Isomer counting for fluctional molecules

Abstract

Provides a technique, using nonrigid symmetry groups, for enumerating the isomers of fluctional molecules.

Pseudo-point groups and subsymmetry-itemized enumeration for characterizing the symmetries of tetrahydropyran and 1,3-dioxane derivatives

“…Since each of the (5 and 6) is C 1 -isomers chiral, it is represented by an arbitrary antipodal pair, the counterpart pair of which can be so easily depicted as to be abbreviated without providing misunderstanding. On the other hand, the (7)…”

“…The two conformers of a pair of Type III are both achiral and di †erent to each other. For example, the 4-monosubstituted tetrahydropyran (7) belongs to the Note that each C s -symmetry. conformer (7a or 7b) itself also belongs to the usual point group where 7a contains an equatorial substituent and 7b C s , contains an axial substituent.…”

Promolecules with a subsymmetry of D.infin.h. Combinatorial enumeration and stereochemical properties

“…The total number of isomers derived from ethane has been reported, but the result is not itemized with respect to symmetries. 33 The three hydrogen atoms of the methyl group construct an orbit governed by C3v(/C$). Hence, we obtain the following SCIs, where we take no account of chirality fittingness:…”

“…The counterpart of this lemma can be proved to be true for the present case in which the groups at issue are factor groups. Hence, we obtain the following figure inventories by using eq 33. These figure inventories are used in place of eqs 30a-30c.…”

Pseudo-point-group approach to stereochemistry and stereoisomerism of cyclohexane derivatives

“…[3] or [4] D6h(/G) t D3d = 2D3d(/G), [5] where G is an anisoenergetic subgroup. Isoenergetic cases have been characterized by two isoenergetic conformers (Q for Type II; A for Type I; or Q and Q for Type I'), as shown in Table I.…”