Volume 210, Issue 2

The principle of the shift lattice has been employed to re-interpret the structures and Fourier transforms of materials containing regular arrays of planar antiphase domains which lie perpendicular to one principal axis of an orthorhombic matrix. The results are illustrated with reference to the alloy phases CuAu II and Ag 3 Mg. The former application is a straightforward shift-lattice interpretation. In the latter, however, the basic g -functions in real space are of non-zero value for so short a distance (less than two unit subcells) that their Fourier transforms, the G -functions in reciprocal space, overlap considerably; in this case, the analysis that has to be performed to reveal the basic G -functions (and hence their inverse transforms, the g -functions) is described. The application of the method is compared with other conventional approaches.

We report about synthesis and crystal structure of the new ternary mixed valence compound TlIn 5 S 6 , which crystallizes in the monoclinic system, space group P 2 1 / m with the lattice constants a = 8.7960(5) Å, b = 3.9129(3) Å, c = 17.458(2) Å, β = 94.71(1)°, ( Z = 2). The threedimensional atomic arrangement can be explained in terms of the formulation Tl + ([In 2 ] 4+ ) 2 (In 3+ )(S 2− ) 6 , implying the simultaneous existence of Tl + and In 3+ besides two distinct In 2 4+ -dumb bells with covalent bonding between In-atoms in different crystallographic surroundings. This structural principle corresponds to the already known solid In 6 S 7 , characterized by the formulation In + [In 2 ] 4+ (In 3+ ) 3 (S 2− ) 7 . In addition the paper contains information about the structurally related compounds In 4 X 3 (X = Se, Te), In 5 S 4 , In 6 X 7 (X = S, Se), M 7 Te 10 (M = Al, Ga, In) and M 3 Te 4 (M = Ga, In) which were poorly characterized up to now.

Potassium beryllium borate fluoride, KBe 2 · BO 3 F 2 , is rhombohedral (hexagonal axes) R 32 (No.155), a = b = 4.427(4) Å, c = 18.744(9) Å, V = 318.3(4) Å 3 , M = 153.93, D m = 2.40g · cm −3 , D x = 2.41 g · cm −3 for Z = 3, F (000) = 222, μ = 11.84 cm −1 , T = 296 K. The crystal structure has been determined by single crystal X-ray diffraction and final R value for 260 unique reflections with I > 3 σ ( I ) is 3.1%. The results reveal a new type of complex polyanions. All B atoms are planar triangularly coordinated while all Be atoms are tetrahedrally coordinated. The feature of the borate framework is infinite sheets [Be 2 BO 3 F 2 ] which may be described in terms of six-membered rings of [Be 2 BO 6 F 2 ] having Be–O and B–O edges in common. The nonlinear optical(NLO) properties of this compound are also discussed here and the [BO 3 ] 3− anionic groups are principally responsible for the second harmonic generation (SHG) effect.

Single crystals of two phases in the binary Mo – Al system were obtained from heat treated aluminum-rich alloys after the dissolution of the remaining solidified aluminum in hydrochloric acid. The crystal structures have been investigated using four-circle diffractometer data: Mo 4 Al 17 was found to be monoclinic (space group C 2, a = 9.158(1) Å, b = 4.9323(8) Å, c = 28.935(5) Å, β = 96.71(1)°, Z = 4), while Mo 5 Al 22 was determined to be orthorhombic (space group Fdd 2, a = 73.82(3) Å, b = 9.161(3) Å, c = 4.933(2) Å, Z = 8). Three different polyhedrons represent the atomic environment: a hexagonal cuboctahedron (CN = 12), a defect cuboctahedron (CN = 11) and a combination from cuboctahedron and rhombododecahedron (CN = 13). The crystal structures are interpreted in terms of the “intergrowth” concept as being built from slab segments taken from the closest packing with the composition TAl 5 (related to WAl 5 structure type, T – transition metal) and segments taken from the TiSi 2 structure type (composition TAl 2 ). The composition of the unit cell is described by the formula Mo 2 m +2 n Al 10 m +4 n ( m – number of TAl 5 -segments and n – number of TiSi 2 -segments in the unit cell).

The compound [Cu(CN-acac)Me 2 en(Br)] (Me 2 en denotes N,N-dimethyl-1,2-diaminoethane) was prepared and investigated by means of structural (X-Ray diffraction) and spectroscopic (IR and electronic) measurements. The compound crystallizes in the monoclinic space group P 2 1 / c with a = 5.959(1) Å, b = 7.465(2) Å, c = 19.338(3) Å, β = 90.89(2)° and Z = 4. The structure consists of discrete [Cu(CN-acac)Me 2 en(Br)] monomeric units, in which copper is five-coordinated. The 1,2-diamine adopts the gauche conformation with a torsional angle of 51.31°, coordinates as bidentate ligand through the nitrogen atoms, and attains the λ configuration. The anion of the 3-cyano-2,4-pentanedione, CN-acac − , is bonded through the oxygen atoms and the six-membered metallocyclic ring exhibits a semi chair conformation. The nitrogen and oxygen donor atoms form a square plane. Copper is also bonded to the bromine atom and a distorted square pyramidal structure around copper exists. The inequalities in the Cu–N distances suggest a second-order Jahn-Teller deformation while the elongation of the Cu–Br bonds implicates d - s orbital mixing. The ligand field excitation energy is appreciably lower than that observed in the [Cu(CN-acac)Me 2 en] + entity. The principal stretching vibrations are assigned and discussed in the light of the structure.

The title compound [C 15 H 10 O 3 , Mw = 238] crystallises in the monoclinic space group P 2 1 / a with a = 25.684(2) Å, b = 5.173(2) Å, c = 18.014(3) Å and β = 110.44(4)°, V = 2245.7(2) Å 3 , Dx = 1.411 Mgm −3 , Z = 8, F (000) = 992, μ = 0.77 mm −1 , T = 293 K. The structure was solved by direct methods to a final R = 0.082 and Rw = 0.084 for 1715 observed reflections. There are two molecules in the asymmetric unit. They are similar in conformation. The benzopyran and phenyl rings are planar and the phenyl ring is rotated by 6.9(3)° and 9.5(3)° from the plane of the benzopyran ring in the two molecules, respectively. The molecules in the unit cell are stabilised by hydrogen bonds across the centre of inversion.

The monoclinic structure of the dark green title compound, [Ni(hfac) 2 ΦenΦ], was elucidated employing a PHILIPS PW1100 PC-computer controlled automatic diffractometer using MoK α radiation. The space group is A 2/ n , Z = 4, and cell dimensions a = 13.932 Å, b = 10.222 Å, c = 19.958 Å, and β = 93.34°. A total of 2105 reflections were measured and the structure was refined by full-matrix least-squares to a conventional R = 0.076 for all observed reflections with I > 2 σ ( I ). The nickel(II) ion is six-coordinated and is positioned at the centre of an almost regular octahedron. The best (equatorial) plane encompasses the nitrogens of the diamine ligand and one carbonyl oxygen atom of each β -dionato metallocyclic ring. The other oxygen donor atoms occupy the remaining apical positions and are equidistant from the metal centre. The Ni – N distances are imperceptibly longer than the Ni – O ones. In the five-membered chelate ring the 1,2-diamine adopts the gauche conformation with the phenyl groups.

Noscapine, C 22 H 24 NO 7 · HCl, has been elucidated as (S)-6,7-dimethoxy-3-(5,6,7,8-tetrahydro-4-methoxy-6-methyl-1,3-dioxolo[4,5-g]isoquinolin-5-ly)-1 (3H)-isobenzofuranone, orthorhombic, P 2 1 2 1 2 1 , a = 8.584(1) Å, b = 22.318(2) Å, c = 25.062(1) Å, Z = 8, D x = 1.245 mgm −3 , μ = 1.75 mm −1 , F (000) = 1804.0, Mw = 450.88, R = 0.070 and Rw = 0.073. The molecule consists of one isoquinoline ring with an endocyclic substituent. There are two molecules in the asymmetric unit and they are similar in their conformations except the conformation of the methoxy group at the isobenzofuranone moiety. In both molecules the dioxolo ring and the oxolo ring are in the envelop conformation and the heterocyclic rings of isoquinolines are in half-chair conformation. The methoxy groups attached to the benzene ring of the isoquinoline are rotated from the mean plane by − 29(2)° and −16(2)° in the two molecules. The angle between the heterocyclic and oxolo rings in the two molecules are 48.6(4)° and 42.6(3)°, respectively. The structure is stabilized by van-der-Waals interactions.

Single crystals of L -histidine dihydrochloride were obtained from an aqueous solution containing L -histidine and diluted hydrochloric acid. The crystals are monoclinic with the cell dimensions, a = 5.243(2) Å, b = 7.257(1) Å, c = 13.350(1) Å, β = 92.65(1)°, space group P 2 1 , and Z = 2. Least-squares refinement using 2685 X-ray (MoK α ) reflections has led to an R factor of 0.029. The L -histidine moiety in this complex exists as a dication where the carboxylic group as well as the amino nitrogen and the imidazole ring are protonated. Based on the N–C α –C β –C γ torsion angle ( ψ ⊥ = 57.1°), the conformation of the histidine molecule in this structure is g + , whereas the conformation in the orthorhombic form of this complex (reported earlier) is g − . There are no direct contacts (hydrogen bonds) between the histidine moieties as all the intermolecular bonding seem to involve Cl − ions.

The crystal structure of the title compound [Ph 2 P(S)C(S)N(H)Me], C 14 H 14 NPS 2 , has been determined at room temperature. The yellow crystals are monoclinic, space group P 2 1 / n with unit cell dimensions a = 12.903(1) Å, b = 7.9719(7) Å, c = 14.493(1) Å, β = 96.380(7)°, Z = 4 and D x = 1.306 Mg m −3 . The structure was solved by direct-methods and refined by a fullmatrix least-squares procedure to final R = 0.046 using 1853 reflections. The molecule features a central P(S)C(S)N chromophore with important parameters: P – S 1.959(1) Å, P–C 1.847(4) Å, C–S 1.642(4) Å and C–N 1.326(5) Å; the conformation about the C = N bond is Z .

The structure of the title compound [Cu(CN-acac)H 2 O(Me 4 en)]ClO 4 (C 12 H 24 ClCuN 3 O 7 ) was determined by X-ray diffraction studies. The structure is orthorhombic, space group Pbca , Z = 8, a = 10.302 Å, b = 15.971 Å, c = 22.945 Å and ϱ x = 1.483 Mgm −3 . The water molecule is covalently bonded to copper. The structure around the central copper atom is distorted square pyramidal with the apex occupied by the oxygen atom of the water molecule and the base formed by the oxygen atoms of the β -dionato (3-cyano-2,4-pentanedionato) moiety and the nitrogen atoms of the N,N,N′,N′-tetramethyl-1,2-diaminoethane, Me 4 en. As a result of this coordination a resonance-stabilised, planar, six-membered β -dionato chelate ring and a five-membered chelate ring with the 1,2-diamine ligand in the gauche conformation are formed. The Perchlorate ion, ClO 4 − interacts electrostatically with the [Cu(CN-acac)H 2 O(Me 4 en)] entity and forms hydrogen bonds with a hydrogen atom of the water molecule.

[(C 2 H 5 ) 4 N] 2 CuCl 4 crystallizes in the tetragonal system ( P 4 2 / nmc , a = 8.98(3) Å; c = 15.08(3) Å; Z = 2; R = 0.057, 442 hkl observed, 53 variables). The two (C 2 H 5 ) 4 N + and CuCl 4 2− ions are disordered about intersecting mirror planes. CuCl 4 2− ion has distorted tetrahedral symmetry with elongation along the tetragonal axis. In moist atmosphere, the compound is transformed, by hydration at solid state, into the hemihydrate: [(C 2 H 5 ) 4 N] 2 CuCl 4 · 0.5 H 2 O with tetragonal symmetry. The new 4 axis of the hydrated crystal is perpendicular to the 4 axis of the anhydrous crystal.

[C(NH 2 ) 3 ] 10 P 10 O 30 · 4 H 2 O is the first organic-cation cyclodecaphosphate elaborated and structurally charaterized by single-crystal X-ray diffraction methods. It crystallizes in the triclinic system, P [unk], with Z = 1 and the following unit-cell dimensions: a = 12.192(8) Å, b = 14.083(9) Å, c = 9.317(6) Å, α = 91.25(3)°, β = 103.61(3)°, γ = 71.22(2)°. The crystal structure was solved using 8862 unique reflections with a final R value of 0.032. The centrosymmetrical P 10 O 30 rings are interconnected through the organic entities and the water molecules by a very intricated network of strong hydrogen bonds. The high stability of the title compound can probably be explained by the strength and the large number of these hydrogen bonds and by its low hydration state.

The crystal structure of [bis(triphenyltin) succinate · 2quinoline N -oxide] · 2[bis(triphenyltin) succinate], C 138 H 116 N 2 O 14 Sn 6 , ( C 2/ c , a = 23.320(3) Å, b = 12.007(1) Å, c = 42.711(8) Å, β = 92.285(8)°) consists of a hexanuclear molecule whose bis(triphenyltin) succinate · 2quinoline N -oxide (Sn1–O = 2.177(7) Å, Sn1 ← O = 2.345(9) Å) moiety is bridged through its carbonyl atoms to two symmetry-related bis(triphenyltin) succinate entities. In the bis(triphenyltin) succinate unit, one tin atom is five-coordinated (Sn2–O = 2.112(9) Å, Sn2 ← O = 2.409(8) Å) in a trigonal bipyramidal geometry and the other is four-coordinated (Sn3–O = 2.04(1) Å) in a tetrahedral geometry.

N , N ′-ethylene-bis(1-ethyl-5,5-dimethyltetramic acid-3-acetiminato)copper(II)/(I) crystallizes in space group P 2 1 / c : a = 11.164(4) Å; b = 12.340(8) Å; c = 17.069(3) Å; β = 99.76(2)°; V = 2317.5 Å 3 ; Z = 4; D x = 1.376 g · cm −3 ; Mo K α = 0.71069 Å; μ = 9.76 cm −1 ; F (000) = 1012; T = 293 K; Conventional R = 0.052; R w = 0.051 for 4864 observed reflections. N , N ′-ethylene-bis(1,5,5-trimethyltetramic acid-3-propiminato)-copper(II)/(II) crystallizes in space group P 2 1 2 1 2 1 : a = 9.682(6) Å; b = 12.025(4) Å; c = 19.733(8) Å; V = 2297.5 Å 3 ; Z = 4; D x = 1.388 g · cm −3 ; Mo K α = 0.71069 Å; μ = 9.85 cm −1 ; F (000) = 1012; T = 293 K; Conventional R = 0.066; R w = 0.066 for 2547 observed reflections. In I and II copper is coordinated by two nitrogen and two oxygen atoms of the ligand molecule as well as by one oxygen atom of a neighboring molecule on the top of a tetragonal pyramid.