Reflection geometric chirality

Lord Kelvin lla> recognized that the term asymmetry does not reflect the essential features, and he introduced the concept of chiralty. He defined a geometrical object as chiral, if it is not superimposable onto its mirror image by rigid motions (rotation and translation). Chirality requires the absence of symmetry elements of the second kind (a- and Sn-operations) lu>>. In the gaseous or liquid state an optically active compound has always chiral molecules, but the reverse is not necessarily true. 

Chirality is the geometric property of a rigid object (or spatial arrangement of points or atoms), which is nonsuperposable on its mirror image such an object has no symmetry elements of the second kind (a mirror plane, a center of inversion, a rotation-reflection axis,. ..). If the object is superposable on its mirror image, the object is described as being achiral. 

Rhodium(III) complexes typically contain anunine, halo, or aqua ligands, or the important bidentate ligands 1,2-diaminoethane (en), oxalato, or pentane-2,4-dionato (acac) and are invariably octahedral. Their wide variety is in part a reflection of the slow reactions, which take place at the low-spin d centers, which allow many intermediates, and geometrical or chiral isomers, to be isolated. It is fairly difficult to oxidize rhodium(III) complexes, but they may be reduced to rhodium(l) species in the presence of suitable ligands. However, there is little current work being carried out on the classical rhodium(III) complexes and even less on the higher oxidation states. 

Chiral A geometric figure, or group of points is chiral if it is nonsuperimposable on its mirror image [82]. A chiral object lacks all of the second order (improper) symmetry elements, a mirror plane), i center of symmetry), and S rotation-reflection axis). In chemistry, the term is (properly) only applied to entire molecules, not to parts of molecules. A chiral compound may be either racemic or nonracemic. An object that has any of the second order symmetry elements i.e., that is superimposable on its mirror image) is achiral. It is inappropriate to use the adjective chiral to modify an abstract noun one cannot have a chiral opinion and one cannot execute a chiral resolution or synthesis. 

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