The first porphyrin–salen based chiral metal–organic framework (ps-CMOF) constructed by judiciously incorporating metalloporphyrin and metallosalen struts into one MOF structure is reported, which can serve as an effective heterogeneous catalyst for the asymmetric cyanosilylation of aldehydes owing to the synergistic function between Lewis acid activation (from metalloporphyrin) and chiral induction (from metallosalen).

A highly stable chiral salen-based metal–organic framework [(Cu4I4)2L4]·20DMF·3CH3CN (1) [L = (R,R)-N,N′-bis(3-tert-butyl-5-(4-pyridyl)salicylidene)-1,2-diphenylethylenediamine nickel(II)] has been synthesized and characterized by single crystal X-ray diffraction and other physicochemical methods. 1 exhibits a rare 8-fold interpenetrated 3D framework constructed by a 4-connecting Cu4I4 cluster and a 2-coordinating L ligand. Remarkably, in spite of 8-fold interpenetration, 1 still possesses two types of 1D chiral hydrophobic channels with pore window sizes of 6.77 × 8.64 Å2 and 6.09 × 10.96 Å2 along the crystallographic a axis. All Ni(salen) moieties of L lie inside the 1D channels and the empty coordination sites of Ni2+ are oriented to the cavities. PXRD and N2 adsorption measurements confirmed that 1 is extremely stable under high temperature (>400 °C), in water vapor (90% relative humidity), in acid/base aqueous solution (pH 0–14), and in saturated NaOH solution at 100 °C, as well as in 30 wt% H2O2 and 70 wt% tert-butyl hydroperoxide solution. 1 was proved to be an excellent recycled heterogeneous catalyst for the conversion of simulated industrial CO2 (that is, involving tiny amounts of water vapor and other acidic gases) with epoxides into cyclic carbonates under mild conditions for the first time. The synthesis of β-hydroxy-1,2,3-triazoles from the same epoxides, alkyne and sodium azide was also catalyzed by 1 in aqueous solution with high yield. Interestingly, the cycloaddition reaction of CO2 to bulky epoxides shows a decrease in the activity with an increase in the alkyl chain length of the substrate because of confinement of the channel size of 1, showing size-dependent selectivity. The plausible catalytic mechanisms for these two reactions have also been proposed.

A three-dimensional (3D) chiral metal–organic framework [Cd2{Ni(salen)}(DMF)3]·4DMF·7H2O (1) based on a new enantiopure tetracarboxyl-functionalized metallosalen Ni(H4salen) {where H6salen is (R,R)-N,N′-bis[3-tert-butyl-5-(3,5-dicarboxybenzyl)salicylidene]-1,2-diphenylethylenediame} was synthesized and characterized by infrared spectroscopy, thermogravimetric analysis, nitrogen and carbon dioxide adsorption, and powder and single-crystal X-ray diffractions. In 1, the dinuclear Cd2 cluster [Cd2(COO)4(DMF)3] as a node is cross-linked by four isophthalate groups on the salen ligands, forming a 2D lamellar structure, which are further linked by Ni(salen) into the 3D network with a 1D open channel (ca. 7.0 × 8.0 Å2) along the a axis. On account of its porosity, Lewis acid sites, and moderate uptake for CO2, 1 can be used as an efficient heterogeneous catalyst for the CO2 cycloaddition with epoxides under relatively mild conditions. Moreover, the bulky epoxide shows a decrease in activity with an increase in the alkyl chain length of the substrate as a result of the confinement effect of 1, showing size-dependent selectivity.

A new asymmetric phenol-based “end-off” dinucleating ligand HL was prepared using a modified methodology through a four-step synthesis. The ligand comprises two different coordination moieties, namely, a rigid 1,4-dimethyl-1,4,7-triazacyclononane unit and a more flexible N-(2-pyridyl)methyl-N-2-(2-pyridylethyl)amine unit. Its dinuclear Ni(II) complex containing two phosphate esters in a μ−η2 binding mode was synthesized and characterized by X-ray crystallography, in which each nickel atom is six-coordinate and adopts a slightly distorted octahedral coordination geometry.

A highly stable chiral salen-based metal–organic framework [(Cu4I4)2L4]·20DMF·3CH3CN (1) [L = (R,R)-N,N′-bis(3-tert-butyl-5-(4-pyridyl)salicylidene)-1,2-diphenylethylenediamine nickel(II)] has been synthesized and characterized by single crystal X-ray diffraction and other physicochemical methods. 1 exhibits a rare 8-fold interpenetrated 3D framework constructed by a 4-connecting Cu4I4 cluster and a 2-coordinating L ligand. Remarkably, in spite of 8-fold interpenetration, 1 still possesses two types of 1D chiral hydrophobic channels with pore window sizes of 6.77 × 8.64 Å2 and 6.09 × 10.96 Å2 along the crystallographic a axis. All Ni(salen) moieties of L lie inside the 1D channels and the empty coordination sites of Ni2+ are oriented to the cavities. PXRD and N2 adsorption measurements confirmed that 1 is extremely stable under high temperature (>400 °C), in water vapor (90% relative humidity), in acid/base aqueous solution (pH 0–14), and in saturated NaOH solution at 100 °C, as well as in 30 wt% H2O2 and 70 wt% tert-butyl hydroperoxide solution. 1 was proved to be an excellent recycled heterogeneous catalyst for the conversion of simulated industrial CO2 (that is, involving tiny amounts of water vapor and other acidic gases) with epoxides into cyclic carbonates under mild conditions for the first time. The synthesis of β-hydroxy-1,2,3-triazoles from the same epoxides, alkyne and sodium azide was also catalyzed by 1 in aqueous solution with high yield. Interestingly, the cycloaddition reaction of CO2 to bulky epoxides shows a decrease in the activity with an increase in the alkyl chain length of the substrate because of confinement of the channel size of 1, showing size-dependent selectivity. The plausible catalytic mechanisms for these two reactions have also been proposed.

The first porphyrin–salen based chiral metal–organic framework (ps-CMOF) constructed by judiciously incorporating metalloporphyrin and metallosalen struts into one MOF structure is reported, which can serve as an effective heterogeneous catalyst for the asymmetric cyanosilylation of aldehydes owing to the synergistic function between Lewis acid activation (from metalloporphyrin) and chiral induction (from metallosalen).