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2‐Formylphenylboronic acid condenses with active methylene reagents like α‐amino esters, ketones, and lactams directly to give benzo‐fused 1‐hydroxy‐2,1‐azaborines in good yields within minutes under microwave‐accelerated conditions. The new stable boron heterocycles prepared to demonstrate this approach were characterized by NMR spectroscopy. Three members of a new diboron heteropentacyclic ring system, 5a,12a‐diaza‐5,12‐dibora‐5,12‐dihydroxypentacene‐6,13‐dione, were prepared, and one of these highly fluorescent compounds was characterized by X‐ray crystallography. Some key solid‐state structural features revealed by the X‐ray analysis provide a basis for explaining the limited solubility of these pentaheterocycles in common organic solvents.

Three five‐coordinate iron(IV) imide complexes have been synthesized and characterized. These novel structures have disparate spin states on the iron as a function of the R‐group attached to the imide, with alkyl groups leading to low‐spin diamagnetic (S=0) complexes and an aryl group leading to an intermediate‐spin (S=1) complex. The different spin states lead to significant differences in the bonding about the iron center as well as the spectroscopic properties of these complexes. Mössbauer spectroscopy confirmed that all three imide complexes are in the iron(IV) oxidation state. The combination of diamagnetism and¹⁵N labeling allowed for the first¹⁵N NMR resonance recorded on an iron imide. Multi‐reference calculations corroborate the experimental structural findings and suggest how the bonding is distinctly different on the imide ligand between the two spin states.

Three five‐coordinate iron(IV) imide complexes have been synthesized and characterized. These novel structures have disparate spin states on the iron as a function of the R‐group attached to the imide, with alkyl groups leading to low‐spin diamagnetic (S=0) complexes and an aryl group leading to an intermediate‐spin (S=1) complex. The different spin states lead to significant differences in the bonding about the iron center as well as the spectroscopic properties of these complexes. Mössbauer spectroscopy confirmed that all three imide complexes are in the iron(IV) oxidation state. The combination of diamagnetism and¹⁵N labeling allowed for the first¹⁵N NMR resonance recorded on an iron imide. Multi‐reference calculations corroborate the experimental structural findings and suggest how the bonding is distinctly different on the imide ligand between the two spin states.