Enhanced and Heteromolecular Guest Encapsulation in Nonporous Crystals of a Perfluorinated Triketonato Dinuclear Copper Complex

Colorimetric Detection of Naphthalene Enabled by Intra- to Intermolecular Charge Transfer Interplay Induced by π-hole⋅⋅⋅π Interactions of a TPA-Attached Pyrazinacene

A new Donor-Acceptor type pyrazinacene derivative (1) featuring strong ICT was synthesized by linking electron-donating triphenylamine (TPA) and electron-accepting CN groups via a pyrazinacene core. The compound exhibits a dramatic color change from greenish blue to red-violet upon selective recognition of naphthalene (3) to form a 1:1 co-crystal (1•3). This color change is induced by intermolecular CT between pyrazinacene and naphthalene's aromatic moieties, driven by π-hole⋅⋅⋅π interactions. Crystal structure analysis and DFT calculations confirm that the molecular recognition process is facilitated by the unique π-hole⋅⋅⋅π interactions, leading to a reversible color switching mechanism. The findings offer new insights into selective molecular recognition and ICT-CT interplay in nonporous adaptive crystals.

Synthesis, Structure and Photoluminescence Properties of Cd and Cd-Ln Pentafluorobenzoates with 2,2′:6′,2′-Terpyridine Derivatives

Six new complexes [Cd(tpy)(pfb)2] (1, tpy = 2,2′:6′,2″-terpyridine), [Ln2Cd2(tpy)2(pfb)10] (Ln = Eu (2Eu), Tb (2Tb)), [Ln2Cd2(tbtpy)2(pfb)10]·2MeCN (Ln = Eu (3Eu), Tb (3Tb), tbtpy = 4,4′,4″-tri-tert-butyl-2,2′:6′,2″-terpyridine), [Eu2Cd2(tppz)(pfb)10]n (4, tppz = 2,3,5,6-tetra-(pyridin-2-yl)pyrazine) based on pentafluorobenzoic acid (Hpfb) have been prepared and investigated. The effect of tridentate ligands on geometry heterometallic scaffolds synthesized complexes is discussed. The supramolecular crystal structures of the new compounds are stabilized by π-π, C-F···π, C-H···O, C-H...F, F….F interactions. Non-covalent interactions have been studied using Hirschfeld surface analysis. The obtained compounds were characterized by single-crystal and powder X-ray diffraction, luminescence spectroscopy, IR spectroscopy, CHN analysis. Complexes 2Ln and 3Ln exhibit metal-centered photoluminescence, but the presence of ligand luminescence bands indicates incomplete energy transfer from the d-block to the lanthanide ion.

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

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.