Band 56, Heft 10

Cs 3 P 11 · 3 NH 3 was obtained from a solution of Cs 3 P 11 in liquid ammonia. Its structure consists of P 11 3- -cage anions, which coordinate the cesium cations together with ammonia molecules, resulting in a three-dimensional network. The compound completes a family of structures that are derived from the binary phosphide Cs 3 P 11 , through the stepwise expanding and dismantling of the three-dimensional network of ions by ammonia molecules of coordination or through the exchange of the cesium cations for voluminous molecular cations.

[Cu 2 L(prz)] (prz = 3,5-dimethylpyrazole and L = 1,3-bis(5-bromo-2-hydroxybenzylidene)- propan-2-ol) was synthesized and its crystal structure determined. It crystallizes in the orthorhombic space group Pbca with a = 14.160(9), b = 15.109(4), c = 21.298(5) Å, V = 4557(1) A3, Z = 8 . Two copper(II) ions are in a square-planar coordination. The metal coordination sphere is four-coordinate, with a planar N 2 O 2 donor set. The dihedral angle between the two coordination planes is 12.14(7)°. The copper(II) centers are separated by 3.365(1) Å and antiferromagnetically coupled (J = -214.3 cm -1 ), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.6 to 310 K. The Cu-O-Cu angle is 125.9(1)° in the super-exchange pathway. The magnetic moment at 310 K is ca. 1.76 B.M. and 0.13 B.M. at 4.6 K.

Reaction of the 1,3-diamine 1 with the methylester of /V,/V-dimethyl-L-phenylalanine 2 afforded the chiral cylic amidine 4 with a pyridine substituent. The CuCl 2 complex of the hydrochloride of ligand 4 has the structure of a trigonal bipyramide. In the Cu-catalyzed cyclopropanation of styrene with ethyl diazoacetate the new multi-nitrogen ligand gave optical inductions up to 15% ee.

Tetraberyllium-oxo-hexabenzoate and -hexa(mesitylcarboxylate) were prepared from benzoic / mesitylcarboxylic acid and freshly precipitated beryllium hydroxide in a tetrahydrofuran / water two-phase system. The crystal structure of the benzoate was deter­ mined from Be 4 O(OCOPh) 6 (C 6 H 6 ) 3 , and that of the mesitylcarboxylate from the phase Be 4 O(OCOMes) 6 (CCl 4 ). The two clusters have the μ 4 -oxo cage structure also detected for the acetate and nitrate complexes, and for the related hexacarbonato hexaanion. The high symmetry of the cluster allows the observation of 9 Be and l7 O signals in the solution NMR spectra. The terminal atoms of the rigid carboxylate groups may be expected to lie at the vertices of large octahedra enclosing the cluster molecules. The axes of the six aryl groups would thus coincide with the axes of the cartesian coordinates with the μ 4 oxygen atom at the origin. This disposition suggests a connectivity suitable for cubic lattices if p-difunctional arene-dicarb-oxylate anions are employed instead of aryl-monocarboxylate anions. However, the new results show that significant deviations of the OBe 2 O 2 C-Ar six-membered rings from planarity cause major deviations from octahedral symmetry and therefore no connectivity in cubic symmetry is to be expected. Fragmentation of the Be 4 O(OCOR) 6 clusters upon ionization in a mass spectrometer leads predominantly to cations [Be 3 O(OCOR) 3 ] + which can be assigned a planar, highly symmet­rical tricyclic core structure of D 3h symmetry. Quantum chemical calculations confirm dis­ crete energy minima for these cations and show that their stability is largely due to the favourable arrangement of alternating charges of neighbouring core atoms. The high polar­ ity of Be-O bonds rules out any significant contributions from aromaticity. The reactions of Be(OH) 2 with 4 -HS-C 6 H 4 -COOH and HS(CH 2 ) 2 COOH give the corresponding cluster com­ pounds Be 4 O(OCORSH) 6 , [R = C 6 H 4 , (CH 2 ) 2 ] with six terminal mercapto functions.

Single crystals of Sm 2 S 2-x Se 1+x (0.1 ≤ x < 0.2) have been obtained for the first time through the oxidation of KSm 2 Cl 5 with an excess of sulfur and selenium in equimolar amounts at 850 °C after seven days in evacuated silica tubes. They emerged as almost black, in thin layers deep red, lath-shaped needles (A and U type, respectively) as well as red, bead-shaped polyhedra (C type) of the gross chemical composition Sm 2 S 2 Se according to X-ray structure analyses. A much simpler method of synthesis is based on the direct fusion of the elements (samarium, sulfur and selenium) in appropriate molar ratios (2:2:1) in the presence of NaCl as a flux under otherwise analogous conditions (silica tubes, 7 d, 850 °C). A-Sm 2 S 1.82 Se 1.18 crystallizes orthorhombically (a = 753.1(3), b = 401.9(1), c = 1565.8(6) pm, Z = 4) in the space group Pnma with the α-Gd 2 S 3 -type structure. Two crystallographically different Sm 3+ cations are coordinated by eight (Sm1) and seven (Sm2) Ch 2- anions (S 2- and Se 2- ) as biand monocapped trigonal prisms, respectively. C-Sm 2 S 1.90 Se 1.10 adopts the cubic γ-Ce 2 S 3 -type structure (I4̅3d; a = 858.7(2) pm, Z = 5.333) with trigon-dodecahedrally coordinated Sm 3+ cations (CN = 8 ). Finally, U-Sm 2 S 1.84 Se 1.16 with the orthorhombic U 2 S 3 -type structure (Pnma; a = 1105.3(6), b = 399.2(1), c = 1074.0(5) pm, Z = 4) exhibits two crystallographically different Sm 3+ cations again, which are coordinated by seven (Sm1) and seven plus one (Sm2) Ch 2- anions, respectively. The preferential occupation of S _ and Se 2- anions at only one in the C-type, but three anionic sites each in the A- and U-type crystal structures of Sm 2 S 2-x Se 1+x (0 .1 ≤ x < 0.2 ) is discussed.

The thermal behaviour of the three coordination polymers 2 ∞ poly[CuX(μ-2-methylpyrazine- N,N′)] (X = Cl (I), Br (II)), and 2 ∞ poly[{Cu 2 l 2 (μ-pyrazine-N,N′) 2 } · 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measurements as well as temperature resolved X-ray powder diffraction in argon and in air. On heating all compounds decompose in two steps. In the first step compound I and II loose one and compound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu 2 Cl 2 (2 -methylpyrazine) (IV) and 2 ∞ poly[Cu 2 X 2 (μ-2 -methylpyrazine-N,N′)] (X = Br (V), I (VI)). From the experiments there is no evidence for the formation of a 1:1 compound of Cul and 2-methylpyrazine as an intermediate phase during the thermal decomposition. On further heating the 2:1 compounds IV, V and VI transform directly to the corresponding copper(I) halides.

1-[N-(4-Iodophenyl)]aminomethylidene-2(1H)naphthalenone (1) (C 17 H 12 NOI) has been studied by X-ray analysis, IR, 1 H NMR, UV and AM1 semi-empirical quantum mechanical methods. It crystallises in the monoclinic space group P2 1 /n with a = 4.844(3), b = 21.428(2), c = 13.726(2) Å, ß = 93.07(2)° (R1 =0.032 for 4132 reflections [I > 2σ(I)]). The title compound is not planar and an intramolecular hydrogen bond connects O1 and N1 [2.530(4) Å]. Complementary IR, 1 H NMR and UV measurements out. Tautomerism and conformations of the title semi-empirical quantum mechanical calculations and the results are compared with the X-ray data.

N-Silyl-aminotin trichlorides, R 1 R 2 N-SnCl 3 [R 1 = R 2 = SiMe 3 (1a), R 1 = SiMe 3 , R 2 = t Bu (1b), R = SiMe 3 , R 2 = 9-borabicyclo[3.3.1]nonyl (1c), R 1 R 2 = Me 2 SiCH 2 CH 2 SiMe 2 (1d)] were prepared by the reaction of tin tetrachloride with the respective bis(amino)plumbylenes, (R 1 R 2 N) 2 Pb 4. The analogous reactions with bis(amino)stannylenes, (R 1 R 2 N) 2 Sn 3, afforded only mixtures of the aminotin trichlorides 1 and bis(amino)tin dichlorides, (R 1 R 2 N) 2 SnCl 2 2 . The products were characterised by 1 H, 11 B, 13 C, 15 N, 29 Si and 119 Sn NMR spectroscopy, and the NMR data of 1 were compared with those of the corresponding N-silylamino(trimethyl)tin compounds 8.

2-Cyanimino-1,3-dimethylimidazoline (3, ImNCN) is obtained from 1,3-dimethyl-2-iminoimidazoline (2) and BrCN. With Mo(CO) 6 , 3 forms the carbonyl complex (ImNCN)Mo(CO) 5 (4). The crystal structure of 3 is reported. The properties of 3 are discussed on comparison with those of (R 2 N) 2 C=NCN (1, R = H).

The title compound (dmaaH) 2 (dmaH) 2 [P 12 S 12 N 12 (NH) 2 ] · 4 dmaa (1) was obtained by crys­tallization from a saturated solution of anhydrous P 12 S 12 N 8 (NH) 6 in N,N-dimethylacetamide (dmaa) as large single crystals. According to the X-ray structure determination (P2 1 /n, a = 1421.8(1), b = 1556.5(2), c = 1645.8(1) pm, ß = 112.207(6)°, Z = 2, 6388 observed reflections, R1 = 0.046, wR2 = 0.111) the anionic cage is built up from twelve P 3 N 3 rings in boat confor­ mation. N,N-dimethylammonium ions (dmaH + ) are directly connected to the cage, and pairs of N,N-dimethylacetamidonium ions (dmaaH + ) and N,N-dimethylacetamide molecules (dmaa) are interconnected by hydrogen-bonds.

The title compounds were prepared through reactions of Li 2 Nb 6 Cl 16 with the corresponding crown ethers in acetone. All three compounds were obtained as dark brown crystals. Their structures were solved with the means of single-crystal X-ray diffraction. [Li(12-crown-4) 2 ][Li(12-crown-4)(OH 2 )] 2 [Nb 6 Cl 18 ]: space group P2 1 /n, Z =2, a = 1320.4(1), b = 1879.1(1), c = 1321.7(1) pm, ß = 92.515(6)°, R 1 = 0.0297 (I>2σ(I)). The crystal structure contains Li + sandwiched by two 12-crown-4-ethers plus Li + coordinated by one 12-crown-4- ether and one water molecule. [Li(15-crown-5) 2 (OH 2 )] 3 [Nb 6 Cl 18 ]: space group R3̅, Z = 3, a = b = 2081.7(1), c = 1991.7(1) pm, R 1 = 0.0395 (I > 2σ(I)). In the crystal structure Li + and one water molecule are sandwiched by two 15-crown-5-ethers. [(18-crown-6) 2 (O 2 H 5 )] 3 [Nb 6 Cl 18 ]: space group P1̅, Z = 1 ,a = 1405.1(1), b = 1461.1(2), c = 1492.2(2) pm; α = 98.80(1)°, ß = 98.15(1)°, γ = 97.41(1)°, R 1 = 0.0538 (I > 2σ(I)). H 5 O 2 + was found in the structure refinement sandwiched between two 18-crown-6-ethers. All compounds reported contain [Nb 6 Cl 18 ] clusters with Nb-Nb distances between 299 and 301 pm. The paramagnetic behaviour expected for [Nb 6 Cl 18 ] 3- in all three compounds was confirmed by magnetic measurements.

A series of monothioimides and dithioimides were synthesised using Lawesson’s reagent. It has been found that two main effects affect thionation reaction. The high polarity of carbonyl groups leads to good yields of mono- and dithioimides. On the other hand, steric hindrance in the vicinity of the carbonyl group strongly inhibits the replacement of the oxygen atom by sulfur.

In order to study packing arrangements and hydrogen bonding networks, low-temperature X-ray structures were determined for pyH + (MeSO 2 ) 2 N - (M, orthorhombic, space group P2 1 2 1 2 1 , Z′ = 1) and 4,4′-bipyH 2 2+ · (MeSO 2 ) 2 N - (D, monoclinic, C2/c, Z′ = 0.5). The structures consist of ionic formula entities assembled by N+-H···N - hydrogen bonds; the dication in D displays crystallographic C 2 symmetry and has its two pyridyl moieties twisted by 43.9°. According to the packing architectures, D represents a supramolecular dimer of the monomeric congener M. In particular, the (MeSO 2 ) 2 N - ions of the M structure are associated via short C(sp 3 ) - H···O contacts to form a diamondoid network, whereas in D a topologically congruent framework is constructed from weakly hydrogen-bonded [(MeSO 2 )N - ] 2 nodes. Hexagonal channels in the anion substructures each include two adjacent stacks of monomeric pyH + or “dimeric” 4,4-bipyH 2 2+ cations that are linked to the channel walls by the strong hydrogen bond(s) and a set of short C ar -H···O contacts. All C - H···O taken into consideration have normalized parameters d(H···O) ≤ 270 pm and θ(C - H···O) ≥ 115°.

In order to study hydrogen bonding networks in ionic crystals, low-temperature X-ray structures were determined for three onium salts of general formula BH + (MeSO 2 ) 2 N - , where BH + is 2,6-dimethylpyridinium (1; monoclinic, space group P2 1 /c, Z′ = 1), 1-hydroxypyridinium (2; triclinic, P1̅, Z′ = 1), or imidazolium (3; monoclinic, Cc, Z′ = 1). The asymmetric units consist of cation-anion pairs assembled in 1 and 3 by ordinary N + - H···N hydrogen bonds, in 2 by a very short N + - O - H···N - bond belonging to the class (+/-)CAHB [H···O 148(3), O···N 253.5(2) pm, O - H···N 175(3)°]. The second N -H donor of the imidazolium ion is involved in a nearly symmetric N - H (···O) 2 three-centre bond to two different anions. In the pyridine derivatives, the (MeSO 2 ) 2 N - ions are associated via short C(sp 3 ) - H···O contacts to form a three-dimensional framework of corrugated and cross-linked layers (1) or an assembly of discrete corrugated layers (2). As a common feature, these anion substructures are pervaded by hexagonal channels parallel to x, each one accommodating two stacks of cations that are linked to the channel walls by the unique strong hydrogen bond and a set of short C ar - H···O contacts; moreover, cations drawn from adjacent stacks in structure 2 create inversion-symmetric dimers based upon a short C ar - H···O(H) - N interaction. In contrast, the structure of 3 displays planar anion layers assembled by short C(sp 3 ) - H···O contacts, intercalating the cations with their ring planes perpendicular to the layer planes and binding them by means of the strong hydrogen bonds and three C ar -H···O interactions. All C - H···O taken into consideration have normalized parameters d( H···O) ≤ 267 pm and θ(C - H···O) ≥ 121°.

Hydroxyresorc[4]arenes are bowl-shaped calixarene compounds. Herein we report the synthesis and the results of X-ray diffraction examinations of six hydroxyresorc[4]arenes, one of them could be crystallized in two conformations. All compounds co-crystallize with different solvent molecules, linked together by hydrogen bonds. It is known that hydroxyresorc[4]arenes are capable of forming large aggregates, a number of different compounds have been prepared, some of them could be crystallized and investigated by single crystal methods. Most of the compounds tend to form polarity-induced double layers.

Enaminones react with a variety of active methyl and methylene reagents in presence of ammonium acetate to yield functionally substituted pyridines in good yields. The reaction proceeded via initial Michael addition across the double bond followed by cyclization. The reaction of enaminone with aromatic aldehyde in acetic acid/ammonium acetate afforded the dihydropyridine that was oxidized to the corresponding pyridine.

A new dinoroleanane triterpene, remangilone D (4), and a new flavone 6 , have been isolated from the leaves of Physena madagascariensis (Physenaceae).

The reaction of the α-chloro tripeptide Boc- Val-DL-Gly(Cl)-ValOMe with 1,1′-bis(hydroxymethyl) ferrocene gives a ferrocenylene bridged pseudohexapeptide which was characterized by its analytical, spectroscopic and ms data.