Magnetically induced ring currents in metallocenothiaporphyrins

Abstract

The magnetically induced current-density susceptibility tensor (CDT) of the lowest singlet and triplet states of the metallocenothiaporphyrins, where the metal is V, Cr, Mn, Fe, Co, Ni, Mo, Tc, Ru,...

Planar inorganic five-membered heterocycles with σ + π dual aromaticity in both S0and T1states

“…Very recently, a unified extended Hu ¨ckel and Baird aromaticity orbital-count rule was used to readily identify that ringshaped molecules in different spin states are aromatic or antiaromatic according to the presence of odd or even number of occupied conjugated valence orbitals. 93 For example, Bz has 3 and 4 conjugated occupied orbitals in the S 0 and T 1 states, thus being aromatic and antiaromatic, respectively. Similarly, there are also 3 orbitals contributing to the conjugation pathway for current rings in the S 0 state.…”

Aromaticity of Singlet and Triplet Boron Disk-like Clusters: A Test for Electron Counting Aromaticity Rules

“…This counting rule has been successfully applied to rationalize the magnetic properties of aromatic species. 45 We are grateful to an anonymous referee for directing our attention to the recent work of Valiev et al 46 in which the Huckel introducing the so-called disk aromaticity concept. 28,47−49 Furthermore, the studied systems are characterized by a unique dynamical behavior.…”

“…This counting rule has been successfully applied to rationalize the magnetic properties of aromatic species . We are grateful to an anonymous referee for directing our attention to the recent work of Valiev et al . in which the Hückel and Baird rules have been unified and reformulated in terms of the number of doubly and singly occupied orbitals: molecules are aromatic (or antiaromatic) if they have an odd (or even) number of doubly and singly occupied conjugated valence orbitals.…”

Diagnosing Ring Current(s) in Figure-Eight Skeletons: A 3D Through-Space Conjugation in the Two-Loops Crossing

“…Over the years, the delocalization concept, defined by Hückel as the (4 n +2) and (4 n ) π-electron rule and easily applicable to the archetypal aromatic (benzene) and antiaromatic (cyclobutadiene) hydrocarbons, respectively, has been deeply modified and substantially extended. 1 Going beyond the fundamental understanding of the concept originally assigned to planar molecules eventually revealed a complexity of this phenomenon 2 especially in the spatial organization of three-dimensional systems where the molecule topology substantially influences the final behavior. The trivial topology described as a planar Hückel, double-sided, and single-looped molecule ( Figure 1 , L k = 0) describes a classic model of aromatic and antiaromatic conjugations with a diatropic (clockwise) or paratropic (counterclockwise) current, respectively.…”

“…Delocalization of π electrons observed in conjugated systems and usually correlated with aromatic or antiaromatic character is one of the most important properties of cyclic unsaturated molecules. Over the years, the delocalization concept, defined by Hückel as the (4 n +2) and (4 n ) π-electron rule and easily applicable to the archetypal aromatic (benzene) and antiaromatic (cyclobutadiene) hydrocarbons, respectively, has been deeply modified and substantially extended . Going beyond the fundamental understanding of the concept originally assigned to planar molecules eventually revealed a complexity of this phenomenon especially in the spatial organization of three-dimensional systems where the molecule topology substantially influences the final behavior.…”