A series of PcMn(III) complexes (Pc [Formula: see text] phthalocyanine) was synthesized and structurally characterized by stripping the chloride from PcMnCl with AgSbF 6 in ortho-dichlorobenzene (DCB) in the presence of DMSO or DMF; this yielded crystals of [PcMn(H[Formula: see text]O)[Formula: see text]]SbF[Formula: see text]⋅2DMSO and [PcMn(H[Formula: see text]O)[Formula: see text]]SbF[Formula: see text]⋅4DMF, respectively, which are insoluble in DCB. The use of AgOSO 2 CF 3 (AgOTf), under similar conditions, yielded DCB-soluble PcMn(DMSO)OTf and PcMn(DMF)OTf, which were structurally characterized. Reacting PcMnCl with AgOTf in DCB, followed by addition of [[Formula: see text]Bu 4 N]OTf generated [Formula: see text]Bu[Formula: see text]N[PcMn(OTf)[Formula: see text]], which is air-stable and soluble in halogenated solvents; structural characterization revealed a six-coordinate Mn(III) “ate” complex with two trans-axially bound triflate anions. The PcMn(III) complexes are green in colour, with Q-band absorptions spanning from 722–739 nm and LMCT bands from 515–547 nm. Addition of neutral donors (THF, OPPh 3 , pyridine, DMSO, DMF) to [Formula: see text]Bu[Formula: see text]N[PcMn(OTf)[Formula: see text]] generated Q-band and LMCT peak shifts consistent with triflate substitution. These results show the utility of axially-bound triflate anions to increase PcM solubility, while still maintaining sufficient lability to permit reactivity at the axial site.

Fluoroalkyl zinc phthalocyanines (F[Formula: see text]PcZn) are an emerging class of functional tetrapyrroles with fluoro and perfluoroalkyl groups decorating the periphery of the macrocycle. F[Formula: see text]PcZn complexes, 16 [Formula: see text] n [Formula: see text] 64, exhibit strong absorptivity in the red region of the visible spectrum. Analysis of absorption, emission, and, most importantly, magnetic circular dichroism spectra, coupled with detailed molecular orbital calculations using time-dependent density functional theory, was used to probe the differential effects of increasing the number of peripheral fluoro groups. The impact of the electronegativity imparted by the fluorine atoms and iso fluoroalkyl groups, as well as the resulting increased steric crowding, was considered in terms of the electronic properties of a range of porphyrins and phthalocyanines. The contribution of F[Formula: see text]PcZn aggregation to the electronic spectra in solution was elucidated by analyzing TD-DFT-calculated spectra and comparing them with the X-ray structure of the solid state.

The alloyed quantum dots, namely, CdSeS/ZnS (QD), undergo spontaneous interaction with a zinc porphyrazine (ZnPz) in toluene. Spectral overlap of the absorption spectrum of ZnPz and fluorescence spectrum of QD elicits an overlap integral value of [Formula: see text] dm 3 .mol[Formula: see text].cm 3 . Fluorescence measurements evoke a considerable amount of quenching of the photoluminescence (PL) of QD (observed at 662 nm) in the presence of ZnPz. PL experiments evoke an immense value of binding constant ([Formula: see text]) of QD-ZnPz system, i.e. [Formula: see text] dm 3 .mol[Formula: see text], which gets outstanding support from the observation of emissive charge transfer band and isoemissive point located at 612 nm and 636 nm, respectively. The estimated value of the bimolecular quenching constant ([Formula: see text] of the QD-ZnPz system ([Formula: see text] dm 3 .mol[Formula: see text].sec[Formula: see text] suggests that the static quenching mechanism prevails over the diffusion-driven process in the present work. Scanning electron microscopy, dynamic light scattering, and fluorescence microscopy experiments reveal significant interaction between QD and ZnPz in solution. The present work opens up excellent opportunities to employ ZnPz as a selective binding receptor for alloyed-type quantum dots in the near future.

Two phthalocyanines were designed and used as sensitizers in dye-sensitized solar cells (DSSCs). These phthalocyanines bear p-coumaric acid as an electron-withdrawing and anchoring group, with bulky 4- [4-(1,1,3,3-tetra-methylbutyl phenoxy groups (CuPc1) and tert-butylphenoxy groups (CuPc2) as electron-donating groups. The impact of electron-donating groups on the energy conversion efficiency of solar cells was also studied. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the dyes were investigated using differential pulse voltammetry (DPV). Additionally, nitrogen-doped carbon quantum dots (N-CQDs) were prepared and used as a counter electrode and co-sensitizer. It was observed that CuPc1 achieved the maximum efficiency of 1.25%. Upon the addition of N-CQDs as a co-sensitizer, the maximum efficiency was 1.69% with CuPc1 as the sensitizer.

This research presents a comparative study of iron-, manganese-, and copper-based porphyrins covalently immobilized on the surfaces of multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO) as heterogeneous nanocatalysts for the oxidation of olefins with molecular oxygen under catalyst-free conditions. All catalysts were synthesized and their structures characterized using UV-Vis, FT-IR, atomic absorption spectroscopy, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Their catalytic performance was then evaluated in olefin oxidation reactions using molecular oxygen as the green oxidant. The results show that MWCNT-supported catalysts, especially Fe(TCPP)Cl@MWCNT and CuTCPP@MWCNT, demonstrate superior catalytic activity and turnover numbers compared to their GOsupported counterparts, with Fe(TCPP)Cl@MWCNT achieving the highest efficiency. The separation and recovery of the nanocatalyst were simple, effective, and economical in this green oxidation process. Overall, these findings highlight the promise of metalloporphyrin-functionalized carbon nanomaterials as efficient, reusable, and environmentally friendly catalysts for aerobic oxidation, emphasizing the critical roles of both the central metal ion and the support material in catalytic performance.

Porphyrin-containing Phthalocyanine Nanoporous Crystals (PNCs) have been prepared previously by the cocrystallisation of octa(2',6'-di-iso-propyphenoxy)phthalocyanine [(dipPhO) 8 Pc] and its metalated derivatives with metal-free tetraphenylporphyrin (TPP). Here we report the effect of the central cations (M = H 2 , Co, Cu, Zn) on heterodimer formation, both in solution and in cocrystallisations, for all sixteen possible combinations of (dipPhO) 8 PcM with TPPM. UV/visible spectroscopy shows a clear trend of Cu 2+ > 2H + > Co 2+ > Zn 2+ for encouraging or discouraging heterodimer formation, which can be rationalised by the propensity of the metal cation to bind to axial ligands when incorporated into porphyrin or phthalocyanine macrocycles. Attempted cocrystallisations of all 16 (dipPhO) 8 PcM/TPPM combinations yielded 13 heterodimer-based PNCs, with only (dipPhO) 8 PcZn failing to provide a cocrystal with TPPM (Co, Cu, Zn). This study further demonstrates the remarkable efficiency of (dipPhO) 8 PcM in directing the structure of PNC cocrystallisations. It suggests a simple method for placing two metal cations of choice within van der Waals distance of one another within a well-defined, predictable crystal structure.

A phthalocyanine bearing eight bis(3,5-trifluoromethyl)phenyl substituents at the peripheral ß positions, H 2 Pc{ß-Ph-3,5-(CF[Formula: see text]} 8 , along with its zinc(II) and cobalt(II) complexes, [ZnPc{ß-Ph-3,5-(CF[Formula: see text]} 8 ] and [CoPc{ß-Ph-3,5-(CF[Formula: see text]} 8 ], were synthesized and characterized using elemental analysis, MALDI-TOF mass spectrometry, and 1 H NMR spectroscopy. X-ray crystallography was performed for [ZnPc{ß-Ph-3,5-(CF[Formula: see text]} 8 (H 2 O)]⋅2(acetone) and [CoPc{ß-Ph-3,5-(CF[Formula: see text]} 8 (py) 2 ]⋅2py. An axial water molecule coordinates the zinc(II) ion in addition to the pyrrole nitrogen atoms of the Pc ring, which is slightly curved toward the opposite side of the axial water molecule. The cobalt(II) ion is axially coordinated by two pyridine molecules along with the equatorial pyrrole nitrogen atoms of the Pc ring, with the Pc ring remaining nearly planar. The zinc(II) and cobalt(II) complexes displayed the Q-band peaks at 690 and 680 nm, respectively, while the metal-free ligand exhibited split Q-band peaks at 670 and 709 nm. These spectral features suggest they exist as monomeric species in solutions in CH 2 Cl 2 at a molar concentration of [Formula: see text] M. Cyclic voltammetry in CH 2 Cl 2 revealed Pc ligand-centered first oxidation and reduction waves at [Formula: see text] 0.45 and -0.51 V (vs SCE) for H 2 Pc{ß-Ph-3,5-(CF[Formula: see text]} 8 , [Formula: see text] 0.43 and -0.85 V (vs SCE) for [ZnPc(ß-Ph-3,5-(CF[Formula: see text]], and [Formula: see text] and -1.23 V (vs SCE) for [CoPc{ß-Ph-3,5-(CF[Formula: see text]} 8 ].

Lanthanide-porphyrin complexes are gaining renewed interest as molecular systems where light and magnetism can be coupled at the excited-state level. Building on the foundation of single-molecule magnetism in lanthanide coordination chemistry, recent studies have uncovered a new magnetic interaction between the angular momentum generated by the localized 4f electronic system (J) and the orbital angular momentum generated by the cyclic [Formula: see text]-conjugated electronic system (L). This phenomenon, called J-L interaction, occurs only upon photoexcitation and has been experimentally confirmed through variable-temperature, variable-magnetic-field magnetic circular dichroism (VTVH MCD) spectroscopy. In particular, terbium and dysprosium complexes show temperature- and magnetic-field-dependent MCD A-terms in the range of Soret and Q-bands region of porphyrin, providing direct evidence of magnetically active excited states. Systematic comparisons among lanthanide ions and capping ligand environments indicate that the magnitude and sign of the J-L coupling are sensitive to the metal identity and ligand field symmetry. Lower-symmetry capping ligands consistently enhance the interaction, and theoretical simulations (using RASSCF/RASSI methods) support the experimental results. These findings may open the door for photoresponsive magnetic materials, where light can control molecular magnetization. This brief review highlights recent experimental and computational advances in this field, focusing on design principles and future prospects for utilizing excited-state magnetism in lanthanide coordination complexes.

UV-vis-NIR spectroscopy and magnetic circular dichroism (MCD) were used to characterize electronic transitions in the dicyano-substituted phthalocyanines [Pc tBu (2[Formula: see text]Cr(III)(CN) 2 ] − , [Pc(2[Formula: see text]Fe(II)(CN) 2 ] 2− , and [Pc(2[Formula: see text]Co(III)(CN) 2 ] − . Density functional theory (DFT) and time-dependent DFT (TDDFT) calculations were used to validate transition assignments, corresponding energies, and orbital contributions. Specifically, calculations were employed to provide insight into the multiple overlapping transitions present in the 250–500 nm region and to propose assignments for all transitions. In addition, energies corresponding to the charge-transfer (CT) transitions were analyzed to study the impact of closed-shell (Fe(II) and Co(III)) and open-shell (Cr(III)) configurations on ligand-centered, charge-transfer, and triplet–multiplet transitions. For dicyano-substituted Cr(III) phthalocyanine, we provide convincing evidence for reassignment of the lowest-energy transitions in the NIR to triplet–quartet transitions and suggest that the lowest-energy ligand-to-metal charge transfer transition is located near 500 nm. This work presents a comprehensive experimental and theoretical investigation of the electronic behavior of three dicyano-substituted metal phthalocyanines (MPcs) and provides a broader context for general trends in ligand-centered and CT transitions in metalated macrocycles.

Hoechst dyes bind noncovalently to DNA with a significant fluorescence enhancement. As a result, they are routinely used to stain the cell nucleus in diverse fluorescence imaging and flow cytometry applications. The short wavelengths necessary for their excitation, however, cause autofluorescence and photodamage. To overcome these limitations, we envisaged the possibility of integrating a borondipyrromethene (BODIPY) chromophore and a Hoechst ligand in the same molecular construct. Here, we report the synthesis of this BODIPY–Hoechst conjugate and demonstrate that the covalent connection of the two components has minimal influence on the photophysical properties of one and the binding ability of the other. Indeed, our compound binds to nuclear DNA, enabling cell imaging under excitation with green light from the BODIPY chromophore and the detection of its intense fluorescence.