Optical properties of highly planar diketopyrrolopyrrole derivatives fixed by coordinate bonds
摘要:
Diketopyrrolopyrrole (DPP) derivatives bearing 2-pyridyl groups were synthesized, which could serve as anionic N,N'-chelate ligands consisting of two nitrogen atoms of the lactam moieties and the pyridyl groups. Coordination of the DPP ligand to boron and platinum yielded the corresponding DPP complexes. Their crystal structures exhibited coplanar structures between the DPP core and the 2-pyridyl groups, which indicated extended pi-conjugation. The maximum absorption wavelength of the DPP complexes was longer than that of the corresponding DPP ligands. The choice of the introduced element affects the optical properties of the DPP complexes; the platinum complex has a longer absorption wavelength than the boron complex. The theoretical calculation revealed that these absorptions can be attributed to the pi-pi* transition. The introduction of the coordinating elements predominantly lowers the band gap. In addition, the substituent on the 2-pyridyl group can also modulate the energy levels. (C) 2014 Elsevier Ltd. All rights reserved.
Template‐Free Self‐Assembly of Molecular Trefoil Knots and Double Trefoil Knots Featuring Cp*Rh Building Blocks
作者:Wei‐Long Shan、Xiang Gao、Yue‐Jian Lin、Guo‐Xin Jin
DOI:10.1002/chem.202000525
日期:2020.4.16
hexanuclear trefoilknotsfeaturing Cp*Rh buildingblocks by the template-free self-assembly of four different rigid and flexible ligands. Transformations between the trefoilknots and the corresponding macrocycles can be induced using concentration effects. Remarkably, the hexanuclear trefoilknot 5 was shown to assemble further, providing rare examples of [12+1] heteronuclear double trefoilknots ( 5a/5b/5c/5d
diketopyrrolopyrroles (DPPs) represents a fundamental step to ensure solubility and further processability. Commonly used nucleophilic substitution in halogenated derivatives is replaced in this work by the Mitsunobureaction affording unprecedented DPPs with α-branched and chiral chains.
encapsulation of twopyrene molecules inside the hydrophobic cavity of 5, due to the twisted 4,4′-bipyridine spacer units between the two ruthenium clips. It also attributed a noncovalent CH−π interaction involving protons of pyrene and the π-electron cloud of 4,4′-bipyridine as well as a weak interaction between pyrene protons and the pendant C═O group of DPPP. Encapsulation of the guest molecule (pyrene) inside
corresponding precursors, isolated as rac diastereomers. Oxidation was observed to occur mainly at the bridging ligand (DPPP2– → DPPP•–), whereas the site of reduction (DPPP, Ru, or L) depends on effects from the ancillary ligands L. The metal coordination of a derivative of the pigment forming 2,5-dihydro-pyrrolo(3,4-c)pyrrole-1,4-dione (DPP) dyes and the analysis of corresponding multistep redox series add to
Same knot, longer rope: altering ligand geometry provides control over nuclearity in self-assembled trefoil knots
作者:Qi-Li-Sha Wang、Yue-Jian Lin、Guo-Xin Jin
DOI:10.1039/d1cc03699h
日期:——
Selective constructions of Cp*Rh(iii)-based hexanuclear and octanuclear trefoil knots are realized using two ester bipyridyl ligands bearing minor differences in geometry.