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BH3 bajo presión: dejando el motivo molecular del diborano
1Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa, ON, K1A 0R6 Canada.
Journal of the American Chemical Society
|November 23, 2011
Resumen
Este estudio investigó teóricamente las estructuras de hidruro de boro (BH) bajo alta presión. Se descubrieron nuevas fases cristalinas, incluido un nuevo polimorfo de diborano (B(2) H(6), con cadenas poliméricas favorecidas a presiones extremas.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química del estado sólido Química del estado sólido
- Química computacional es la química computacional.
Sus antecedentes:
- El diborano (B2H6) existe en varias formas cristalinas.
- Comprender la evolución estructural dependiente de la presión de los hidratos de boro es crucial para la ciencia de los materiales.
Objetivo del estudio:
- Explorar teóricamente las estructuras moleculares y cristalinas de (BH(3)) ((n) bajo presiones de hasta 100 GPa.
- Para identificar nuevas polimorfas y fases estabilizadas a presión de hidratos de boro.
Principales métodos:
- Se emplearon cálculos de la Teoría Funcional de Densidad Periódica (DFT, por sus siglas en inglés).
- Estudio teórico de las estructuras cristalinas dentro del rango de presión de 1 atm a 100 GPa.
Principales resultados:
- Se propuso un nuevo polimorfo de B ((2) H ((6), consistente con los datos históricos de difracción de rayos X.
- Se identificaron estructuras oligoméricas metastables (trimeros, tetrámeros y hexámeros).
- A ~4 GPa, un cristal trímero se convierte en la fase más estable, seguido de cadenas poliméricas por encima de 36 GPa.
Conclusiones:
- La estructura cristalina de los hidratos de boro es muy sensible a la presión externa.
- Se predice que las cadenas unidimensionales poliméricas son la fase más estable a altas presiones (por encima de 36 GPa).
- Esta investigación proporciona información sobre el comportamiento a alta presión de los simples hidratos de boro.
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