Related Experiment Video
Updated: May 15, 2026

Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
Calixarene building block bis(2-hydroxyphenyl)methane (2HDPM) and hydrogen-bonded 2HDPM-H₂O complex in electronic
Se Wang1, Ce Hao, Zhanxian Gao
1State Key Laboratory of Fine Chemicals, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
Abstract:
Intramolecular and intermolecular hydrogen bonding in electronic excited states of calixarene building blocks bis(2-hydroxyphenyl)methane (2HDPM) monomer and hydrogen-bonded 2HDPM-H₂O complex were studied theoretically using the time-dependent density functional theory (TDDFT). Twenty-four stable conformations (12 pairs of enantiomers) of 2HDPM monomer have been found in the ground state. From the calculation results, the conformations 1a and 1b which both have an intramolecular hydrogen bond are the most stable ones. The infrared spectra of 2HDPM monomer and 2HDPM-H₂O complex in ground state and S₁ state were calculated. The stretching vibrational absorption band of O₂-H₃ group in the monomer and complex disappeared in the S1 state. At the same time, a new strong absorption band appeared at the C=O stretching region. From the calculation of bond lengths, it indicates that the O₂-H₃ bond is significantly lengthened in the S₁ state. However, the C₁-O₂ bond is drastically shortened upon electronic excitation to the S₁ state and has the characteristics of C=O band. Furthermore, the intramolecular hydrogen bond O₂-H₃ · · · O₄ of the 2HDPM monomer and the intermolecular hydrogen bonds O₂-H₃ · · · O₇ and O₇- H₉...O₄ of 2HDPM-H₂O complex are all shortened and strengthened in the S₁ state.
Related Concept Videos
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Resonance and Hybrid Structures
Resonance Structures and Resonance Hybrids
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N–O and N=O bonds.
Thermal and Photochemical Electrocyclic Reactions: Overview
Radical Formation: Homolysis
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous overlap of p...

