In conversations between native speakers, words such as ‘same’ and ‘identical’ do not usually cause much difficulty. We take it for granted that others use them with the same sense as we do. If it is unclear whether numerical or qualitative identity is intended, a brief gloss such as ‘one thing not two’ for the former or ‘exactly alike’ for the latter removes the unclarity. In this paper, numer...

In the title compound, C(18)H(24)NO(2) (+)·Cl(-), the absolute configuration of the new stereogenic centre (the C atom with a CH(2)OH substituent) was unambiguously determined to have an R configuration. The dihedral angle between the two aromatic rings is 30.82 (2)°. Inter-molecular N-H⋯Cl and O-H⋯Cl hydrogen bonds and intra-molecular N-H⋯O hydrogen bonds stabilize the crystal structure.

The absolute configuration of the title compound, C(18)H(24)O(5)·H(2)O, was not been determined by anomalous-dispersion effects, but has been assigned by reference to an unchanging chiral centre in the synthetic procedure. Intra-molecular O-H⋯O hydrogen bonds stabilize the mol-ecular conformation. In the crystal, O-H⋯O hydrogen bonds link the main mol-ecules and the water mol-ecules, forming an...

The title compound, C(16)H(20)N(2)O(2), was synthesized from (S)-tryptophan methyl ester hydro-chloride and butyraldehyde. The absolute configuration 9S,10S was assigned on the basis of the unchanging chirality of the C9 centre. The NH group of the indole ring is involved in inter-molecular N-H⋯O hydrogen bonding, while the NH group of the six-membered ring is not. This latter ring has a half-c...

The title salt, C24H24N(+)·BF4 (-), is one of two possible dias-tereoisomers having a different configuration of the asymmetric centre in the α-phenyl-ethyl substituent, whose absolute configuration was established to be R. The two phenyl substituents of the cation have a cofacial orientation, albeit with a long centroid-centroid separation of 4.129 (3) Å. The crystal structure exhibits numerou...

background because of great concerns about mortality and morbidity of infection in febrile neutropenic patients, the appropriate empirical antibiotic should be started immediately. although there are established guidelines for the use of empirical therapy, local microbiological pattern and antibiotic susceptibility should be considered. objectives the current study aimed to identify the etiolog...

Fundamental notions concerning absolute structure and absolute configuration, and their determination from single-crystal diffraction measurements, are presented and reviewed. A glossary of terms with definitions useful in this field is provided. For absolute structure and its determination, the separate but interacting influences of the structure and the inversion-distinguishing power of an X-...

Absolute luminosity measurements are of general interest for colliding-beam experiments at storage rings. These measurements are necessary to determine the absolute cross-sections of reaction processes and are valuable to quantify the performance of the accelerator. Using data taken in 2010, LHCb has applied two methods to determine the absolute scale of its luminosity measurements for proton-p...