Introducing Phosphorus into the Overcrowded Thiele's hydrocarbon Family: Unveiling Contorted Main Group Diradicaloids with Dynamic Redox Behavior.

Thiele's Hydrocarbons (THs) featuring a 9,10-anthrylene core with switchable geometric and electronic configurations offer exciting possibilities in advanced functional materials. Despite significant advances in main group-based diradicaloids in contemporary chemistry, main group THs containing an anthrylene cores have remained elusive, primarily due to the lack of straightforward synthetic strategies and the inherent high reactivity of these species. In this study, we utilize an anthracene-based phosphine synthon to demonstrate, for the first time, a facile and high-yielding synthetic strategy for robust P-functionalized overcrowded ethylenes (OCEs) within the TH family.

Aminomethylations of electron-deficient compounds-bringing iron photoredox catalysis into play.

The α-functionalisation of -containing compounds is an area of broad interest in synthetic chemistry due to their presence in biologically active substances among others. Visible light-induced generation of nucleophilic α-aminoalkyl radicals as reactive intermediates that can be trapped by electron-deficient alkenes presents an attractive and mild approach to achieve said functionalisation. In this work, [Fe(iii)(phtmeimb)]PF (phtmeimb = phenyl(tris(3-methylimidazol-2-ylidene))borate), an N-heterocyclic carbene (NHC) complex based on Earth-abundant iron, was used as photoredox catalyst to efficiently drive the formation of α-aminoalkyl radicals from a range of different α-trimethylsilylamines and their subsequent addition to a number of electron-deficient alkenes under green light irradiation.

How Rigidity and Conjugation of Bidentate Ligands Affect the Geometry and Photophysics of Iron -Heterocyclic Complexes: A Comparative Study.

Two iron complexes featuring the bidentate, nonconjugated N-heterocyclic carbene (NHC) 1,1'-methylenebis(3-methylimidazol-2-ylidene) (mbmi) ligand, where the two NHC moieties are separated by a methylene bridge, have been synthesized to exploit the combined influence of geometric and electronic effects on the ground- and excited-state properties of homoleptic Fe-hexa-NHC [Fe(mbmi)](PF) and heteroleptic Fe-tetra-NHC [Fe(mbmi)(bpy)](PF) (bpy = 2,2'-bipyridine) complexes. They are compared to the reported Fe-hexa-NHC [Fe(btz)](PF) and Fe-tetra-NHC [Fe(btz)(bpy)](PF) complexes containing the conjugated, bidentate mesoionic NHC ligand 3,3'-dimethyl-1,1'-bis(-tolyl)-4,4'-bis(1,2,3-triazol-5-ylidene) (btz). The observed geometries of [Fe(mbmi)](PF) and [Fe(mbmi)(bpy)](PF) are evaluated through L-Fe-L bond angles and ligand planarity and compared to those of [Fe(btz)](PF) and [Fe(btz)(bpy)](PF).

Tailoring the Photophysical Properties of a Homoleptic Iron(II) Tetra -Heterocyclic Carbene Complex by Attaching an Imidazolium Group to the (CNC) Pincer Ligand─A Comparative Study.

We here report the synthesis of the homoleptic iron(II) -heterocyclic carbene (NHC) complex [Fe(miHpbmi)](PF) (miHpbmi = 4-((3-methyl-1-imidazolium-1-yl)pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) and its electrochemical and photophysical properties. The introduction of the π-electron-withdrawing 3-methyl-1-imidazol-3-ium-1-yl group into the NHC ligand framework resulted in stabilization of the metal-to-ligand charge transfer (MLCT) state and destabilization of the metal-centered (MC) states. This resulted in an improved excited-state lifetime of 16 ps compared to the 9 ps for the unsubstituted parent compound [Fe(pbmi)](PF) (pbmi = (pyridine-2,6-diyl)bis(3-methylimidazol-2-ylidene)) as well as a stronger MLCT absorption band extending more toward the red spectral region.