Volume 47, Issue 2

Several routes for the preparation of ω-cyanoalkyldiorgano phosphines RR′P (CH 2 ) n CHR″CN (R = CH 3 , C 2 H 5 , C 3 H 7 , i-C 3 H 7 , C 4 H 9 , i-C 4 H 9 , t -C 4 H 9 , C 5 H 11 , c-C 5 H 9 , c-C 6 H 11 ; R′ = i-C 3 H 7 , t-C 4 H 9 , C 6 H 5 ; R″ = H, Si(CH 3 ) 3 ; n = 1, 2, 3, 4) have been investigated: (1) reaction of lithium diorganophosphides with ω-chloroalkylnitriles, (2) quaternization of secondary phosphines with co-haloalkylnitriles followed by deprotonation of the resulting H -phosphonium halides with aqueous bases, (3) hydrophosphination of secondary phosphines with unsaturated nitriles, (4) reaction of trimethylsilyl phosphines with (y-chloroalkylnitriles followed by Me 3 SiCl-elimination, and (5) addition of acrylonitrile to trimethylsilyl phosphines. The reaction of 3-chloropropionitrile with trimethylsilyl phosphines leads to the formation of a mixture of the expected phosphine and the corresponding β-silylated derivative. A mechanistic interpretation of the last reaction is given. All new compounds were characterized by elemental analyses, IR and NMR spectra.

A, B Starting materials are the sterically hindered diazagermylenes and C o f the general formula [R (Me 3 Si)N] 2 Ge (R = o-disubstituted aryl or mesityl). A and B react with arylsulfonylazides to give the polymeric N ,N -bis(amino)-N '-sulfonylgermazane derivatives 1 and 2. With phenylazidoformiate, A, B and C yield the corresponding diamino(phenoxy)(isocyanato)- germanium (IV ) derivatives 3 -5, while with N ,N -dimethylcarbamoylazide the impure diamino(dimethylamino)(isocyanato)germanium (IV ) com pound 6 is formed. Reactions of A and B with O ,O -diphenyl-phosphorylazide afford the eight-membered (GeNPO) 2 ring compounds 7 and 8 . The substances are characterized by C, H , N analyses, 1 - 8 by their mass spectra, and 3 - 8 by NMR ( 1 H, l3 C, 29 Si, 31 P). Characteristic IR group frequencies are given for the isocyanato compounds 3 - 6 . Single crystal X -ray structure analyses are reported for C, 4, 5 and 8 .

1 The reaction of ClSO 2 N = PPh 2 Cl () with NH 3 yields H 2 NSO 2 N = PPh 2 NH 2 ( 2 ).This compound is converted to Me 3 Si(H)NSO 2 N = PPh 2 N(H)SiMe 3 ( 3 ) by Me 3 SiNMe 2 . 3 reacts with WOCl 4 under elimination of (Me 3 Si) 2 O and ClSO 2 NH 2 to yield the eight-membered ring system (Cl 3 WNPPh 2 N) 2 ( 4 ).The molecular structure of 4 was investigated by an X-ray structure analysis.

The relative rate of hydrogenation of various alkenes has been determined by competition experiments in the gas phase on platinum films. Despite big structural differences in the alkenes there is a good correlation of the relative rate of hydrogenation with the calculated heat of hydrogen atom addition to the double bond, indicating thermodynamic control of this reaction.

The crystal structure of the acetic acid adduct of the so far unknown samarium(III) acetate dihydrate was determined from single-crystal four-circle diffractometer data. It has the composition [Sm (CH 3 COO) 3 (H 2 O) 2 ] CH 3 COOH containing {[Sm(CH 3 COO) 3 (H 2 O) 2 ]} 2 dimers and crystallizes in the trigonal system, R3̄̄̄̄, a = 2695.1(3), c = 1030.8(4) pm, V m = 216.97(5) cm 3 /mol, R = 0.041, R w = 0.030.

Reactions of tris[(N-morpholinothiocarbonyl)benzamidato]cobalt(III) and of the free ligand in the presence of CoCl 2 , with SOCl 2 in acetonitrile yield stable acetonitrile trichlorocobaltate(II) salts with 2,6-dimorpholino-4-phenyl-1,3,5-oxadiazinium cations, suitable for X-ray structure determination. Space group P2 1 ,/n, Z = 4, 4387 observed unique reflexions, R = 0.049, Lattice dimensions (22 °C): a = 772.94(9), b = 1611.5(4), c = 1911.1(5) pm; β = 96.23(2)°.

A study has been made of the solubility of MeSO 4 · nH 2 O (Me = Fe, Co, Ni, Zn, Mg; n = 7, 6 , 4, 1) in the organic solvents CH 3 OH and C 2 H 5 OH in the temperature interval of 20 - 50 °C. The data obtained are presented with the polytherms of solubility and the equilibrium hydrates for particular conditions have been identified. The densities of the respective liquid phases have also been determined. The dependence between lgS = f(l/ε 0 ) has been indicated for some o f the systems.

U Cr6P4 was prepared from a tin flux in two forms at low (a) and high (ß) temperatures (880 °C and 1000 °C), respectively. The crystal structures o f both m odifications were deter­

K 2 Sn 2 S 5 and K 2 Sn 2 Se 5 were prepared by reacting stoichiometric powdered mixtures of the binary compounds K 2 S or K 2 Se with Sn and the corresponding chalcogen at 1070 K, followed by slow cooling of the melt. The two compounds are isostructural and crystallize with the Tl 2 Sn 2 S 5 structure type, s.g. C 2/c, Z = 4 with a = 11.072(5) Å, b = 7.806(3)Å, c = 11.517(5)Å, β = 108.43(2)° for K 2 Sn 2 S 5 and a = 11.613(5)Å, b = 8.189(3) Å, c = 11,897(6) Å, β = 108.28(2)° for K 2 Sn 2 Se 5 . The crystal structures were refined to conventional R-factors of 0.032 and 0.031, respectively. Sn-atoms are in a distorted trigonal-bipyramidal chalcogen coordination. The average equatorial bond lengths are Sn -S: 2.427 Å and Sn -Se: 2.552 Å , the axial ones are Sn -S: 2.600 Å and Sn -Se: 2.774 Å.

Fibrous red crystals of the new compound K 2 TiS 3 were obtained by reacting K 2 S, Ti and S at 1070 K. K 2 TiS 3 is monoclinic, space group C 2/c with a = 11.667(6) Å, b = 8.325(4) Å, c = 6.494(4) Å, β = 9 i.81(4)°, Z = 4. The crystal structure was refined to a conventional residual of 0.070. The atomic arrangement is characterized by pseudo-one-dimensional - ∞ -[TiS 3 ] 2− chains formed by distorted TiS 5 square pyramids sharing opposite edges of their basal planes. The structure - though closely related to that of Cs 2 TiS 3 - is of a new type.

K 2 Se 5 has been prepared by crystallization from a potassium polyselenide solution in DMF. In a similar way [Na(15-crown-5)] 2 Se 5 can be prepared by crystallization from a sodium polyselenide solution in DMF in the presence of 15-crown-5. Both compounds were characterized by FIR spectroscopy as well as by X-ray structure determinations. K 2 Se 5 : Space group P 2 1 2 1 2 1 , Z = 4, 1659 observed independent reflections, R = 0.061. Lattice dimensions at - 90 °C; a = 671.5(5), b = 694.9(5), c = 1776.4(9) pm. The compound crystallizes with the K 2 S 5 type structure. [Na(15-crown-5)] 2 Se 5 : Space group P 1̄, Z = 2, 3026 observed indenpendent reflections, R = 0.140. Lattice dimensions at -100 °C: a = 853.7(5), b = 1042.8(10), c = 2011.0(10) pm; α = 88.95(5)°, β = 79.42(5)°, γ = 66.15(5)°. The compound forms an ion triple, in which the sodium ions are coordinated by the five oxygen atoms of the crown ether molecules as well as by the terminal selenium atoms of the pentaselenide chain. The rather high R value is a result of the disordered crown ether molecules.

The title compound is prepared by combining hot solutions of the components. X-ray analysis shows hexamethoxytetrathiatetrahydropentacene to act as a bifunctional donor, each of its dimethoxybis(organylthio)benzene units being in contact with a dichlorodicyanoquinone molecule. In the crystal stacks of the type DA 2 ,DA 2 , ··· with an alternating arrangement o f donor and acceptor molecules are formed. In the complex the donor has a cis -conformation (boat form) in contrast to its pure form where the trans-conformation (chair form) is found.

The silenes A and B are formed by reacting 1,3-di t butyl-2,4-dichloro-2,4-divinyl-1,3-diaza- 2.4-disilacyclobutane (2) and 1,3-dichloro-2,4-dineopentyl-1,3-divinyl-1,3-disilacyclobutane (15) with LiBu t in n-pentane in the temperature range from −10 to 0 °C. The reaction primarily leads to the corresponding α-lithioadducts (addition of LiBu t to the vinyl group of 2 and 15), and with subsequent 1,2-LiCl elimination yields A and B as intermediates. A can be trapped by polar reagents Me 3 SiX (X = OMe, OSO 2 CF 3 ) as well as by organic dienes which add across the Si = C bond; in the absence of a trapping agent the spiro compound 6 is isolated. The silenes A and B differ in their cycloaddition behaviour to butadienes, norbornadiene and cyclohexa-1,3-diene: Whereas for A the regioselective [2 + 2]-cycloaddition to yield monosilacyclobutane derivatives is preferred due to electronic reasons, the reaction of B leads mainly to Diels-Alder products. Thus, A is quite comparable in its reactivity to dichloroneopentylsilene, while B reacts like its diorgano substituted analogues R 2 Si = CHCH 2 Bu t (R = Me, Bu t or Ph).

The diphosphenyl complex (η 5 -C 5 Me 5 )(CO) 2 Fe -P = P -Mes* (1) (Mes* = 2,4,6tBu 3 C 6 H 2 ) reacts with equimolar amounts of the azo compounds R(O)C -N = N - C(O)R (2a: R = OEt; 2b: R = O-tBu; 2c: R = OCH 2 C 6 H 5 ; 2d: R = NC 5 H 10 ) in a cheletropic [1 +4] cycloaddition to afford stereoselectively the metal substituted oxadiazaphospholenes The products have been characterized by elemental analysis as well as by spectroscopic data (IR, 1 H, 13 C, 31 P NMR, MS). The molecular structure of 3a has been elucidated by single crystal X-ray analysis.

The crystal structure of anhydrous lithium formate, published recently by Kansikas and Hermansson, is in fact that of a quenchable high-temperature modification (LiHCOO-I). The low-temperature modification LiHCOO-II can be obtained by thermal dehydration of the monohydrate, LiHCOO · H 2 O , or by drying it over P 4 O 10 . LiHCOO-II persists up to 228 °C, at which temperature it transforms to LiHCOO-I, which in turn is stable up to its melting point at 272 °C. LiHCOO-I is also the modification which crystallizes when a melt of lithium formate is cooled down, in spite of the fact that solidification occurs only at 165 °C, i.e. at a temperature well within the stability region of LiHCOO-II. The Raman spectra of the different forms of lithium formate are discussed in some detail. Single crystals of LiHCOO-II, obtained by slow evaporation of a saturated solution of anhydrous LiHCOO in absolute methanol, are hexagonal, space group P6 3 , with a = 14.915(2) Å, c = 5.543(1) Å and Z = 18. All lithium atoms are tetrahedrally coordinated by oxygen. The LiO 4 tetrahedra are connected by corner-sharing and by bridging formate groups to form a complicated three dimensional network comprising tunnels running along [0 0 0 1 ]. No indications for an at least partial occupation o f these tunnels have been found.

Reaction of (C 8 H 12 )Pt(CH 2 CMe 3 ) 2 with ( + )-(1 S)-Ph 2 PCH(Ph)CH 2 PPh 2 , S-PHEPHOS, gave (S-PHEPHOS)Pt(CH 2 CMe 3 ) 2 (1). Cleavage of one of the Pt-C bonds of this compound with methanolic HCl yielded (S-PHEPHOS)PtCl(CH 2 CMe 3 ) (2) which could be converted to (S-PHEPHOS)PtH(CH 2 CMe 3 ) (3) by treatment with Na[HB(OMe) 3 ], The complexes so obtained were characterized by NMR spectroscopy (preferentially 31 P) as well as by an X-ray structure analysis performed on the dineopentyl derivative 1. While thermal generation of (S-PHEPHOS)Pt(0) from 3 in the presence of HC ≡ CC(O)OCMe 3 produced the alkyne coordination compound (S-PHEPHOS)Pt(HC ≡ CC(O)OCMe 3 ) (4) efficiently, thermolysis of 3 in the presence of PhC ≡ CH resulted in smooth trapping of the 14e intermediate to form the product of oxidative C - H addition, (S-PHEPHOS)PtH(C≡CPh) (5). In contrast, only indiscriminate reactions were observed to occur on thermal generation of (S-PHEPHOS)Pt(O) from neopentyl hydride 3 in C 6 H 6 at 70 °C.

Black crystals of Ru 2 S 4 Cl 13 have been obtained by reaction of Ru with SCl 2 in closed quartz ampoules at 125 °C. The crystal structure of the mixed-valence ruthenium(II, III) compound (monoclinic, a = 8.0262(15)Å, b = 14.9612(33)Å, c = 32.8876(55)Å, β = 97.03(1)°, space group P2 1 /c, Z = 4) consists of molecules Ru 2 Cl 5 (SCl 2 ) 4 , in which the two Ru atoms are unsymmetrically substituted by Cl and SCl 2 ligands. Octahedral units of RuCl 5 (SCl 2 ) and RuCl 3 (SCl 2 ) 3 are Cl bridged to binuclear complexes Cl 2 (SCl 2 )Ru(μ-Cl) 3 Ru(SCl 2 ) 3 .

The methylene-bis(dialkylaminochlorophosphines) 2a and 2b react with N,N′-dimethyl- N,N′-bis(trimethylsilyl)urea 1 to give the 1,5-diaza-2,4-diphosphorinan-6-ones, 4a and 4b, each of which exists as two isomers. Sulfuration of 4a and 4b led to the stable derivatives, 5a and 5b, which, with the help of column chromatography, were separated into pure cis- and trans-isomers. The structures were established, based upon NMR-spectroscopic, chemical and analytical data.

The melting diagram of the system tetramethylammonium hydroxide-water has been reinvestigated in the region of 66.67 - 100 mol% H 2 O , using DTA , DSC and temperature-dependent X-ray powder diffraction. This was done as correction and supplementation of a previous study in the same laboratory (D. Mootz, R. Seidel, J. Incl. Phenom. 8 , 139 (1990)). The system is now considered to contain as many as eight stable hydrates, three of them dimorphic with a low-temperature α and a high-temperature β form. The compositions are Me 4 NOH · χH 2 O with χ = 2 (α and β), 4, 4.6 (α and β), 5 (α and β), 6.67, 7.5, 8.75 and 10. A second 7.5-hydrate, called 7 .5 α in the previous study, is now regarded as metastable. - Structure determinations have been performed for the new phases with x = 4.6 (α), 6.67 and 8.75. The 4.6 α-hydrate, transforming to 4.6 β at 32 °C, is cubic with space group Pa3̄ and Z = 40 formula units per unit cell. The lattice constant is a = 21.493 Å at -160 °C. The 6.67-hydrate, melting with decomposition at 13 °C, is monoclinic with space group P2 1 /m and Z = 6 . It was studied as the O-deuterated isotype with unit-cell dimensions a = 11.874, b = 20.019, c = 8.272 Å and β = 103.84° at 3 °C. The 8.75-hydrate, melting with decomposition at - 3 °C, is cubic with space group 14̄3 d, Z = 16 and a = 18.38(2) Å at - 20 °C. The three structures, as most others of the higher hydrates of the system studied previously, are those of polyhedral clathrate hydrates. For the hydrates 4 .6 α and 6.67 deviations of the anionic, i.e. proton-deficient, new water structures from being fully four-connected are described in detail. The 8.75-hydrate is isostructural with the hitherto unparalleled 9.75-hydrate of t-butyl amine. - The phase identity and structure of the 4.6 β-hydrate were recognized as those attributed to an erroneously assumed 5 β-phase in the previous study. 5 β now denotes the room-temperature form of the pentahydrate, previously called 5 α. The present 5 α is another of the new phases and the only one of the system with its structure still undetermined.

A study was made of the intramolecular donor-acceptor interaction in N,N′,N′-trimethylethylenediamine- substituted phosphorus compounds, involving λ 3 -, λ 4 - and λ 5 -phosphorus atoms, as a function of the nature of the substituents at phosphorus. The reaction of N-trimethylsilyl-N,N′,N′-trimethylethylenediamine (1) with (Pr i O) 2 PCl furnished the acyclic, trimethylethylenediamine-substituted phosphorus(III) compound 4. There is no NMR spectroscopic evidence for an intramolecular donor-acceptor interaction between the phosphorus atom and the nitrogen atom of the dimethylamino group in 4. The oxidation of the trivalent phosphorus atom in 4 and in the related compound 5 by sulfur, selenium, tetrachloroo- benzoquinone, and hexafluoroacetone led to the corresponding λ 4 P compounds 6 - 9 and to the λ 5 P compounds 10 and 11. No intramolecular donor-acceptor interaction could be detected in any of these products. There was no reaction between 5 and elemental tellurium. The reaction products were characterized by NMR spectroscopy, mass spectrometry, and by elemental analysis.

From the aerial parts of Eriostemon tomentellus five coumarins have been isolated. These have been characterized as ostruthin (6-geranyl-7-hydroxycoumarin (1)) and the novel compounds, 8-geranyl-7-hydroxycoumarin (2), (E)-6-(7-hydroxy-3,7-dimethylocta-2,5-dienyl)- 7-hydroxycoumarin (3), (E)-6-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-7-hydroxycoumarin (4), and 6-(6-hydroxy-3,7-dimethylocta-2,7-dienyl)-7-hydroxycoumarin (5). In addition tembamide (2-{4-methoxyphenyl}-2-hydroxy-N-benzoylethylamine (6 ) was isolated and the l3 C NMR spectrum reported for the first time.

Ion pairs of 1,10-phenanthrolin-5,6-dione radical anion [M · ⊖ Me ⊕n ] · ⊕(n−1) with Me ⊕n = Mg ⊕⊕ , Ca ⊕⊕ , Sr ⊕⊕ , Zn ⊕⊕ , Cd ⊕⊕ , Pb ⊕⊕ and La ⊕⊕⊕ are advantageously prepared in aprotic DMF solution containing appropriate metal salts Me ⊕n X ⊖ by using the ‘mild’ single-electron reducing agent tetra(n-butyl)ammonium-boranate R 4 N ⊕ BH 4 ⊖ . For comparison, the ‘naked’ radical anion with the largely interaction-free [K ⊕ (2.2.2)-cryptand] ⊕ counter cation is chosen, which is formed on reduction with potassium in THF solution of (2.2.2)-cryptand. Addition of excess Na ⊕ [B(C 6 H 5 ) 4 ] ⊖ to the reduction solution only yields a solvent-separated ion pair (M · ⊖ )DMF ··· (Na ⊕ )DMF, whereas in the presence of multiply charged counter cations Me ⊕n the respective contact ion pair radical cations [M · ⊖ Me ⊕n ] · ⊕(n−1) are formed. Their g values decrease with increasing nuclear charge of Me ⊕n and their metal-s-spin densities increase with the effective counter cation charge n ⊕ /r Me ⊕n. The ESR /ENDOR data recorded suggest Me ⊕n complexation by the δ⊖ OC -CO δ⊖ chelate tongs and the ion pair stability, which is modified by the dielectric properties of the solvent used, may be rationalized by the Coulombic attraction between the radical anion M · ⊖ and the counter cations Me ⊕n .