Graphical Representation of Stereochemical Configuration

TUCAN: A molecular identifier and descriptor applicable to the whole periodic table from hydrogen to oganesson

“…In contrast, the situation is much less clear in molecular inorganic chemistry, as overlap of the d-orbitals allows for bond orders higher than three [3] , only the left structure preserves the correct symmetry but has an electron count that is too high by four electrons, the center structure tries to preserve the electron count by using "zero-order" bonds [2] indicated as dashed lines at the expense of an artificially lowered symmetry, and the right structure uses "banana bonds" to capture the three-center-two-electron (3c-2e) nature of the B-H-B bonding which however cannot be represented with traditional graph concepts, C different representations of ferrocene ([Fe(C 5 H 5 ) 2 ]), with only the 3rd to 5th from the left properly representing the 10 equal Fe-C bonds observed in X-ray structures, D Without explicit hydrogen atoms, it is impossible to distinguish between the bis-µ-oxo (left) and bis-µ-hydroxo (right) structures often encountered in inorganic chemistry, as there is no known algorithmic way to decide whether H atoms have to be added to the M 2 O 2 core or not can be present in a wide variety of coordination environments, both in terms of the number of bound ligand atoms (= coordination number) and in the geometrical structure they assume in 3D space (= coordination polyhedron), often leading to complicated stereochemistry [4,5]. Furthermore, (organo)metal compounds are often characterized by a high degree of electron delocalization and multi-centric bonding, which cannot be captured in simple Lewis formulas (Fig.…”

TUCAN: A molecular identifier and descriptor applicable to the whole periodic table from hydrogen to oganesson

“…In molecular inorganic chemistry, on the other hand, the situation is much less clear, as overlap of the dorbitals allows for bond orders higher than three [5] and metal centers can be present in a wide variety of coordination environments, both in terms of the number of bound ligand atoms (= coordination number) and in the geometrical structure they assume in 3D space (= coordination polyhedron), often leading to complicated stereochemistry. [6,7] Furthermore, (organo)metal compounds are often characterized by a high degree of electron delocalization and multi-centric bonding, which cannot be captured in simple Lewis formulas (Fig. 1C + D).…”