{Tris[2-(5-bromo-2-oxidobenzyl­idene­amino)eth­yl]amine}manganese(III)

In the title complex, [Mn(C27H24Br3N4O3)], the MnIII ion is six-coordinated in a distorted octa­hedral environment by three N atoms and three O atoms from the trianion of the hexa­dentate ligand tris­[2-(5-bromo-2-oxidobenzyl­idene­amino)eth­yl]amine. All three N (and O) atoms are cis to each other. The three N and the three O atoms are in a fac conformation among each other

Cyclo­hexane-1,2-diammonium bis­(pyridine-2-carboxyl­ate)

In the dication of the title salt, C6H16N2 2+·2C6H4NO2 −, the two ammonium groups are in the equatorial positions of the chair-shaped cyclo­hexyl ring. In the crystal, the cations and anions are linked by N—H⋯O and N—H⋯N hydrogen bonds, forming a layer network parallel to the ac plane. Weak π–π inter­actions between adjacent pyridine rings with a centroid–centroid distance of 3.589 (2) Å are also present

Bis(2,2′-bipyridine-κ2 N,N′)dichlorido­platinum(IV) dichloride monohydrate

In the title complex, [PtCl2(C10H8N2)2]Cl2·H2O, the Pt4+ ion is six-coordinated in a distorted octa­hedral environment by four N atoms from the two 2,2′-bipyridine ligands and two Cl atoms. As a result of the different trans influences of the N and Cl atoms, the Pt—N bonds trans to the Cl atom are slightly longer than those trans to the N atom. The compound displays inter­molecular hydrogen bonding between the water mol­ecule and the Cl anions. There are inter­molecular π–π inter­actions between adjacent pyridine rings, with a centroid–centroid distance of 3.962 Å

catena-Poly[[[aqua­manganese(II)]-di-μ-sulfato-[aqua­manganese(II)]-μ-N,N,N′,N′-tetra­kis(2-pyridylmeth­yl)hexane-1,6-diamine] hexa­hydrate]

In the polymeric title compound, {[Mn2(SO4)2(C30H36N6)(H2O)2]·6H2O}n, the two Mn2+ ions are bridged by two sulfate anions to form dinuclear complexes, and these dinuclear species are linked by the hexa­dentate ligand N,N,N′,N′-tetra­kis(2-pyridylmeth­yl)hexane-1,6-diamine (tphn), forming a one-dimensional chain structure running in the [101] direction. The repeat unit of the polymer, Mn2(SO4)2(H2O)2(tphn), is disposed about a twofold axis passing through the centre of the dinuclear unit. The coordination geometry around the Mn centre is distorted octa­hedral. Two methylene groups are each disordered equally over two positions

Diacetato[N,N′-bis­(2-pyridylmethyl­idene)cyclo­hexane-1,2-diamine]manganese(II) hexa­hydrate

The asymmetric unit of the title compound, [Mn(C2H3O2)2(C18H20N4)]·6H2O, consists of a neutral MnII complex with six solvent water mol­ecules. In the complex, the Mn2+ ion is eight-coordinated in a distorted square-anti­prismatic environment by four N atoms from the tetra­dentate ligand N,N′-bis­(2-pyridylmethyl­idene)cyclo­hexane-1,2-diamine (bpic) and four O atoms from two acetate ligands. The compound displays inter­molecular O—H⋯O hydrogen-bond inter­actions to form various kinds of ring structures and cyclic water clusters

Optical Spectroscopy of Supernova Remnants in M81 and M82

We present spectroscopy of 28 SNR candidates as well as one H II region in M81, and two SNR candidates in M82. Twenty six out of the M81 candidates turn out to be genuine SNRs, and two in M82 may be shocked condensations in the galactic outflow or SNRs. The distribution of [N II]/H{\alpha} ratios of M81 SNRs is bimodal. M81 SNRs are divided into two groups in the spectral line ratio diagrams: an [O III]-strong group and an [O III]-weak group. The latter have larger sizes, and may have faster shock velocity. [N II]/H{\alpha} ratios of the SNRs show a strong correlation with [S II]/H{\alpha} ratios. They show a clear radial gradient in [N II]/H{\alpha} and [S II]/H{\alpha} ratios: dLog ([N II]/H{\alpha})/dLog R = -0.018 {\pm} 0.008 dex/kpc and dLog ([S II]/H{\alpha})/dLog R = -0.016 {\pm} 0.008 dex/kpc where R is a deprojected galactocentric distance. We estimate the nitrogen and oxygen abundance of the SNRs from the comparison with shock-ionization models. We obtain a value for the nitrogen radial gradient, dLog(N/H)/dLogR = -0.023 {\pm} 0.009 dex/kpc, and little evidence for the gradient in oxygen. This nitrogen abundance shows a few times flatter gradient than those of the planetary nebulae and H II regions. We find that five SNRs are matched with X-ray sources. Their X-ray hardness colors are consistent with thermal SNRs.Comment: 19 pages, 24 figures, 5 tables, ApJ accepte

Axial strain dependence of all-fiber acousto-optic tunable filters

We report the axial strain dependence of two types of all-fiber acousto-optic tunable filters based on flexural and torsional acoustic waves. Experimental observation of the resonant wavelength shift under applied axial strain could be explained by theoretical consideration of the combination of acoustic and optical effects. We discuss the possibility of suppressing the strain effect in the filters, or conversely, the possibility of using the strain dependence for wavelength tuning or strain sensors

catena-Poly[hemi(hexane-1,6-diammonium) [[aqua­dibromido­manganese(II)]-μ-pyridine-2-carboxyl­ato]]

The asymmetric unit of the title compound, {(C6H18N2)0.5[MnBr2(C6H4NO2)(H2O)]}n, contains the repeat unit of the complex anion and one-half of a hexane-1,6-diammonium cation that is located on a twofold rotation axis. In the anionic polymer, the Mn2+ ions are bridged by the pyridine­carboxyl­ate (pic) anion ligand, forming a chain structure along the c axis. The Mn2+ ion is six-coordinated in a distorted octa­hedral environment by one N atom of the pyridine ring, two O atoms of the two carboxyl­ate groups, one O atom of the water mol­ecule and two Br atoms. The compound displays inter­molecular N—H⋯O, N—H⋯Br, O—H⋯Br and O—H⋯O hydrogen bonding. There may also be inter­molecular π–π inter­actions between adjacent pyridine rings, with a centroid–centroid distance of 3.992 (4) Å

Tetra­chlorido(1,10-phenanthroline-κ2 N,N′)platinum(IV) monohydrate

In the title complex, [PtCl4(C12H8N2)]·H2O, the Pt4+ ion is six-coordinated in a distorted octa­hedral environment by two N atoms of a 1,10-phenanthroline ligand and by four Cl atoms. As a result of the different trans effects of the N and Cl atoms, the Pt—Cl bonds trans to the N atom are slightly shorter than those trans to the Cl atom. The compound displays inter­molecular π–π inter­actions between the six-membered rings, with a centroid–centroid distance of 3.834 Å. There are also weak intra­molecular C—H⋯Cl hydrogen bonds. According to the IR spectrum, solvent water was present in the crystal, but owing to the high thermal motion of the uncoordinated O atom, the H atoms could not be detected

Tetra­chlorido(1,10-phenanthroline-κ2 N,N′)platinum(IV) acetonitrile hemisolvate

The asymmetric unit of the title compound, [PtCl4(C12H8N2)]·0.5CH3CN, contains two crystallographically independent PtIV complexes with very similar geometry and one solvent mol­ecule. In the complexes, each PtIV ion is six-coordinated in a distorted octa­hedral environment by two N atoms of the 1,10-phenanthroline ligand and four Cl atoms. Because of the different trans effects of the N and Cl atoms, the Pt—Cl bonds trans to the N atom are slightly shorter than those trans to the Cl atom. The compound displays numerous inter­molecular π–π inter­actions between six-membered rings, with a shortest centroid-to-centroid distance of 3.654 Å. There are also weak intra- and inter­molecular C—H⋯Cl hydrogen bonds