Orientation of the chromophores in the reaction center of Rhodopseudomonas viridis. Comparison of low-temperature linear dichroism spectra with a model derived from X-ray crystallography

Eight ester and ether derivatives of propargyl alcohol with varying electron demand were structurally characterised using low temperature X-ray crystallography, these were combined with seven derivatives obtained from the Cambridge Structural Database. Variable oxygen probe analysis of these derivatives provided evidence that the ethynyl substituent is a relatively weak π-electron donor, and is a slightly less effective donor than the C–C bond of an ethyl substituent.

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Comments on Identification of a hydrogen bond in the Phe-M197→Tyr mutant reaction center of the photosynthetic purple bacterium Rhodobacter sphaeroides by X-ray crystallography and FTIR spectroscopy (FEBS 23044)

FEBS Letters ◽

10.1016/s0014-5793(00)01695-1 ◽

2000 ◽

Vol 477 (3) ◽

pp. 283-283

Author(s):

Eliane Nabedryk ◽

Jacques Breton

Keyword(s):

Hydrogen Bond ◽

Ftir Spectroscopy ◽

Reaction Center ◽

Rhodobacter Sphaeroides ◽

Purple Bacterium ◽

X Ray ◽

X Ray Crystallography

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Crystal Packing and Supramolecular Motifs in Four Phenoxyalkanoic Acid Herbicides—Low-Temperature Redeterminations

Organic Chemistry International ◽

10.1155/2011/608165 ◽

2011 ◽

Vol 2011 ◽

pp. 1-5 ◽

Cited By ~ 4

Author(s):

Lesław Sieroń ◽

Joanna Kobyłecka ◽

Anna Turek

Keyword(s):

Low Temperature ◽

Propionic Acid ◽

Crystal Packing ◽

Dichlorophenoxyacetic Acid ◽

X Ray ◽

Π Interactions ◽

X Ray Crystallography ◽

Supramolecular Motifs ◽

2,4 Dichlorophenoxyacetic Acid ◽

Acid Herbicides

A low-temperature redetermination by X-ray crystallography of four phenoxyalkanoic acid herbicides, 4-chloro-2-methylphenoxyacetic acid (MCPA), rac-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4-dichlorophenoxybutyric acid (2,4-DB), allowed the supramolecular structures of these compounds to be precisely described in terms of C⋯O/C–H⋯π interactions. The geometric parameters of the redetermined structures agree with those previously reported, but with improved precision.

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Low-Temperature Heat Capacities and Thermodynamic Properties of a New Complex [Na(H2O)2]6[MoCo6O12(H2O)12]•4.3H2O(s)

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.525.141 ◽

2014 ◽

Vol 525 ◽

pp. 141-145

Author(s):

Qing Fen Meng ◽

Xiao San Xia

Keyword(s):

Heat Capacity ◽

Low Temperature ◽

Adiabatic Calorimeter ◽

Heat Capacities ◽

Dehydration Process ◽

X Ray ◽

X Ray Crystallography ◽

Temperature Heat ◽

Enthalpy And Entropy ◽

Heat Capacity Measurements

A new complex [Na (H2O)2]6[MoCo6O12(H2O)12]·4.3H2O(s) was synthesized and determined by X-ray crystallography. Low-temperature heat capacities of the compound was measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 380 K. An obvious dehydration process was found in the heat capacity curve of the title compound. The temperature, enthalpy and entropy of the dehydration process were determined to be (370.266±0.292) K, (187.455±0.354) kJ·mol-1, (50.627±0.078) J·K-1·mol-1 by three series of repeated heat capacity measurements in the region of thermal decomposition.

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