Volume 39, Issue 3

The crystal and molecular structures of two trans-1,2,4,5-tetraza-diphospha-3,6-cyclohexane- 3,6-disulfides, 2 and 3, have been determined by X-ray diffraction methods. The 3,6-diphenyl- 1,2,4,5-tetramethyl-derivative 2 crystallizes in the monoclinic system, space group C He. Its P2N 4 heterocycle adopts a twist conformation. In contrast, the hexamethyl derivative 3 is triclinic, space group P1̅, and its ring shows chair conformation. Torsion angles in these two compounds and similar ones reveal less interaction between lone pairs of electrons on adjacent N-atoms in the chair conformation but stronger interaction of those bound to phosphorus. It is suggested that the latter interaction is responsible for the larger N -P -N bond angle (107°) as compared to the smaller one (101°) in the P 2 N 4 rings present in twist conformation.

The novel polycyclic organophosphanes b-P 9 R 5 , P 10 R 6, P 10 R 4, P 11 R 5, and P 13 R 5 (R = Me, Et, i-Pr) have been obtained by reacting RPCl 2 with white phosphorus and magnesium or by thermolysing P 7 R 5 (perhaps in the presence of P 8 R 6 , P 9 R 5 or (PR)5). A strategy for the enrichment or isolation of polycyclic organophosphanes P n R m (m < n) from complex reaction mixtures is described. The structures of the above mentioned compounds have been unambiguously clarified by 31 P NMR spectroscopy or X-ray structure analysis. The results clearly indicate that the corresponding phosphorus hydrides P n N m have the same structures. The general structural principles of polycyclic phosphanes are dicussed.

Carboxydiphcnyl phosphane sulfides (C 6 H 5 ) 2 P(S)(OC(O)R) (2) (R = CH 3 2a, C 2 H 5 2b, C 17 H 35 2c, (CH 3 ) 3 C 2d, C 6 H 5 2e) were prepared by reacting silver salts of carboxylic acids AgOC(O)R with (C 6 H 5 ) 2 P(S)Cl (Scheme 1) or by treating carboxylic acids with (C 6 H 5 ) 2 P(S)Cl in the presence of triethyl amine (Scheme 2) and spectroscopically characterized. Thermal stability and stability against hydrolysis of the mixed anhydrides is unusually high.

The melting diagram of the quasi-binary system NH 3 -HF between the limits NH 4 HF 2 and HF was redetermined. The compounds NH 3 · 4HF, NH 3 · 5HF and NH 3 · 8HF with melting points of 26, -14 (dec.) and -95 °C (dec.), respectively, were established as the stable phases. Their crystal structures were determined as those of ammonium hydrogen fluorides NH 4 [F(HF)4], NH 4 [F(HF) 4 ] and NH 4 [HF 2 (HF) 3 ] · 3HF with extended N-H···F and F-H···F hydrogen bonding.

The liquidus and solidus lines of the quasi binary system CF 3 COOH-H 2 O were determined by low temperature difference thermal analysis and the resulting phase relations controlled by X-ray powder diffraction. Formation of a monohydrate and a tetrahydrate, melting congruently at -43 and -16 °C, respectively, is confirmed. In addition a metastable form of the monohydrate and a low temperature form of the tetrahydrate, stable below -47 °C, are indicated. The crystal structures of the stable high temperature forms were determined. From these the monohydrate (tetragonal, space group I42d, Z = 16) is a true acid hydrate, CF 3 COOH-H 2 O, and the tetrahydrate (triclinic, P1̅, Z = 2) a hydrated oxonium salt, (H 5 O 2 ) + [H(CF 3 COO) 2 ] - · 6H 2 O.

From new DTA and powder diffraction measurements in the binary system sulfur-chlorine a consistent construction of the melting diagram for the region 50-100 atom-% CI was possible. It contains sulfur chlorides of the elemental ratios 1:1, 1:2, 1:3, and 1:4 as the stable intermediate phases, which melt at -80 °C (congr.), -125 °C (incongr.). -75 °C (incongr.) and -34 °C (congr.), respectively. SCI is S 2 C 12 as characterized by its crystal structure by R. Kniep, L. Korte and D. Mootz, Z. Naturforsch, 38b, 1 (1983). Of SC 12 a single crystal was grown by zone melting in a capillary and its structure determined as composed of angular molecules SC 12 arranged in bimolecular layers (orthorhombic space group P2 1 2 1 2 1 ; a = 400.19, b = 918.8, c = 1750.5 pm at -134 °C; Z = 4). With SCl 3 a new binary solid of the system is reported of a yet unknown structure. SCl 4 from its powder diffraction pattern is made probable as an isotype of α-SeCl 4 , with tetrameric cubane-like molekules S 4 Cl 16 .

The crystal structure of In I In III I 4 (Indium-diiodide) has been determined by single crystals X-ray methods. The compound crystallized with a GaCl 2 -type arrangement in the orthorhombic space group Pnna (lattice constants: a = 842.7(3) pm, b = 1096.5(3) pm, c = 1117.3(3) pm). Coordination polyhedra and bond lengths are discussed in comparison with other In iodides.

The new compound SFCl was obtained by UV photolysis of FC(O)SCl in rare gas matrix and by UV photolysis of Cl 2 /SF 3 SF in the gas phase. Isotopic substitution verifies the molecular identity. Eight frequencies from three isotropic molecules determine the force constants f SF = 4.30 and f scl = 2.90 10 2 N/m.

Tetramethyldistibane which shows a colour change from deep red to pale yellow upon melting, has been subjected to single-crystal x-ray diffraction analyses at -21° and -139 °C (orthorhombic, Pnma, Z = 4, -139 °C: a = 1150.9(3); b = 1136.8(2) ; c = 651.6(2) pm). The molecules adopt the antiperiplanar conformation with the crystallographically imposed symmetry m (C s ) and are aligned in extended linear antimony chains with short intermolecular contacts (-139 °C: Sb-Sb 283.8(1), Sb···Sb 367.8(1) pm; Sb-Sb---Sb 179.2°). The structure is compared with those of similar compounds.

δ( 31 P) NMR data of the complexes [Nb(Cp)(CO) 3 PZ 3 ] (Cp = η 5 -C 5 H 5 ) and cis- [Nb(Cp)(CO) 2 (PZ 3 ) 2 ] [Z = H, R (alkyl and aryl), OR, NMe 2 , PR 2 ] are interpreted on the basis of varying P(3p σ ) and P(3d π ) contributions to the bond-order density matrix in the paramagnetic deshielding term of the overall shielding constant. For Z = R, shielding of the 31 P nucleus of the coordinated phosphine decreases as the cone angle θ increases, as a result of increasing p contribution. For Z = OR and NMe 2 , P-Nb π interactions dominate, and the decrease of the P(3d π ) occupation with increasing θ leads to an increase of shielding. In the case of alkoxiphosphines, decreasing 31 P shielding is accompanied by an increase of the shielding of the metal nucleus [quantified here by δ( 51 V) of the vanadium complexes], while, for the substantially less powerful π interacting alkylphosphines, shielding trends for the two nuclei parallel each other. Coordination shifts Δδ(P) are somewhat greater for small phosphines but, spanning a range of 80 ± 30 ppm, tend to be comparatively invariant. In [V(Cp)(CO) 3 PZ 3 ], the 31 P nucleus is deshielded by 10 to 30 ppm with respect to the corresponding niobium complexes.

The title compound 1 was synthesized as reaction product of pentacarbonyl iron with 2-ethylimidazole. A Zerewitinoff-determination shows that we are rather dealing with hydrido-tetracarbonylferrate(- II) than with tetracarbonylferrate(-I) as supposed in a preceding paper. A new crystal structure analysis of 1 was performed. With respect to [HFe(CO) 4 ] - we found that three CO groups are ordered with normal tetrahedral angles, while the fourth CO group shows statistical distribution over three sites (disordered sites). The temperature parameters of the disordered CO sites are considerably more anisotropic than those of the ordered CO sites. Experimental Mössbauer spectra have been recorded between 4.2 K and 288.7 K. 1 exhibits a Mössbauer pattern with two subspectra, one for each of the cations and the anions. The cation subspectrum reflects normal ferrous high-spin behavior, while the anion subspectrum shows peculiar anomalies around 200 K. On the basis of our X-ray structure results molecular orbital calculations have been performed with the aim of deriving electric field gradient tensors for the various stochastic substates of [HFe(CO) 4 ] - . These tensors were then used within the frame on an analytical lineshape formula. It turns out that the statistical distribution of the fourth CO group over three sites is associated with a jump behavior, similar to trapped diffusion, of the CO group among the three sites and not with static disorder. The Fe atom follows this jumb behavior, however, its triangular displacement body with jump distance d ~ 0.30 Å is considerably smaller than that of the CO group.

Heterocyclic cage compounds of type I (compounds 8-10) have been prepared by condensation reactions of 1,2,2-trifunctional disilanes Me(R)XSiSiMeX 2 (R = Me, Ph, OEt; X = NMe 2 , OEt) with triethanolamine using the “Dilution Principle”. The starting compounds are obtained by Si-Me cleavage of Si 2 Me 6 with acetylchloride/AlCl 3 followed by either aminolysis with HNMe 2 or alcoholysis with EtOH. 1 H NMR spectra indicate N→Si(1) intraction with the more acidic Si atom in 8 and 9. This result is proved by the X-ray structure analysis of 8 (monoclinic, P2 1 /c; a = 7,088(2), b = 15,070(4), c = 12,701(4) Å, β = 104,96(2) at -130 °C, Z = 4); the Si(1)···N distance is found to be 2,768 Å , connected with a significant angular distortion of the tetrahedral coordination around Si(1) towards a trigonal bipyramid. In compound 10, too, N→Si(1) coordination is observed at room temperature in spite of almost equal acidity for both Si atoms. This can be explained by the preference of 5- over 6-membered chelating ring systems. At higher temperatures the 1 H NMR spectra show a fluctuation of the N-donor between the two Si centres.

The redox reactions between the iodogallanes Gal 3 as well as PhGaI 2 and the disulfides CH 3 SSCH 3 and PhSSPh lead to the monoalkylthio- and monoarylthiogallanes CH 3 SGaI 2 and PhSGaI 2 respectively. No reaction occurs between Inl 3 and these disulfides, whereas, surprisingly, Phlnl 2 does react to give the monoalkylthio- and monoarylthioindanes CH 3 SInI 2 and PhSInI 2 , respectively, Ph 2 GaI and Ph 2 InI form only the thioether adducts with the disulfides, which were not isolated. Initative mechanisms of these reactions are reported.

The insertion of hexafluoroisopropylidenimine (1) into the P - H bonds of the phosphanes PH 3 , MePH 2 and Me 2 PH yields the (1,1,1-Trifluoro-2-amino-2-trifluoromethyl)ethylphospanes (2-4). Trimethylphosphane is oxidized to give the phosphine-imine Me 3 P = N-CH(CF 3 ) 2 (5).

Syntheses of 2,2′-disubstituted cis-Bis(phenyl)bis(ligand)platinum(II) compounds are described with respect to the influence of the ortho-substituents on reaction paths. Configuratior and conformation of the substituted phenyl rings are established by an X-ray structure determination of cis-Bis(2-nitrophenyl)bis(triphenylphosphane)platinum(II).

2-Benzylindenes (1, 1a ) are hydrogenated to 2-benzylindanes (2) using tris-(triphenylphosphine)- rhodium (I)-chloride in benzene by a strict cis-1,2 addition of hydrogen to the double bond. Thus, stereo- and regio-specific deuterium labelling at the five-membered ring of various 2-benzylindanes has been carried out. The high selectivity of deuterium incorporation is shown independently by 1 H NMR and mass (MIKE*) spectrometry of selected 2-benzylindanes.

Cocondensation of chromium atoms with anthracene vapor affords bis(η 1.2.3.4.4a.9a -anthracene)- chromium (1) which was characterized as the radical cation 1 +̣ in fluid solution by means of ESR spectroscopy. Conspicuous features of this new π-complex are the ease of ligand displacement (τ 1/2 ≈ 10 min. THF, 233 K) and the ready hydrogenation in 9,10-position of the ligand which already occurs under mild conditions (e.g. methanol). The product of hydrogenation, bis (η 1.2.3.4.4a.9a -9,10-dihydroanthracene)chromium (2) was synthesized independently and studied by 1 H, 13 C NMR (2) and ESR(2 +̣ ) spectroscopy. A qualitative rationalization is given for the observed trend of increasing lability and propensity to hydrogenation: (η 6 -biphenyl) 2 chromium < (η 6 -phenanthrene) 2 chromium < (η 6 -naphthalene) 2 chromium < (η 6 -anthracene) 2 chromium.

Attempts to oxidize the 1,5-benzothiazepin-2,4-3H,5H-dione (1) using NaNO 2 /Acetic acid lead to isolation of two ring contracted products, namely the 1,4-benzthiazin-derivatives 4 and 5. A reasonable reaction pathway concerning the formation of these compounds is discussed. A simple synthesis of 6-methyI-1,5-benzoxazepin-2,4-3H,5H-dione (13) is described, the transformation of which into the corresponding vic. trione fails, even using a great number of oxidizing procedures. In some cases so far unknown malonic acid derivatives 14, 15 and 16 can be obtained.

The 5-arylmethylene derivatives of 2-phenylhydrazono-4-thiazolidinone (1) reacted with phenacyl bromide and with ethyl bromoacetate to yield the thiazolo[2,3-c]triazine derivatives (3) and (4). The reaction of 1 with carbon disulphide in alkaline solution afforded the bis(N 1 - 2-phenylhydrazono-4-thiazolidinone)thiocarbonyl derivatives (6). Cyanoethylation of 1 afforded the N 1 -β-cyanoethylphenylhydrazono derivatives (7).

Upon heating to 300 °C partial luteolinemethylethers undergo transmethylation. A reaction mechanisme is put foreward.

The ampicillin coupling on BIOZAN R (a polysaccharide of microbial synthesis Xanthomonas campestris) is studied by the activation of carboxylic groups by dicyclohexylcarbodiimide. The following optimum reaction parameters are settled on the basis of an experimental program: time = 7.5 h, temperature = 10 °C, dicyclohexylcarbodiimide concentration = 1.10 -3 mole, ampicilline concentration = 2.4·10 -3 mol. Under these conditions up to 37% of ampicillin with respect to the polymer is coupled. The microbiological and hydrolysis studies under the conditions of the human physiological pH attest the ampicillin maintains its activity and may be released in oral administration.

One of the sulfido bridges in the cluster Fe 3 (CO) 9 S 2 1 is oxidized by meta-chloroperbenzoic acid to give the known thionyl complex Fe 3 (CO) 9 S(SO) 2.

A convenient synthesis of the naturally occurring deoxyamino sugar forosamine from glucose as starting material is described. The yields for the intermediates (ethyl-4,6-di-O-toxyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside, 4-iodo-2,3,4-tride-oxy-6-O-tosyl-α-D-threo-hex-2-enopyranoside, ethyl 4-azido-2,3,4-trideoxy-6-O-tosyl-α-D-erythro hex-2-enopyranoside, ethyl 4-amino-2,3,4,6-tetradeoxy-α-D-erythro-hexopyranoside) are all in the range between 70 to 80%.