scholarly journals Interstellar chemistry: oxygen and its influence on complex molecule formation and complex molecules containing oxygen in dark clouds

1992 ◽  
Vol 258 (2) ◽  
pp. 347-359 ◽  
Author(s):  
R. P. A. Bettens ◽  
R. D. Brown
Keyword(s):  
Complex Molecule ◽  
Complex Molecules ◽  
Interstellar Chemistry ◽  
Dark Clouds ◽  
Molecule Formation

scholarly journals Complex molecule formation around massive young stellar objects

2014 ◽  
Vol 168 ◽  
pp. 81-101 ◽  
Author(s):  
Karin I. Öberg ◽  
Edith C. Fayolle ◽  
John B. Reiter ◽  
Claudia Cyganowski
Keyword(s):  
Complex Molecule ◽  
Environmental Parameters ◽  
Young Stellar Objects ◽  
Evolutionary Stage ◽  
Complex Molecules ◽  
Stellar Objects ◽  
Molecule Formation ◽  
General Chemical ◽  
Complex Chemistry ◽  
Complex Organic

Interstellar complex organic molecules were first identified in the hot inner regions of massive young stellar objects (MYSOs), but have more recently been found in many colder sources, indicating that complex molecules can form at a range of temperatures. However, individually these observations provide limited constraints on how complex molecules form, and whether the same formation pathways dominate in cold, warm and hot environments. To address these questions, we use spatially resolved observations from the Submillimeter Array of three MYSOs together with mostly unresolved literature data to explore how molecular ratios depend on environmental parameters, especially temperature. Towards the three MYSOs, we find multiple complex organic emission peaks characterized by different molecular compositions and temperatures. In particular, CH3CCH and CH3CN seem to always trace a lukewarm (T ≈ 60 K) and a hot (T > 100 K) complex chemistry, respectively. These spatial trends are consistent with abundance–temperature correlations of four representative complex organics – CH3CCH, CH3CN, CH3OCH3 and CH3CHO – in a large sample of complex molecule hosts mined from the literature. Together, these results indicate a general chemical evolution with temperature, i.e. that new complex molecule formation pathways are activated as a MYSO heats up. This is qualitatively consistent with model predictions. Furthermore, these results suggest that ratios of complex molecules may be developed into a powerful probe of the evolutionary stage of a MYSO, and may provide information about its formation history.

scholarly journals Structure of a dinuclear cadmium complex with 2,2′-bipyridine, monodentate nitrate and 3-carboxy-6-methylpyridine-2-carboxylate ligands: intramolecular carbonyl(lone pair)...π(ring) and nitrate(π)...π(ring) interactions

2015 ◽  
Vol 71 (8) ◽  
pp. 890-894
Author(s):  
Juan Granifo ◽  
Sebastián Suarez ◽  
Ricardo Baggio
Keyword(s):  
Complex Molecule ◽  
Solvent Molecule ◽  
Lone Pair ◽  
Dinuclear Complex ◽  
Cadmium Complex ◽  
Nitrate Anion ◽  
Coordination Geometry ◽  
Complex Molecules ◽  
Carboxylate Ligands ◽  
Solvent Molecules

The centrosymmetric dinuclear complex bis(μ-3-carboxy-6-methylpyridine-2-carboxylato)-κ3N,O2:O2;κ3O2:N,O2-bis[(2,2′-bipyridine-κ2N,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-methylpyridine-2,3-dicarboxylic acid (mepydcH2) and 2,2′-bipyridine in methanol. The asymmetric unit consists of a CdIIcation bound to a μ-κ3N,O2:O2-mepydcH−anion, anN,N′-bidentate 2,2′-bipyridine group and anO-monodentate nitrate anion, and is completed with a methanol solvent molecule at half-occupancy. The Cd complex unit is linked to its centrosymmetric image through a bridging mepydcH−carboxylate O atom to complete the dinuclear complex molecule. Despite a significant variation in the coordination angles, indicating a considerable departure from octahedral coordination geometry about the CdIIatom, 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 toa, further bound by C—H...O contacts alongbto form planar two-dimensional arrays parallel to (001). The juxtaposed planes form interstitial columnar voids that are filled by the methanol solvent molecules. These in turn interact with the complex molecules 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-κ3coordination mode found in the title compound.

scholarly journals Chiral crystallization of a zinc(II) complex

2021 ◽  
Vol 77 (5) ◽  
pp. 542-546
Author(s):  
Shabana Noor ◽  
Shintaro Suda ◽  
Tomoyuki Haraguchi ◽  
Fehmeeda Khatoon ◽  
Takashiro Akitsu
Keyword(s):  
Hydrogen Bond ◽  
Schiff Base ◽  
Complex Molecule ◽  
Solvent Molecule ◽  
Hirshfeld Surface ◽  
Supramolecular Interactions ◽  
Orthorhombic Space Group ◽  
Complex Molecules ◽  
Trigonal Bipyramidal ◽  
Distorted Trigonal Bipyramidal

The compound, {6,6′-dimethoxy-2,2′-[(4-azaheptane-1,7-diyl)bis(nitrilomethanylidyne)]diphenolato}zinc(II) methanol monosolvate, [Zn(C22H27N3O4)]·CH3OH, at 298 K crystallizes in the orthorhombic space group Pna21. The Zn atom is coordinated by a pentadentate Schiff base ligand in a distorted trigonal–bipyramidal N3O2 geometry. The equatorial plane is formed by the two phenolic O and one amine N atom. The axial positions are occupied by two amine N atoms. The distorted bipyramidal geometry is also supported by the trigonality index (τ), which is found to be 0.85 for the molecule. In the crystal, methanol solvent molecule is connected to the complex molecule by an O—H...O hydrogen bond and the complex molecules are connected by weak supramolecular interactions, so achiral molecules generate a chiral crystal. The Hirshfeld surface analysis suggests that H...H contacts account for the largest percentage of all interactions.

A Sensitive Resonance Scattering Method for the Determination of Trace Berberine Based on Formation of Particles

2013 ◽  
Vol 718-720 ◽  
pp. 557-560
Author(s):  
Qing Ye Liu ◽  
Li Sheng Wang ◽  
Ai Hui Liang
Keyword(s):  
Complex Molecule ◽  
Resonance Scattering ◽  
Scattering Method ◽  
Complex Molecules ◽  
Real Samples ◽  
System A ◽  
Nanoparticle System ◽  
Hcl Medium ◽  
Association Complex

In diluted HCl medium, berberine (BB) cationic ion and I3-combine to BB-I3association complex molecule. These complex molecules self-aggregate to (BB-I3)nassociation nanoparticlees in size of about 50 nm. It exhibits a strongest resonance scattering peak at 520 nm and a fluorescence peak at 470 nm for the nanoparticle system. A novel and sensitive resonance scattering spectral method has been proposed for the determination of trace amounts of BB in the range of 10 to 800 ng/ml, with detection limit of 3ng/ml BB. The method has been applied to the determination of trace berberine in real samples, with satisfactory results.

scholarly journals Crystal structure of bis{N′-[(E)-4-hydroxybenzylidene]pyridine-4-carbohydrazide-κN1}diiodidocadmium methanol disolvate

2017 ◽  
Vol 73 (1) ◽  
pp. 28-30 ◽  
Author(s):  
Farhad Akbari Afkhami ◽  
Harald Krautscheid ◽  
Zeliha Atioğlu ◽  
Mehmet Akkurt
Keyword(s):  
Hydrogen Bonding ◽  
Rotation Axis ◽  
Complex Molecule ◽  
Three Dimensional ◽  
Chain Structure ◽  
Complex Molecules ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network ◽  
Ethanol Solvate ◽  
A Chain

In the title compound, [Cd(C13H11IN3O2)2]·2CH3OH, which crystallizes withZ= 4 in the space groupPbcn, the CdIIatom is located on a twofold rotation axis and coordinated by two I−anions and two N atoms from the pyridine rings of the twoN′-[(E)-4-hydroxybenzylidene]pyridine-4-carbohydrazide ligands. The geometry around the CdIIatom is distorted tetrahedral, with bond angles in the range 94.92 (11)–124.29 (2)°. The iodide anions undergo intermolecular hydrogen-bonding contacts with the C—H groups of the organic ligands of an adjacent complex molecule, generating a chain structure along thebaxis. Furthermore, an extensive series of O—H...O, N—H...O and C—H...O hydrogen-bonding interactions involving both the complex molecules and the ethanol solvate molecules generate a three-dimensional network.

scholarly journals Diaquabis(benzoato-κO)bis[4,4,5,5-tetramethyl-2-(pyridin-4-yl-κN)imidazoline-1-oxyl 3-oxide]cobalt(II)

2012 ◽  
Vol 68 (4) ◽  
pp. m506-m506
Author(s):  
Kun-Miao Wang ◽  
Jie Zhou ◽  
Fen-Hua Qian ◽  
Jing Liu
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Complex Molecule ◽  
Solvent Evaporation ◽  
Water Molecules ◽  
Stacking Interactions ◽  
Solvent Evaporation Method ◽  
Complex Molecules ◽  
Evaporation Method ◽  
Distorted Octahedral

The title compound, [Co(C7H5O2)2(C12H16N3O2)2(H2O)2], was obtained from a conventional solvent evaporation method. The complex molecule is centrosymmetric, so pairs of equivalent ligands lietransto each other in a slightly distorted octahedral CoN2O4geometry. The CoIIion is coordinated by the pyridine N atoms from NITpPy ligands [NITpPy is 4,4,5,5-tetramethyl-2-(pyridin-4-yl)imidazoline-1-oxyl 3-oxide), water O atoms and two monodentate benzoate O atoms. The complex molecules are connected by O—H...O hydrogen bonds between water molecules and benzoate ligands, forming chains parallel to [100]. π–π stacking interactions between the benzoate ligands with centroid–centroid distances of 3.752 (2) Å connect the chains into layers parallel to (10-1).

scholarly journals Tetra-μ3-iodido-tetrakis{[ethyl 2-(1H-benzimidazol-1-yl)acetate-κN 3]copper(I)}

2012 ◽  
Vol 68 (6) ◽  
pp. m796-m796
Author(s):  
Lili Yang ◽  
Zhengyi Zhang
Keyword(s):  
Complex Molecule ◽  
Three Dimensional ◽  
Ring System ◽  
Inversion Symmetry ◽  
Tetrahedral Geometry ◽  
Complex Molecules ◽  
Iodide Ions ◽  
Distorted Tetrahedral Geometry ◽  
Dimensional Network ◽  
Crystal Complex

The complex molecule of the tetranuclear cubane-type title compound, [Cu4I4(C11H12N2O2)4], has crystallographically imposed fourfold inversion symmetry. The CuI ions are coordinated in a distorted tetrahedral geometry by an N atom of a benzimidazole ring system and three μ3-iodide ions, forming a Cu4I4 core. In the crystal, complex molecules are connected into a three-dimensional network by C—H...O hydrogen bonds involving H and O atoms of adjacent ethoxycarbonyl groups.

scholarly journals Complex molecule formation in grain mantles

2010 ◽  
Vol 517 ◽  
pp. A1 ◽  
Author(s):  
P. Hall ◽  
T. J. Millar
Keyword(s):  
Complex Molecule ◽  
Molecule Formation

scholarly journals Crystal structure of {N 1,N 3-bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methylidene]-2,2-dimethylpropane-1,3-diamine}bis(thiocyanato)iron(II)

2021 ◽  
Vol 77 (5) ◽  
pp. 573-578
Author(s):  
Kateryna Znovjyak ◽  
Maksym Seredyuk ◽  
Sergey O. Malinkin ◽  
Iryna O. Golenya ◽  
Vladimir M. Amirkhanov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Complex Molecule ◽  
Three Dimensional ◽  
Bond Distance ◽  
High Spin State ◽  
Neutral Complex ◽  
Complex Molecules ◽  
Dimensional Network ◽  
Intermolecular Contacts

The unit cell of the title compound, [FeII(NCS)2(C19H32N8)], consists of two charge-neutral complex molecules. In the complex molecule, the tetradentate ligand N 1 ,N 3-bis[(1-tert-butyl-1H-1,2,3-triazol-4-yl)methylene]-2,2-dimethylpropane-1,3-diamine coordinates to the FeII ion through the N atoms of the 1,2,3-triazole and aldimine groups. Two thiocyanate anions, also coordinated through their N atoms, complete the coordination sphere of the central Fe ion. In the crystal, neighbouring molecules are linked through weak C—H...C/S/N interactions into a three-dimensional network. The intermolecular contacts were quantified using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H...H 50.8%, H...C/C...H 14.3%, H...S/S...H 20.5% and H...N/N...H 12.1%. The average Fe—N bond distance is 2.170 Å, indicating the high-spin state of the FeII ion, which does not change upon cooling, as demonstrated by low-temperature magnetic susceptibility measurements. DFT calculations of energy frameworks at the B3LYP/6–31 G(d,p) theory level were performed to account for the interactions involved in the crystal structure.

Sign in / Sign up

Export Citation Format

Share Document