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N-(n-Dec-yl)-4-nitro-aniline, C(16)H(26)N(2)O(2), crystallizes with two essentially planar mol-ecules in the asymmetric unit. The decyl chains are fully extended in an anti conformation. The mol-ecules pack in planar layers, within which mol-ecules are linked into chains by two approximately linear N-H⋯O hydrogen bonds between the amine N atom and one O atom of the nitro group of an adjacent mol-ecule. These mol-ecular chains propagate via inter-leaving of the decyl chains to form the two dimensional sheets. The sheets are associated exclusively via non-bonded contacts. The structure has features in common with those of other N-alkyl-4-nitro-anilines, but also subtle differences in packing.

5-Ammonionaphthalene-1-sulfonate monohydrate, C10H9NO3S x H2O, contains layers of zwitterionic molecules with the acidic sulfonic acid H atom transferred to the amine N atom. Within each layer, the charged groups (NH3(+) and SO3(-)) are directed to the surface of the layer and are inverted on adjacent molecules. The naphthalene rings in a given layer are all parallel. The layers are held together by N-H...O and O-H...O hydrogen bonds involving the ammonium, sulfonate and water atoms. The Mn and Ni salts crystallize as fully aquated trihydrates, namely hexaaquamanagnese(II) bis(5-aminonaphthalene-1-sulfonate) trihydrate, [Mn(H2O)6](C10H8NO3S)2 x 3 H2O, (II), and hexaaquanickel(II) bis(5-aminonaphthalene-1-sulfonate) trihydrate, [Ni(H2O)6](C10H8NO3S)2 x 3 H2O, (III), in which layers of hexaaquametal(II) complexes alternate with layers of 5-aminonaphthalene-1-sulfonate anions. The cations reside on twofold rotation axes and display regular octahedral coordination. The additional water molecules are found in the inorganic layer between the complex cations, one on a twofold axis and one in a general position. The anions are packed in a herring-bone arrangement with the rings of neighboring rows of anions approximately 43 degrees out of parallel. The NH2 and SO3(-) groups line the surface of the layer, where they participate in numerous hydrogen bonds with the water molecules. Whereas the Mn and Ni salts are orthorhombic, the Co salt, hexaaquacobalt(II) bis(5-aminonaphthalene-1-sulfonate) dihydrate, [Co(H2O)6](C10H8NO3S)2 x 2 H2O, (IV), crystallizes in a triclinic cell of similar dimensions, with the cations situated on centers of inversion. The overall packing is very similar to that of the Mn and Ni salts, with the main differences being the absence of the solvent water molecule on the special position and subtle modifications in the positioning of the anions within their layers. This series of salts is compared with those of the same metals with the 5-aminonaphthalene-2-sulfonate and 4-aminonaphthalene-1-sulfonate isomers, allowing for similarities and differences in packing to be discussed on the basis of the differing substitution of the naphthalene ring and, in some cases, differing degrees of hydration.

The photophysical and electrochemical properties of a platinum(II) diimine complex bearing the bidentate diacetylide ligand tolan-2,2'-diacetylide (tda), Pt(dbbpy)(tda) [dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine] (1), are compared with two reference compounds, Pt(dbbpy)(C[triple bond]CPh)(2) (2) and Pt(dppp)tda [dppp = 1,3-bis(diphenylphosphino)propane] (3), respectively. The X-ray crystal structure of 1 is reported, which illustrates the nearly perfect square planarity exhibited by this metallacycle. Chromophore 2 possesses low-lying charge-transfer excited states analogous to 1, whereas structure 3 lacks such excited states but features a low-lying platinum-perturbed tda intraligand triplet manifold. In CH(2)Cl(2), 1 exhibits a broad emission centered at 562 nm at ambient temperature, similar to 2, but with a higher photoluminescence quantum yield and longer excited-state lifetime. In both instances, the photoluminescence is consistent with triplet-charge-transfer excited-state parentage. The rigidity imposed by the cyclic diacetylide ligand in 1 leads to a reduction in nonradiative decay, which enhances its room-temperature photophysical properties. By comparison, 3 radiates highly structured tda-localized triplet-state phosphorescence at room temperature. The 77 K emission spectrum of 1 in 4:1 EtOH/MeOH becomes structured and is quantitatively similar to that measured for 3 under the same conditions. Because the 77 K spectra are nearly identical, the emissions are assigned as (3)tda in nature, implying that the charge-transfer states are raised in energy, relative to the (3)tda levels in 1 in the low-temperature glass. Nanosecond transient absorption spectrometry and ultrafast difference spectra were determined for 1-3 in CH(2)Cl(2) and DMF at ambient temperature. In 1 and 2, the major absorption transients are consistent with the one-electron reduced complexes, corroborated by reductive spectroelectrochemical measurements performed at room temperature. As 3 does not possess any charge-transfer character, excitation into the pipi* transitions of the tda ligand generated transient absorptions in the relaxed excited state assigned to the ligand-localized triplet state. In all three cases, the excited-state lifetimes measured by transient absorption are similar to those measured by time-resolved photoluminescence, suggesting that the same excited states giving rise to the photoluminescence are responsible for the absorption transients. ESR spectroscopy of the anions 1- and 2- and reductive spectroelectrochemistry of 1 and 2 revealed a LUMO based largely on the pi* orbital of the dbbpy ligand. Time-dependent density functional theory calculations performed on 1-3 both in vacuum and in a CH(2)Cl(2) continuum revealed the molecular orbitals, energies, dipole moments, and oscillator strengths for the various electronic transitions in these molecules. A DeltaSCF-method-derived shift applied to the calculated transition energies in the solvent continuum yielded good agreement between theory and experiment for each molecule in this study.

To relate the molecular electrostatic potential to the biological activities of estrogens, a comparative charge density study of different derivatives has been initiated. The second completed charge density analysis of this series for 17beta-estradiol*urea is presented here. This is a large organic system with 52 atoms in a noncentrosymmetric space group, therefore special tools such as an optimal coordinate system and slow, initially constrained refinement have been used to accomplish this study. Our results for the urea molecule reasonably agree with previous experimental and theoretical results. In the 17beta-estradiol molecule, the oxygen atoms appear to be close to sp3 in shape, exhibiting two consistent, distinct lone pairs despite different chemical environments. No significant interaction of the hydroxyl group oxygen with the orbitals of the aromatic ring is observed. Analysis of the electrostatic potential revealed that the negative potential in the lone pair region of the two oxygen atoms is quite different. The topological analysis of the electron density has been performed, and the atomic charges have been estimated.

Crystals of the recently published [Bolotina, Kirschbaum & Pinkerton (2005). Acta Cryst. B61, 577-584] triclinic (P\overline1) structure of 5-nitro-2,4-dihydro-1,2,4-triazol-3-one (alpha-NTO) occur as fourfold twins. There are Z' = 4 independent molecules per asymmetric unit. We show that the structure contains layers with 2-periodic layer-group symmetry p2(1)/b 1 (1). This symmetry is lost through the stacking of the layers, which is a possible explanation for Z' = 4. A layer can assume four different but equivalent positions with respect to its nearest neighbor. Twinning arises through stacking faults and is an instructive example of the application of order-disorder theory using local symmetry operations. The near-neighbor relations between molecules remain unchanged through all twin boundaries. The four structures with maximum degree of order, one of which is the observed one, and the family reflections common to all domains are identified. Rods of weak diffuse scattering confirm the stacking model.

The title compound, [Tb2(C24H12F9O6S3)2(C8H6N4)].C4H8O2, has two terbium(III) centers bridged by the polyazine ligand 2,2'-bipyrimidine (bpm), which is distorted from planarity by 7.0 (2) degrees . The terminal ligand 4,4,4-trifluoro-1-(2-thienyl)butane-1,3-dione (tta) is bidentate, coordinating through the two O atoms, while the bridging ligand is bis-bidentate, coordinating through four equivalent N atoms. Both the complex and the ethyl acetate solvent molecules are disordered. The structure was refined as a non-merohedral twin.

17a-hydroxyprogesterone caproate is a naturally occurring metabolite of progesterone that is produced in significant quantities during pregnancy. The demand for 17a-hydroxyprogesterone caproate, the lack of a commercially available manufactured form approved by the US Food And Drug Administration, and publication of the results of a large trial to determine the effectivenss of the drug in the prevention of preterm delivery have spawned an increased interest in compounded formulations of the drug. The demand also has necessitated a review of the available literature and of past clinical studies, and a look at present and planned studies. Owing to the importance of this drug in pregnancy and the need for safety, accuracy in potency, and sterility in an intramuscular injection (the most common route of administration), compounding pharmacies must be in compliance with the United States Pharmacopeia Chapter 797 standards should they wish to compound this formulation.

The first derivative of a new class of perylene bisimide chromophores, N,N'-bis(octyl)-3,9-bis(phenyl)perylene-1,2,7,8-tetracarboxyl bisimide, 1, has been synthesized and its fundamental photophysical and electrochemical properties assessed. The extended, Z-shaped structure was achieved by use of the classic photoenolization of an o-methylbenzophenone analogue, 1,5-dibenzoyl-9,10-dihydroanthracene, and in situ Diels-Alder trapping of the resulting o-xylylenol intermediates with N-octylmaleimide. Subsequent dehydration and aromatization of the resulting bisadduct afforded 1. In dichloromethane, bisimide 1 has an absorption lambdamax at 491 nm (epsilon = 29,600 M-1 cm-1), a fluorescence lambdamax at 517 nm with a high quantum yield (Phi = 0.70), and a single-exponential fluorescence decay (tau = 5.01 ns). Pure crystals of 1 have red emission, suggesting exciplex formation in the solid state. X-ray crystallographic analysis of 1 revealed significant twisting of its perylene core.

The prevalent polymorph of the energetic material 5-nitro-2,4-dihydro-1,2,4,-triazol-3-one, alpha-NTO, crystallizes as a four-component twin with triclinic symmetry (space group P\bar 1). All crystals under investigation were fourlings, i.e. they contained each of the four possible twin components. Complete data sets were collected for two crystals, one with a predominant amount of one individual component (55%) and one with approximately equal volumes of each component. In both cases the fourling components are related by the twofold axes inherent in the holohedral symmetry of a pseudo-orthorhombic superlattice with a(o) = a(t), b(o) = b(t) and c(o) = a(t) + b(t) + 2c(t). The triclinic unit cell contains four crystallographically independent planar molecules in the asymmetric unit, each of which forms a hydrogen-bonded flat chain parallel to a(t). Pairs of chains are combined into planar ribbons by additional hydrogen bonds. Thus, two independent ribbons extend parallel to a(t), creating a dihedral angle of approximately 70 degrees. The origin of the twinning is derived from consideration of the crystal packing and the hydrogen-bonding scheme.

We report isomer-pure synthesis of thieno[2,3-f:5,4-f ']bis[1]benzothiophene and thieno[3,2-f:4,5-f ']bis[1]benzothiophene, the anti and syn isomers of a pentacyclic compound consisting of alternating thiophene and benzene rings. The optical and electrochemical properties of both are reported. In the anti isomer, the ribbonlike embedding of three thiophene units leads to a near-planar molecule with favorable pi-pi stacking behavior in the solid state as shown by X-ray crystal structure analysis.

Room-temperature reaction of carbon monoxide with tri-tert-butylaluminum at atmospheric pressure yields the dimeric tert-butylacyl complex [tBu2AlC(O)tBu]2 (1). This unprecedented CO insertion into an aluminum-carbon bond is apparently made possible by the three-coordinate aluminum center in the tri-tert-butylaluminum starting material.

The acid H(2)B(12)(OH)(12) can be isolated as a crystalline solid by protonation of the hydroxylated borane anion, B(12)(OH)(12)(2)(-). This acidic compound has low solubility in water, conducts protons in the solid state, and has thermal stability to a temperature of 400 degrees C. The conductivity mechanism is a Grotthuss mechanism with a low activation enthalpy (9-13 kcal/mol). This new acid represents an addition to the class of oxoacids, of which sulfuric and phosphoric acid are the most prominent examples.

The molecular structures and magnetic properties of six dinitroxide biradicals are described. Five of the dinitroxides are trimethylenemethane-type (TMM-type) biradicals; that is, the intramolecular exchange parameter, J, is modulated by a carbon-carbon double bond. However, the efficacy of the carbon-carbon double bond as an exchange coupler is determined by the molecular conformation. Our results show that the exchange parameters correlate with phenyl-ring torsion angles (phi) via a simple Karplus-Conroy-type relation: J = 44 cos(2) phi - 17. Comparison of these results to those obtained for our isostructural series of bis(semiquinone) biradicals shows that both the magnitude of J and the resistance of ferromagnetic J to bond torsions is proportional to the spin density adjacent to the exchange coupler.

2,2'-Di(3-methylindolyl)methanes (L(2)H(2)) are introduced as dianionic, bidentate ligands of reduced pi-donating ability. Four complexes of the type L(2)Ti(NEt(2))(2) and L(2)Zr(NEt(2))(2)(THF) have been synthesized and characterized by elemental analysis, NMR ((1)H, (13)C) spectroscopy, and X-ray crystallography. Structural data confirm the reduced pi-donating ability of the eta(1)-indolyl moiety compared to that of diethylamido. Preliminary catalytic activities of these group 4 complexes for the polymerization of ethylene are reported.

Helium is a more efficient cryogen than nitrogen, and for macromolecular data collection at high-flux beamlines will deliver lower temperatures. An open-flow helium cryostat developed at the University of Toledo (the Pinkerton Device) has been used for macromolecular data collection. This device differs from standard commercial He cryostats by having a much narrower aperture providing a high velocity stream of He around the crystal that maximizes convective and conductive heat exchange between the crystal and the cryogen. This paper details a series of experiments conducted at the IMCA-CAT 17ID beamline using one crystal for each experimental condition to examine whether helium at 16 K provided better radiation-damage abatement compared with nitrogen at 100 K. These studies used matched high-quality crystals (0.94 A diffraction resolution) of D-xylose isomerase derived from the commercial material Gensweet SGI. Comparisons show that helium indeed abates the indicators of radiation damage, in this case resulting in longer crystal diffractive lifetimes. The overall trend suggests that crystals maintain order and that high-resolution data are less affected by increased radiation load when crystals are cooled with He rather than N(2). This is probably the result of a lower effective temperature at the crystal with concomitant reduction in free-radical diffusion. Other features, such as an apparent phase transition in macromolecular crystals at lower temperatures, require investigation to broaden the utility of He use.

Alkylation of the zwitterionic heterocycle 8-chloro-bis[1,2,3]dithiazolo[4,5-b:5',4'-e]pyridine (ClBP) with alkyl triflates affords 8-chloro-4-alkyl-4H-bis[1,2,3]dithiazolo[4,5-b:5',4'-e]pyridin-2-ium triflates [ClBPR][OTf] (R = Me, Et, Pr). Reduction of these salts with decamethylferrocene affords the corresponding ClBPR radicals as thermally stable crystalline solids. The radicals have been characterized in solution by cyclic voltammetry and EPR spectroscopy. Measured electrochemical cell potentials and computed (B3LYP/6-31G) gas-phase disproportionation enthalpies are consistent with a low on-site Coulombic barrier U to charge transfer in the solid state. The crystal structures of ClBPR (R = Me, Et, Pr) have been determined by X-ray crystallography (at 293 K). All three structures consist of slipped pi-stacks of undimerized radicals, with many close intermolecular S.S contacts. ClBPMe undergoes a phase transition at 93 K to a slightly modified slipped pi-stack arrangement, the structure of which has also been established crystallographically (at 25 K). Variable-temperature magnetic and conductivity measurements have been performed, and the results interpreted in light of extended Hückel band calculations. The room-temperature conductivities of ClBPR systems (sigma(RT) approximately 10(-)(5) to 10(-)(6) S cm(-)(1)), as well as the weak 1D ferromagnetism exhibited by ClBPMe, are interpreted in terms of weak intermolecular overlap along the pi-stacks. The latter is caused by slippage of the molecular plates, a feature necessitated by the steric size of the R and Cl groups on the pyridine ring.

The first structural report of an unprecedented organotellurate(IV) inorganic-organic hybrid macrocyclic host encapsulating a bromide anion guest is described.

Treating [Li(tmeda)]2[Zr(CH3)6] with aryl thiols, HSC6H4-4-R, in a 1:6 stoichiometry in diethyl ether affords excellent yields of [Li(tmeda)]2[Zr(SC6H4-4-R)6], where R = CH3 (1(2-)) or OCH3 (2(2-)) and tmeda denotes N,N,N',N'-tetramethylethylenediamine. These complexes are air-sensitive canary-yellow solids, soluble in hexane, diethyl ether, THF, and acetonitrile, that form yellow single crystals of [Li(tmeda)](2)1 (diethyl ether solution) or [Li(THF)3](2)2 (THF solution) from saturated solutions at -20 degrees C. Both complexes were characterized by X-ray crystallography and consist of a zirconium atom coordinated solely by the sulfur atoms of six aryl thiolate ligands in a nonoctahedral geometry. In each structure the lithium cation coordinates to the three sulfur atoms on the triangular faces of the S6 pseudotrigonal prism. These lithium-sulfur interactions appear to play a role in determining the coordination geometry about the metal center by orienting the sulfur lone pairs of electrons slightly out of the plane defined by the S3 triangular face and tilted away from the zirconium atoms. A likely consequence is the positioning of the sulfur lone pairs of electrons away from orthogonality with the zirconium-sulfur vector, and hence, they are poorly arranged to pi-interact with zirconium. Complex 1(2-) with a twist angle of ca. 9.18 degrees (trigonal prism, 0 degree; octahedron, 60 degrees) agrees with the interpretations of computational studies on d degree complexes, which suggest that a nearly trigonal prismatic geometry is favored when the interaction between metal and ligand is primarily through sigma-bonds. The intrinsically weak pi-donor thiolate ligand is probably converted to a primarily sigma-bonding system by the lithium-sulfur interaction. On the other hand complex 2(2-) with a twist angle of ca. 30.38 degrees is trigonally twisted to the midpoint of the trigonal prismatic-to-octahedral reaction coordinate. In complex 2(2-) the 4-OCH3 group is an electron donor by resonance effects that possibly may lead to the movement away from the expected trigonal prismatic geometry due to either pi-interactions or electrostatics repulsion.

The syntheses, molecular structures and properties of homoleptic 1,2-S(2)C(6)H(4) complexes of thallium(I) and thallium(III) with four-coordinated metal centers are described. Anaerobic treatment of TlCl, TlNO(3), or Tl(2)CO(3) with solutions of sodium methanolate and 1,2-(HS)(2)C(6)H(4) in methanol gave after metathesis with [NEt(4)]Br yellow solutions of [NEt(4)](2)[{Tl(1,2-(&mgr;-S)(2)C(6)H(4))}(2)] ([NEt(4)](2)1). Yellow single crystals were obtained from saturated acetone solutions at -10 degrees C and the crystal data for [NEt(4)](2)1 are monoclinic, P2(1)/c, with Z = 2, a = 7.440(1) Å, b = 16.373(3) Å, c = 13.201(2) Å, and beta = 97.08(1) degrees. Complex 1(2)(-)(), the first structurally characterized homoleptic ionic thiolate complex of thallium(I), contains rectangular bipyramidal [TlS(4)Tl] cages with the four sulfur atoms defining the equatorial plane and the two thallium atoms in axial positions. The S(2)C(6)H(4) fragments are almost coplanar with the S(4) plane. In the crystal lattice, nearly linear Tl.Tl chains align along the a-axis (offset ca. 3.0 degrees ) with the ligand planes parallel to the bc-plane. Within and between dimers short Tl.Tl distances are observed (Tl.Tl' within a dimeric unit, 3.5116(4) Å; Tl.Tl between dimeric units, 3.9371(3) Å) with the distance between dimeric units being the shortest contact between anions-Tl.S distances between dimeric units are longer than 5.8 Å. Aerobic treatment of TlCl, TlNO(3), or Tl(2)CO(3) with solutions of sodium methanolate and 1,2-(HS)(2)C(6)H(4) in methanol and metathesis with [NEt(4)]Br led to [NEt(4)][Tl(1,2-S(2)C(6)H(4))(2)] ([NEt(4)]2). Yellow single crystals were obtained from saturated acetone solutions at 0 degrees C and the crystal data for [NEt(4)]2 are orthorhombic, Pnn2, with Z = 2, a = 11.449(2) Å, b = 10.060(2) Å, c = 9.950(2) Å. Complex 2(-) is the first homoleptic four-coordinate thiolate of thallium(III) and contains the unusually short Tl-S distance of 2.469(4) Å. In solution, ion pairing results in chemical and magnetic inequivalence of the S(2)C(6)H(4) ligands. Although both preparations employ the reaction of thallium(I) salts with 1,2-(NaS)(2)C(6)H(4) in a 1:2 stoichiometry, complex 1(2)(-) is probably not an intermediate to the formation of 2(-). Exposing anaerobically prepared solutions of 1(2)(-) to air results in a series of color changes in the solution over a 20 min period; however, 2(-) could not be observed by NMR spectroscopy.

We describe the synthesis and tissue biodistribution of two 21-[fluoro-18F]progestin 16 alpha, 17 alpha-furanyl ketals, potential agents for imaging progesterone receptor (PR)-positive breast tumors in humans, using positron emission tomography. 21-Fluro-16 alpha, 17 alpha-[(R)-(1'-alpha-furylmethylidene)dioxy]-19- norpregn-4-ene-3,20-dione (endo-10a) and 21-fluoro-16 alpha, 17 alpha-[(R)-(1'-alpha-furylethylidene)dioxy]-19- norpregn-4-ene-3,20-dione (endo-10b) were chosen for radiochemical synthesis from a series of seven novel progestin 16 alpha, 17 alpha-(furanyldioxolanes) on the basis of their high relative binding affinity to PR (190% and 173%, respectively, relative to R5020 = 100%), their low nonspecific binding (NSB) (log P o/w = 3.87 and 4.13, respectively), and their resulting high binding selectivity indices (BSI; i.e., the ratio of their PR binding affinity to nonspecific binding). Radiochemical synthesis of these two species in high radiochemical purity and at high effective specific activity was accomplished by treatment of the corresponding diastereomerically pure 21-trifluoromethanesulfonates with fluorine-18 anion. In tissue biodistribution studies in estrogen-primed immature female Sprague-Dawley rats, both [18F]-endo-10a and [18F]endo-10b demonstrated high PR-selective uptake in the principal target tissues, the uterus and the ovaries, and relatively low uptake in fat and bone. The metabolism at the 21-position in these progestins (as monitored by in vivo defluorination) appears to be less than that in other 21-fluoroprogestins; this may reflect steric inhibition of metabolism at this site due to the bulk of the furan-substituted dioxolane ring at the 16 alpha, 17 alpha-position. Comparison with other fluorine-18-labeled progestins shows that the PR-specific uptake in uterine tissue correlates with the BSI of the ligand and that the fat uptake correlates with the NSB of the ligand at high levels of statistical significance. These two dioxolanes may prove to be useful as breast tumor-imaging agents in humans.

p-Dimethoxyaryl analogs of certain potent catechol-derived dopaminergic agonists show dopaminergic properties for which no structure-activity relationship has yet been defined. (S)-3-(3-Hydroxyphenyl)-N-n-propylpiperidine (1, S-"3-PPP") is a dopaminergic autoreceptor agonist, and at high doses it also exhibits postsynaptic antagonism. (R)-1 is a postsynaptic agonist. In a continuation of studies of effects of the p-dimethoxy moiety at dopamine receptors, synthesis and resolution of the 2,5-dimethoxy analog 3 of 3-PPP was undertaken. The two enantiomers and the racemic modification showed cardiovascular effects consistent with actions at DA-2 receptors. The potency of all three compounds was much lower than that of 3-PPP, although they displayed approximately the same duration of action. Absolute configuration does not seem to be a major determinant of these compounds' ability to interact with DA-2 receptors.