Ionic Radii and Related Concepts

1) For a number of good reasons, solid-state chemists are structure aficionados. For self-training purposes, it is therefore highly recommended to get an overview of the structures and structural principles within inorganic chemistry [5]. 

2) Our language is rather casual here. The crystal structure of copper is of the cubic dose-packed (cep) type and, because there is only one type of atom, this is ecprivalent to the face-centered cubic (fee) structure for this special case. Although not every F-centered crystal structure belonging to the cubic system (e.g.. Si or NaQ) can be considered dosely packed, the simplified notion cep = fee is so ubiquitous in the literature that we also use it in this book. 

A modern approach would probably go as follows Grow a nice NaCl crystal, perform an X-ray diffraction measurement to determine the electron density along the line Na-Cl, search for the minimum density somewhere between the two atoms, and then interpret this value as the crossover from the cation (Na+) to the anion (Cl ). Yet, the systems of ionic radii we know of have been generated following other recipes [8], and three approaches seem to be especially worth mentioning. 

For isoelectronic ions such as Na+ and F which both have the electronic configuration of Ne, [ls 2s 2p ], the values for C must be identical, whatever 

3) Quantum-mechanically inspired recipes for the calculation of the screening values s have been proposed by Pauling [12] and Slater [13]. 

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The stabilization of metal bonds was very successful when applying trianionic tripod ligands tris(aminoethyl)amine (tren) ortris(aminodimethylsilyl)methane (ts).This concept was adapted from earlier studies on related group IV- TM bimetallic complexes and nicely illustrates that steric protection is a most important factor governing the accessibility of such d° complexes. Despite the differing ionic radii of (75 pm), Zr (86 pm), (85 pm), and U (103 pm) [56], the formation of anal-... 

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