Our work in the area of carbon-monoxide-releasing molecules led to the synthesis and crystallization of new flavone derivatives as intermediates. Herein we report the first crystal structure of the title compound, C16H12O3, a hydroxy-substituted flavone where the 2-phenyl group has been replaced by a p-tolyl group. The introduction of the 3-hydroxy group allows the formation of intermolecular O—H...O=C hydrogen bonds, used to build centrosymmetric R 2 2(10) ring motifs in the crystal.

A novel family of four 1‐bromo‐2,6‐bis{[(λ5‐phosphanylidene)imino]methyl}benzene ligands has been synthesized and characterized. The phosphiniminomethyl substituents are decorated with either three phenyl groups, two phenyl and one cyclohexyl group, one phenyl and two cyclohexyl groups, or three cyclohexyl groups. Each ligand was metallated using zero‐valent nickel through an oxidative addition to form a family of organonickel(II) complexes, namely (2,6‐bis{[(triphenyl‐λ5‐phosphanylidene)imino]methyl}phenyl‐κ3N,C1,N′)bromidonickel(II) dichloromethane hemisolvate, [NiBr(C44H37N2P2)]·0.5CH2Cl2, (2,6‐bis{[(cyclohexyldiphenyl‐λ5‐phosphanylidene)imino]methyl}phenyl‐κ3N,C1,N′)bromidonickel(II) diethyl ether hemisolvate, [NiBr(C44H49N2P2)]·0.5C4H10O, (2,6‐bis{[(dicyclohexylphenyl‐λ5‐phosphanylidene)imino]methyl}phenyl‐κ3N,C1,N′)bromidonickel(II), [NiBr(C44H61N2P2)], and (2,6‐bis{[(tricyclohexyl‐λ5‐phosphanylidene)imino]methyl}phenyl‐κ3N,C1,N′)bromidonickel(II), [NiBr(C44H73N2P2)]. This family of complexes represents a useful opportunity to investigate the impact of incrementally changing the steric characteristics of a complex on its structure and reactivity.

Our work in the area of synthesis of metal–organic frameworks (MOFs) based on organic N-oxides led to the crystallization of pyridine-4-carboxamidoxime N-oxide. Herein we report the first crystal structure of the title compound, C6H7N3O2 [systematic name: (Z)-4-(N′-hydroxycarbamimidoyl)pyridine N-oxide]. The hydroxycarbamimidoyl group is essentially coplanar with the aromatic ring, r.m.s.d. = 0.112 Å. The compound crystallizes in hydrogen-bonding layers built from the formation of strong O—H...O hydrogen bonds between the oxime oxygen atom and the oxygen atom of the N-oxide, and the formation of N—H...O hydrogen bonds between one amine nitrogen atom and the N-oxide oxygen atom. These combined build R 3 4(24) ring motifs in the crystal. The crystal structure has no π–π interactions.