Inclusion Ability of 4-Phenylpyridine-Extended Nickel(II) Dibenzoylmethanate, a New Metal−Complex Host

Abstract

A new host complex, [Ni(4-PhPy)2(DBM)2], has been prepared by modification of nickel dibenzoylmethanate (Ni(DBM)2; DBM = C6H5COCHCOC6H5 -) with 4-phenylpyridine (4-PhPy). Of 17 organic solvents that were tested as guest candidates, 6 inclusion compounds were isolated, mostly as bulk products. All compounds were characterized with XRD methods. With benzene, fluoro-, chloro-, and bromobenzenes, toluene, and o-xylene, 1:1 inclusions form; they are all green, relatively stable, and isostructural (triclinic, P1̄, Z = 2). The guest species accommodate flattened cages formed upon van der Waals packing of host molecules. The guest inclusion influences the distortion in the bischelate fragment of the host molecule, as the dihedral angle between two chelate rings ranges up to 12°. This distortion is probably responsible for the green color of these phases. The series of inclusions exhibits an order of thermal stability opposite to that which would be expected from the volativity of the neat guests; the order indicates strong preference of the inclusion matrix to benzenes with smaller substituents. With benzene, one more inclusion phase was isolated as a metastable product, with a host-to-guest ratio of 1:4; it is brown and of a distinct structural type (triclinic, P1̄, Z = 1). The guest species are found in alternating layers of closely packed host molecules. The guest-free host phase is brown; its crystal structure (triclinic, P1̄, Z = 1) is different from the inclusion compounds. In all the materials studied the host molecule is a trans-configured octahedral complex with two DBMs chelating the nickel(II) center in an equatorial plane and two 4-PhPy ligands coordinating axially.

Flexible metal-organic framework compounds: In situ studies for selective CO2 capture

“…It is recognized as one of the "DBM"class of MOFs, elegantly described by Soldatov. [71][72][73][74][75][76] Interestingly, both of these materials have nearly identical gate opening pressure responses to CO 2 at 303 K. This coincidence in CO 2 adsorption behavior between two highly contrasted crystallographic structures with very different degrees of freedom available for structure transitions during gas adsorption make these two materials an ideal model system for investigating how structures respond and evolve to the adsorption of guest molecules.…”

“…However, the diffraction peak shape and position of NiBpene is different under the same partial pressures of CO 2 in pure and CO 2 /N 2 mixtures, indicating some degree of co-adsorption of N 2 . These intriguing differences in mechanisms between the two materials with such similar CO 2 adsorption/desorption isotherms offer an opportunity to study the influence of structure on adsorption selectivity in flexible MOFs.We conclude by noting that both NiBpene and NiDBM-Bpy belong to material classes where aspects of the structure can be adjusted in a controllable way [70][71][72][73][74][75][76]. Controllable aspects include the length of the linker d-spacing and consequent size of the void spaces available for CO 2 adsorption, the fineness of the powder grain morphology, and the concentration of synthetically incorporated impurity guest species that reduce the dynamically available space for CO 2 adsorption/desorption.…”

“…The DBM ligands or fragments correspond to the disks (paddle wheels) inFigure 2b. The DBM fragment has a flexible architecture that can be easy converted from one structure to another (can be planar, twisted, or bent depending on the guest molecules present) [71][72][73][74][75][76]79]. The guest species fill the residual pocket space between the DBM fragments and form van der Waals contact with each other and with the host.…”

Different coordination modes and supramolecular aggregations in copper(II) pentane-2,4-dionato compounds with 2-pyridone and 3-hydroxypyridine

“…Metal complexes of b-diketonate ligands are of interest in solid-state supramolecular chemistry mostly owing to their promise as building blocks for the design of porous and supramolecular materials with interesting electronic, magnetic, and optical properties [1][2][3][4]. Furthermore, metal complexes of b-diketonate derivatives can be good precursors in metal-organic chemical vapour deposition (MOCVD) [5].…”

Morpholine adducts of Co, Ni, and Mn benzoylacetonates: isostructurality and C–H···O hydrogen bonding

“…In the earlier times, they have mostly attracted attention due to their applications in synthetic and industrial processes such as extraction of metals, catalytic processes, preparation of metal oxide thin films, etc. Over the past 20 years, they have also attracted ever growing attention as building blocks in crystal engineering [1][2][3][4][5]. There are two main pathways for their use in the rational design of metalorganic solids-the use of functionalised diketones which can further connect into supramolecular architectures [6][7][8][9][10] and the use of metals which remain coordinationaly unsaturated after the formation of a neutral diketonate complex.…”