Volume 41, Issue 5

Bis(phosphite)-substituted formyl complexes (OC) 2 (ON)L 2 WCHO L = P(OMe) 3 (4a), P(OEt) 3 (4b), P(OiPr) 3 (4c) were generated from the corresponding cationic (OC) 3 (ON)WL 2 + system s using borohydride reagents. The decomposition of 4a-4c leads to hydride com pounds (OC) 2 (ON)L 2 WH or (OC) 3 (ON)LWH , L=P(OMe) 3 (5a, 6a), L=P(OEt) 3 (5b, 6b), L=P(OiPr) 3 (5c, 6c).

(CO) 4 FeP(R)Cl 2 reacts with Na 2 Cr 2 (CO) 10 to give the μ 3 RP capped trigonal heterom etallic closed cluster Fe(CO) 3 Cr(CO) 4 Cr(CO) 5 (μ 3 -PR)(1) as a major product. ACr(CO) 5 -derivative of a metal substituted phosphane [(μ 2 ( t BuPCl)Fe 2 (CO) 7 )( t BuPH)]Cr(CO) 5 (2) is obtained as a minor component. The analogous reaction with (CO) 4 FeP(Ph)Cl 2 only gives the known cluster Fe 3 (CO) 9 (μ 3 -PR) 2 (3), while (CO) 4 FeP(c-hexyl)Cl 2 results in 4, a pentacarbonylchromiumderivative of the diiron species Fe 2 (CO) 6 μ-(PR) 3 . Species o f this type, containing an Fe 2 (CO) 6 entity doubly bridged by μ 2 -PR entities, which are them selves linked by another PR-group, are obtained in a systematic high yield process by reacting Fe 2 (CO) 6 (μ 2 -RPH)2 with n-BuLi/TMEDA , RPCl 2 . For com pound identification, analytical and spectroscopic data as well as four X-ray analyses are presented.

Ru 2 (C 6 H 5 COO) 4 (C 6 H 5 COOH) 2 (1) is formed as main product besides small amounts of Ru 2 (C 6 H 5 COO) 5 ·C 6 H 5 COOH (2) by the reaction of Ruthenium (III) acetylacetonate in molten benzoic acid. 1 forms monoclinic black crystals with the space group P2 1 /n and the lattice constants a = 1091.0, b = 1164.1, c = 1526.8 pm, β = 90.53°, Z = 2.2 is obtained as triclinic red needles with the space group P1̄ and the lattice constants a - 1178.4, b = 1605.3, c = 1043.9 pm, a = 99.07°, β = 95.45°, y - 83.22°, Z = 2. Both com pounds exhibit carboxylate bridged dimers [Ru 2 (C 6 H 5 COO) 4 ] n+ (n=0, 1). In case of the isolated Ru(II) dimer 1 two benzoic acid m olecules occupy axial positions and form hydrogen bridges to carboxylate O-atoms. 1 is paramagnetic with two unpaired electrons per dimeric unit corresponding to an electron configuration σ 2 π 4 δ 2 π* 3 δ* and a bond order of 2 (Ru-Ru = 226.3 pm ). It decomposes at 230 °C to Ru 2 (C 6 H 5 COO) 4 and at 350 °C to Ru metal. 2 is polymeric. A benzoate anion functions as bridging ligand between [Ru 2 (C 6 H 5 COO) 4 ] + dimers. The benzoic acid molecule is weakly associated to the polymer by an H-bridge. A Ru-Ru bond order of 2.5 and a Ru-Ru distance of 227.7 pm are observed.

The structure of P 12 (iPr) 4 , C 12 H 28 P 12 , has been determined by single crystal X-ray techniques (R f = 0.026, wR f = 0.029 for 3549 observed reflections with |F o | ≥ 4σ(F o )). The compound crystallizes in the triclinic space group P1 with a = 879.8, b = 1088.5, c = 1414.1 pm, α = 93.01, β - 107.61, γ = 92.92° and Z = 2. The molecule contains a polycyclic P 12 -unit of nearly C 2v symmetry, which represents an essential structural unit of Hittorf’s phosphorus.

A systematic natural abundance 15 N NMR study of diazaphospholes is presented for the first time, giving accurate values for chemical shifts, δN , and coupling constants J( 31 P 15 N), J( 15 N 1 H ). 14 N NMR spectra can be used to predict the magnitude of 1 J( 31 P 14 N) if the broadening of the 31 P resonance by scalar relaxation is known. The relaxation behaviour of the 14 N nuclei corresponds to that found in azoles indicating a comparable electronic ground state structure. The comparison of the chemical shifts, δN, in the diazaphospholes with δN of corresponding triazoles reveals differences which can be traced to the N-P σ-bonds and to the influence o f the phosphorus atom on the π-system. A linear correlation δN/δP exists coordinate nitrogen and phosphorus, respectively.

By reaction of trithiazylchloride, (NSCl) 3 , with PPh 4 [RuCl 4 (NO)] 2 in dichloromethane the thiazylchloridenitrosyl complex PPh 4 [RuCl 4 (NO)(NSCl)] is obtained; its vacuum pyrolysis at 200-220 °C yields the thionitrosyl com plex (PPh 4 ) 2 [RuCl 4 (NS)] 2 which crystallizes from CH 2 Cl 2 solution with four molecules of CH 2 Cl 2 . Both com pounds were charaterized by their IR spectra and by X-ray crystal structure determinations. Crystal data: PPh 4 [RuCl 4 (NO)(NSCl)], mono­clinic, space group P 2 1 /n, Z = 4, a = 982.6, b = 1700.0, c = 1772.3 pm , β = 104.79° (2548 observed reflexions, R = 0.046); (PPh 4 ) 2 [RuCl 4 (NS)] 2 ·4CH 2 Cl 2 , triclinic, P1̄ , Z = 1, a = 952.9, b = 1380.0, c = 1458.5 pm , α = 112.91, β = 106.67, γ = 92.61° (3760 observed reflexions, R = 0.053). In the [RuCl 4 (NO)(NSCl)] ⊖ ion the nitrosyl and thiazyl chloride ligands occupy ex ­ positions; bond lengths indicate double bonds in the linear Ru=N=O group, while the NSCl molecule is attached by a donor-acceptor interaction Ru-N≡S̲-Cl , although with a rather short Ru-N bond of 198 pm (N≡S 144 pm, S-Cl 213 pm). The centrosymmetric [RuCl 4 (NS)] 2 2⊖ ions have chloro bridges and NS ligands in axial positions; the nearly linear Ru=N=S group has bond lengths Ru=N 175 pm and N=S 147 pm.

The cuticular hydrocarbons of the Colorado beetle Leptinotarsa decemlineata say consist of 2-methylalkanes, internally branched monomethylalkanes, dimethyl-, trimethyl-and tetramethyl-alkanes. The hydrocarbons differ from those of most of the other insects so far investigated. The major components were found to be the dim ethyl branched alkanes, 2,6-and/or 7,22-dimethyl-octacosane and the tetram ethylalkane, 3,10,16,23-tetram ethyltritriacontane. The hydrocarbons identified are members of homologous series which differ by two m ethylene groups. The identification of hydrocarbons was achieved by mass spectrom etry and gas chromatographic determination of Kovats retention indices on two high efficiency capillary columns coated with Dexsil 300 and OV-1.

[2,3-Bis(diphenylphosphino)-N-methylmaleimide]PtCl 2 reacts with Pt(PPh 3 ) 4 to form a new diamagnetic Pt-complex 4. Its formation is a result of P-C-cleavage by insertion of Pt. The structure was determined by single crystal X-ray analysis. 4 crystallizes in the triclinic space group P1̄ (4 A), and in the monoclinic space group P 2 1 /c (4B). The lattice constants (at 180 K) are: 4A: a = 1069.9(8), b = 1494.9(11), c = 2013.7(18) pm, α = 84.27(3), β = 86.24(2), γ = 71.91(2)°;4B: a = 1480.8(5), b = 1488.6(5), c = 3302.8(13) pm, β = 102.61(3)°.

Among the reaction products of S 4 N 4 with SnCl 4 in chloroform, that contains acetic acid and small amounts of water, there are two salts S 4 N 4 H + [SnCl 5 (H 2 O)] - (A) and (S 3 N 2 NH 2 + ) 2 [SnCl 6 ] 2- (B), both containing protonated S n N m units. The crystal and molecular structures of A and B have been determined by X-ray diffraction. A: monoclinic, P2 1 /c, a = 9.084(2), b - 23.758(4), c = 6.587(1) Å , β = 101.86(3)°, D c = 2.383 g·cm -3 and Z = 4. B: monoclinic, P2 1 /n, a = 9.882(3), b = 12.873(4), c = 6.807(2) Å , β = 93.77(5)°, D c = 2.352 g·cm -3 and Z = 2. The structures of the cations in both compounds agree well with those found of other salts containing these cations.

Aluminium trichloride forms a 1:1 addition product with tetramethylurea (1) the structure of which has been determined by X-ray methods. Tetramethylurea is bound to the AlCl 3 unit via its oxygen atom; consequently, a lengthening of the CO bond is observed. The (CH 3 ) 2 N units are less twisted relative to the OCN 2 plane than in the free ligand. Solutions of AlCl 3 ·OC(NMe 2 ) 2 in diethylether contain both the initial molecular adduct 1 and the ether adduct AlCl 3 ·OEt 2 . In tetramethyl urea, compound 1 dissociates predominantly into the ions AlCl 4- and {Cl 2 Al[OC(NMe 2 ) 2 ] 2 } + . These solutions have been studied by 27 Al NMR spectroscopy.

Both title com pounds show an antifluorite-like arrangement of (CH 3 ) 4 N + cations and TeCl 6 2- anions. The remaining octahedral holes in this array can be filled with CH 3 CN molecules forming the inclusion com pound by crystallization from CH 3 CN solution. [(CH 3 ) 4 N] 2 TeCl 6 (space group Fd3̄c with a = 25.791(3) Å at 265(5) K and Z = 32) contains almost regular TeCl 6 2- octahedra. In contrast, in [(CH 3 ) 4 N] 2 (CH 3 CN)TeCl 6 (space group Cmcm with a = 12.765(6), b = 14.349(7), c = 12.716(3) Å and Z = 4) the anion is statically distorted with the approximate point symmetry 4 mm. At temperatures above 320 K the solvent molecules can be removed yielding the Fd3c phase. Finally, structural relationships between antifluorite-like phases A 2 BX 6 and elpasolites A 2 B′BX 6 considering halogenides and cyanides are discussed.

Tricarbonyl-η 5 -cyclopentadienyl-methyl-tungsten (1) reacts upon UV irradiation with conjugated dienes, like 1,3-butadiene (2), E-1,3-pentadiene (3), 2-methyl-1,3-butadiene (4), 2,3-dimethyl-1,3- butadiene (5), 1,3-cyclopentadiene (6) and 1,3-cyclohexadiene (7), to give the corresponding, quasisquare- pyramidal [(η 5 -C 5 H 5 )W(CO)(COCH 3 )(η 4 -diene)] complexes (8-13). With the unsymmetrically substituted dienes 3 and 4, only one of the possible diastereotopic complexes are obtained. At 200 to 230 K, 8-12 show two isomers, which are distinguished by the orientations (o or u) of the diene with respect to the other ligands. The interconversion of the o- and u-isomers was studied by dynamic 1 H NMR spectroscopy and is explained by an intramolecular ±180° rotation of the diene ligands in the molecular plane. The barriers o f activation ⊿G* 300 are between 57.8 and 61.0 ± 1 kJ/mol.

EPh 2 bridged dicyano octacarbonyl dimetalates {Ph 2 E[Mn(CO) 4 CN] 2 } 2- are formed by the reaction of bis(carbonyl-metalates) of tin and lead Ph 2 E[Mn(CO) 5 ] 2 with NaN(SiMe 3 ) 2 . The new dicyano anions can be transformed with trialkyloxonium tetrafluoroborates [R′ 3 O]BF 4 or chlor-trimethylsilane and -germane into the corresponding diisonitrile complexes Ph 2 E[Mn(CO) 4 CNR′] 2 (R′=Me, Et, SiMe 3 , GeMe 3 ). In the case of Ph 2 E [Mn(CO) 4 CNR′] 2 (R′=Me, Et; E=Sn, Pb) the two phenyl groups can be removed with dry hydrogenchloride to give Cl 2 E[Mn(CO) 4 CNR′] 2 .NMR and mass spectra are discussed. The vibrational spectra of the new compounds show cis-coordination of the Sn atoms and the cyano or isonitrile ligands in the carbonylmetalate fragments. This is confirmed by the X-ray structure analysis of Ph 2 Sn[Mn(CO) 4 CNMe] 2 (space group P2 1 /n).

The reaction of bis(dialkylaminoalkyl)-and bis(4-alkoxybutyl)magnesium inner complexes with MgEt 2 leads to the formation of ethyl(dialkylaminoalkyl)-and ethyl(4-alkoxybutyl)magnesium compounds. The X-ray crystal structures of ethyl(3-N,N-dimethylam inopropyl)magnesium and ethyl(3-N-cyclohexyl-3-N-methylaminopropyl)magnesium confirm that the com pounds are dimeric with the α-C-atom of the chelating ligand bridging the magnesium atoms. The difference in reactivity of the Mg-Et and Mg-C n H 2n X bonds (X = NR′R″, OR) makes itself apparent in the reaction of these complexes with ethylene: up to six ethylene molecules are inserted, whereby in the case of the ethyl(4-alkoxybutyl)magnesium compounds insertion occurs preferentially into the Mg-Et bond whereas in the case o f the ethyl(dialkylaminoalkyl)magnesium compounds both bonds are equally reactive.

Reduction of MentPBr 2 M(CO) 5 1 (M = Cr, W) with magnesium in THF yields the diphos­phene complex (CO) 5 M(Ment)P=P(Ment)M(CO) 5 2 as the main product. In addition, a phosphinidene complex, (CO) 5 M(Ment)PM(CO) 5 (3) is also formed. The latter is obtained in larger amounts, if the reaction is carried out in the presence of M(CO) 5 THF. The proposed structures are confirmed by NMR and UV data as well as - in the case of the chromium compounds (2a, 3a) - by crystal structure analysis. Compound 2a is obtained only as the frans-isomer. The P-P distance in 2a (204.0 pm) indicates a double bond which does not participate in the complex formation. The P-Cr distance in 3a (average: 230.3 pm) is within the low est range found for this element combination. Reaction of 2a with LiAlH 4 yields the diphosphane complex (CO) 5 CrMent(H)P-P(H)MentCr(CO) 5 4 as a mixture of “meso” and “rac” diastereomers.

By reduction of the tetramic acids 1 or their derivatives 5 and 6 with complex borohydrides the pyrrolidinones 2 and 7 are obtained. Dehydration of 2 and 7 leads to the title compounds 3 and 8, respectively.

Fruiting bodies of several Suillus species contain a colourless compound, suillin, which is concentrated in the cuticle of the pileus. Its structure has been established as 4-acetoxy-3-geranyl-geranyl-1,2 -dihydroxybenzene (1) by spectroscopic evidence, conversion into a cyclic carbonate 2 and synthesis of its deacetyl derivative 3.

Starting from tetramethoxysilane, sila-triparanol 4b and sila-ethamoxytriphetol 8b were synthesized by four-step syntheses. 4b and 8b exhibit a strong hypolipidemic activity in mice after p.o. administration. Whereas 4b and its carbon analogue triparanol (4a) show a similar hypolipidemic potency, 8b was found to be less potent than its carbon analogue ethamoxy­-triphetol (8a). The silicon com pounds 4b and 8b are less toxic (repeated administration over a period o f 8 days) than the corresponding carbon analogues 4a and 8a, respectively.

In contrast to former assumptions pyridinium salts with a tertiary 2-α-C-atom like 2 a and 16 are not oxidized to pyridinium-carbinol intermediates during alkaline hexacyanoferrate(III) oxidation because 10 yields the pyridones 11 and 12, both missing after oxidation of 2a. The title compounds 2 show the same reactivity against alkaline hexacyanoferrate(III). The pseudobases 14 suffer ring fission simultaneously forming the pyridones 6-8. 4 and 5 were characterized as further oxidation products of 2.

The compound MoRhCl(μ-dppm) 2 (CO) 2 (μ-CO)(M-SO 2 ) (1) is ob­tained from MoRhCl(μ-dppm) 2 (CO) 4 and SO 2 . 1 is the first hetero-bimetallic complex of sulfur dioxide.

A phase equilibrium study of the system aluminiumchloride and pyridiniumchloride has been carried out. The phase diagram of the system indicates the existence of four congruently melting compounds of the molar ratio AlCl 3 /PyHCl 1:1, 1:2, 1:3, 2:3 .