Supramolecular association of M²⁺⋯π induced by different electrostatic properties using naphthyl substituted β-diketonate complexes (metal = Cu, Pd, Pt)

Abstract

Expanded π-conjugated coordination complexes, [M(L2)2] (M = Cu2+, Pd2+, Pt2+; L2 = dinaphthoylmethanido−), were prepared and their unique electron contributions and electrophile/nucleophile characteristics were found due to the supramolecular associations.

Co-crystal structure, Hirshfeld surface analysis and DFT studies of 3,4-ethylenedioxythiophene solvated bis[1,3-bis(pentafluorophenyl)propane-1,3-dionato]copper(II)

“…6); the total elimination of EDOT was found to be 33.6%, which is almost the same as the calculated value of 33.0% around 50-130 C. The release curve is gentle, and the coordinated EDOT and solvated EDOT are gradually separated from the crystals without being distinguished, confirming the weak coordination bond due to the Jahn-Teller effect of the Cu ion. In the complex, the positive electrostatic potential on the copper (+206.41 kJ mol À1 ) in the independent crystal of Cu(L) 2 was higher than that of the corresponding non-fluorinated complex, +116.71 kJ mol À1 for Cu(dbm) 2 (Kusakawa et al, 2020) due to the substitution of the pentafluorophenyl groups, indicating that the present EDOT recognition was induced. For the same procedure, Pd(L) 2 and EDOT were combined to give brown needle-shaped crystals, which are clearly characterized as Pd(L) 2 as a single component and no guest release was observed by the brown crystals of Pd(L) 2 ; the electrostatic potentials on the metal center of Pd(L) 2 and Pd(dbm) 2 are À1.0 and À73 kJ mol À1 , respectively (Kusakawa et al, 2020).…”

Synthesis and Crystal Structures of Rhomb-Shaped Dimeric Pd(II) Complexes with Arylethynyl-Substituted 2,2′-Bipyridine through CH⋯π Interactions in the Crystalline States

“…We reported that the supramolecular association of square-planar Pt 2+ , Pd 2+ , and Cu 2+ β-diketonate complexes [15,16], which nucleophile characteristics of Pt 2+ and Pd 2+ are clearly shown in the results of their crystal packings in the solid state and DFT calculations. The axial surface on the Pt 2+ center in complexes shows high negative ESP and nucleophile that on Pd 2+ center remarkably changed the surrounding substitutions, e.g., the negative value for [Pd(dbm) 2 ] and neutral~positive for the corresponding perfluorinated complex, [Pd(L) 2 ] (L = bis(pentafluorobenzoyl)methanido − ), indicating the possibility of strict adjustment of the metal characteristics [15]. Such fields prompted us to develop the investigation of 4,4 ′ -di(phenylethynyl)-2,2 ′ -bipyridine (L 1 ), which forms a 1:1 cocrystal with 4,4 ′ -bis(pentafluorophenylethynyl)-2,2 ′ -bipyridine to give alternately stacking materials [17] through π-hole• • • π interactions [18,19].…”

“…The Pt 2+ [10] and Pd 2+ [11] centers of square-planar metal complexes can act as halogen-bond acceptors upon their interaction with σh-donating organohalides, and the complexes are co-crystallized with πh-donating perfluoroaromatic species giving the sandwich structures based on π-hole• • • π interactions [12,13] when the nucleophile metal center and electron-poor molecule are opposite charge distributions [14]. We reported that the supramolecular association of square-planar Pt 2+ , Pd 2+ , and Cu 2+ β-diketonate complexes [15,16], which nucleophile characteristics of Pt 2+ and Pd 2+ are clearly shown in the results of their crystal packings in the solid state and DFT calculations. The axial surface on the Pt 2+ center in complexes shows high negative ESP and nucleophile that on Pd 2+ center remarkably changed the surrounding substitutions, e.g., the negative value for [Pd(dbm) 2 ] and neutral~positive for the corresponding perfluorinated complex, [Pd(L) 2 ] (L = bis(pentafluorobenzoyl)methanido − ), indicating the possibility of strict adjustment of the metal characteristics [15].…”

Ligand Steric Hindrances Switch Bridging (μ2-I)···O,O to Two-Center I···O Halogen-Bonding Mode in the Assembly of Diketonate Copper(II) Species

“…The supramolecular assembly of metal diketonates is commonly associated with π–π, , M−π, M···M metallophilic interactions, − intermolecular hydrogen bonding, and also with M···O semicoordination. ,, Some recent reports have been focused on the application of (acac)­M (Hacac = acetylacetone) complexes as synthons for crystal engineering studies that utilize halogen bonding (abbreviated as HaB; for recent reviews on HaB, see refs − ) as a structure-directing interaction.…”