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Interacciones anión-pi como elementos controladores en las reacciones de autoensamblaje de complejos Ag(I) con

Brandi L Schottel¹, Helen T Chifotides, Mikhail Shatruk

¹Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, USA.

Journal of the American Chemical Society

|April 28, 2006

Resumen

Las interacciones anión-pi influyen en las reacciones de autoensamblaje. Los complejos de plata con ligandos de 3,6-bis(2'-piridil) -1,2,4,5-tetrazina (bptz) y 3,6-bis(2'-piridil) -1,2-piridazina (bppn) muestran estructuras variables basadas en la pi-acidez del ligando y el tipo de anión.

Área de la Ciencia:

Coordinación Química de la Coordinación
Química supramolecular de las moléculas.
Ciencia de los materiales Ciencia de los materiales.

Sus antecedentes:

La estructura de los ligandos y la identidad de los contra-aniones influyen críticamente en el autoensamblaje de los complejos metal-orgánicos.
Comprender estas interacciones es clave para diseñar nuevos materiales con propiedades personalizadas.

Objetivo del estudio:

Para investigar la diversidad estructural de los complejos de plata formados con 3,6-bis(2 omino-piridil) -1,2,4,5-tetrazina (bptz) y 3,6-bis(2 omino-piridil) -1,2-piridazina (bppn) ligandos.
Para aclarar el papel de las interacciones anión-pi en la determinación de los resultados de autoensamblaje.

Principales métodos:

Síntesis y caracterización estructural de complejos de plata mediante difracción de rayos X.
Cálculos de la teoría funcional de la densidad (DFT), incluido el mapeo del potencial electrostático.

Principales resultados:

Los ligandos Bptz formaron estructuras poliméricas, dinucleares y de tipo hélice, con interacciones anión-pi observadas entre los aniones y el anillo de tetrazina con déficit de electrones.
Los ligandos de Bppn forman exclusivamente estructuras tipo cuadrícula, exhibiendo interacciones anión-pi más débiles con el anillo de piridazina más rico en electrones.
Los cálculos de DFT confirmaron la transferencia de densidad de electrones de los aniones a los anillos bptz, pero no a los anillos bppn.

Conclusiones:

Las interacciones anión-pi son una fuerza impulsora significativa en el autoensamblaje de estos complejos de plata.
La pi-acidez del anillo central del ligando y la naturaleza del contra-anión dictan la arquitectura supramolecular final.

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