2-[(5-Methyl-1,3,4-thia-diazol-2-yl)sulfan-yl]-'-(4-nitro-benzyl-idene)acetohydrazide monohydrate.

In the title hydrate, CHNOS·HO, the dihedral angle between the aromatic rings is 9.6 (3)°. In the crystal, N-H⋯O and O-H⋯N hydrogen bonds link the components into (101) sheets.

Synthesis and Crystal Structures of β-Diketonate-Associated Aluminum Complexes as Potential Catalysts for the Ring-Opening Polymerization of ε-Caprolactone.

A couple of novel crystalline aluminum(III) derivatives containing tridentate Schiff base ligand (HL) and β-diketones (acetylacetone = acac, benzoylacetone = bnzac, and dibenzoylmethane = dbnz), namely, [Al(L)bnzac] [Al1], [Al(L)dnbz] [Al2], and [Al(L)acac] [Al3], are synthesized and characterized using different spectroscopic techniques and elemental analysis. Single crystal X-ray diffraction analysis of Al2 and Al3 exhibits hexacoordinated geometry around aluminum center atom which is also confirmed using density functional theory (DFT). The ring-opening polymerization (ROP) of caprolactone is evaluated to determine the catalytic potential of the complexes Al1-Al3 in the absence and presence of benzyl alcohol (BnOH).

Late-stage Ligand Modification After Coordination Strengthens Stereoselectively Self-Assembled Hemiaminal Ether Complexes.

Fragile hemiaminal ether linkages present in the backbone of koneramines (L OR'), tridentate ligands, bound to copper(II) in stereoselectively self-assembled syn-[Cu(L OR')X ] complexes were transformed into sturdy methylene linkages to make corresponding rac-[Cu(L H)Cl ] complexes by late-stage ligand modification after coordination with the retention of coordination sphere. The generality of stereoselective self-assembly of koneramine complexes is shown by utilising a number of metal ions, anions, amines, alcohols and thiols with complete characterisations.

Observation and deconvolution of a unique EPR signal from two cocrystallized spin triangles.

A 16-line pattern has been theoretically predicted, but hitherto not reported, for the Electron Paramagnetic Resonance (EPR) spectrum of antiferromagnetically coupled CuII triangles experiencing isotropic exchange of isosceles magnetic symmetry. Now, the crystallization of such a triangular species and its X-ray structure determination in a polar space group, R3 (No. 146), has enabled its single crystal EPR study.

Stereospecific Ring-Opening Metathesis Polymerization of Norbornene Catalyzed by Iron Complexes.

Developing well-defined iron-based catalysts for olefin metathesis would be a breakthrough achievement in the field not only to replace existing catalysts by inexpensive metals but also to attain a new reactivity taking advantage of the unique electronic structure of the base metals. Here, we present a two-coordinate homoleptic iron complex, Fe(HMTO) [HMTO=O-2,6-(2,4,6-Me C H ) C H ], that is capable of performing ring-opening metathesis polymerization of norbornene to produce highly stereoregular polynorbornene (99 % cis, syndiotactic). The use of heteroleptic Fe(HMTO)(RO) [RO=(CH ) CF CO, CH (CF ) CO, or Ph(CF ) CO] prepared in situ significantly increases the polymerization rate while preserving selectivity.

Eudesmacarbonate, a Eudesmane-Type Sesquiterpene from a Marine Filamentous Cyanobacterial Mat (Oscillatoriales) in the Florida Keys.

A new, cyclic carbonate eudesmane-type sesquiterpene, eudesmacarbonate (), was isolated from marine filamentous cyanobacterial mats associated with apparent ingestion-related intoxications of captive bottlenose dolphins in the Florida Keys. Sequencing of 16S rDNA revealed that mats were composed of closely related Oscillatoriacean species including a previously undocumented species of . The structure of was elucidated by (+)-HRESIMS, 1D and 2D NMR, single-crystal X-ray diffraction, and vibrational circular dichroism data.

Origin of Ferromagnetism and Magnetic Anisotropy in a Family of Copper(II) Triangles.

Previously reported ferromagnetic triangles (NnBu ) [Cu (μ -Cl) (μ-4-NO -pz) Cl ] (1), (PPN) [Cu (μ -Cl) (μ-pz) Cl ] (2), (bmim) [Cu (μ -Cl) (μ-pz) Cl ] (3) and newly reported (PPh ) [Cu (μ -Cl) (μ-4-Ph-pz) Cl ] (4) were studied by magnetic susceptometry, electron paramagnetic resonance (EPR) spectroscopy and ab initio calculations to assess the origins of their ferromagnetism and of the magnetic anisotropy of their ground S=3/2 state (PPN =bis(triphenylphosphine)iminium, bmim =1-butyl-3-methylbenzimidazolium, pz =pyrazolate). Ab initio studies revealed the d character of the magnetic orbitals of the compressed trigonal bipyramidal copper(II) ions. Ferromagnetic interactions were attributed to weak orbital overlap via the pyrazolate bridges.

Discovery and optimization of novel phenyldiazepine and pyridodiazepine based Aurora kinase inhibitors.

Aurora B plays critical role in the process of chromosome condensation and chromosome orientation during the regulation of mitosis. The overexpression of Aurora B has been observed in several tumor types. As a part of our ongoing effort to develop Aurora B inhibitors, herein, we described the design, synthesis and evaluation of phenyl/pyridine diazepine analogs.

Coordination polymers of Cd and Pb with croconate show remarkable differences in coordination patterns: a structural and spectroscopic study.

The croconate dianion is a highly versatile ligand with two tautomeric forms making it useful for building large superstructures in the solid state. The single-crystal X-ray structures of Pb- and Cd-croconate coordination polymers, namely catena-poly[[[diaqualead(II)]-μ-croconato-κO,O:O,O] monohydrate], {[Pb(CO)(HO)]·HO}, 1, and catena-poly[[triaquacadmium(II)]-μ-croconato-κO,O:O,O], [Cd(CO)(HO)], 2, have been determined. Both polymers form one-dimensional (1D) structures; 1 is a nonplanar 1D zigzag coordination polymer extended along the crystallographic b axis, whereas 2 is a planar 1D ribbon parallel to the [101] direction.

Nitrite Reduction by Trinuclear Copper Pyrazolate Complexes: An Example of a Catalytic, Synthetic Polynuclear NO Releasing System.

Two trinuclear Cu pyrazolato complexes with a Cu(μ-E)-core (E = O or OH) and terminal nitrite ligands in two coordination modes were characterized crystallographically, spectroscopically, and electrochemically. One-electron oxidation of the μ-O species produces a delocalized, mixed-valent, formally CuCu-nitrite, but no nitrate. In contrast, under reducing conditions-addition of PhSH as an electron and proton donor-both complexes mediate the reduction of nitrite, releasing NO.

Phenyleneethynylene trimer-based rigid-flexible [2+2] macrocycles for nucleic acid labelling in live cells.

Fluorescent macromolecules were developed for intracellular labeling in live cells. Coupling rigid rod phenyleneethynylene trimers with flexible amphiphilic diamines via the imine-bond formation chemistry yielded rigid-flexible [2+2] macromolecules showing nucleic acid selectivity and nontoxicity in live cells.

Interactions between H-bonded [Cu(μ-OH)] triangles; a combined magnetic susceptibility and EPR study.

The X-ray crystal structure of the CuII complex [Cu3(μ3-OH)(μ-pz)3(PhCOO)3]- (pz- = pyrazolato anion) shows an isosceles triangular core, further forming a hexanuclear H-bonded aggregate. Cleavage of the H-bonds in solution results in isolated trinuclear species. Analysis of variable temperature magnetic susceptibility data of a powder sample shows an antiferromagnetically-coupled Cu3-core with a doublet ground state and isotropic exchange parameters (Jave = -355 cm-1, Hiso = -JijSiSj).

Crystal structure and conformational analysis of doxorubicin nitrate.

Crystal structure determination of doxorubicin nitrate, (DoxH)NO, systematic name (7,9)-7-{[(2,4,5,6)-4-azaniumyl-5-hy-droxy-6-methyl-oxan-2-yl]-oxy}-6,9,11-trihy-droxy-9-(2-hy-droxy-acet-yl)-4-meth-oxy-8,10-di-hydro-7-tetra-cen-5,12-dione nitrate, shows two formula units present in the asymmetric unit. In the crystal lattice, hydrogen-bonded pairs of (DoxH) cations and segregation of the aglycone and sugar moieties are observed. Inspection of mol-ecular overlays reveals that the conformation of (DoxH)NO resembles that of DNA-inter-calated, but not of protein-docked (DoxH).

Synthesis of 8-(1,2,3-triazol-1-yl)-7-deazapurine nucleosides by azide-alkyne click reactions and direct C-H bond functionalization.

Treatment of toyocamycin or sangivamycin with 1,3-dibromo-5,5-dimethylhydantoin in MeOH (r.t./30 min) gave 8-bromotoyocamycin and 8-bromosangivamycin in good yields.

Crystal structure of μ-chlorido-nona-kis-(μ-4-chloro-pyrazolato)bis-μ-methoxo-hexa-copper(II).

The hexa-nuclear title compound, [{Cu(μ-OCH)(μ-CHClN)}(μ-CHClN)(μ-Cl)] or [Cu(CHClN)(CHO)Cl], crystallizes in the space group , with individual mol-ecules being located on a twofold rotation axis. The mol-ecule adopts a trigonal prismatic shape, with two trinuclear units linked by three 4-chloro-pyrazolate ligand bridges by encapsulating a Cl anion in a μ-coordination mode. In the crystal, individual mol-ecules are stacked into rods parallel to [1-10] that are arranged in a pseudo-hexa-gonal packing.

A [Cu3(μ3-O)]-pyrazolate metallacycle with terminal nitrate ligands exhibiting point group symmetry 3.

The trinuclear triangular cuprate anion of the title compound, tris-[bis-(tri-phenyl-phospho-ranyl-idene)ammonium] tris-(μ2-4-chloro-pyrazolato-κ(2) N:N')-μ3-oxido-tris-[(nitrato-κ(2) O,O')cuprate(II)] nitrate monohydrate, (C36H30P2N)[Cu3(C3H2ClN2)3(NO3)3O]NO3·H2O, has point group symmetry 3., with the μ3-O atom located on the threefold rotation axis. The distorted square-pyramidal coordination sphere of the Cu(II) atom is completed by two N atoms of trans-bridging pyrazolate groups and a chelating nitrate anion.

Uracil Nucleosides with Reactive Group at C5 Position: 5-(1-Halo-2-sulfonylvinyl)uridine Analogues.

The transition-metal-catalyzed or radical-mediated halosulfonylation of 5-ethynyluridine provided (E)-(1-halo-2-tosylvinyl)uridines. These (β-halo)vinyl sulfones undergo efficient stereoselective addition-elimination with amines or thiols to provide Z-β-aminovinyl or E-β-thiovinyl sulfones tethered to the C5 position of the uracil ring.

A trigonal prismatic Cu6-pyrazolato complex containing a μ6-F ligand.

The encapsulation of a fluoride ion in a trigonal prismatic CuII6-pyrazolato cage results in a small expansion of the Cu6-host. The structural, electronic and magnetic features of the Cu6-complex, containing an endohedral fluoride in the rare μ6-F coordination mode, are compared with those of the parent complex with a vacant Cu6-cage.

Spin-glass behavior of a hierarchically-organized, hybrid microporous material, based on an extended framework of octanuclear iron-oxo units.

Inspired by the stepwise addition of octanuclear iron units into mammalian ferritin, a "stop-and-go" synthesis strategy was used to prepare two microporous (Langmuir surface area, 490 m(2) g(-1); effective pore size, 4-5 Å) hierarchical materials {[Fe8(μ4-O)4(μ-pz)12Cl0.3(μ-O)1.85}n () and {[Fe8(μ4-O)4(μ-4-Me-pz)12Cl0.

3,5-Bis(2,4-dinitro-phen-yl)-4-nitro-1H-pyrazole acetone monosolvate.

The title structure, C(15)H(7)N(7)O(10)·C(3)H(6)O, was prepared by penta-nitration of 3,5-diphenyl-1H-pyrazole. The proton attached to a pyrazole N atom forms a hydrogen bond with the O atom of the acetone solvent mol-ecule, owing to the NO(2) enhanced acidity of the proton. The NO(2) group on the phenyl C atom is twisted by 33.

Electronic structure and magnetic properties of a trigonal prismatic Cu(II)6 cluster.

A combination of detailed magnetisation studies and electronic-structure analysis using broken-symmetry DFT is used to explore the electronic structure of a trigonal prismatic Cu(II)(6) cluster. The presence of six paramagnetic metal centres with S = 1/2 gives rise to a maximum multiplicity of S = 3 and a total of 31 broken-symmetry states with M(S) < 3. Computed differences in energy between the high-spin and broken-symmetry states are expressed in terms of the 15 distinct Heisenberg exchange coupling parameters, J(ij), and the equations are solved by a least-squares fitting procedure.