Related Experiment Video
Updated: Sep 18, 2025
Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
Published on: September 12, 2014
Cationic π-Stacked 3a,6a-Diaza-1,4-diphosphapentalenes (DDP): Tuning the Energy of Electronic Transitions by Changing
Vyacheslav Sushev1, Natalia Zolotareva1, Alexandra Khristolyubova1
1G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences, 49 Tropinin str., Nizhny Novgorod 603137, Russia.
Abstract:
Double-decker dications of 3a,6a-diaza-1,4-diphosphapentalenes [(R1R2DDP)2]2+ (where R1R2 = peripheral substituents Me,Me; Et,Me; c-Hex-annelated) behave as π-acceptors when interacting with planar π-donor molecules. The interaction of double-decker ditriflates with free diazadiphosphapentalenes leads to the formation of deeply colored EPR silent triple-decker compounds [(R1R2DDP)3]2+(TfO-)2. According to DFT calculations, the largest positive charge in the dication is concentrated on the phosphorus atoms of the middle deck. The UV-vis absorption spectra of the obtained compounds have absorption band maxima at 563, 619, and 670 nm for (MeMeDDP)3(OTf)2 (5), (EtMeDDP)3(OTf)2 (10), and (cHexDDP)3(OTf)2 (11), respectively. We explain such a significant difference in the energy of electron transitions by the different distances between the decks in the given compounds, caused by steric factors. DFT calculations using the dication [(MeMeDDP)3]2+ as an example showed that λmax shifts from 500 to 831 nm with an increase in the interdeck distance from 2.9 to 3.5 Å. Weaker π-donors─carbazole and dibenzothiophene─form one-dimensional stacks with the double-decker ditriflate (MeMeDDP)2(OTf)2, consisting of alternating donor and double-decker acceptor molecules.
More Related Videos
12:51A 'Plug and Play' Method to Create Water-dispersible Nanoassemblies Containing an Amphiphilic Polymer, Organic Dyes and Upconverting Nanoparticles
Published on: November 14, 2015
05:51Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Related Concept Videos
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
01:27π Electron Effects on Chemical Shift: Overview
01:24π Molecular Orbitals of 1,3-Butadiene
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
![[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2Ffiles%2Fmedia%2Fscience-education%2Fscience-education-thumbs%2F12417.jpg&w=3840&q=75)
01:16[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
01:14π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds