IR and NMR properties of N-base:PH2F:BeX2 ternary and corresponding binary complexes stabilised by pnicogen and beryllium bonds
Ab initio MP2/aug’-cc-pVTZ calculations have been performed to determine selected stretching frequencies and chemical shieldings for ternary complexes N-base:PHF:BeX and the corresponding binary complexes, with NH, HC=NH, and HCN as the nitrogen bases and H, F, and Cl as the substituents X. Be-F and...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/252854 |
| Acceso en línea: | http://hdl.handle.net/10261/252854 |
| Access Level: | acceso abierto |
| Palabra clave: | Non-covalent interactions NMR chemical shifts NMR spin–spin coupling constants IR stretching frequencies |
| Sumario: | Ab initio MP2/aug’-cc-pVTZ calculations have been performed to determine selected stretching frequencies and chemical shieldings for ternary complexes N-base:PHF:BeX and the corresponding binary complexes, with NH, HC=NH, and HCN as the nitrogen bases and H, F, and Cl as the substituents X. Be-F and P-F stretching frequencies depend on the Be-F and P-F distances, respectively, while P and F chemical shieldings depend on the N-P and P-F distances, respectively. The graph of the P chemical shieldings versus the P-F distance bears a remarkable resemblance to the graph of the P-F stretching frequencies versus that same distance. EOM-CCSD spin–spin coupling constants have also been evaluated for binary and ternary complexes. J(N-P) is negative at the longer N-P distances found in ternary complexes with HCN in which the N P bond is a traditional pnicogen bond with some phosphorous-shared character, gains phosphorus-shared character as the N-P distance continues to decrease, and then becomes a phosphorous-transferred bond with ion-pair character at the shorter distances in the complexes with NH and HC=NH. J(P-F) values are large and negative in complexes with HCN, but increase and become positive in complexes with HC=NH and NH as the P-F distance increases. |
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