Structural and Photophysical Differences in Crystalline Trigonal Planar Copper Iodide Complexes with 1,2-Bis(methylpyridin-2-yl)disilane Ligands.

We synthesized trigonal planar Cu(I) iodide complexes with 1,2-bis(methylpyridin-2-yl)disilane ligands - and investigated how the substitution position of the methyl group on the pyridine ring in σ-π conjugation affects their structure and physical properties. The structures were characterized by NMR, elemental analysis, and single-crystal X-ray diffraction. In the crystalline state, the methylpyridyl groups of - were coordinated with Cu(I) in an conformation relative to the Si-Si σ bond, whereas those of were coordinated with Cu(I) in a conformation relative to the Si-Si σ bond.

Reversible Transition between Discrete and 1D Infinite Architectures: A Temperature-Responsive Cu(I) Complex with a Flexible Disilane-Bridged Bis(pyridine) Ligand.

A thermoresponsive structural change based on a disilane-bridged bis(pyridine) ligand and CuI is reported. Single-crystal X-ray analysis revealed that there are two polymorphs in the Cu(I) complex: octanuclear copper(I) complex at 20 °C and 1D staircase copper(I) polymer complex at -173 °C. The formation of these polymorphs is due to the flexibility of the ligand.

N CP/MAS NMR as a Tool for the Mechanistic Study of Mechanical Stimuli-Responsive Materials: Evidence for the Conformational Change of an Emissive Dimethylacridane Derivative.

Mechanochromic luminescent molecules are currently attracting considerable attention because of their promising technological applications, but understanding their mechanism of action is challenging and is thus hindering our deeper understanding of these materials. The conformational change of 9,9'-dimethyl-9,10-dihydroacridane derivative was examined using solid-state N nuclear magnetic resonance (NMR) spectroscopic techniques without using a specifically N-labeled compound. A difference between the two conformers was clearly observed in the measurements and was assigned to the ⟨pl⟩ and ⟨bf⟩ spatial structures.

A Series of D-A-D Structured Disilane-Bridged Triads: Structure and Stimuli-Responsive Luminescence Studies.

A series of σ-π extended octamethyltetrasilanes, which have phenothiazine, 9,9-dimethyl-9,10-dihydroacridine, or phenoxazine (, , and ) groups as donor moieties and thienopyrazine or benzothiadiazole ( and ) groups as acceptor fragments, has been prepared, and their optical properties have been studied as an extension of our work. All six compounds exhibited fluorescence in the solid state with maximum wavelengths centered in the range of 400 and 650 nm upon excitation by a UV lamp. Compound showed apparent dual emission behavior in solution, which depends on solvent polarity, and a reversible photoluminescent change under mechanical and thermal stimuli in the solid state.

Crystal structures and electrochemical properties of nickel(II) complexes with ,','',-tetra-dentate Schiff base ligands.

The thiol-ate nickel complexes {2-[({2-[(2-amino-ethyl-κ)(meth-yl)amino-κ]eth-yl}imino-κ)meth-yl]benzene-thiol-ato-κ}nickel(II) chloride, [Ni(CHNS)]Cl (), and [2-({[2-(piperazin-1-yl-κ , )eth-yl]imino-κ}meth-yl)benzene-thiol-ato-κ]nickel(II) hexa-fluoro-phosphate di-chloro-methane monosolvate, [Ni(CHNS)]PF·CHCl (), were synthesized by the reactions of 2-(-butyl-thio)-benzaldehyde, tri-amines, and nickel(II) salts. Both complexes have a nickel ion surrounded by an ,','',-tetra-dentate ligand, forming a square-planar geometry. The terminal ,-chelating moiety is ,-di-alkyl-ethane-1,2-di-amine for and 1-alkyl-piperazine for .

Synthesis, Structure, and Photophysical Properties of Yellow-Green and Blue Photoluminescent Dinuclear and Octanuclear Copper(I) Iodide Complexes with a Disilanylene-Bridged Bispyridine Ligand.

The synthesis, structural, and photophysical investigations of CuI complexes with a disilanylene-bridged bispyridine ligand are herein presented. Dinuclear () and ladder-like () octanuclear copper(I) complexes were straightforwardly prepared by exactly controlling the ratio of CuI/ligand . Single-crystal X-ray analysis confirmed that dinuclear complex had no apparent π…π stacking whereas octanuclear complex had π…π stacking in the crystal packing.

Luminescent Behavior Elucidation of a Disilane-Bridged D-A-D Triad Composed of Phenothiazine and Thienopyrazine.

A σ-π extended aryldisilane, comprising a thienopyrazine group as an acceptor fragment and phenothiazine groups as the donor moiety, has been prepared through the introduction of two Si-Si bridges (compound 1). X-ray diffraction analysis determined the crystal structure of 1, and experimental and theoretical approaches investigated its optical properties. Solvatochromic studies revealed the dual emission of 1 in all solvents tested.

Thermosalience in Macrocycle-Based Soft Crystals via Anisotropic Deformation of Disilanyl Architecture.

We describe here the preparation of soft crystals using disilanyl macrocycle possessing four -phenylenes circularly connected by four flexible disilane bonds. Single crystals of exhibited a reversible thermal single-crystal-to-single-crystal (SCSC) phase transition behavior between two crystal phases accompanied by remarkable mechanical motion (thermosalient effect), as revealed by thermal analyses and X-ray diffraction measurements. Detailed structural analyses implied that flexibility of the parallelogram disilanyl architecture and molecular packing mode via weak intermolecular interactions facilitated a concerted structural transformation (parallel crank motion) of macrocycles in the crystal, thus resulting in the SCSC phase transition accompanied by anisotropic shrinking/elongation of the cells to induce the thermosalient effect.

CO Release from N,C,S-Pincer Iron(III) Carbonyl Complexes Induced by Visible-to-NIR Light Irradiation: Mechanistic Insight into Effects of Axial Phosphorus Ligands.

Light-induced CO release from newly synthesized N,C,S-pincer iron(III) carbonyl complexes with two phosphorus ligands- trans-[Fe(L-κ N,C,S)(CO)(PRR')]PF ([1]PF, R = Me, R' = Ph; [2]PF, R = R' = Me; [3]PF, R = R' = OEt)-were investigated. All the iron(III) carbonyl complexes were stable in solution and showed light-inducible CO release under ambient conditions. Studies on the wavelength dependence of photoreaction revealed that the phosphite complex [3]PF exhibited the most extended photosensitivity including all visible and a part of near-IR light (390-800 nm wavelengths).

Visible-light-induced release of CO by thiolate iron(iii) carbonyl complexes bearing N,C,S-pincer ligands.

Iron(iii) carbonyl complexes are stabilized by a pincer ligand containing pyridine-N, phenyl-C and thiolate-S donors and two axial phosphine ligands. The N,C,S-pincer iron(iii) carbonyl complexes show CO-releasing properties induced by visible light.