A Computational Study of the NMR Chemical Shifts of Polynitropyrazoles
The 1H, 13C, 15N, and 17O chemical shifts of 91 nitro-1H-pyrazoles, as well as 1-amino-1H-pyrazole, were calculated using the Gauge-Invariant Atomic Orbital/Becke Three-parameter Lee-Yang-Parr [GIAO/B3LYP/6-311++G(d,p)] method. The majority of these compounds are polynitropyrazoles, including substi...
| Authors: | , , , |
|---|---|
| Format: | article |
| Status: | Published version |
| Publication Date: | 2025 |
| Country: | España |
| Institution: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repository: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/405336 |
| Online Access: | http://hdl.handle.net/10261/405336 https://api.elsevier.com/content/abstract/scopus_id/105019198407 |
| Access Level: | Open access |
| Keyword: | 17O NMR GIAO/B3LYP/6–311++G(d,p) amino‐nitro intramolecular hydrogen bonds nitro‐1H‐pyrazoles solid‐state NMR effects |
| Summary: | The 1H, 13C, 15N, and 17O chemical shifts of 91 nitro-1H-pyrazoles, as well as 1-amino-1H-pyrazole, were calculated using the Gauge-Invariant Atomic Orbital/Becke Three-parameter Lee-Yang-Parr [GIAO/B3LYP/6-311++G(d,p)] method. The majority of these compounds are polynitropyrazoles, including substituents such as N-nitro, C-nitro, and N-trinitromethyl groups. The calculated chemical shifts were compared with available experimental data using an empirical equation that relates absolute shieldings to chemical shifts. However, a new equation was required to accurately account for the oxygen atoms in the nitro groups. Additionally, some conformational studies were performed to better understand the chemical shifts, particularly those of the OH and NO2 substituents at position 1. Different statistical methods were used to analyze the calculated 15N chemical shifts. |
|---|