Characterization of coordination polyhedra.

Ellipsoidal analysis of coordination polyhedra

The idea of the coordination polyhedron is essential to understanding chemical structure. Simple polyhedra in crystalline compounds are often deformed due to structural complexity or electronic instabilities so distortion analysis methods are useful. Here we demonstrate that analysis of the minimum bounding ellipsoid of a coordination polyhedron provides a general method for studying distortion...

Distortion parameters for coordination polyhedra

Fins. I and z: FIG. I (left). Calculated mean quadratic elongation (h)-bond angle variance (~) distributions for four ideal types of distortion in coordination octahedra arising from the progressive shortening of the octahedral edges emphasized in insets a, b, c, and d: RGR, trend line for observed data (Robinson et al., I97I). FIG. 2 (right). Calculated mean quadratic elongation (;~)-bond angl...

Explorer Ellipsoidal analysis of coordination polyhedra

Structural design principles for self-assembled coordination polygons and polyhedra.

Strategies for the design of ligands that combine with metal ions to form high-symmetry coordination assemblies are reviewed. Evaluation of crystal structure evidence reveals that prior design approaches, based on the concept of complementary bonding vector angles, fail to predict the majority of known examples. After explaining the reasons for this failure, it is shown how an alternative appro...

Fullerenes and coordination polyhedra versus half-cube embeddings

A fullerene F, is a 3-regular (or cubic) polyhedral carbon molecule for which the n vertices the carbons atoms are arranged in 12 pentagons and (n/210) hexagons. Only a finite number of fullerenes are expected to be, up to scale, isometrically embeddable into a hypercube. Looking for the list of such fullerenes, we first check the embeddability of all fullerenes F, for n < 60 and of all prefera...