...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Vapor phase infrared spectroscopy and Ab initio fundamental anharmonic frequencies of ammonia borane
【24h】

Vapor phase infrared spectroscopy and Ab initio fundamental anharmonic frequencies of ammonia borane

机译：氨硼烷的汽相红外光谱和从头算的基本非谐频率

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The infrared absorption spectrum of ammonia borane vapor has been recorded between 3600 and 600 cm ~(-1). Of the eleven infrared active fundamental vibrational modes, seven modes of NH _3 ~(11)BH _3 and four modes of NH _3 ~(10)BH _3 were observed. The spectra were recorded with sufficient resolution to observe the rotational structure of the bands, which allowed for preliminary least-squares fitting of the band origins and rotational constants. First-principles electronic structure calculations were performed to obtain anharmonic band origins and their intensities. The band assignments are discussed in relation to other spectroscopic techniques that have been previously used to study this molecule. A semi-empirical estimate of the vapor pressure of ammonia borane at room temperature (22 °C) was made and found to be ～1 × 10 ~(-4) Torr. The assignment of the measured modes was aided by the calculated anharmonic frequencies and their infrared intensities. The combination of the CCSD(T) harmonic frequencies with the B3LYP anharmonicities, obtained from second-order vibrational perturbation theory, was found to produce an overall best agreement with the measured band origins.
机译：氨硼烷蒸气的红外吸收光谱已记录在3600至600 cm〜（-1）之间。在这11种红外主动基本振动模式中，观察到7种NH _3〜（11）BH _3模式和4种NH _3〜（10）BH _3模式。以足够的分辨率记录光谱，以观察带的旋转结构，这允许对带起点和旋转常数进行初步的最小二乘拟合。进行第一性原理电子结构计算以获得非谐频带的起源及其强度。与先前已用于研究该分子的其他光谱技术讨论了谱带分配。对室温（22°C）下氨硼烷的蒸气压进行了半​​经验估算，得出的值为〜1×10〜（-4）Torr。计算出的非谐频率及其红外强度有助于测量模式的分配。从二阶振动摄动理论获得的CCSD（T）谐波频率与B3LYP非谐性的组合，被发现与所测量的频带起源总体上最佳吻合。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号