Dehydro[12]- and [18]annulene-Fused Ball-Shaped Ruthenium Complex Oligomers: Synthesis, Aromatic/Antiaromatic Effect, and Symmetry for Near-Infrared Optical Properties.

The appropriate arrangement of near-infrared (NIR) chromophores allows for the modification of the peak wavelength in the NIR region and efficient use of NIR light. However, the preparation of novel NIR chromophores using simple procedures remains a formidable challenge. Herein, we report the synthesis of ball-shaped ruthenium complex oligomers.

Cationic Axial Ligand Effects on Sulfur-Substituted Subphthalocyanines.

Herein, we report the synthesis of sulfur-substituted boron(III) subphthalocyanines (SubPcs) with cationic axial ligands. Subphthalocyanines were synthesized by a condensation reaction using the corresponding phthalonitriles and boron trichloride as a template. An aminoalkyl group was introduced on the central boron atom; this process was followed by -methylation to introduce a cationic axial ligand.

Red-light-activatable ruthenium phthalocyanine catalysts.

Phthalocyanine ruthenium complexes were identified as red-light activatable catalysts for trifluoromethylation reactions. The red-light mediated chlorotrifluoromethylation of alkenes could proceed without any sacrificial reducing reagents. This reaction exhibited good compatibility with a blue-light-absorbing substrate, while under irradiation with blue light, , under traditional photoreaction conditions, this substrate decomposed completely.

Direct Near Infrared Light-Activatable Phthalocyanine Catalysts.

The high penetration of near-infrared (NIR) light makes it effective for use in selective reactions under light-shielded conditions, such as in sealed reactors and deep tissues. Herein, we report the development of phthalocyanine catalysts directly activated by NIR light to transform small organic molecules. The desired photocatalytic properties were achieved in the phthalocyanines by introducing the appropriate peripheral substituents and central metal.

Temperature-dependent changes in the molecular orientation and visible color of phthalocyanine films.

A simple phthalocyanine zinc complex exhibits a visible color change in response to weak external stimuli, , changes in solvent and temperature. Its chromism was attributed to its controlled aggregation weak interactions between the central metal and peripheral oxygen atoms. In solution, intense absorption and fluorescence bands appeared in both the longer-wavelength and NIR region in non-coordinating solvents, while a simple sharp Q band was observed in coordinating solvents.

One-step synthesis of ball-shaped metal complexes with a main absorption band in the near-IR region.

The design of near-IR materials is highly relevant to energy and pharmaceutical sciences due to the high proportion of near-IR irradiation in the solar spectrum and the high penetration of near-IR light in biological samples. Here, we show the one-step synthesis of hexacoordinated ruthenium and iron complexes that exhibit a main absorption band in the near-IR region. For that purpose, novel tridentate ligands were prepared by condensation of two diimines and four cyanoaryl derivatives in the presence of ruthenium and iron template ions.

Chemoselective Synthesis of Aryloxy-Substituted Phthalocyanines.

The synthesis of the first examples of 8-fold α-aryloxy-substituted phthalocyanines is described. 3,6-Diiodophthalonitrile was used as a precursor for a series of 3,6-aryloxy-substituted phthalonitriles, and a lead-mediated macrocyclization was employed to afford the corresponding free-base phthalocyanine complexes. The optical, electrochemical, and aggregation properties of these complexes can be tuned by varying the substituents on the aryloxy groups or by changing the pH value.

(1,3)Pyrenophanes containing crown ether moieties as fluorescence sensors for metal and ammonium ions.

Crown ether containing (1,3)pyrenophanes 1-6 were synthesized, and UV absorption and fluorescence spectroscopic studies were carried out to determine their abilities to form complexes with metal and ammonium ions. The fluorescence spectra of 1.0 × 10-5 M solutions of 1, 2, 4 and 6 in 1 : 1 v/v CH2Cl2 : CH3CN were comprised of both monomer and intramolecular excimer emission bands, while only monomer emission bands were present in the fluorescence spectra of 3 and 5.

Cationic axial ligands on sulfur substituted silicon(iv) phthalocyanines: improved hydrophilicity and exceptionally red-shifted absorption into the NIR region.

Herein, we report the exceptionally red-shifted absorption of sulfur-substituted silicon(iv) phthalocyanines upon introduction of cationic axial ligands. The Q band was red-shifted to approximately 900 nm with improved hydrophilicity by the combination of peripheral sulfur substituents and axial ammonium ligands. One such phthalocyanine exhibited remarkable photocytotoxicity upon irradiation with NIR light (∼810 nm) in live cells.

Ethynylpyrene Linked Benzocrown Ethers as Fluorescent Sensors for Metal Ions.

Substances containing ethynylpyrenes linked to either one or four benzocrown ethers were synthesized, and their absorption and fluorescence spectroscopic responses to metal ions were assessed. Addition of metal perchlorates to solutions of these substances promotes short wavelength shifts in their absorption and fluorescence maxima and increases in their fluorescence intensities. The magnitudes of the fluorescence intensity increases are dependent on the ring size and number of the crown ether and the nature of the metal cation.

Extremely Photostable Electron-Deficient Phthalocyanines that Generate High Levels of Singlet Oxygen.

A robust lead-mediated synthetic procedure for the generation of phthalocyanines substituted with electron-withdrawing groups has been developed. The free-base phthalocyanine and various metal complexes were prepared without discernible degradation of the peripheral electron-withdrawing substituents. Upon irradiation with red light, some of the thus-obtained metal complexes generated high levels of singlet oxygen.

Effects of substituents in silyl groups on the absorption, fluorescence and structural properties of 1,3,6,8-tetrasilylpyrenes.

1,3,6,8-Tetrasilylpyrenes and related germyl and stannyl derivatives were synthesized, and their absorption and fluorescence spectroscopic and structural properties were elucidated. The results show that the UV-vis absorption maxima of these substances in CH2Cl2 solutions shift to longer wavelengths as the size of the alkyl groups and numbers of phenyl groups on silicon increase. Fluorescence quantum yields of tetrasilylpyrenes in cyclohexane are larger than that of pyrene, and a pentamethyldisilyl derivative has an emission efficiency of 0.

Intramolecular Photoreactions of 9-Cyanophenanthrene-Linked Arylcyclopropanes.

With the aim of developing efficient and useful processes for the preparation of polycyclic organic compounds, intramolecular [3 + 2] photoreactions of 9-cyanophenanthrene-linked arylcyclopropanes were investigated. Photoreactions of , which contain respective -methoxyphenylcyclopropane and phenylcyclopropane moieties, form the intramolecular [3 + 2] photocycloadducts, endo- and exo-, along with the dihydroisochroman derivatives, cis- and trans-. The efficiency of the photoreaction of is higher when benzene rather than acetonitrile is used as a solvent.

Synthesis and fluorescence properties of dioxa-, dithia-, and diselena-[3.3](1,3)pyrenophanes.

[3.3](1,3)Pyrenophanes tethered by oxygen (1), sulfur (2) and selenium (3) atoms were synthesized and the structural and physical properties of these substances were determined. The absorption maxima of the [3.

[4 + 2] Dimerization and Cycloaddition Reactions of alpha,beta-Unsaturated Selenoaldehydes and Selenoketones.

The reactions of alpha,beta-unsaturated aldehydes and ketones with bis(dimethylaluminum) selenide, (Me(2)Al)(2)Se, yield the corresponding alpha,beta-unsaturated selenoaldehydes and selenoketones. They are too unstable to be isolated in the monomeric form, but they undergo regioselective [4 + 2] dimerization via a "head-to-head" oriented transition state to afford diselenin derivatives (trans and cis isomers). Theoretical calculations at the density functional theory level show that this selectivity occurs because the "head-to-head" dimerization is thermodynamically favored over the "head-to-tail" by about 14 kcal/mol.