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The synthesis of novel bis-axially coordinated ruthenium(II) complexes with tetra-15-crown-5-phthalocyanine and N-donor ligands (R₄Pc)Ru(L₂) (R₄Pc^2- = 4,5,4',5',4'',5'', 4''',5'''- tetrakis(1,4,7,10,13-pentaoxotridecamethylene)phthalocyaninate-ion, L = pyridine (py), isoquino-line (iqnl), triethylamine (Et₃N)) is reported. The preparation technique involves the interaction of (R₄Pc)Ru(CO)(CH₃OH) with trimethylamine oxide in an N-donor solvent. The advantage of this method consists in selective carbonyl ejection from (R₄Pc)Ru(CO)X with simultaneous substi-tution by N-donor ligands. The application of this procedure allowed us to decrease essentially the reaction time, as compared with photochemical methods, as well as to increase substantially the yield of reaction products. UV-visible, ¹H NMR, FT-IR and mass-spectrometry were used for characterization of the obtained compounds.

The development of synthetic strategies for functional building units plays a central role in supramolecular chemistry. Both porphyrin and crown ethers have attracted the attention of researchers worldwide owing to their unique properties. It is envisioned that the integration of the two molecules will result in hybrid materials with potential applications in many fields. In the present study, a new porphyrin derivative 3 appended with four 18-crown-6 (18C6) ether moieties was synthesized through the Suzuki-Miyaura coupling of boronic ester porphyrin 1 and 4-bromobenzo-18-crown-6 2 in 80% yield. Porphyrin 3 was fully characterized by ¹H/${}^{13}$C NMR spectroscopy and high resolution mass spectrometry. The tendency of the 18C6 to form host-guest complexes with ammonium cations was exploited to assemble cation responsive hybrid material of porphyrin 3 and ammonium immobilized mesoporous silica nanoparticles (MSNs). Furthermore, the potential application of the 3/MSNs conjugate as a cation-responsive drug delivery vehicle was investigated in solution by UV-vis and fluorescence spectroscopies.

This micro-review presents an overview of molecular materials derived from phthalocyanines which are substituted with crown ether rings. These flat disk-like molecules can self-assemble into ordered, well-defined structures with or without the aid of alkali metal ions. Highly ordered assemblies of crown ether phthalocyanines are capable of transporting electrons and ions, which is of interest for sensor applications.

Mechanically-interlocked photosensitizer–quencher systems based on free-base tetraphenylporphyrin (H₂TPP)–gold nanoparticle (AuNP) composites has been designed and synthesized by utilizing a rotaxane architecture comprised of secondary ammonium and crown ether subunit. The H₂TPP-substituted 24-crown-8 was able to shuttle along the alkanethiolate axle, triggered by deprotonation/protonation at the ammonium station, altering the H₂TPP–AuNP distance and the photoexcitation energy transfer efficiency. Upon switching, quantum yields for photosensitized singlet oxygen (¹O${}_2)$ generation and fluorescence after deprotonation were quenched by 46% and 42%, respectively. External environment-responsive ¹O₂ generation based on such a protonation/deprotonation-driven molecular switch is potentially advantageous for a variety of applications including photodynamic therapies.

New complexes of ytterbium with porphyrins containing crown- and other oxygen-containing cyclic substituents were obtained. The absorption, excitation, ligand luminescence and 4f-luminescence spectra have been investigated. It has been shown that 4f-luminescence of ytterbium Yb(III) ions was a result of the intramolecular energy transfer from the triplet level of the ligands to the resonance ²F_5/2 level of Yb(III). It has been also established that in presence of alkali metal Na, K and Cs the dimer complexes (sandwich-type) of ytterbium-crown-porphyrin were formed. Molecular luminescence of the porphyrin matrix was quenched completely in these dimers, but at the same time the quantum yield and lifetime of 4f-luminescence increase in the complexes.

A substituted porphyrin bearing a crown ether unit, H₂(M18C6P), was synthesized from the reaction between (5-mono(o-aminophenyl)10,15,20-triphenylporphyrin) and the acyl derivative of the ether (4-carboxy-18-crown-6). The corresponding iron porphyrin, Fe(M18C6P)Cl, was obtained through iron insertion into H₂(M18C6P). The new free-base porphyrin was analyzed by C, N, and H elemental analysis, UV-vis and IR spectroscopies, electrospray mass spectrometry (MS) and ¹H NMR. It selectively extracts 18% of the K⁺ ions present in aqueous medium to the organic phase (chloroform). UV-vis spectroscopy studies showed that H₂(M18C6P) is also capable of forming aggregates with K⁺, probably the 1:1 complex, in methanol. This happens because the ionic radius of the potassium ion is appropriate for its accommodation inside the cavity of the crown ether, and also because of the associative effect between the porphyrin and the crown ether unit. The iron porphyrin Fe(M18C6P)Cl was used as catalyst for the epoxidation of cyclooctene by iodosylbenzene or sodium hypochlorite, in methanol or biphasic water/dichloroethane system, respectively. The results obtained with sodium hypochlorite show that Fe(M18C6P)Cl is a potential catalyst for selective oxidations, because the crown ether unit can select or orient substrates. This iron porphyrin can also be employed as a catalyst in a biphasic water/organic solvent system, with no need of a phase transfer agent.

The synthesis and spectroscopic characterization of two new substituted tetraphenyl-porphyrins with one or two benzo-9-crown-3 appended units are described.

The synthesis of novel ruthenium(II) meso-tetra-(benzo-15-crown-5)-porphyrinates, meso-[(B15C5)₄Por]Ru(CO)(MeOH) (1) and meso-[(B15C5)₄Por]Ru(L)₂ (2)-(4) (meso-[(B15C5)₄Por]₂-= 5,10,15,20-tetrakis-(benzo-15-crown-5)-porphyrinato-dianion; L = pyridine (py), pyrazine (pyz), 4,4′-bipyridyl (4,4′-bpy)), where CO and MeOH, or two N-donor ligands are axially coordinated to the central metal, are reported. The metalation of the free ligand performed by the reaction of Ru₃(CO)₁₂ with meso-[(B15C5)₄Por]H₂ in 1,2,4-trichlorobenzene (TCB, bp = 215°C), gives (1) in a high yield. The synthesis of (2)-(4) involves the decarbonylation of (1) with trimethylamine N-oxide ((CH₃)₃NO) in the presence of an excess of the N-donor ligand. The coordination of the axially bonded ligands is evidenced by different spectroscopic data.

We report herein, the synthesis, and spectral and electrochemical characterization of a series of phthalocyaninato zinc complexes where two biomedically potential structures; crown ether and phthalocyanine moities were gathered on the same molecule. The effect of number of crown ether moieties on metal ion binding properties, as well as proton sensitivity were investigated by using electronic absorption and fluorescence emission spectra. Spectral behaviors of the zinc phthalocyanine complexes fused with one crown ether; Zn[Pc(15C5)(C₆H₁₃)₆] and four crown ether; Zn[Pc(15C5)₄] in presence of Na⁺ and K⁺ ions were investigated into detail because of host-guest interactions of subjective ions with crown ether moieties, and compared with the crown ether free phthalocyanine; Zn[Pc(C₆H₁₃)₈].

The synthesis of a series of novel tetra-(benzo-24-crown-8)-phthalocyanines (Mg(II), Ni(II) and Co(II)) as well as a modified procedure for the free-base ligand and its Zn(II) and Cu(II) complexes are reported. The tendency of these phthalocyanines to undergo supramolecular cofacial dimerization induced by interaction with a viologen ($N,N$-di(but-3-ynyl)-4,4$\prime$-bipyridinium) was investigated by UV-vis absorption and EPR spectral studies in solution. The nature of the metal cation in phthalocyanine, the concentration, as well as the solvent all influenced the assembly processes.