The 1:1 cocrystal of rac-7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxylic acid and 2-amino­benzothia­zole

In the crystal structure of the title compound, rac-7-oxabicyclo­[2.2.1]heptane-2,3-dicarboxylic acid–2-amino­benzo­thia­zole (1/1), C8H10O5·C7H6N2S, mol­ecules of each component are linked into centrosymmetric dimers by inter­molecular N—H⋯O hydrogen bonds. These dimers are connected by O—H⋯O hydrogen bonds into a chain along the b axis. In addition, π–π inter­actions between aromatic heterocycles occur [centroid–centroid distance of 3.4709 Å and inter­planar spacing of 3.4374 Å between symmetry-related benzothia­zole ring systems

catena-Poly[[diaqua­copper(II)]-μ-7-oxa­bicyclo­[2.2.1]heptane-2,3-dicarboxyl­ato]

In the crystal structure of the title compound, [Cu(C8H8O5)(H2O)2]n, the Cu(II) cation is in a Jahn–Teller distorted six-coordination by two O atoms from water molecules, by the bridging O atom from the bicyclo moiety, by two carboxylate O atoms from two different carboxylate groups and by one carboxylate O atom from a symmetry-related bridging ligand.The polymeric structure is made up from double-strands propagating parallel to the c axis that are held together via inter­molecular O—H⋯O hydrogen bonds

catena-Poly[[diaqua­nickel(II)]-μ-7-oxabicyclo­[2.2.1]heptane-2,3-di­carboxyl­ato]

In the crystal structure of the title compound, [Ni(C8H8O5)(H2O)2]n, the NiII cation is in a Jahn–Teller-distorted octahedral coordination environment binding to two O atoms from water molecules, the bridging O atom of the bicycloheptane unit, two carboxylate O atoms from different carboxylate groups and one carboxylate O atom from a symmetry-related bridging ligand. The crystal structure is made up from layers propagating parallel to the bc plane

Diaqua­bis(ciprofloxacinato)manganese(II) 2,2′-bipyridine solvate tetrahydrate

In the crystal structure of the title compound {systematic name: diaquabis­[1-cyclo­propyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-dihydro­quinoline-3-carboxyl­ato]manganese(II) 2,2′-bi­pyridine solvate tetrahydrate}, [Mn(C17H17FN3O3)2(H2O)2]·C10H8N2·4H2O, the pyridone O and one carboxyl­ate O atom of the two ciprofloxacin ligands are bound to the MnII ion and occupy the equatorial positions, while the two aqua O atoms lie in the apical positions resulting in a distorted octa­hedral geometry. The crystal packing is stabilized by N–H⋯O and O–H⋯O hydrogen bonding interactions

Tailoring of spatial coherence in a multimode fiber by selectively exciting groups of eigenmodes

Control of the properties of speckle patterns produced by mutual interference of light waves is important for various applications of multimode optical fibers. It has been shown previously that a high signal-to-noise ratio in a multimode fiber can be achieved by preferential excitation of lower order spatial eigenmodes in optical fiber communication. Here we demonstrate that signal spatial coherence can be tailored by changing relative contributions of the lower and higher order multimode fiber eigenmodes for the research of speckle formation and spatial coherence. It is found that higher order spatial eigenmodes are more conducive to the final speckle formation. The minimum speckle contrast occurs in the lower order spatial eigenmodes dominated regime. This work paves the way for control and manipulation of the spatial coherence of light in a multimode fiber varying from partially coherent or totally incoherent light

Anti-Vibrio Indole-Diterpenoids and C-25 Epimeric Steroids From the Marine-Derived Fungus Penicillium janthinellum

A systematic chemical exploration of the marine-derived fungus Penicillium janthinellum led to the isolation of four indole-diterpenoid derivatives (1–4), including new penijanthines C and D (1 and 2), and a pair of new steroidal epimers, penijanthoids A and B (5 and 6). The calculated ECD spectra and Snatzke's method for the new compound 1 were carried out to determine its absolute configuration. The absolute configuration of 3 was established by X-ray diffraction and calculated ECD methods for the first time. DP4plus approach was used to elucidate the absolute configurations of the C-25 epimeric steroids 5 and 6. 25-Epimeric 5 and 6 represent the first examples of steroids forming a five-membered lactone between C-23 and C-27 from marine fungi. Compounds 1, 2, 5, and 6 displayed significant anti-Vibrio activity (Minimum inhibitory concentration, MIC values ranging from 3.1 to 50.0 μM) against three pathogenic Vibrio spp