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The crystalline structures of four homologues of the 1,2-dibromo-4,5-dialkoxybenzene series [Br2C6H2(OCnH2n + 1)2 for n = 2, 12, 14 and 18] have been solved by means of single-crystal crystallography. Comparison along the series, including the previously reported n = 10 and n = 16 derivatives, shows a clear metric trend (b and c essentially fixed along the series and a growing linearly with n), in spite of some subtle differences in space groups and/or packing modes. A uniform packing pattern for the aliphatic chains has been found for the n = 12 to 18 homologues, which slightly differs from that of the n = 10 derivative. The crystalline structures of all the higher homologues (n = 10-18) seem to arise from van der Waals interchain interactions and, to a lesser extent, type II Br· · ·Br interactions. The dominant role of interchain interactions provides direct structural support for the usual interpretation of melting point trends like that found along this series. Atoms in Molecules (AIM) analysis allows a comparison of the relative magnitude of the interchain and Br· · ·Br interactions, an analysis validated by the measured melting enthalpies. [ABSTRACT FROM AUTHOR]

A cocrystal, C15H22O3·C15H22O3, (I), obtained from Drimys winteri, is composed of two isomeric drimane sesquiterpene lactones, namely valdiviolide, (I a), and 11-epivaldiviolide, (I b), neither of which has been reported in the crystal form. Both diastereoisomers present three chiral centres at sites 5, 10 and 11, with an SSR sequence in (I a) and an SSS sequence in (I b). O-H...O hydrogen bonds bind molecules into chains running along [20] and the chains are in turn linked by π-π stacking interactions to define planar weakly interacting arrays parallel to (001). [ABSTRACT FROM AUTHOR]

The natural compound dendocarbin A, C15H22O3, is a sesquiterpene lactone isolated for the first time from Drimys winteri for var chilensis. The compound crystallizes in the orthorhombic space group P212121 and its X-ray crystal structure confirmed the S/ R character of the chiral centres at C-5/C-10 and C-9/C-11, respectively. The α-OH group at C-11 was found to be involved in intermolecular hydrogen bonding, defining chains along the <100> 21 screw axis. [ABSTRACT FROM AUTHOR]

The natural compound hobartine {systematic name: (1 R)-3-[(1 S,5 S)-(4,4,8-trimethylbicyclo[3.3.1]non-7-en-2-yl)methyl]-2,3-dihydro-1 H-indole}, C20H26N2, (I), is an indole alkaloid isolated from Aristotelia chilensis as part of a study of secondary metabolites from Chilean flora. The colourless compound has a tetracyclic structure closely related to the strongly coloured polymorphic structures discussed in Paz et al. [ Acta Cryst. (2013), C 69, 1509-1512] and Watson et al. [ Acta Cryst. (1989), C 45, 1322-1324]. The main differences reside in the absence of a keto group in (I) compared with the previous structures, as well as an endo double bond in (I) contrasting with the exo double bond found in the previous structures. The supramolecular structure of (I) in strongly related to the twofold screw axis, around which isolated chains build up, internally linked by an N-H...N hydrogen bond which is the only significant intermolecular interaction present in the structure. [ABSTRACT FROM AUTHOR]

Controlled heating of single crystals of the previously reported [Köferstein & Robl (2007). Z. Anorg. Allg. Chem. 633, 1127-1130] dihydrate {[Co(pht)(bpy)(H2O)2]·2H2O} n, (II) [where pht is phthalate (C8H4O4) and bpy is 4,4′-bipyridine (C10H8N2)], produced a topotactic transformation into an unreported diaqua anhydrate, namely poly[diaqua(μ2-benzene-1,2-dicarboxylato-κ2 O1: O2)(μ2-4,4′-bipyridine-κ2 N: N′)cobalt(II)], [Co(C8H4O4)(C10H8N2)(H2O)2] n, (II a). The structural change consists of the loss of the two solvent water molecules linking the original two-dimensional covalent substructures which are the `main frame' of the monoclinic P2/ n hydrate (strictly preserved during the transformation), with further reaccommodation of the latter. The anhydrate organizes itself in the orthorhombic system (space group Pmn21) in a disordered fashion, where the space-group-symmetry restrictions are achieved only in a statistical sense, with mirror-related two-dimensional planar substructures, mirrored in a plane perpendicular to [100]. Thus, the asymmetric unit in the refined model is composed of two superimposed mirror-related `ghosts' of half-occupancy each. Similarities and differences with the parent dihydrate and some other related structures in the literature are discussed. [ABSTRACT FROM AUTHOR]

The three transition-metal complexes, ( meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N)bis(perchlorato-κ O)copper(II), [Cu(ClO4)2(C18H40N4)], (I), ( meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N)bis(nitrato-κ O)zinc(II), [Zn(NO3)2(C18H40N4)], (II), and aquachlorido( meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ4 N)copper(II) chloride, [CuCl(C18H40N4)(H2O)]Cl, (III), are described. The molecules display a very similarly distorted 4+2 octahedral environment for the cation [located at an inversion centre in (I) and (II)], defined by the macrocycle N4 group in the equatorial sites and two further ligands in trans-axial positions [two O-ClO3 ligands in (I), two O-NO2 ligands in (II) and one chloride and one aqua ligand in (III)]. The most significant difference in molecular shape resides in these axial ligands, the effect of which on the intra- and intermolecular hydrogen bonding is discussed. In the case of (I), all strong hydrogen-bond donors are saturated in intramolecular interactions, while weak intermolecular C-H...O contacts result in a three-dimensional network. In (II) and (III), instead, there are N-H and O-H donors left over for intermolecular interactions, giving rise to the formation of strongly linked but weakly interacting chains. [ABSTRACT FROM AUTHOR]

The isomorphous title compounds, [Tr(S4O6)(C12H12N2)2]·2C3H7NO (Tr = CdII and ZnII), consist of metal centres to which one tetrathionate and two 4,4′-dimethyl-2,2′-bipyridine chelating ligands bind. The structures are completed by two symmetry-related dimethylformamide solvent molecules. Each metal-centred complex is bisected by a twofold axis running through the metal centre and halving the chelating tetrathionate dianion through the central S-S bond. The ancillary symmetry-related 4,4′-dimethyl-2,2′-bipyridine ligands act as chelates. This results in a distorted six-coordinate geometry, with similar Tr-O/N distances but central angles differing substantially from 90 and 180°. Both ligands are basically featureless from a geometric point of view, with torsion angles in both coordinated tetrathionate groups suggesting a trend linking metal size (covalent radius) and ligand `openness'. Packing is directed by (C-H)aromatic...O bridges and π-π offset stacked interactions defining chains along [001], further linked by weaker (C-H)methyl...O bridges, some of them mediated by the dimethylformamide solvent molecules. [ABSTRACT FROM AUTHOR]

Two copper complex solvatomorphs, namely (3,10-C- meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane)bis(perchlorato-κ O)copper(II) 1.2-hydrate, [Cu(ClO4)2(C18H40N4)]·1.2H2O, (I), and (3,10-C- meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane)bis(perchlorato-κ O)copper(II), [Cu(ClO4)2(C18H40N4)], (II), are described and compared with each other and with a third, already reported, anhydrous diastereomer, denoted (III). Both compounds present very similar centrosymmetic coordination environments, with the CuII cation lying on an inversion centre in a distorted 4+2 octahedral environment, defined by the macrocyclic N4 group in the equatorial sites and two perchlorate groups in trans-axial positions [one of the perchlorate ligands in (I) is partially disordered]. The most significant difference in molecular shape is seen in the orientation of the perchlorate anions, and the influence of this on the intramolecular hydrogen bonding is discussed. The (partially) hydrated state of (I) favours the formation of chains along [011], while the anhydrous character of (II) and (III) promotes loosely bound structures with low packing indices. [ABSTRACT FROM AUTHOR]

The title ionic compound, [Ni(C12H12N2)(H2O)4]SO4·H2O, is composed of an NiII cation coordinated by a chelating 4,4′-dimethyl-2,2′-bipyridine ligand via its two N atoms [mean Ni-N = 2.056 (2) Å] and by four aqua ligands [mean Ni-O = 2.073 (9) Å], the net charge being balanced by an external sulfate anion. The whole structure is stabilized by a solvent water molecule. Even though the individual constituents are rather featureless, they generate an extremely complex supramolecular structure consisting of a central hydrogen-bonded two-dimensional hydrophilic nucleus made up of complex cations, sulfate anions and coordinated and solvent water molecules, with pendant hydrophobic 4,4′-dimethyl-2,2′-bipyridine ligands which interact laterally with their neighbours viaπ-π interactions. The structure is compared with closely related analogues in the literature. [ABSTRACT FROM AUTHOR]

The title compound, [Zn(C19H12N5)2], crystallizes in the tetragonal space group P43212, with the monomer residing on a twofold axis. The imidazole N-bound H atoms are disordered over the two positions, with refined occupancies of 0.59 (3) and 0.41 (3). The strong similarities to, and slight differences from, a reported P42212 polymorph which has a 50% smaller unit-cell volume [Harvey, Baggio, Muñoz & Baggio (2003). Acta Cryst. C 59, m283-m285], to which the present structure bears a group-subgroup relationship, are discussed. [ABSTRACT FROM AUTHOR]

The title compound, C21H21NO7S3, consists of an SO2ON(SO2)2 central fragment and three terminal 4-methylphenyl groups each attached at a sulfonyl S atom. The most obvious characteristic is the presence of two nearly face-to-face benzene rings, with their centroids separated by a rather short distance [3.7808 (18) Å], but with a rather slanted relative orientation [dihedral angle = 20.63 (13)°] so as to preclude a strong intramolecular π-π interaction. The third benzene ring is nearly perpendicular to the other two [dihedral angles = 71.62 (14) and 70.4 (13)°]. The packing of the structure is directed by two C-H...O hydrogen bonds involving aromatic H atoms (methyl H atoms are strictly non-interacting), which define chains running in the [100] direction. These one-dimensional chains evolve parallel to each other and exhibit no significant lateral interactions. [ABSTRACT FROM AUTHOR]

Nickel/carbon nanotube (Ni/CNT) composites with varying amounts of CNTs are deformed by high‐pressure torsion (HPT) at different deformation temperatures to high strains, where no further refinement of the Ni matrix microstructure is observed. Mean Ni grain sizes increase with increasing HPT deformation temperature, while the size of the CNT agglomerates is significantly reduced. Additionally, the distribution of the agglomerates in the metal matrix becomes more homogenous. To investigate the mechanical performance of the HPT‐deformed composites, uniaxial tensile and compression tests are conducted. Depending on the HPT deformation temperature and the resulting microstructure, either brittle or ductile fracture occurs, and the ultimate tensile strength varies between 900 and 2100 MPa. Increased HPT deformation temperatures induce a decrease in the anisotropy of the mechanical properties, mainly caused by a shrinking of the CNT agglomerates. It is shown, that tuning the HPT deformation temperature is the key for optimizing both the microstructure and the mechanical performance. High pressure torsion (HPT) of Nickel with carbon nanotube (CNT) additives can lead to homogenous, nanograined metal matrix composites. The mechanical performance of such composites is investigated with tensile and compression tests for different CNT contents and HPT deformation temperatures. The HPT deformation temperature is the key to fabricate high strength Nickel/CNT metal matrix composites with reasonable ductility. [ABSTRACT FROM AUTHOR]

The Argentine Osteoporosis Society convened renowned specialists in the care of transgender people to prepare the first local position on the evaluation of bone health in this population. Law 26.743 on "Gender Identity" recognize all identities and guarantees free care throughout the health system. The impact of different gender affirmation treatments on bone mass has been topic of international debate. To date the evidence remains limited and different societies have issued suggestions and recommendations. For this reason, we believe it is relevant to mention our experience, capturing through this document a series of suggestions to be used in medical care.

We report the synthesis, crystal structure, and characterisation of a dinuclear Co(II) compound with thiodiacetate (tda) and phenanthroline (phen) as ligands (1), and of a series of metal complexes isomorphous to 1 with different Co : Zn ratios (2, 4 : 1; 3, 1 : 1; 4, 1 : 4; 5, 1 : 10). General characterisation methodologies and X-ray data showed that all the synthesised complexes are isomorphous to Zn(II) and Cu(II) analogues (CSD codes: DUHXEL and BEBQII). 1 consists of centrosymmetric Co(II) ion dimers in which the ions are 3.214 Å apart, linked by two μ-O bridges. Each cobalt atom is in a distorted octahedral environment of the N 2 O 3 S type. UV-vis spectra of 1 and 5 are in line with high spin ( S = 3/2) Co(II) ions in octahedral coordination and indicate that the electronic structure of both Co(II) ions in the dinuclear unit does not significantly change relative to that of the magnetically isolated Co(II) ion. EPR spectra of powder samples of 5 (Co : Zn ratio of 1 : 10) together with spectral simulation indicated high spin Co(II) ions with high rhombic distortion of the zfs [ E / D = 0.31(1), D > 0]. DC magnetic susceptibility experiments on 1 and analysis of the data constraining the E / D value obtained by EPR yielded g = 2.595(7), | D | = 61(1) cm -1 , and an intradimer ferromagnetic exchange coupling of J = 1.39(4) cm -1 . EPR spectra as a function of Co : Zn ratio for both powder and single crystal samples confirmed that they result from two effective S ' = 1/2 spins that interact through dipolar and isotropic exchange interactions to yield magnetically isolated S ' = 1 centres and that interdimeric exchange interactions, putatively mediated by hydrophobic interactions between phen moieties, are negligible. The latter observation contrasts with that observed in the Cu(II) analogue, where a transition from S = 1 to S ' = 1/2 was observed. Computational calculations indicated that the absence of the interdimeric exchange interaction in 1 is due to a lower Co(II) ion spin density delocalisation towards the metal ligands.

The centrosymmetric dinuclear complex bis-(μ-3-carb-oxy-6-methyl-pyridine-2-carboxyl-ato)-κ(3) N,O (2):O (2);κ(3) O (2):N,O (2)-bis-[(2,2'-bi-pyridine-κ(2) N,N')(nitrato-κO)cadmium] methanol monosolvate, [Cd2(C8H6NO4)2(NO3)2(C10H8N2)2]·CH3OH, was isolated as colourless crystals from the reaction of Cd(NO3)2·4H2O, 6-methyl-pyridine-2,3-di-carb-oxy-lic acid (mepydcH2) and 2,2'-bi-pyridine in methanol. The asymmetric unit consists of a Cd(II) cation bound to a μ-κ(3) N,O (2):O (2)-mepydcH(-) anion, an N,N'-bidentate 2,2'-bi-pyridine group and an O-mono-dentate nitrate anion, and is completed with a methanol solvent mol-ecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH(-) carboxyl-ate O atom to complete the dinuclear complex mol-ecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octa-hedral coordination geometry about the Cd(II) atom, the Cd-O and Cd-N distances in this complex are surprisingly similar. The crystal structure consists of O-H⋯O hydrogen-bonded chains parallel to a, further bound by C-H⋯O contacts along b to form planar two-dimensional arrays parallel to (001). The juxtaposed planes form inter-stitial columnar voids that are filled by the methanol solvent mol-ecules. These in turn inter-act with the complex mol-ecules to further stabilize the structure. A search in the literature showed that complexes with the mepydcH(-) ligand are rare and complexes reported previously with this ligand do not adopt the μ-κ(3) coordination mode found in the title compound.

Controlled heating of single crystals of the previously reported [Köferstein & Robl (2007). Z. Anorg. Allg. Chem. 633, 1127-1130] dihydrate {[Co(pht)(bpy)(H2O)2]·2H2O}n, (II) [where pht is phthalate (C8H4O4) and bpy is 4,4'-bipyridine (C10H8N2)], produced a topotactic transformation into an unreported diaqua anhydrate, namely poly[diaqua(μ2-benzene-1,2-dicarboxylato-κ(2)O(1):O(2))(μ2-4,4'-bipyridine-κ(2)N:N')cobalt(II)], [Co(C8H4O4)(C10H8N2)(H2O)2]n, (IIa). The structural change consists of the loss of the two solvent water molecules linking the original two-dimensional covalent substructures which are the `main frame' of the monoclinic P2/n hydrate (strictly preserved during the transformation), with further reaccommodation of the latter. The anhydrate organizes itself in the orthorhombic system (space group Pmn2(1)) in a disordered fashion, where the space-group-symmetry restrictions are achieved only in a statistical sense, with mirror-related two-dimensional planar substructures, mirrored in a plane perpendicular to [100]. Thus, the asymmetric unit in the refined model is composed of two superimposed mirror-related `ghosts' of half-occupancy each. Similarities and differences with the parent dihydrate and some other related structures in the literature are discussed.

The Co(II) cation in poly[[aqua(μ-benzene-1,2-dicarboxylato-κ(3)O(1),O(2):O(1))(μ-4,4'-bipyridine-κ(2)N:N')cobalt(II)] trihydrate], {[Co(C8H4O4)(C10H8N2)(H2O)]·3H2O}n, is octahedrally coordinated by two N atoms of two 4,4'-bipyridine ligands, three O atoms from phthalate anions and a fourth O atom from a coordinated water molecule. The packing consists of planes of coordination polymers linked by hydrogen bonds mediated by three solvent water molecules; the linkage is achieved by the water molecules forming intricate oligomeric clusters which also involve the O atoms of the phthalate ligands.

The three transition-metal complexes, (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)bis(perchlorato-κO)copper(II), [Cu(ClO₄)₂(C₁₈H₄₀N₄)], (I), (meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)bis(nitrato-κO)zinc(II), [Zn(NO₃)₂(C₁₈H₄₀N₄)], (II), and aquachlorido(meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-κ⁴N)copper(II) chloride, [CuCl(C₁₈H₄₀N₄)(H₂O)]Cl, (III), are described. The molecules display a very similarly distorted 4+2 octahedral environment for the cation [located at an inversion centre in (I) and (II)], defined by the macrocycle N₄ group in the equatorial sites and two further ligands in trans-axial positions [two O-ClO₃ ligands in (I), two O-NO₂ ligands in (II) and one chloride and one aqua ligand in (III)]. The most significant difference in molecular shape resides in these axial ligands, the effect of which on the intra- and intermolecular hydrogen bonding is discussed. In the case of (I), all strong hydrogen-bond donors are saturated in intramolecular interactions, while weak intermolecular C-H∙∙∙O contacts result in a three-dimensional network. In (II) and (III), instead, there are N-H and O-H donors left over for intermolecular interactions, giving rise to the formation of strongly linked but weakly interacting chains.

Two copper complex solvatomorphs, namely (3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane)bis(perchlorato-κO)copper(II) 1.2-hydrate, [Cu(ClO4)2(C18H40N4)]·1.2H2O, (I), and (3,10-C-meso-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane)bis(perchlorato-κO)copper(II), [Cu(ClO4)2(C18H40N4)], (II), are described and compared with each other and with a third, already reported, anhydrous diastereomer, denoted (III). Both compounds present very similar centrosymmetic coordination environments, with the Cu(II) cation lying on an inversion centre in a distorted 4+2 octahedral environment, defined by the macrocyclic N4 group in the equatorial sites and two perchlorate groups in trans-axial positions [one of the perchlorate ligands in (I) is partially disordered]. The most significant difference in molecular shape is seen in the orientation of the perchlorate anions, and the influence of this on the intramolecular hydrogen bonding is discussed. The (partially) hydrated state of (I) favours the formation of chains along [011], while the anhydrous character of (II) and (III) promotes loosely bound structures with low packing indices.

The title compound, [Zn(C(19)H(12)N(5))(2)], crystallizes in the tetragonal space group P4(3)2(1)2, with the monomer residing on a twofold axis. The imidazole N-bound H atoms are disordered over the two positions, with refined occupancies of 0.59 (3) and 0.41 (3). The strong similarities to, and slight differences from, a reported P4(2)2(1)2 polymorph which has a 50% smaller unit-cell volume [Harvey, Baggio, Muñoz & Baggio (2003). Acta Cryst. C59, m283-m285], to which the present structure bears a group-subgroup relationship, are discussed.

The asymmetric unit of the title complex, [Ni(C12H8N2)3]S2O8·2C3H7NO·H2O, consists of a complex [Ni(phen)3](2+) cation and one isolated pds anion, with two DMF mol-ecules and one water mol-ecule as solvates (where phen is 1,10-phenanthroline, pds is the hexa-oxido-μ-peroxoido-di-sulf-ate dianion and DMF is dimethyl-formamide). The [Ni(phen)3](2+) cation is regular, with an almost ideal Ni(II) bond-valence sum of 2.07 v.u. The group, as well as the water solvent mol-ecule, are well behaved in terms of crystallographic order, but the remaining three mol-ecules in the structure display different kinds of disorder, viz. the two DMF mol-ecules mimic a twofold splitting and the pds anion has both S atoms clamped at well-determined positions but with a not-too-well-defined central part. These peculiar behaviours are a consequence of the hydrogen-bonding inter-actions: the outermost SO3 parts of the pds anion are heavily connected to the complex cations via C-H⋯O hydrogen bonding, generating an [Ni(phen)3]pds network and providing for the stability of the terminal pds sites. Also, the water solvent mol-ecule is strongly bound to the structure (being a donor of two strong bonds and an acceptor of one) and is accordingly perfectly ordered. The peroxide O atoms in the pds middle region, instead, appear as much less restrained into their sites, which may explain their tendency to disorder. The cation-anion network leaves large embedded holes, amounting to about 28% of the total crystal volume, which are occupied by the DMF mol-ecules. The latter are weakly inter-acting with the rest of the structure, which renders them much more labile and, accordingly, prone to disorder.

The mol-ecular structure of the title compound, NH(4) (+)·C(7)H(7)O(4)S(-), is featureless [the methoxy C atom deviating 0.173 (6) Å from the phenyl mean plane] with inter-atomic distances and angles in the expected ranges. The main feature of inter-est is the packing mode. Hydro-philic (SO(3) and NH(4)) and hydro-phobic (PhOCH(3)) parts in the structure segregate, the former inter-acting through a dense hydrogen-bonding scheme, leading to a well connected two-dimensional structure parallel to (100) and the latter hydro-phobic groups acting as spacers for an inter-planar separation of c/2 = 10.205 (2) Å. In spite of being aligned along [110], the benzene rings stack in a far from parallel fashion [viz. consecutive ring centers determine a broken line with a 164.72 (12)° zigzag angle], thus preventing any possible π-π inter-action.