Orbitals in Inorganic Chemistry: Metal Rings and Clusters, Hydronitrogens, and Heterocyles

Abstract

A chemical orbital theory is useful in inorganic chemistry. Some applications are described for understanding and designing of inorganic molecules. Among the topics included are: (1) valence electron rules to predict stabilities of three- and four-membered ring metals and for those of regular octahedral M(6) metal clusters solely by counting the number of valence electrons; (2) pentagon stability (stability of five- relative to six-membered rings in some classes of molecules), predicted and applied for understanding and designing saturated molecules of group XV elements; (3) properties of unsaturated hydronitrogens N( m )H( n ) in contrast to those of hydrocarbons C( m )H( n ); (4) unusually short nonbonded distances between metal atoms in cyclic molecules.

Goodenough–Kanamori rules applied to wurtzite crystals

“…For this reason, GK rules have attracted widespread research interest, whether for gaining a deeper understanding of the physics underlying their origin as well as the range of their applicability [8][9][10][11][12] or for cases of their violation [13,14]. Inagaki [15] and Fukui and Inagaki [16,17] and later Naruse and Takamori [18] propose an orbital phase perspective of GK rules in superexchange interaction. On the other hand, GK rules proved to be a signi cant tool for the synthetic chemist in controlling the magnetic interactions [9,10,19].…”

Reactive Sites for Chiral Selective Growth of Single-Walled Carbon Nanotubes: A DFT Study of Ni55–Cn Complexes

“…The frontier orbital theory has been widely used to study the chemical reactivity of molecules in organic or organometallic reactions. − The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is used as a simple measure for the kinetic stability or chemical reactivity of aromatic molecules. A small or no HOMO–LUMO gap implies a high chemical reactivity.…”

Electrocatalytic Methane Functionalization with d0 Early Transition Metals Under Ambient Conditions

“…We propose that the electrochemically generated d 0 -M-L •+ intermediate is partly stabilized by the orbital delocalization between the metal's d orbitals and the radical-bound O 2p orbital. [7] A corollary of this hypothesis is that a smaller energy difference between the metals' d orbital and O 2p one in d 0 -M-L •+ warrants a more effective orbital delocalization, [20] a more stable d 0 -M-L •+ once electrochemically generated, and a larger probability of CH4 activation despite CH4's limited solubility before the deactivation of d 0 -M-L •+ due to detrimental side reactions. As the energy differences between metals' 3d (-9.2 ~ -10.7 eV) and O 2p (-15.8 eV) orbitals are appreciably smaller than that for 4d metals (-8.3 ~ -9.1 eV) and even smaller than 5d metals (-6.1 ~ -8.7 eV) (Table S3), the proposed mechanism predicts decreasing CH4-activating activities when the metal in d 0 -M-L •+ intermediate changes from Period 4 to Period 6, consistent with our experimental observation (Figure 4).…”