Issue 12, 2002

An ab initio direct classical trajectory study of s-tetrazine photodissociation

Abstract

The photodissociation of s-tetrazine via a three-body fragmentation channel (C2N2H2 → 2HCN + N2) has been studied by ab initio direct classical trajectory calculations using Hartree–Fock and density functional methods with split valence and polarized basis sets [HF/3-21G, HF/6-31G(d) and B3LYP/6-31G(d)]. The calculated transition state is planar. At our most reliable method (CBS-APNO), the heat of reaction and barrier height are −53.0 kcal mol−1 and 41.1 kcal mol−1, respectively. To simulate the experimental photolysis of s-tetrazine, trajectories were started from a microcanonical ensemble at the transition state with 12 kcal mol−1 excess energy distributed among the vibrational modes and the transition vector. At all levels of theory, the HCN product has a very broad rotational distribution, ranging up to J = 64, and has extensive excitation of the bending vibration. By contrast, N2 is produced with low J and with only a small amount of vibrational excitation in agreement with experiments. In accord with the experiment, the relative translation motion of the products receives about 80–83% of the available energy.

Article information

Article type
Paper
Submitted
17 Dec 2001
Accepted
11 Mar 2002
First published
09 May 2002

Phys. Chem. Chem. Phys., 2002,4, 2554-2559

An ab initio direct classical trajectory study of s-tetrazine photodissociation

X. Li, S. Anand, J. M. Millam and H. B. Schlegel, Phys. Chem. Chem. Phys., 2002, 4, 2554 DOI: 10.1039/B111390A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements