Study of Energetics and Structure of 1,2,3-Benzotriazin-4(3H)-one and its 1H and Enol Tautomers

• Type: Article in International Scientific Journal
• Date: 2011

Authors

Margarida S Miranda (Author) FCUP; Agostinha A R Matos (Author) FCUP; Victor M F Morais (Author) ICBAS; Joel F Liebman (Author) Other

Journal

Title: Journal of Physical Chemistry B

Vol. 115 No. 24

Pages: 6616-6622

ISSN: 1520-6106

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 9 Citations

Scopus - 7 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-002-RCN

DOI: 10.1021/jp2011149

Abstract (EN): This paper reports an experimental and computational study on the energetics of 1,2,3-benzotriazin-4(3H)-one. The standard (p degrees = 0.1 MPa) molar enthalpy of formation of solid 1,2,3-benzotriazin-4(3H)-one, at T = 298.15 K, was derived from its standard massic energy of combustion measured by static bomb combustion calorimetry in oxygen. The Calvet high-temperature vacuum sublimation technique was used to measure the respective standard molar enthalpy of sublimation at T = 298.15 K From these two experimentally determined thermodynamic parameters, we have calculated the standard molar enthalpy of formation of 1,2,3-benzotriazin-4(3H)-one in the gas phase at T = 298.15 K, (200.9 +/- 3.8) kJ . mol(-1). Interrelations between structure and energy for 1,2,3-benzotriazin-4(3H)-one, the tautomer 1,2,3-benzotriazin-4(1H)-one, and the enol tautomer 1,2,3-benzotriazin-4-ol were discussed based on density functional theory (DFT) calculations with the B3LYP hybrid functional and the 6-311++G(d,p) basis set. The gas-phase enthalpy of formation of 1,2,3-benzotriazin-4(3H)-one was estimated from quantum chemical calculations using the G3(MP2)//B3LYP composite method. Nucleus-independent chemical shifts (NICS) were also calculated with the purpose of analyzing the aromaticity of the benzenic and heterocyclic rings of the title molecule and others related tautomerically to it.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7