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The symmetry adapted cluster (SAC)/SAC-configuration interaction method was applied to calculate the ground and excited states of zinc porphyrin monomers (without and with phenyl groups, ZnP and ZnPPh, respectively) and meso-meso linked (Zn[sub 2]PMM) and doubly fused (Zn[sub 2]PDF) zinc porphyrin dimers. Various features of the absorption spectra are studied, clarified, and assigned theoretically. The calculated electronic spectrum of ZnPPh, in comparison with that of ZnP, showed that the phenyl groups affect the spectrum in both the peak positions and intensities. In the dimers, Zn[sub 2]PMM and Zn[sub 2]PDF, the interactions of the monomer's four-orbitals result in an eight-orbital model of the dimers, which plays an important role in the interpretation of the excited states observed in the spectra. In Zn[sub 2]PMM, the interaction is smaller and each peak in the split Soret (BI and BII) bands consists of two peaks, in contrast to the prediction based on Kasha's exciton rule. In Zn[sub 2]PDF, the interaction between the two monomer units is so strong that the small highest occupied molecular orbital-lowest unoccupied molecular orbital gap causes the red-shifted Q (1.16 eV) and BI (2.13 eV) bands. In addition, the excitations out of the eight orbitals appear in the low-energy region of the spectrum, which is very different from the case of the monomer. A comprehensive and pictorial analysis is given for the excited states of the dimers in comparison with those of the monomer. [ABSTRACT FROM AUTHOR]

Precise control of assembled structures of quantum dots (QDs) is crucial for realizing the desired photophysical properties, but this remains challenging. Especially, the one-dimensional (1D) control is rare due to the nearly isotropic nature of QDs. Herein, we propose a novel strategy for controlling the 1D-arrangement range of cubic perovskite QDs in solution based on the morphological modification of a supramolecular polymer (SP) template. The original template with a short and tangled fibrous structure is prepared in a low-polarity solvent mixture via self-assembly of a naphthalenediimide-functionalized cholesterol derivative with an adhesion group for QDs. Mixing this template with QDs leads to the co-aggregation into short-range 1D-arrays of QDs on the templates. Notably, subsequent heating and cooling of the co-aggregate solution forms longer-range 1D-arrays of QDs with lateral growth, where arranged QDs are sandwiched between reconstructed SP templates. Furthermore, the longer-range 1D-array of QDs is achieved via an alternative route involving the pre-organization of templates into longer and dispersed fibers by heating and cooling of the original template, succeeded by co-assembly with QDs. Finally, we reveal continuous fluorescence resonance energy transfer between 1D-arranged QDs by an in-depth analysis of the photoluminescence decay curves., (© 2025 Wiley‐VCH GmbH.)

This work reported "trinitarian" porphyrin nanobelts, contained hetero-trimetal ions. The high-resolution mass spectrometry and X-ray crystallography proved PNBNiCuPd consisting of three different bent porphyrin(2.1.2.1) metal complex moieties. The redox properties indicate porphyrin nanobelts demonstrate the multielectron donating and accepting properties, more than nine redox processes., (© 2024 Wiley-VCH GmbH.)

Supramolecular polymers (SPs) formed via the stacking of π-conjugated molecules are attractive nanomaterials because of their potential optoelectronic properties derived from the non-covalent interaction between the π-skeletons. Especially, SPs possessing naphthalenediimide (NDI) core units can act as superior electron acceptors due to their deep lowest unoccupied molecular orbital (LUMO). Interaction of such SP with electron donors can realize a charge transfer system, but this has not been established. Herein, we report a photoinduced electron transfer system from cesium lead bromide quantum dot (QD) as an electron donor to SP composed of cholesterol-functionalized NDI derivatives. The supramolecular polymerization in a non-polar solvent was analyzed in detail via microscopic and spectroscopic analyses. Upon mixing the SP with QDs, the photoluminescence intensity and lifetime of QDs decreased significantly, indicating efficient photoinduced electron transfer from QD to SP., (© 2024 Wiley-VCH GmbH.)

A novel rosarin di-Cu complex 2Cu-1 and a linear six-pyrrolic mono-copper complex 1Cu-1 were synthesized using rosarin as the ligand. The molecular conformations of these complexes were confirmed by X-ray crystallography. The optical study of 1Cu-1 indicated NIR-II absorption due to the long six-pyrrolic ligand and the ICT effect. The 2Cu-1 complex exhibited a very narrow electronic reduction-oxidation gap of 0.50 eV, attributed to the antiaromatic characteristics of the rosarin ring. The first HER study of the di-copper rosarin complex 2Cu-1 indicated that the multi-metal poly-pyrrolic complexes are promising molecular hydrogen evolution reaction catalysts.

Aromaticity is one of the most important and widely used concepts in chemistry. Among the various experimentally discovered and theoretically predicted compounds that possess different types of aromaticity, conflicting aromaticity, where aromatic and antiaromatic electron delocalization is present in one molecule simultaneously, remains one of the most controversial and elusive concepts, although theoretically predicted 15 years ago. In this work, we synthesized a novel conflicting aromatic trirhodium complex that contains a σ-aromatic metal fragment surrounded by the π-antiaromatic organic ligand and characterized it by nuclear magnetic resonance spectroscopy, high-resolution mass spectrometry, and X-ray single crystal structure analysis. Experimental characterization and quantum chemical calculations confirm the unique conflicting aromaticity of the synthesized trirhodium molecule. Thus, this novel conflicting aromatic molecule expands the family of aromatic compounds. This discovery will enable researchers to develop and understand the phenomena of conflicting aromaticity in chemistry.

The " precursor approach " has proved particularly valuable for the preparation of insoluble and unstable π-conjugated polycyclic compounds (π-CPCs), which cannot be synthesized via in-solution organic chemistry, for their improved processing, as well as for their electronic investigation both at the material and single-molecule scales. This method relies on the synthesis and processing of soluble and stable direct precursors of the target π-CPCs, followed by their final conversion in situ, triggered by thermal activation, photoirradiation or redox control. Beside well-established reactions involving the elimination of carbon-based small molecules, i.e., retro-Diels-Alder and decarbonylation processes, the late-stage extrusion of chalcogen fragments has emerged as a highly promising synthetic tool to access a wider variety of π-conjugated polycyclic structures and thus to expand the potentialities of the " precursor approach " for further improvements of molecular materials' performances. This review gives an overview of synthetic strategies towards π-CPCs involving the ultimate elimination of chalcogen fragments upon thermal activation, photoirradiation and electron exchange., (Copyright © 2024, Okba et al.)

Novel hybrid porphyrin(2.1.2.1)s and their boron and copper complexes were synthesized using the "toy bricks" synthetic method. Crystal data, frontier molecular orbital calculations, and electrostatic potential surface maps reveal that hybridization in the porphyrin(2.1.2.1) donor-acceptor unit controls the selective coordination of BF 2 .

To investigate the host ability of a simple macrocycle, 1,3-phenylene-bridged naphthalene hexamer N6, we evaluated the complexation of N6 with fullerenes in toluene and in the crystals. The complexes in the solid-state demonstrate the one-dimensional alignment of fullerenes. The single-crystals of the C 60 @N6 composite have semiconductive properties revealed by photoconductivity measurements., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Fused-benzoheptagon-installed Ni II porphyrins were synthesized by a protocol consisting of (2-formyl)arylation at the meso-position(s) of Ni II porphyrins, conversion of formyl group to methoxyethene group by Wittig reaction, and final Bi(OTf) 3 -catalyzed cyclization. The structures of these porphyrins have been revealed by X-ray analysis. Owing to the installed heptagon ring(s), these porphyrins show curved structures with conformational flexibility. Dimer has been shown to have a small activation barrier for inversion and to capture C 60 and C 70 with large association constants with adjustable conformational changes., (© 2023 Wiley-VCH GmbH.)

Molecular design strategy to control the crystal structure of two-dimensional (2D) π-extended organic semiconductors has not been intensively explored. We synthesized an unsymmetric tetrabenzoporphyrin derivative (TIPS-Ph-BP) to demonstrate the effect of molecular symmetry on crystal packing. TIPS-Ph-BP formed an antiparallel slipped π-stacking and 2D herringbone-like structure. An unsymmetric structure would make 2D π-stacking more stable than a one-dimensional (1D) columnar structure to counteract steric and electronic imbalance in the crystal. As a result, TIPS-Ph-BP achieved the high hole mobility of 0.71 cm 2 V -1 s -1 .

An atropisomerism of large cycloarylenes was studied using [n]cyclo-4,10-pyrenylenes (n=6-21) as an illustrative example with two simple assumptions: (1) alternating configurations (R,S,R,S,…) are thermodynamically most stable, and (2) three consecutive identical configurations (R,R,R or S,S,S) are prevented. Ni-mediated coupling of a 5,9-diiodopyrene gave a series of directly-linked cyclic pyrene oligomers in one-pot reaction. As-synthesized cyclic hexamer was assigned as an (R,S,S,R,R,S) structure, converted into an (R,S,R,S,R,S)-form upon heating. Cyclic heptamer consists of two types of C 2 symmetric structures predicted from assumption (2), one of which was convergent to one another by heating. Three atropisomers of cyclic octamer were analyzed from the possible five candidates by means of 1 H nuclear magnetic resonance (NMR) spectroscopy, and the conversion process to (R,S,R,S,R,S,R,S) configurations upon heating was investigated. In total, according to two simple rules, the analysis of atropisomerism could be performed smoothly., (© 2023 Wiley-VCH GmbH.)

The molecular structure, electrochemistry, spectroelectrochemistry and electrocatalytic oxygen reduction reaction (ORR) features of two Co II porphyrin(2.1.2.1) complexes bearing Ph or F 5 Ph groups at the two meso-positions of the macrocycle are examined. Single crystal X-ray analysis reveal a highly bent, nonplanar macrocyclic conformation of the complex resulting in clamp-shaped molecular structures. Cyclic voltammetry paired with UV/Vis spectroelectrochemistry in PhCN/0.1 M TBAP suggest that the first electron addition corresponds to a macrocyclic-centered reduction while spectral changes observed during the first oxidation are consistent with a metal-centered Co II /Co III process. The activity of the clamp-shaped complexes towards heterogeneous ORR in 0.1 M KOH show selectivity towards the 4e - ORR pathway giving H 2 O. DFT first-principle calculations on the porphyrin catalyst indicates a lower overpotential for 4e - ORR as compared to the 2e - pathway, consistent with experimental data., (© 2023 Wiley-VCH GmbH.)

1ReH•Cl , a highly robust and antiaromatic rhenium(I) complex of triarylrosarin, is synthesized. The 1 H NMR spectrum of 1ReH•Cl shows upfield-shifted pyrrole protons and highly downfield-shifted inner protons that confirm its antiaromatic nature, with density functional theory calculations strongly supporting this interpretation. Antiaromatic 1ReH•Cl absorbs from the UV to near-IR region of the optical spectrum; cyclic voltammetry, thin-layer UV-vis spectroelectrochemistry, and spin-density distributions clearly reveal that the rosarin backbone of 1ReH•Cl undergoes redox chemistry. The X-ray structure of 1ReH•Cl shows a fully coordinated and protonated inner cavity that effectively prevents proton-coupled electron transfer when treated with an acid. A remarkably negative NICS(0) value, clockwise anisotropy of the induced current density ring current, and the aromatic shielded inner cavity in the 2D ICSS(0) map reveal that the T 1 state of 1ReH•Cl is aromatic based on Baird's rule.

2,7,12,17-Tetrakis(pinacolatoboryl) Ni II porphyrin 5 Ni was synthesized in 75 % yield by Ir-catalyzed borylation of porphine followed by Ni II metalation and has been demonstrated to be a useful synthon, giving 2,7,12,17-tetraaryated Ni II porphyrins 6 a-d, peripherally octaarylated Ni II porphyrins 8 a-d, quadruply bridged face-to-face non-offset Ni II -porphyrin dimer 12, and cross-shaped β-meso singly linked porphyrin pentamers and nonamers. Oxidation of cross-shaped β-meso singly linked porphyrin pentamers 14 Ni and 14 Zn gave fused pentameric tapes 15 Ni and 15 Zn. The structures of 12, 14 Zn, and 15 Ni have been revealed by X-ray diffraction analysis. Optical separation of 12 has been accomplished, showing a bisignate coupling pattern for exciton-coupled blue-shifted Soret band. Pentameric porphyrin tape 15 Zn exhibits a red-shifted absorption band at 1156 nm and seven reversible redox waves., (© 2023 Wiley-VCH GmbH.)