Synthesis and electrochemical characteristics of a donor–acceptor porphyrinate rotor mounted on a naphthalocyaninato europium complex

Rare-earth based tetrapyrrolic sandwiches: chemistry, materials and applications

This review summarises advances in chemistry of tetrapyrrole sandwiches with rare earth elements and highlights the current state of their use in single-molecule magnetism, organic field-effect transistors, conducting materials and nonlinear optics.

Photochromic Diarylethenes Designed for Surface Deposition: From Self-Assembled Monolayers to Single Molecules

The efficient switching that can occur between two stable isomers of diarylethenes makes them particularly promising targets for opto- and molecular electronics. To examine these classes of molecules for electronics applications, they have been subjected to a series of scanning tunneling microscopy (STM) experiments, which are the focus of this Review. A brief introduction to the chemical design of diarylethenes in terms of their switching capabilities along with the basics of STM are presented. Next, initial STM studies on these compounds under ambient conditions are discussed. An overview of how molecular design affects the isomerization and self-assembly of diarylethenes at the solid-liquid interface as investigated by STM is then presented, as well as single-molecule studies under ultrahigh vacuum. The last section presents further prospects for molecular design in the field.

Raman spectra of rare earth double-decker complexes with porphyrinato and 2,3-naphthalocyaninato ligands

The Raman spectra of the mixed (naphthalocyaninato)[tetrakis(4-[Formula: see text]-butylphenyl)porphyrinato] rare earth double-decker compounds M(Nc)(TBPP) (M = Y, La, Ce, Eu, Dy, Lu) were studied with Density Functional Theory for the first time. The results reveal the fingerprint band for naphthalocyanine to be around 1455–1615 cm[Formula: see text] and porphyrin around 693–749 cm[Formula: see text]. Coupled Nc–Por ring–ring interaction vibration modes are also detected at 1470–1522 cm[Formula: see text], owing to the stretching between the central metal and the N atoms. These vibration modes are recognized as the dominating components in the Raman spectra of those double-decker compounds.

Simultaneous and coordinated rotational switching of all molecular rotors in a network

A range of artificial molecular systems has been created that can exhibit controlled linear and rotational motion. In the further development of such systems, a key step is the addition of communication between molecules in a network. Here, we show that a two-dimensional array of dipolar molecular rotors can undergo simultaneous rotational switching when applying an electric field from the tip of a scanning tunnelling microscope. Several hundred rotors made from porphyrin-based double-decker complexes can be simultaneously rotated when in a hexagonal rotor network on a Cu(111) surface by applying biases above 1 V at 80 K. The phenomenon is observed only in a hexagonal rotor network due to the degeneracy of the ground-state dipole rotational energy barrier of the system. Defects are essential to increase electric torque on the rotor network and to stabilize the switched rotor domains. At low biases and low initial rotator angles, slight reorientations of individual rotors can occur, resulting in the rotator arms pointing in different directions. Analysis reveals that the rotator arm directions are not random, but are coordinated to minimize energy via crosstalk among the rotors through dipolar interactions.

Regiospecific synthesis of lanthanum(III) and neodymium(III) triple-decker (tetrakis-meso-(3-bromophenyl)-porphyrinato)(crownphthalocyaninates)

The triple-decker complexes of symmetrical type [m Br 4 TPP ] Ln [(15 C 5)4 Pc ] Ln [m Br 4 TPP ] ( Ln -m TD ; Ln = La , Nd ; [(15 C 5)4 Pc ] = tetra-(15-crown-5)-phthalocyaninato-ligand; [m Br 4 TPP ] = tetrakis-meso-(3-bromophenyl)-porphyrinato-ligand) are synthesized for the first time with 43% and 36% yield. The applicability of the previously developed selective one-step synthetic approach for the preparation of the mentioned complexes is demonstrated and the limitations, determined by meta-substitution of meso-aryl-fragments, are revealed. The spectral features of the obtained complexes is determined by means of UV-vis and NMR spectroscopy. The hindered rotation of porphyrin meso-substituents in the obtained complexes and formation of statistical set of atropisomers are demonstrated.