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本文采用简正坐标方法详细考察了ZSM-5分子筛双五元环结构发现符合该结构的力场接近我们建立的力场V.计算结果表明1000cm~(-1)以上的振动频率是由Si-O键的内部和外部伸缩振动产生的;800cm~(-1)左右的谱峰是Si-O键伸缩和O-Si-O变角共同振动的结果;460cm~(-1)左右的谱峰是由Si-O-si,O-Si-O及扭转角影响产生的,文献上把550cm~(-1)谱峰归属为双五元环的特征频率,在理论计算上没有得到确认。
In this paper, we investigate in detail the double five-membered ring structure of ZSM-5 molecular sieve by using the simple coordinate method and find that the force field in accordance with this structure is close to the force field V. The calculation results show that the vibration frequency above 1000cm ~ (-1) O bond generated by the internal and external telescopic vibration; about 800cm ~ (-1) of the peak around the Si-O stretching and O-Si-O variable angle common vibration results; 460cm ~ (-1) about the peak Is caused by the influence of Si-O-Si, O-Si-O and torsion angle. The characteristic peaks of the 550 cm ~ (-1) peak are assigned to the double five-membered ring in the literature and have not been confirmed theoretically.