The one‐pot synthesis of 2,5‐bis(diarylphosphoryl)‐3,6‐bis(arylamino)cyclohexa‐2,5‐diene‐1,4‐diones has been achieved by AgI‐mediated full C–H functionalization of 1,4‐benzoquinone (BQ) through regioselective dual phosphination and amination reactions. BQ, diarylphosphine oxides [SPOs, Ar2PH(=O)], and imines reacted to give the products under mild conditions. 1,4‐Naphthoquinone (NQ) could also be used instead of BQ. When aniline was used instead of the corresponding imine, a lower yield of the desired product was obtained. In the absence of Ag2CO3, hydrophosphinylation of the imine by the SPO occurred as a competitive side‐reaction. AgI plays versatile roles in this reaction, as a mediator for facilitating the consecutive additions of Ar2P(=O)– and aniline to the related β‐carbon atoms of BQ, as an oxidant of hydroquinone (HQ) intermediates to form the substituted BQ counterpart, and as an inhibitor of the hydrophosphinylation side‐reaction of the imine by the SPO. The X‐ray crystal structures of several new products have been determined. A reaction mechanism is also proposed based on the experimental results.
Three unsymmetrical semirigid ligands, HInMe-n-py (n = 2, 3, 4), showing positional isomerism have assembled with ZnCl 2 and CdCl 2 to yield supramolecular coordination assemblies. Compoundhas a two-dimensional rhombus gridlike (4,4) layer structure constructed from the dinuclear paddlewheel [Zn 2 (O 2 C) 4 N 2 ] units with two pendant side-arms. Compound [Zn 2 Cl 2 (InMe-3-py) 2 (HInMe-3-py) 2 ] (2) forms a discrete armed M 2 L 2 macrocycle, which connects with others by intermolecular O-H⋯O and C-H⋯Cl hydrogen bonds to give rise to a decorated three-dimensional supramolecular pcu net. Compound [Zn(InMe-4-py) 2 ]•1/2H 2 O (3) adopts a two-dimensional chiral wavy (4,4) square grid. Opposite-handedness chiral wavy grids are stacked in an ABAB type of sequence that has small voids accommodating lattice water molecules. Compound [CdCl(InMe-3-py)] (4) displays a two-dimensional achiral meso layer in which the opposite-handedness Cd-L helical chains are interconnected by the Cd-O bridging bonds and stitched by zigzag Cd-Cl chains. Compound [Cd(InMe-4-py) 2 (H 2 O) 2 ] (5) features a two-dimensional rhombus gridlike (4,4)-net.Through the connections of net-to-net O-H⋯O hydrogen bonds, the grids are offset-stacked to be a hydrogen-bonded three-dimensional oblique pcu net. The structural diversity and complexity in these supramolecular coordination architectures are most likely attributed to the various coordination modes adopted by these N-and O-donor ligands of different substituent position and the coordination preference exhibited by the metal ions. Thermogravimetric (TG) analyses showed that all the frameworks of compounds 1-5 exhibit a thermal stability higher than 300 °C. In addition, the solid-state photoluminescent properties of compounds 1-5 were investigated.
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