten bromo-iodo-osmates(IV) [OsBr n I 6-n ] 2- , n = 0-6, including the geometrical isomers for n = 2, 3, 4, have been recorded at low temperature. The vibrational spectra are completely assigned according to point groups O h , D 4h , C 4v , C 3v , and C 2v , as supported by normal coordinate analyses based on a general valence force field. Due to the different trans-influences Br<I in asymmetric axes Br′–Os–I′, the Os–I′ bonds are strengthened and the Os–Br′ bonds are weakened, as indicated by valence force constants, for Os–I′ on average 4% higher and for Os–Br′ 4% lower, as compared with the values calculated for symmetric I–Os–I and Br–Os–Br axes, respectively.

[K(18-crown-6)] 2 S 6 •2CH 3 CN was obtained from K 2 S 5 and 18-crown-6 in acetonitrile. The crystalline compound easily loses the incorporated acetonitrile. Its crystal structure was determined by X-ray diffraction with 3095 reflexions, R = 0.058. Crystal data: a = 1621.4(8), b = 812.1(3), c = 3271(2) pm, β = 90.75(4)°, space group C2/c, Ζ = 4. The chain-like S 6 2- ion has transoid conformations. Each of its terminal atoms is coordinated to one K + ion, which in turn is surrounded by one crown ether molecule.

Reaction of ozone with (PPh 4 )2[As2Cl8] in CH 2 C1 2 at low temperatures yields a red compound, possibly an ozonide. Upon evaporation of the solvent at –78 °C the ozone is released again. At -40 °C or above a subsequent reaction yields PPh 4 [AsCl 6 ], PPh 4 Cl · H 3 AsO 4 , and other products. The crystal structure of PPh 4 Cl · H 3 AsO 3 was determined by X-ray diffraction (4253 observed reflexions, R = 0.031). It is triclinic, space group P1̅, and consists of H 3 AsO 4 molecules joined to dimer units via H bridges and associated via O–H · · · Cl - bridges to strands. The packing of the PPh 4 + ions is discussed. Products of the reaction of (PPh 4 ) 2 [Sb 2 Cl 8 ] with ozone in CH 2 C1 2 are PPh 4 [SbCl 6 ] and (PPh 4 ) 2 [SbOCl 4 ] 2 · 2 CH 2 Cl 2 .

The reaction of the tetrahydrosalen ligand H 2 L = N,N′-bis(2-hydroxy-3-t-butyl-5-methylbenzyl)- 1,2-diaminoethane with iron(III) chloride in the presence of sodium methoxide affords a neutral complex of the composition [FeL(OMe)]. Single crystal X-ray analysis of this complex shows dinuclear units, [FeL(OMe)] 2 = 1, with two methoxide bridges. Complex 1 crystallizes in the monoclinic space group C 2/c with a = 31.67(1)Å, b = 12.544(4)Å, c = 14.135(5)Å and β = 101.33(1)°. The two edge-sharing FeO 4 N 2 -octahedra are distorted and connected by a center of inversion. The iron(III) centers are separated by 3.203 Å and weakly antiferromagnetically coupled (J = —5.7 cm -1 ), which follows from temperature-dependent magnetic susceptibility measurements in the range 4.2 to 280 K. The effective magnetic moment per iron(III) is µeff = 5.24 μ Β at 280 K. The observed small coupling constant J fits well into the magnetostructural relationship suggested recently by Gorun and Lippard (Inorg. Chem. 30,1625 (1991)).

The crystal structure of the novel pink Li 5 CrCl 8 oC28 has been determined by both single crystal X-ray and neutron powder studies. The title compound crystallizes in a hitherto unknown structure type (space group C mmm, Z = 2). The final R values are R = 3.4% (715 independent reflections with I > 3a I ) and R wp = 11.5%, respectively (a = 1019.79(3), b = 723.94(2) and c = 726.16(3) pm). The structure consists of edge-connected Li(l)Cl 6 and alternating edge-connected Li(2)Cl 6 and CrCl 6 octahedra, respectively. It is related to the NaCl super structure SnMn 2 S 4 type. IR and Raman spectra as well as symmetry coordinates are given and discussed in terms of CrCl 6 and LiCl 6 breathing modes.

(CH 3 ) 3 SiN(SO 2 CH 3 ) 2 (1), m. p. 69-70 °C, is obtained by metathesis of AgN(SO 2 CH 3 ) 2 with (CH 3 ) 3 SiCl (improvement of a known procedure) or, more conveniently, by silylation of HN(SO 2 CH 3 ) 2 with [(CH 3 ) 3 Si] 2 NH. The 1 H, 13 C and 29 Si NMR solution spectra and the 29 Si NMR solid-state spectrum suggest the constitution of 1 in solution (CDC1 3 , CD 2 C1 2 , CDCl 2 –CDCl 2 ) to be an equilibrium mixture of the N-silylated form (CH 3 ) 3 Si–N(SO 2 CH 3 ) 2 (I) and the O-silylated form (CH 3 ) 3 Si–O–S(O)(CH 3 )=NSO 2 CH 3 (II) in a molar ratio of 2:1 at room temperature, whereas in the known crystal structure of 1 only form I is present. The solid-state NMR experiment acted as a bridge between X-ray crystallography and solution-state NMR, enabling assignments of the resonances to be made with confidence to the tautomers. At room temperature, form II undergoes a rapid intramolecular 1.5-migration of silicon between oxygen centers of the two sulfonyl groups. As shown by kinetic measurements using 1 H NMR spectroscopy, 1 is a highly reactive agent for silylating ketones in the presence of triethylamine. Hydroxy and thiol functions, even when sterically hindered, are silylated by 1 in uncatalyzed reactions. It is further shown that HN(SO 2 CH 3 ) 2 is an efficient catalyst for silylations with [(CH 3 ) 3 Si] 2 NH.

2+2 Cyclocondensation of benzil with aliphatic diamines viz. 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane or 1,12-diaminododecane in the presence of Co(II) as a template yields a series of pentacoordinated high spin Co(II) complexes of the type [CoLX]X (where L = N 4 macrocycle having 12- to 32-membered ring and X = NO 3 , Cl). The complexes have been characterized by elemental analyses, IR and diffuse reflectance spectra, conductances and magnetic measurements.

The azavinylidene osmium complex [OsH(=N=CPh2)(CO)(PiPr 3 ) 2 ] (2) is prepared either from [OsHCl(CO)(PiPr 3 ) 2 ] (1) and MN=CPh 2 (M = Li, Na) or from [OsHCl(NH=CPh 2 )(CO)(PiPr 3 ) 2 ] (3) by HCl elimination with ΚΟ-t-Bu. The IR and NMR spectroscopic data of 2 provide evidence that a linear Os—N—C unit is present. Complex 2 reacts with CH 3 OH to give the isomeric ortho-metallated compound [OsH{NH=C(Ph)C 6 H 4 }(CO)(PiPr 3 ) 2 ] (5). With CD 3 OD instead of CH 3 OH, the mono-deuterated derivative [OsH{ND=C(Ph)C 6 H 4 }(CO)(PiPr 3 ) 2 ] (5-d 1 ) is obtained.

[1,4-Bis(diphenylphosphinyl)butane]digold dichloride 1 and [1,5-bis(diphenylphosphinyl)-pentane]digold dichloride 2 have been prepared from R 2 SAuCl (R = CH 2 CH 2 OH) and the corresponding bidentate phosphines Ph 2 P(CH 2 ) n PPh 2 (n = 4 or 5) in good yields. The structures of the compounds have been determined by single crystal X-ray diffraction (1 · CH 2 C1 2 : space group P1̅, Z = 2; 2·0.5 CH 2 Cl 2 : space group C 2/c, Z = 8). While the monomers [Ph 2 P(CH 2 ) 5 PPh 2 ] (AuCl) 2 are associated through intermolecular Au···Au contacts (3.323 Å) to form a chain-like structure, the crystal lattice of 1· CH 2 Cl 2 features independent [Ph 2 P(CH 2 ) 4 PPh 2 ](AuCl) 2 molecules which show no intra- or intermolecular Au···Au interactions. This exceptional behaviour can be rationalized on the basis of efficient packing of solvent molecules and molecules 1 with a particularly favourable conformation, which cannot be altered by weak Au(d 10 )—Au(d 10 ) interactions.

Beryllium and its compounds are highly toxic to most living cells, but the mechanisms of the interference with the biological substrates on the molecular level is not understood. From observations in (attempted) chemotherapy of beryllium poisoning using a variety of complexing agents it has been concluded that Be 2+ is interacting predominantly with carboxyl as well as hydroxyl functions of protein bio-polymers, with complete deprotonation of the alkoxy or phenoxy functions involved. As a first support for this hypothesis, an analytically well-defined beryllium complex of glycolic acid has now been isolated from aqueous solutions under nearphysiological conditions, crystallized and its structure determined by X-ray diffraction. The hexanuclear complex features beryllium in two different environments, mono- and bis-chelated by glycolate ligands with deprotonated hydroxyl groups. In 9 Be-NMR studies of aqueous solutions of the complex (pH 6) the persistence of complexation in two different environments of Be 2+ could also be confirmed. The new structure may serve as a model for beryllium complexation with larger bio-ligands.

Treatment of C[B(OMe) 2 ] 4 with four equivalents of a (tert-phosphine)gold(I) chloride LAuCl with L = P(c-C 6 H 11 ) 3 or (2-MeC 6 H 4 ) 3 P in the presence of CsF in hexamethylphosphoric triamide (HMPT) affords the first complexes of the type (LAu) 4 C. The product is formed together with salts (LAu) 5 C + BF 4- as the by-product for L = tricyclohexylphosphine, from which it can be separated by fractional crystallisation. With Ph 2 (2-MeCH 4 )P only the hexacoordinate species (LAu) 6 C 2+ 2 BF 4- is obtained, while with Ph(2-MeC 6 H 4 ) 2 P a mixture of (LAu) 6 C 2+ and (LAu) 5 C + salts is generated. The title compounds are stable, colourless solids readily identified by standard analytical and spectroscopic techniques, including 13 C NMR of 13 C-enriched material.

Polyaurated carbon complexes of the type [(L–Au) 6 C] 2+ with functionalized phosphine ligands have been prepared by the reaction of the phosphinegold(I) chlorides R(Ph) 2 PAuCl (R = p-C 6 H 4 -Cl 2a,p-C 6 H 4 -Br 2b,p-C 6 H 4 -CH 3 2c,p-C 6 H 4 -OCH 3 2d,p-C 6 H 4 -COOH 2e, p-C 6 H 4 –N(CH 3 ) 2 2f), R 2 (Ph)PAuCl (R = p-C 6 H 4 -N(CH 3 ) 2 2g) and R 3 PAuCl (R = p-C 6 H 4 -N(CH 3 ) 2 2h) with tetrakis(dimethoxyboryl)methane in HMPT at room temperature. Clearly depending on the different inductive and mesomeric effects, the preparation of the clusters with substituents like –CH 3 3c, –OCH 3 3d and –N(CH 3 ) 2 3f needs shorter reaction times and the products show better solubility in organic solvents than those with functional groups like –Cl 3a, –Br 3b and –COOH 3e. The 31 P magnetic resonance parameters are correlated with electronic effects of the substituents, but the chemical shift of the interstitial carbon atom in the 13 C-NMR spectra is largely independent of the coordinating ligands. For the phosphinegold(I) chlorides 2f–h X-ray structure analyses have been performed.

Reactions of CuCl 2 with 1.3.5-trithiane and 1.4.7-trithiacyclononane yield crystals of CuCl 2 · C 3 H 6 S 3 , and CuCl 2 • C 6 H 12 S 3 , resp. According to X-ray structure analyses, CuCl 2 • C 3 H 6 S 3 forms infinite chains, whereas CuCl 2 • C 6 H 12 S 3 consists of discrete molecules. In CuCl 2 • C 3 H 6 S 3 the thioether molecules act as bridging ligands. Each Cu is coordinated to two S atoms belonging to two adjacent ligands, and to two Cl atoms; thus a distorted square planar coordination results. In CuCl 2 · C 6 H 12 S 3 the Cu is penta-coordinated to the three S atoms of the ligand and to two Cl atoms. One Cu–S bond is significantly longer than the two others; the coordination polyhedron may be regarded as a distorted tetragonal pyramid.

The thallium(I)-2-pyridyl-cyanoxime complex was prepared in a 82% yield. An X-ray crystallographic study of C 7 H 4 N 3 OT1 (Space group P2 1 /c, a = 4.134(1), b = 8.875(2), c = 22.217(6) Å, β = 92.55(2)°, Ζ = 4, R = 4.36%, wR = 3.94% for 930 reflections) showed that the complex contains thallium(I) in a trigonal bipyramidal arrangement.

Colorless K 4 O(CN) 2 has been prepared. The compound crystallizes in the tetragonal anti-K 2 NiF 4 structure type (space group I4/mmm) with a = 515.5(1) and c = 1606.7(3) pm, Z = 2. The structure was determined by single crystal X-ray diffraction, R = 3.35%.

Carbonyliron tin complexes CpFe(CO) 2 –SnMe 3 (1), cis-(CO) 4 Fe(SnMe 3 ) 2 (2), cis-(CO) 4 Fe(SnMe 2 Cl) 2 (3), [R 2 SnFe(CO)4] 2 (4a, R = Me; 4b, R = Bu), {Me 2 Sn[Fe(CO) 4 ] 2 } 2 Sn (5), Me 2 Sn[Fe(CO) 4 ] 2 Sn[Fe(CO) 4 ] 2 (6) and Sn[Fe(CO) 4 ] 4 (7) were studied by 119 Sn NMR. It proved possible for the first time to observe coupling constants 1 J( 119 Sn 57 Fe) in the range of 36 to 64 Hz. The large magnitude of geminal coupling constants | 2 J( 119 SnFe 119 Sn)| (1400 to 1800 Hz) in the cyclic compounds 4 to 6 indicates the presence of tin-tin interactions as an efficient coupling pathway. Extreme deshielding of 119 Sn nuclei in the complexes 6 (δ 119 Sn + 953) and 7 (δ 119 Sn + 1532) is associated with three-centre FeSnFe bonds in these compounds.

The structures of two polymeric complexes of chromium(III) azide with pyridine, KCr(py) 4 (N 3 ) 4 (1), and RbCr(py) 3 (N 3 ) 4 (2), were determined by X-ray crystallography. Crystal data: 1, C 20 H 20 N 16 CrK, monoclinic, space group C2/c, a = 1611.2(5), b = 1050.6(3), c = 1609.0(5) pm, β = 91.69(3)°, Ζ = 4 and Rw = 0.037 for 923 diffractometer data; 2, C 15 H 15 N 15 CrRb, monoclinic, space group P2 1 /n, a = 1311.9(3), b = 1139.0(4), c = 1523.3(4) pm, β = 109.39(2)°, Ζ = 4 and R w = 0.046 for 2336 data. The crystal structure of 1 contains six-coordinated chromium and potassium cations with two pyridine ligands and four µ(1,3) bridging azido groups forming a three-dimensional network structure. The chromium atoms are trans-coordinated by the pyridine ligands, whereas the potassium cations are cis-coordinated. The polymeric complex 2 features di-µ(l,1,3) azido bridged CrRbN 2 rings, distorted octahedral chromium(III) coordination geometry, sevencoordinated rubidium, and di-μ(1,3) azido bridges which link the binuclear RbCr(pyridine) 3 (N 3 ) 2 moieties into infinite chains parallel to the b axis.

The molecular surfaces of five different sandalwood odour molecules were investigated and subsequently used as a basis for a mean surface and compared to each other. It was possible to find a specific surface part with a significant pattern, which seems to be necessary for evoking the typical odour.

9,10-Di(1-naphthyl)phenanthrene (5 a) and 9,10-di(2-naphthyl)phenanthrene (5 b) have been synthesized. It is shown that 5 a and 5b both form two stable rotational (cis/trans) isomers with the naphthalene molecular planes perpendicular to the phenanthrene plane. In the case of 5 a the mixture of the two isomers has been separated in a preparative scale and each isomer characterized by e. g., NMR spectroscopy. Photocyclization of 5a leads to benzo[e]phenanthro[1,2,3,4-ghi]perylene (9) while 5 b yields phenanthro[9,10-i]pentahelicene (14); both hydrocarbons have not been previously described in the literature. The observed selectivities of photocyclization are explained on the basis of the structures and stabilities of the initially formed photoproducts (dihydro structures 15 and 14 a). The role of intramolecular non-radiative singlet-singlet energy transfer (naphthalene → phenanthrene) as competing with photocyclization is discussed in detail.

The absorption and luminescence properties of 6-acetyl-2,3-dihydro-4(1H)-quinolinone are described and compared to those of the parent 2,3-dihydro-4(1H)-quinolinone. The character of the electronic transitions is determined by PPP quantum chemical calculations. An N-acyl migration leading to the formation of 6-acetyl-2,3-dihydro-4(1H)-quinolinone takes place upon UV irradiation or heating with polyphosphoric acid of 1-acetyl-2,3-dihydro-4-(1H)-quinolinone. A radical mechanism of the photochemical rearrangement is proposed.

In order to find a new synthesis of gephyrotoxin 1 an alkaloid from the neotropical poison frog Dendrobatidae the compounds 3 and 4 were synthesized. However they reacted not to the decahydroquinoline derivative 2 but to the title compound 5.

The 2-methyl-2,3-butadienamides 4a—m are directly synthesized by the reaction of the corresponding allenic acid chloride 2 with the secondary amines 3. At heating, 4a—j undergo the intramolecular Diels-Alder reaction, by using their ω-standing double bond and the π-system of the directly bonded phenyl groups or of the “methylenic” bonded arenes or furans. Thereby the tricycles 6a—g (bearing five-membered lactam moreties) and/or the tricycles 7-9 (bearing six-membered lactam moreties) are formed. The influence of the geminai methyl group on the chemoselectivity and on the velocity of the IMDA reactions is investigated. The N-allyl derivatives of 4 (s. 41 and m) form the bicycles 10 by intramolecular [2+2]-Cycloaddition.

The polynuclear complex [CuICu2II(CN) 4 (′N 2 S′) 2 ]SCN was obtained by gel diffusion of the sodium salt of 4,7-Bis(dithiocarboxylato)-1-thia-4,7-diazacyclononane and K 3 Cu(CN) 4 . Its structure consists of an infinite band of edge-sharing Cu I (Cu II )4 tetrahedra, where the Cu 1 and Cu II ions are connected via CN~ bridges. Cu II is additionally coordinated by the N 2 S macrocycle 1-thia-4,7-diazacyclononane. Crystal data: monoclinic, space group C 2/c, a = 1936.6(4), b = 1287(3), c = 1337(2) pm, β = 133.07(2)°, Ζ = 4, 2336 reflections, 203 parameter, R (Rw) = 0.027 (0.031).

The phospha-arsa-mangana-cyclopropane (OC) 4 Mn–PPh 2 –AsAr (4) [Ar = 2,4,6-(t-Bu) 3 C 6 H 2 ] is obtained in a one-pot reaction proceeding in the sequence Mn 2 (CO) 10 → HMn(CO) 5 (1) → HMn(CO) 4 PPh 2 H (2) → Li 2 [(OC) 4 Mn—⃛PPh 2 ] (3) → 4. According to an X-ray structural analysis 4 has a short P–As bond (229 pm) and a long Mn–As distance (262 pm).

A simple synthesis of 4-(herniarine-3-yl)-2-methyl-3-buten-2-ol from umbelliferone in relatively high yield is described.

5-Acetyltetrazole can be obtained in 75% yield by reacting 5-tetrazolecarbonitrile (the latter available by an efficient literature procedure) with an excess of methylmagnesium iodide.